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The Structural Acoustic Properties of Stiffened Shells Downloaded from orbit.dtu.dk on: Sep 27, 2021 The structural acoustic properties of stiffened shells Luan, Yu Published in: Acoustical Society of America. Journal Link to article, DOI: 10.1121/1.2932806 Publication date: 2008 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Luan, Y. (2008). The structural acoustic properties of stiffened shells. Acoustical Society of America. Journal, 123(5), 3063-3063. https://doi.org/10.1121/1.2932806 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. MONDAY MORNING, 30 JUNE 2008 AMPHI GRAND, 8:40 TO 11:50 A.M. Session 1aID Opening Ceremony 1a MON. AM The Opening Ceremony will include a special welcome from the Vice-President of Ile de France Regional Council, addresses by National sponsors, and addresses by the Presidents of the Acoustical Society of America, the European Acoustics Association, and the French Acoustical Society. Musical interludes will be given and two plenary lectures will be presented. Plenary Lectures Introduced by George Frisk, Florida Atlantic University, USA 10:30 1aID1. How sound from human activities affects marine mammals. Peter Tyack ͑Woods Hole Oceanographic Institution, Ap- plied Ocean Physics & Engineering Dept., Woods Hole, MA 02543, USA, [email protected]͒ Effects of sound on marine mammals have traditionally been defined either as injury or disruption of behavior. The earliest concern about behavioral disruption was that elevated noise could reduce the range of communication by masking faint signals. Few studies have documented this effect, but recent work emphasizes mechanisms animals use to compensate for elevated noise. Many studies have documented changes in behavior as a function of exposure, but it has proven difficult to relate these to effects on the welfare of indi- vidual animals or on the status of populations. Promising approaches to interpreting effects include avoidance of habitat, energetics of foraging, and applying models of anti-predator behavior to human disturbance. During the 1990s acoustic criteria for injury were des- ignated based upon temporary hearing loss. Accumulating evidence of atypical mass strandings of beaked whales coincident with naval sonar exercises suggest that injury or death may result from behavioral responses of some species at lower exposure levels in some settings. A tagged beaked whale showed similar but weaker responses to experimental playback of a mid-frequency sonar sound com- pared to calls of killer whales, suggesting that anti-predator response may harm animals after exposure to levels of sound very unlikely to cause injury directly. Introduced by Luigi Maffei, Second University of Naples, Italy 11:10 1aID2. New Trends in Aeroacoustics: From acoustic analogies to direct numerical simulations. Daniel Juvé ͑Ecole centrale de Lyon, 36 avenue Guy de Collongue, 69134 Ecully cedex, France, [email protected]͒ Modern aeroacoustics started in the early 1950’s when Lighthill developed his famous acoustic analogy in an attempt to understand, and reduce, the terrifying noise generated by jet aircrafts. For nearly 50 years the subject of aerodynamic sound was dominated by approaches based upon this analogy or variants of it. Recently, the availability of powerful computing facilities combined with the development of numerical algorithms specially designed to simulate sound propagation over large distances has paved the way for Љa second golden age of aeroacousticsЉ ͑to quote Lighthill himself͒. In this talk we will first give an overview of this evolution from acoustic analogies to computational aeroacoustics ͑CAA͒. Typical illustrations of the CAA approach will then be presented and appli- cations for transportation systems will be discussed. 