Sökning: "Hardness"

Visar resultat 1 - 5 av 426 avhandlingar innehållade ordet Hardness.

  1. 1. Hardness of Constraint Satisfaction and Hypergraph Coloring : Constructions of Probabilistically Checkable Proofs with Perfect Completeness

    Författare :Sangxia Huang; Johan Håstad; Rishi Saket; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Combinatorial optimization; approximation; inapproximability; hardness; probabilistically checkable proofs; pcp; perfect completeness; boolean constraint satisfaction problem; csp; graph coloring; hypergraph coloring; direct sum; superposition; label cover; Computer Science; Datalogi;

    Sammanfattning : A Probabilistically Checkable Proof (PCP) of a mathematical statement is a proof written in a special manner that allows for efficient probabilistic verification. The celebrated PCP Theorem states that for every family of statements in NP, there is a probabilistic verification procedure that checks the validity of a PCP proof by reading only 3 bits from it. LÄS MER

  2. 2. Radiation Hardness of 4H-SiC Devices and Circuits

    Författare :Sethu Saveda Suvanam; Anders Hallén; Carl-Mikael Zetterling; Ulrike Grossner; KTH; []
    Nyckelord :Silicon carbide; radiation hardness; protons; gamma radiation; bipolar junction transistors; aluminium oxide; surface recombination.; Informations- och kommunikationsteknik; Information and Communication Technology;

    Sammanfattning : Advances in space and nuclear technologies are limited by the capabilities of the conventional silicon (Si) electronics. Hence, there is a need to explore materials beyond Si with enhanced properties to operate in extreme environments. In this regards, silicon carbide (4H-SiC), a wide bandgap semiconductor, provides suitable solutions. LÄS MER

  3. 3. ICME guided development of cemented carbides with alternative binder systems

    Författare :Martin Walbrühl; John Ågren; Annika Borgenstam; Henrik Larsson; Claudio Miguel Lousada Patricio; Jan Qvick; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cemented carbide; ICME; Materials Design; alternative binder; hardness; AIMD; liquid diffusion; frozen-in solubilities; DICTRA; surface gradients; labyrinth factor; Materials Science and Engineering; Teknisk materialvetenskap;

    Sammanfattning : The development of alternative binder systems for tungsten carbide (WC) based cemented carbides has again become of relevance due to possible changes in EU regulations regarding the use of Cobalt (Co). A framework for the ICME (Integrated Computational Materials Engineering) based Materials Design is presented to accelerate the development of alternative binder systems. LÄS MER

  4. 4. Resonator sensor technique for medical use : an intraocular pressure measurement system

    Författare :Anders Eklund; Umeå universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sensor; Vibration; Hardness; Prostate; intraocular pressure; resonator; eye; applanation; glaucoma;

    Sammanfattning : In the work of this doctoral dissertation a new resonator sensor technique, first presented in 1989, has been further developed and evaluated with focus on technical characteristics and applications within the medical field. In a first part a catheter-type tactile sensor using the resonator sensor technique was evaluated in a silicone model and applied to human prostate in vitro. LÄS MER

  5. 5. On Thermal Conductivity and Strength in Compacted Graphite Irons : Influence of Temperature and Microstructure

    Författare :Martin Selin; Ingvar L. Svensson; Attila Diószegi; Steve Dawson; Jönköping University; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Compacted Graphite Iron; Thermal Conductivity; Mechanical Properties; Hardness; Microstructure; Plastic Deformation; Hollomon Equation; Elevated Temperature; Materials science; Teknisk materialvetenskap;

    Sammanfattning : Thermal conductivity, hardness and strength are all highly important material properties, affecting the performance and life expectancy of components operating at elevated temperatures. The main purpose of this work has been to increase the knowledge and understanding concerning how mechanical and physical properties are affected by temperature and microstructure in compacted graphite irons. LÄS MER