Some identities involving harmonic numbers

Inspired by the recent work of Wei, we prove five identities involving harmonic numbers by the application of the operator method, a well-poised $_5F_4$-series due to Dougall and two hypergeometric transformations due to Chu and Zhang. All of them are the series expansions of $\log 2/\pi$ and Sun's four conjectural series are solved.Comment: 9 page

Amino acid residues constituting the agonist binding site of the human P2X3 receptor and subunit stoichiometry of heteromeric P2X2/3 and P2X2/6 receptors

Homotrimeric P2X3 and heteromeric P2X2/3 receptors are present in sensory ganglia and participate in pain perception. In order to develop pharmacological antagonists for these receptors, it is important to clarify which amino acid (AA) residues constitute the agonist binding pouch as well as to learn the stoichiometry of the receptor subunits forming a heteromeric receptor. We expressed the homomeric human (h)P2X3 receptor or its mutants in HEK293 cells and measured the ATP-induced responses by the whole-cell patch-clamp method. For the binding-site mutants, all conserved and some non-conserved AAs in the four nucleotide binding segments (NBSs) of the P2X3 subunit were sequentially replaced by alanine. Especially the positively charged AAs Lys and Arg appeared to be of critical importance for the agonist effects. We concluded that groups of AAs organized in NBSs rather than individual amino acids appear to be responsible for agonist binding at the P2X3 receptor. These NBSs are located at the interface of the three subunits forming a functional receptor. We were also interested to find out, whether two heteromeric receptors (P2X2/3 and P2X2/6), where P2X2 combines with two different partners, have an obligatory subunit stoichiometry of 1:2 or whether the subunit stoichiometry may be variable. For this purpose we used non-functional P2X2, P2X3 and P2X6 subunit-mutants to investigate the composition of heteromeric P2X2/3 and P2X2/6 receptors. The subunit stoichiometry of P2X2/3 and P2X2/6 was found to be 1:2 and 2:1, respectively. Thus, recognitions sites between P2X2 and its partners rather than random association may govern the subunit compositions of the receptor trimers.:Index of contents Introductory remarks „Wissenschaftlicher Anteil des Promovenden an der Publikation“ „Bibliographische Beschreibung“ I. Introduction Pain as a sensory quality Neuronal circuitry for pain processing and sensation in the PNS and CNS Transformation of thermal, mechanical and chemical stimuli into electrical activity by nociceptors; nociceptor-targeted therapeutic approaches Release mechanisms for nucleotides and their fate in the extracellular space Nucleotide receptor-types ATP-sensitive P2 receptors and pain-sensation References II. Scientific background and aims of my thesis ATP binding-sites of P2X3 receptors; subunit composition of P2X2/3 and P2X2/6 heteromeric receptors The aims of the present work III. Publications IV. Summary and conclusions Amino acid residues constituting the agonist binding site of the human P2X3 receptor ATP binding site mutagenesis reveals different subunit stoichiometry of functional P2X2/3 and P2X2/6 receptors „Eigenständigkeitserklärung“ Curriculum vitae Acknowledgement

Switching Time Delay Optimization for “SiC+Si” Hybrid Device in a Phase-leg Configuration

Compared to SiC MOSFET, the switching loss of Si IGBT is much higher due to its slow switching speed and tail current. Si IGBT/SiC MOSFET hybrid switch device can reach to optimal performance with low static and dynamic loss, which can improve the current capacity of SiC devices and reduce the power loss of Si IGBT based converters. With the separated gate control signals, the switching moments of the two devices can be controlled independently to ensure Si IGBT under zero-voltage switching (ZVS) conditions. This measurement tends to reduce the switching loss of Si IGBT. However, the switching time delay between these two devices has significant impacts on its power loss. In this paper, the switching time delay optimization method is proposed to minimize the power loss of the hybrid switch. The static and dynamic characteristics of Si IGBT/SiC MOSFET hybrid-paralleled switch are studied, and a generalized power loss model for hybrid switch is developed. The influence of switching time delay on the characteristics of hybrid switch is analyzed and verified through double pulse tests in a phase-leg configuration. The experimental results show that the optimal turn-on delay time is that the two devices turn on at the same time and the turn-on loss can be reduced by about 73% compared with the solely Si IGBT and by about 52% compared with the solely SiC MOSFET. While the optimal turn-off sequence is that the Si IGBT turns off ahead of the SiC MOSFET. Under the proposed optimal turn-off delay time of the hybrid switch, the turn-off loss is reduced by about 61.4%. This optimization strategy is used in a Buck converter to verify the superiority of the SiC/Si hybrid switch and the optimal switching sequence. Simulation results show that the optimal switching sequence is consistent with theoretical analysis, and the efficiency is improved by 2.5% compared with Buck converter using solely Si IGBT

BCI Competition IV – Data Set I: Learning Discriminative Patterns for Self-Paced EEG-Based Motor Imagery Detection

Detecting motor imagery activities versus non-control in brain signals is the basis of self-paced brain-computer interfaces (BCIs), but also poses a considerable challenge to signal processing due to the complex and non-stationary characteristics of motor imagery as well as non-control. This paper presents a self-paced BCI based on a robust learning mechanism that extracts and selects spatio-spectral features for differentiating multiple EEG classes. It also employs a non-linear regression and post-processing technique for predicting the time-series of class labels from the spatio-spectral features. The method was validated in the BCI Competition IV on Dataset I where it produced the lowest prediction error of class labels continuously. This report also presents and discusses analysis of the method using the competition data set

Examining how time flies at destinations based on visitors’ perceived consistency of destination experiences

Domestic Chinese tourists traveling to rural destinations in China often face the challenge of local dialects. Based on the theories of flow (Csikszentmihalyi & Csikzentmihaly, 1990; Nakamura & Csikszentmihalyi, 2009), individuals’ need for uniqueness (Tian, Bearden, & Hunter, 2001), and confirmation-disconfirmation (Parasuraman et al., 1994), this study explores two main antecedents for visitors’ perceived absorption experiences during visits at destinations (i.e., the sense of immersion and feeling time flies). Specifically, we suggest that visitors are more likely to experience absorption when they have a positive attitude toward the local dialect of the destination as well as perceive the destination to be distinct. In addition, both of these effects are moderated by visitors’ evaluation of their experiences compared to their expectations (perceived consistency of destination of experiences). With a sample of 352 visitors in a rural destination in China, this study provides strong support for these propositions

Hearing Lips: Improving Lip Reading by Distilling Speech Recognizers

Lip reading has witnessed unparalleled development in recent years thanks to deep learning and the availability of large-scale datasets. Despite the encouraging results achieved, the performance of lip reading, unfortunately, remains inferior to the one of its counterpart speech recognition, due to the ambiguous nature of its actuations that makes it challenging to extract discriminant features from the lip movement videos. In this paper, we propose a new method, termed as Lip by Speech (LIBS), of which the goal is to strengthen lip reading by learning from speech recognizers. The rationale behind our approach is that the features extracted from speech recognizers may provide complementary and discriminant clues, which are formidable to be obtained from the subtle movements of the lips, and consequently facilitate the training of lip readers. This is achieved, specifically, by distilling multi-granularity knowledge from speech recognizers to lip readers. To conduct this cross-modal knowledge distillation, we utilize an efficacious alignment scheme to handle the inconsistent lengths of the audios and videos, as well as an innovative filtering strategy to refine the speech recognizer's prediction. The proposed method achieves the new state-of-the-art performance on the CMLR and LRS2 datasets, outperforming the baseline by a margin of 7.66% and 2.75% in character error rate, respectively.Comment: AAAI 202