Nonlinear modes of clarinet-like musical instruments

The concept of nonlinear modes is applied in order to analyze the behavior of a model of woodwind reed instruments. Using a modal expansion of the impedance of the instrument, and by projecting the equation for the acoustic pressure on the normal modes of the air column, a system of second order ordinary differential equations is obtained. The equations are coupled through the nonlinear relation describing the volume flow of air through the reed channel in response to the pressure difference across the reed. The system is treated using an amplitude-phase formulation for nonlinear modes, where the frequency and damping functions, as well as the invariant manifolds in the phase space, are unknowns to be determined. The formulation gives, without explicit integration of the underlying ordinary differential equation, access to the transient, the limit cycle, its period and stability. The process is illustrated for a model reduced to three normal modes of the air column

Teaching Emotional Intelligence In The Business School Curriculum

The ability to manage one’s emotions and to manage one’s interactions with others is tantamount  to effective  managerial leadership.  Students  in  business  schools will need to be prepared  to integrate their  emotional  intelligence with their  everyday  behavior if they are to achieve  success  in  whatever  field  of  endeavor they  have chosen.  In this article I will outline a curriculum  design  that will  enable students to understand, appreciate and apply  the  principles  embedded in the emotional  intelligence model.  The following topics will be  discussed in this article as part of this  self management curriculum:  assessing  one’s level  of emotional intelligence;  the distinction between  emotional  and intellectual  competency;  what  research  shows in terms  of the relationship between emotional intelligence and success in life;  and  a description  of  the self management course which I currently teach  within the emotional  intelligence framework

Nonlinear normal modes of a two degree of freedom oscillator with a bilateral elastic stop

A study of the non linear modes of a two degree of freedom mechanical system with bilateral elastic stop is considered. The issue related to the non-smoothness of the impact force is handled through a regularization technique. In order to obtain the Nonlinear Normal Mode (NNM), the harmonic balance method with a large number of harmonics, combined with the asymptotic numerical method, is used to solve the regularized problem. These methods are present in the software "package" MANLAB. The results are validated from periodic orbits obtained analytically in the time domain by direct integration of the non regular problem. The two NNMs starting respectively from the two linear normal modes of the associated underlying linear system are discussed. The energy-frequency plot is used to present a global vision of the behavior of the modes. The dynamics of the modes are also analyzed comparing each periodic orbits and modal lines. The first NNM shows an elaborate dynamics with the occurrence of multiple impacts per period. On the other hand, the second NNM presents a more simple dynamics with a localization of the displacement on the first mass

Examining the Experiences of First-Year Honors Engineering Students in Service-Learning

Although research projects and skill-based courses are central to engineering and computer science curricula, service-learning has also been highlighted as a pedagogy that has proven beneficial to students\u27 learning within these disciplines. This qualitative investigation examines the experiences of two cohorts of students in an Honors Introduction to Engineering course during Fall 2016 and Fall 2017. As part of a mandatory service-learning project, students worked in teams to deliver a presentation and prepare a hands-on activity to expose underprivileged adolescents to Science, Technology, Engineering, and Math (STEM). Participants in this study were surveyed to assess the efficacy of service-learning. In particular, students\u27 abilities to develop their skills in effective communication, practice strategic teamwork, and develop a clear self-concept as engineers or computer scientists were examined following their service-learning experiences. Learning how to communicate with a non-technical audience was noted as an important takeaway by both cohorts of student-participants. The second cohort of students highlighted teamwork as a major obstacle that they had to work through to successfully execute their projects. Finally, students voiced a feeling of duty to improve access to higher education for underprivileged adolescents in the community, seeing themselves as peers with an obligation to improve the educational prospects of these local adolescents, rather than as future professionals in a technical environment

The DNA damage response promotes Polyomavirus JC infection by nucleus to cytoplasm NF-Kappa B activation.

Background: Infection of glial cells by human neurotropic polyomavirus JC (JCV), the causative agent of the CNS demyelinating disease progressive multifocal leukoencephalopathy (PML), rapidly inflicts damage to cellular DNA. This activates DNA damage response (DDR) signaling including induction of expression of DNA repair factor Rad51. We previously reported that Rad51 co-operates with the transcription factor NF-κB p65 to activate JCV early transcription. Thus Rad51 induction by JCV infection may provide positive feedback for viral activation early in JCV infection. DDR is also known to stimulate NF-κB activity, a phenomenon known as nucleus to cytoplasm or “insideout” NF-κB signaling, which is initiated by Ataxia telangiectasia mutated (ATM) protein, a serine/threonine kinase recruited and activated by DNA double-strand breaks. Downstream of ATM, there occurs a series of posttranslational modifications of NF-κB essential modulator (NEMO), the γ regulatory subunit of inhibitor of NF-κB (IκB) kinase (IKK), resulting in NF-κB activation. Methods: We analyzed the effects of downstream pathways in the DDR by phosphospecific Western blots and analysis of the subcellular distribution of NEMO by cell fractionation and immunocytochemistry. The role of DDR in JCV infection was analyzed using a small molecule inhibitor of ATM (KU-55933). NEMO sumoylation was investigated by Western and association of ATM and NEMO by immunoprecipitation/Western blots. Results: We show that JCV infection caused phosphorylation and activation of ATM while KU-55933 inhibited JCV replication. JCV infection caused a redistribution of NEMO from cytoplasm to nucleus. Co-expression of JCV large Tantigen and FLAG-tagged NEMO showed the occurrence of sumoylation of NEMO, while co-expression of ATM and FLAG-NEMO demonstrated physical association between ATM and NEMO. Conclusions: We propose a model where JCV infection induces both overexpression of Rad51 protein and activation of the nucleus to cytoplasm NF-κB signaling pathway, which then act together to enhance JCV gene expression

Analysis of stationary random vibrating systems using smooth decomposition

International audienceA modified Karhunen-Loève Decomposition/Proper Orthogonal Decomposition method, named Smooth Decomposition (SD) (also named smooth Karhunen-Lo'eve decomposition), was recently introduced to analyze stationary random signal. It is based on a generalized eigenproblem defined from the covariance matrix of the random process and the covariance matrix of the associated time-derivative random process. The SD appears to be an interesting tool in terms of modal analysis. In this paper, the SD will be described in case of stationary random processes and extended also to stationary random fields. The main properties will be discussed and illustrated on a randomly excited clamped-free beam

Hyper-connected and spaced in a distressing era: some notes about facultas agendi in pandemic

  The purpose of this brief analysis is to identify the limits of web society in the period of the Pandemic in the light of the primary physiopsychic needs of freedom and privacy of people. Hence the focus is on the social cleavage generated between activities that can be carried out online and activities prevented by the pandemic. Furthermore, we try to frame: 1) the issue of hypothetical responsibilities for the contagion from the point of view of the legal system of Italy as the first massively infected western country;2) the question of the reasonableness of State restrictions on freedom of movement