2969 J. Acoust. Soc. Am., Vol. 123, No. 5, Pt. 2, May 2008 Acoustics’08 Paris 2969 Downloaded 29 Jun 2010 to 192.38.67.112. Redistribution subject to ASA license or copyright; see http://asadl.org/journals/doc/ASALIB-home/info/terms.jsp MONDAY AFTERNOON, 30 JUNE 2008 ROOM 202”203, 1:00 TO 4:40 P.M. Session 1pAAa Architectural Acoustics and Noise: Acoustics of Open-Plan Spaces I Kenneth P. Roy, Cochair Armstrong Building Products, 2500 Columbia Ave, Lancaster, PA 17603, USA Valtteri O. Hongisto, Cochair Finnish Institute of Occupational Health, Lemminkäisenkatu 14-18 B, Turku, 20520, Finland Stephen Sinclair, Cochair Centre for Interdisciplinary Research in Music Media & Technology, Schulich School of Music, McGill Univ., Montreal H3A IE3, QC, Canada Invited Papers 1:00 1pAAa1. Spatial decay, behaviour and space planning models European and International standards on open office acoustics. Pierre Chigot ͑Saint Gobain Ecophon SA, box 30030, 60 291 Rantigny, France, [email protected]͒ Recent standardisation work on open plan offices acoustics is characterized by a shift in the way room acoustics is handled. Spatial decay ͑expressed through rate of spatial decay per doubling of distance, DL2͒ is preferred to temporal decay ͑expressed through re- verberation time, RT͒. The complexity of open plan office acoustic design results from the fundamental contradiction of communication and concentration. DL2 reflects better the challenges of sound control in such rooms, which is basically sound propagation control. Beyond, this contradiction, specific space analysis models and tools can help to visualize the acoustic interactions between workstations, teams and departments accommodated in the same room. These models are now ready to be included in standardization work. Inter- national technical standard for field measurements of DL2 integrates new descriptive models for open plan office acoustics, taking into account geometric proportions, presence of screens and furniture as well as group behaviour and speech characteristics, such as in- creased energy contents at low frequencies, voice levels, raised hearing sensitivity at high frequencies. Also, normative guidelines from Netherlands and France integrating this approach will be presented. 1:20 1pAAa2. Acoustics and sustainable design in exposed structures. Kenneth P. Roy ͑Armstrong Building Products, 2500 Columbia Ave, Lancaster, PA 17603, USA, [email protected]͒, Anita L. Snader ͑Armstrong World Industries, 2500 Columbia Ave, R&D Bldg. 5, Lancaster, PA 17604, USA, [email protected]͒ Two very important emerging architectural trends in the USA are to 1͒ ’open up’ the space design as exposed structures, and 2͒ incorporate sustainable design into building interiors. We as acoustic designers would like to know the consequences of both on acous- tics performance and occupant satisfaction and work performance. The first concern is addressed in a study by CISCA evaluating the effects of ceiling plenum vs. exposed structures in both office and retail spaces. And the second issue of compatibility of sustainable design objectives with acoustic performance is addressed by a pertinent field survey by the Center for the Built Environment ͑CBE at Univ. of CA, Berkeley͒ on occupant satisfaction and performance. The issue of the availability and use of ’green’ acoustic building materials that not only meet sustainability and energy goals, but also serve to ensure that our buildings actually work for their intended purposes will be addressed. Finally, the increased awareness of the acoustic impact of ’green’ design on occupant satisfaction is being seen in the evolution of LEED and other ’green’ rating systems. 1:40 1pAAa3. Differences in perception of noise and privacy in different office types. Christina Bodin Danielsson ͑The Royal Insti- tute of Technology, KTH, Roslagsgatan 37, 113 54 Stockholm, Sweden, [email protected]͒ Differences between office types with regard to their architectural and functional features may have an impact on the employees’ disturbance by noise and perception of privacy. These aspects may in its turn have an impact on employees’ satisfaction and psycho- logical responses to the office environment. In a study 469 employees in 26 different companies have rated their satisfaction with the office environment in seven different office-types: cell-office, shared room office, small open plan office, medium open plan office, large open plan office, flex-office and combi-office. This paper discusses the results concerning the employees’ perception of noise and pri- vacy and put the results in relation to the two different aspects of privacy, visual and acoustic privacy, and the role of personal control. In the statistical analysis adjustments for potential confounders as age, gender, job rank and line of business were done, which are known to have an influence on perception and satisfaction. Substantial differences between employees in different office-types were found. The fact that there were such differences between different types of offices that mean sharing
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