@inproceedings{AntretterMayerWellisch2011, author = {Antretter, F. and Mayer, C. and Wellisch, Ulrich}, title = {An approach for a statistical model for the user behaviour regarding window ventilation in residential buildings}, series = {Proceedings of Building Simulation 2011: 12th Conference of International Building Performance Simulation Association, Sydney}, booktitle = {Proceedings of Building Simulation 2011: 12th Conference of International Building Performance Simulation Association, Sydney}, year = {2011}, language = {en} } @phdthesis{Wellisch1999, author = {Wellisch, Ulrich}, title = {Asymptotic behaviour of solutions of estimating equations with functional parameter}, school = {Technische Hochschule Rosenheim}, year = {1999}, language = {en} } @techreport{PruschkaWellisch1997, author = {Pruschka, H. and Wellisch, Ulrich}, title = {Asymptotic behaviour of estimation equations with functional nuisance or working parameter.}, year = {1997}, abstract = {We are concerned with the asymptotic theory of semiparametric estimation equations. We are dealing with estimation equations which have a parametric component of interest and a functional (nonparametric) nuisance component. We give sufficient conditions for the existence and the asymptotic normality of a consistent estimation equation estimator for the parameter of interest. These conditions concern the asymptotic distribution of the estimation function and of its derivative as well as the effect of the functional nuisance part in the estimation equation. In order to treat the nonparametric component we introduce a general differential calculus and a general mean value theorem. For the nonparametric part in the estimation equation we distinguish two cases: the situation of a (classical) nuisance parameter and the case of a so called working parameter. As a special case we get regularity conditions for estimation equations with finite dimensional nuisance or working parameter. As an example we present the semiparametric linear regression model.}, language = {en} } @techreport{KuechenhoffWellisch1997, author = {K{\"u}chenhoff, H. and Wellisch, Ulrich}, title = {Asymptotics for generalized linear segmented regression models with an unknown breakpoint}, year = {1997}, abstract = {We consider asymptotic theory for the maximum likelihood estimator in the generalized linear model with an unknown breakpoint. A proof for the asymptotic normality is given. The methods are based on the work of Huber (1967). The main problem is the non--differentiability of the likelihood and the score function, which requires non--standard methods. An example from epidemiology is presented, where confidence intervals for the parameters are calculated with the asymptotic results.}, language = {en} } @techreport{Bischof1998, author = {Bischof, Wolfgang}, title = {On the Stability of Polling-Systems for General Arrival Processes}, series = {Report No. 384 des Instituts f{\"u}r Mathematik, Universit{\"a}t Augsburg}, journal = {Report No. 384 des Instituts f{\"u}r Mathematik, Universit{\"a}t Augsburg}, pages = {3}, year = {1998}, language = {en} } @techreport{Bischof1999, author = {Bischof, Wolfgang}, title = {M/G/1-queues with Setup Times and Vacations under Various Service Disciplines}, series = {Report No. 417 des Instituts f{\"u}r Mathematik, Universit{\"a}t Augsburg}, volume = {1999}, journal = {Report No. 417 des Instituts f{\"u}r Mathematik, Universit{\"a}t Augsburg}, year = {1999}, language = {en} } @article{Bischof2001, author = {Bischof, Wolfgang}, title = {Analysis of M/G/1-queues with Setup Times and Vacations under Six Different Service Disciplines}, series = {Queueing Systems: Theory and Applications (QUES)}, volume = {39}, journal = {Queueing Systems: Theory and Applications (QUES)}, number = {4/2001}, publisher = {Springer US}, pages = {265 -- 302}, year = {2001}, abstract = {Single server M/G/1-queues with an infinite buffer are studied; these permit inclusion of server vacations and setup times. A service discipline determines the numbers of customers served in one cycle, that is, the time span between two vacation endings. Six service disciplines are investigated: the gated, limited, binomial, exhaustive, decrementing, and Bernoulli service disciplines. The performance of the system depends on three essential measures: the customer waiting time, the queue length, and the cycle duration. For each of the six service disciplines the distribution as well as the first and second moment of these three performance measures are computed. The results permit a detailed discussion of how the expected value of the performance measures depends on the arrival rate, the customer service time, the vacation time, and the setup time. Moreover, the six service disciplines are compared with respect to the first moments of the performance measures.