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Visar resultat 1 - 5 av 31 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Bone Conduction Hearing in Human Communication - Sensitivity, Transmission, and Applications

   Författare :Sabine Reinfeldt; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; transcutaneous; one s own voice; bone conduction; occlusion effect; communication system; sensitivity; bone conduction implant; transmission; bone-anchored hearing aid; bone conduction microphone;

   Sammanfattning : Sound perceived via Bone Conduction (BC) consists of vibrations transmitted to the cochleae through the skull bone from either one's own voice, the surrounding sound field, or a BC transducer. In two-way communication systems, BC is believed to improve the sound quality when used in specific environments, e.g. LÄS MER

3. 2. A Novel Bone Conduction Implant System

   Författare :Hamidreza Taghavi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sound radiation; amplitude modulation; low-power systems.; bone conduction implant; feedback; bone anchored hearing aid; RF power amplifier; gain headroom; implantable transducer; wireless power and data transmission; RF power and data link;

   Sammanfattning : Bone conduction is the process by which an acoustic signal vibrates the skull bones to stimulate the cochlea. Patients with pure conductive hearing loss, mixed hearing loss, and single sided deafness are sometimes poorly rehabilitated by conventional air conduction hearing aids due to for example the functionality losses in the middle ear. LÄS MER

4. 3. Modular Battery Systems for Electric Vehicles based on Multilevel Inverter Topologies - Opportunities and Challenges

   Författare :Anton Kersten; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic reconfiguration; Energy storage; Energy efficiency; Drive cycle efficiency; Power MOSFET; vehicles; H-bridge; Multilevel systems; Electromagnetic compatibility; Modular battery systems; Battery system performance; Modular multilevel converters; Conduction losses; Electric vehicles; Batteries; Dual battery pack; Cascaded converters; DC-AC power converters; BMS; Common mode noise; Battery modeling; vehicle electrification;

   Sammanfattning : Modular battery systems based on multilevel inverter (MLI) topologies can possibly overcome some shortcomings of two-level inverters when used for vehicle propulsion. The results presented in this thesis aim to point out the advantages and disadvantages, as well as the technical challenges, of modular vehicle battery systems based on MLIs in comparison to a conventional, two-level IGBT inverter drivetrain. LÄS MER

5. 4. Characterization of Conduction and Polarization Properties of HVDC Cable XLPE Insulation Materials

   Författare :Hossein Ghorbani; Hans Edin; Erling Ildstad; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC insulation; power cable insulation; cross-linked polyethylene insulation; conductivity; dielectric losses; space charge; HVDC isolation; kraftkabel isolation; tvärbunden polyeten isolationsmaterial; elektrisk ledningsförmåga; dielektriska förluster; rymdladdning; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Since its first introduction in 1998, extruded direct current (DC) cable technology has been growing rapidly leading to many cable system installations with operation voltages up to 320 kV. Cable manufacturers invest heavily on technology development in this field and today extruded DC cable systems for operation voltages as high as 525 kV are commercially available. LÄS MER

7. 5. Characterization of Conduction and Polarization Properties of HVDC Cable XLPE Insulation Materials

   Författare :Hossein Ghorbani; Hans Edin; Gilbert Teyssedre; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC insulation; power cable insulation; cross-linked polyethylene insulation; conductivity; dielectric losses; space charge; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : High voltage direct current (HVDC) cables with extruded insulation system were introduced in 1998. Since then this technology has been growing rapidly with many installations that are today operational at voltages up to 320 kV. LÄS MER