BEGIN:VCALENDAR
CALSCALE:GREGORIAN
VERSION:2.0
X-WR-CALNAME:DAGA 2016
METHOD:PUBLISH
PRODID:-//ORGANIZER//FH-CITY
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TZID:Europe/Paris
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RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
DTSTART:19810329T020000
TZNAME:GMT+02:00
TZOFFSETTO:+0200
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RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
DTSTART:19961027T030000
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BEGIN:VEVENT
CREATED:19700101T000000Z
UID:96
DTEND;TZID=Europe/Paris:20190914T140100
TRANSP:OPAQUE
SUMMARY:DAGA 2016
DTSTART;TZID=Europe/Paris:20190914T140000
DTSTAMP:20190914T140000Z
SEQUENCE:1
DESCRIPTION: Cornelis Johannes Nederveen --- Resonators of reed wind instruments are tubular ducts with one open \nand one closed end. The ratio of pressure\nresponse to flow excitation at the closed end is the input impedance. \nResonance frequencies of the duct are near\nto peaks in the impedance spectrum. Damping due to visco-thermal \neffects at the walls influences the frequency\nand the magnitude of the impedance-spectrum peaks, which \ninfluence \nintonation, playing behaviour and timbre.\nFor cylindrical instruments theory to account for wall losses is \navailable \nand experimentally confirmed. The\nwave equation in a conical tube while accounting for dissipative \neffects \nat the walls appears to be complicated.\nFour approximative solutions are compared: (1) Nederveen (1969) \npresented an approximate analytical solution\nwhile neglecting some higher order terms. (2) a transmission line \nmethod mimicking the conical pipe as a series\nof short conical (or cylindrical) pipes, (3) directly solving the equation \nwith a Runge-Kutta procedure, (4)\napplying a finite difference method. For a Â“simplified bassoonÂ” (a \nperfect cone of 3000 mm length, input\ndiameter 4.2 mm, output diameter 46.9 mm) the four methods give \ndifferent results. Measurements are planned,\nbut the narrow tube entrance and smoothness requirements make a \nhigh accuracy difficult. Suggestions are\nwelcome.\n
LOCATION:Summer Theater
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