}, language = {en} } @inproceedings{HanfstaenglParzingerSpindleretal.2020, author = {Hanfstaengl, Lucia and Parzinger, Michael and Spindler, Uli and Wellisch, Ulrich and Wirnsberger, Markus}, title = {Identifying occupant presence in a room based on machine learning techniques by measuring indoor air conditions}, series = {E3S Web of Conferences, 12th Nordic Symposium on Building Physics (NSB 2020)}, volume = {172}, booktitle = {E3S Web of Conferences, 12th Nordic Symposium on Building Physics (NSB 2020)}, pages = {22005}, year = {2020}, abstract = {Knowing about the presence and number of people in a room can be of interest for precise control of heating, ventilation and air conditioning. To determine the number and presence of occupants cost-effectively, it is of interest to use already existing air condition sensors (temperature, humidity, CO2) of the building automation system. Different approaches and methods for determining presence have attracted attention in recent years. We propose an occupancy detection method based on a method of supervised machine learning. In an experiment, measurement data were recorded in a research apartment with controllable boundary conditions. The presence of people was simulated by artificial injection of water vapour, CO2 and heat dissipation. The variation of the number of artificial users, the duration of presence and the supply air volume flow of the ventilation resulted in a total of 720 combinations. By using artificial users, the boundary conditions were accurately defined, and different presence situations could be measured time-effectively. The data is evaluated with a method of supervised machine learning called random forest. The statistical model can determine precisely the number of people in over 93\% of the cases in a disjoint test sample. The experiments took part in the Rosenheim Technical University of Applied Sciences laboratory.}, language = {en} } @article{ParzingerHanfstaenglSiggetal.2020, author = {Parzinger, Michael and Hanfstaengl, Lucia and Sigg, Ferdinand and Spindler, Uli and Wellisch, Ulrich and Wirnsberger, Markus}, title = {Residual Analysis of Predictive Modelling Data for Automated Fault Detection in Building's Heating, Ventilation and Air Conditioning Systems}, series = {Sustainability}, volume = {12}, journal = {Sustainability}, number = {17}, pages = {6758}, year = {2020}, abstract = {Faults in Heating, Ventilation and Air Conditioning (HVAC) systems affect the energy efficiency of buildings. To date, there rarely exist methods to detect and diagnose faults during the operation of buildings that are both cost-effective and sufficient accurate. This study presents a method that uses artificial intelligence to automate the detection of faults in HVAC systems. The automated fault detection is based on a residual analysis of the predicted total heating power and the actual total heating power using an algorithm that aims to find an optimal decision rule for the determination of faults. The data for this study was provided by a detailed simulation of a residential case study house. A machine learning model and an ARX model predict the building operation. The model for fault detection is trained on a fault-free data set and then tested with a faulty operation. The algorithm for an optimal decision rule uses various statistical tests of residual properties such as the Sign Test, the Turning Point Test, the Box-Pierce Test and the Bartels-Rank Test. The results show that it is possible to predict faults for both known faults and unknown faults. The challenge is to find the optimal algorithm to determine the best decision rules. In the outlook of this study, further methods are presented that aim to solve this challenge.}, language = {en} } @inproceedings{ParzingerWellischHanfstaengletal.2020, author = {Parzinger, Michael and Wellisch, Ulrich and Hanfstaengl, Lucia and Sigg, Ferdinand and Wirnsberger, Markus and Spindler, Uli}, title = {Identifying faults in the building system based on model prediction and residuum analysis}, series = {E3S Web of Conferences, 12th Nordic Symposium on Building Physics (NSB 2020)}, volume = {172}, booktitle = {E3S Web of Conferences, 12th Nordic Symposium on Building Physics (NSB 2020)}, pages = {22001}, year = {2020}, abstract = {The energy efficiency of the building HVAC systems can be improved when faults in the running system are known. To this day, there are no cost-efficient, automatic methods that detect faults of the building HVAC systems to a satisfactory degree. This study induces a new method for fault detection that can replace a graphical, user-subjective evaluation of a building data measured on site with an automatic, data-based approach. This method can be a step towards cost-effective monitoring. For this research, the data from a detailed simulation of a residential case study house was used to compare a faultless operation of a building with a faulty operation. We argue that one can detect faults by analysing the properties of residuals of the prediction to the actual data. A machine learning model and an ARX model predict the building operation, and the method employs various statistical tests such as the Sign Test, the Turning Point Test, the Box-Pierce Test and the Bartels-Rank Test. The results show that the amount of data, the type and density of system faults significantly affect the accuracy of the prediction of faults. It became apparent that the challenge is to find a decision rule for the best combination of statistical tests on residuals to predict a fault.}, language = {en} } @unpublished{KimmerleDvorskyLiessetal.2022, author = {Kimmerle, Sven-Joachim and Dvorsky, Karl and Liess, Hans-Dieter and Avenhaus, Rudolf}, title = {Time to Failure under Varying Thermal Stresses}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-19126}, pages = {30}, year = {2022}, abstract = {Varying thermal stresses influence significantly the time to failure of electric components as used, for instance, in automotive devices. For applications as autonomous driving a high reliability has to be guaranteed. In this article we discuss how to combine probability distributions for failure. Discrete and continuous changes of the probability distribution in time are both considered. It turns out that the temporal order of the distributions, corresponding to the succession of stresses in applications, is essential. The latter observation restricts the general applicability of the widely used temperature collectives where only the total time of a temperature stress is considered neglecting the order of the stresses. An application of our results are thermal overstress tests on electric components. We may explain yet not well understood measurements for automotive electric cables.}, language = {en} } @misc{KimmerleDvorskyLiess2025, author = {Kimmerle, Sven-Joachim and Dvorsky, Karl and Liess, Hans-Dieter}, title = {Failure Rates from Data of Field Returns - How to Prove High Reliability for Electric Components?}, series = {MATHMOD 2025 (11th Vienna International Conference on Mathematical Modelling)}, journal = {MATHMOD 2025 (11th Vienna International Conference on Mathematical Modelling)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-29421}, pages = {1}, year = {2025}, abstract = {To determine failure rates is a challenge, if there are only a few failures and a low failure rate should be checked. As an application example, we are interested in failure rates of electrical automotive components for automated/autonomous driving. Basically, three methods are common: (i) exploitation of field data, (ii) standardized handbooks with failure rates, e.g. the FIDES guide, and (iii) laboratory long term exposure tests. We discuss shortly the (dis)advantages of each method and focus on the statistics behind method (i). Moreover, our poster sketches how this can be applied to data as available in industry.}, subject = {Reliabilit{\"a}t}, language = {en} } @misc{KimmerleDvorskyLiess2025, author = {Kimmerle, Sven-Joachim and Dvorsky, Karl and Liess, Hans-Dieter}, title = {Failure Rates from Data of Field Returns}, series = {MATHMOD Short Contribution Volume 2025}, journal = {MATHMOD Short Contribution Volume 2025}, publisher = {reposiTUm, TU Wien}, address = {Wien}, doi = {10.34726/9011}, pages = {23 -- 24}, year = {2025}, abstract = {To determine failure rates is a challenge, if there are only a few failures and typical failure rates are low. As an application example we are interested in failure rates of electrical automotive components for automated/autonomous driving. As method we focus here on the exploitation of field data. Our contribution classifies different approaches from statistics and shows how this can be applied to real-world production figures as available in industry.}, subject = {Mathematische Modellierung}, language = {en} } @misc{HelbigSeliger2025, author = {Helbig, Michael and Seliger, Norbert}, title = {Combinatorics of Inductance States in Reconfigurable Air Coils}, series = {Proceedings 2nd International Conference on Recent Advances in Mathematics and Informatics (ICRAMI'25)}, journal = {Proceedings 2nd International Conference on Recent Advances in Mathematics and Informatics (ICRAMI'25)}, isbn = {978-9909-00-770-9}, pages = {8}, year = {2025}, abstract = {We propose a group theory based mathematical model for unambiguous inductance states of a reconfigurable air coil inductor utilizing elastic snapping of wire segments. Vertical (axial) and horizontal winding symmetries under group actions reveal distinguishable tuning regions and individual variation states therein. The model is applied to coils of prismatic (cylinder like) and truncated pyramidal (conical like) shape with edges forming a regular polygon as basis, and verified by numerical magnet field simulation.}, language = {en} } @phdthesis{Helbig2009, author = {Helbig, Michael}, title = {Lifting of Nichols Algebras}, doi = {10.5282/edoc.10378}, school = {Technische Hochschule Rosenheim}, pages = {107}, year = {2009}, abstract = {Nichols algebras are a fundamental building block of pointed Hopf algebras. Part of the classi cation program of nite-dimensional pointed Hopf algebras with the lifting method of Andruskiewitsch and Schneider [6] is the determination of the liftings, i.e., all possible deformations of a given Nichols algebra. The classi cation was carried out in this way in [11] when the group of group-like elements is abelian and the prime divisors of the order of the group are > 7. In this case the appearing Nichols algebras are of Cartan type. Based on recent work of Heckenberger about diagonal Nichols algebras [29, 28, 27] we compute explicitly the liftings of some Nichols algebras not treated in [11]; namely we lift - all Nichols algebras with Cartan matrix of type A2 (Theorem 6.3.3), - some Nichols algebras with Cartan matrix of type B2 (Theorem 6.4.3), and - some Nichols algebras of two Weyl equivalence classes of non-standard type (Theorem 6.5.3), giving new classes of nite-dimensional pointed Hopf algebras. Crucial is the knowledge of a good presentation of the Nichols algebra and its liftings: We want to have an explicit description in terms of generators and (non-redundant) relations, and a basis; this requires new ideas and methods that generalize those in [11]. In this spirit, we describe Hopf algebras generated by skew-primitive elements and an abelian group with action given via characters (including Nichols algebras and their liftings) in Theorem 5.4.1. The relations form a Grobner basis and are given by a combinatorial property involving the theory of Lyndon words. Furthermore, in Theorem 7.3.1 we give a necessary and su cient criterion to check whether a given set of iterated q-commutators establishes a restricted PBW basis for a given realization of the relations. Also with the help of this criterion we determine the redundant relations in the examined Nichols algebras and their liftings.}, language = {en} } @book{Helbig2009, author = {Helbig, Michael}, title = {Lifting of Nichols Algebras - A Contribution to the Classification of Pointed Hopf Algebras}, publisher = {S{\"u}dwestdeutscher Verlag f{\"u}r Hochschulschriften}, address = {Saarbr{\"u}cken}, isbn = {978-3-8381-1084-4}, publisher = {Technische Hochschule Rosenheim}, pages = {112}, year = {2009}, abstract = {Nichols algebras are a fundamental building block of pointed Hopf algebras. Part of the classification program of finite-dimensional pointed Hopf algebras with the lifting method of Andruskiewitsch and Schneider is the determination of the liftings, i.e., all possible deformations of a given Nichols algebra. The classification was carried out in this way in several special cases when the appearing Nichols algebras are of Cartan type. We compute explicitly the liftings of some Nichols algebras not of Cartan type or of Cartan type without restrictions on the group order. These build up new classes of finite-dimensional pointed Hopf algebras. Furthermore, we give a necessary and sufficient PBW basis criterion for a class of pointed Hopf algebras and present them in terms of generators and relations. These Hopf algebras can be seen as generalized Quantum groups.}, language = {en} } @unpublished{Helbig2010, author = {Helbig, Michael}, title = {A PBW basis criterion for pointed Hopf algebras}, doi = {10.48550/arxiv.1011.0140}, pages = {1 -- 33}, year = {2010}, abstract = {We give a necessary and sufficient PBW basis criterion for Hopf algebras generated by skew-primitive elements and abelian group of group-like elements with action given via characters. This class of pointed Hopf algebras has shown great importance in the classification theory and can be seen as generalized quantum groups. We apply the criterion to classical examples and liftings of Nichols algebras which were determined in arxiv.org:1003.5882.}, language = {en} } @unpublished{Helbig2010, author = {Helbig, Michael}, title = {On the presentation of pointed Hopf algebras}, doi = {10.48550/arXiv.1003.5879}, pages = {1 -- 13}, year = {2010}, abstract = {We give a presentation in terms of generators and relations of Hopf algebras generated by skew-primitive elements and abelian group of group-like elements with action given via characters. This class of pointed Hopf algebras has shown great importance in the classification theory and can be seen as generalized quantum groups. As a consequence we get an analog presentation of Nichols algebras of diagonal type.}, language = {en} } @misc{SchaefleLuxNeubert2024, author = {Sch{\"a}fle, Claudia and Lux, Christine and Neubert, Julia}, title = {Classroom observation in SCALE-UP settings - first results}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-32456}, year = {2024}, abstract = {SCALE-UP (Student-Centered Active Learning Environment for Upside-down Pedagogies) is a pedagogic approach to foster active learning, originally developed for undergraduate physics courses (Beichner et al., 2007). Instead of receiving lectures in SCALE1UP students work actively together in small groups, mostly at round tables and are guided by teaching staff. This concept is implemented at Rosenheim University of Applied Sciences, Germany, in several classes of physics and mathematics for engineering students. Classroom observations have been carried out in summer term 2023and winter term 2023/24 in order to investigate student learning in the SCALE-UP setting. The observations are based on ELCOT-3, the Engineering Learning Classroom Observation Tool (Sanders et al., 2018). An observation includes the overt student behavior in combination with the students' output. The data have been analyzed with respect to the ICAP-framework (Chi\&Wylie, 2014), where the different observed activities have been assigned to Interactive, Constructive, Active, and Passive mode. In this contribution we present examples on how students interact with the offered material, that means in which ICAP-modes students work with different learning activities in the SCALE-UP setting. Moreover, we show that in all observed courses students have been learning a substantial part of class time in interactive and constructive mode.}, language = {en} } @misc{SchaefleStanzelLuxetal.2025, author = {Sch{\"a}fle, Claudia and Stanzel, Silke and Lux, Christine and Neubert, Julia and D{\"o}lling, Hanna}, title = {Using the ICAP model with classroom observations to improve active learning}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:861-opus4-32833}, year = {2025}, language = {en} }