Accuracy and precision of an intraoral scanner in complex prosthetic rehabilitations: an in vitro study

The main purpose of this study is to measure the accuracy and the precision of the intraoral optical scanner CS3500® (Carestream Dental LLC, Atlanta, USA) in complex clinical situations as full arch rehabilitations on impl ants. 50 scans of the acrylic resin model were performed by using CS3500® (Carestream Dental LLC, Atlanta, USA) scanner. Each scan was compared with the virtual model derived from scanning with the laboratory scanner Dscan3® (Enhanced Geometry Soluti on, Bologna, Italy) to measure a possible misalignment. The alignment error was found to be 79,6 ( ± 12,87)  m. The measurement was taken at the level of 2 distal scan - abutments. The scanner's precision ranges from 24 to 52  m , depending on the dist ance between scan - abutment. CS3500® (Carestream Dental LLC, Atlanta, USA) intraoral scanner has detected a valid device in the execution of complex rehabilitations on implants. His accuracy and precision values fall within the range established in li terature to define acceptable the prosthetic fitting on full arch implant rehabilitation

O tema água em livros didáticos de ciências e questões controversas

Entre os temas relacionados à temática ambiental o tema água tem sido enfatizado nos currículos escolares e tem sido explorado pelos livros didáticos. A água tem inúmeros significados tanto em relação a sua importância como um elemento natural quanto em seus sentidos simbólicos para diferentes sociedades. Essa multiplicidade de contextos e significados caracterizam este tema como controverso. Os temas controversos são apontados como possibilidades instigantes para o trabalho em sala de aula. Partindo desses pressupostos, o objetivo dessa investigação foi o de procurar identificar se estes materiais didáticos abordam controvérsias relacionadas com este tema. A análise temática realizada nos indicou que dentre todos os temas relacionados à água, somente os conteúdos ligados a construção de barragens eram abordados a partir da perspectiva dos temas controversos

Polynomial multiplication over binary finite fields : new upper bounds

When implementing a cryptographic algorithm, efficient operations have high relevance both in hardware and in software. Since a number of operations can be performed via polynomial multiplication, the arithmetic of polynomials over finite fields plays a key role in real-life implementations\u2014e.g., accelerating cryptographic and cryptanalytic software (pre- and post-quantum) (Chou in Accelerating pre-and post-quantum cryptography. Ph.D. thesis, Technische Universiteit Eindhoven, 2016). One of the most interesting papers that addressed the problem has been published in 2009. In Bernstein (in: Halevi (ed) Advances in Cryptology\u2014CRYPTO 2009: 29th Annual International Cryptology Conference, Santa Barbara, CA, USA, August 16\u201320, 2009. Proceedings, pp 317\u2013336. Springer Berlin Heidelberg, Berlin, Heidelberg, 2009), Bernstein suggests to split polynomials into parts and presents a new recursive multiplication technique which is faster than those commonly used. In order to further reduce the number of bit operations (Bernstein in High-speed cryptography in characteristic 2: minimum number of bit operations for multiplication, 2009. http://binary.cr.yp.to/m.html) required to multiply n-bit polynomials, researchers adopt different approaches. In CMT: Circuit minimization work. http://www.cs.yale.edu/homes/peralta/CircuitStuff/CMT.html a greedy heuristic has been applied to linear straight-line sequences listed in Bernstein (High-speed cryptography in characteristic 2: minimum number of bit operations for multiplication, 2009. http://binary.cr.yp.to/m.html). In 2013, D\u2019angella et al. (Applied computing conference, 2013. ACC\u201913. WEAS. pp. 31\u201337. WEAS, 2013) skip some redundant operations of the multiplication algorithms described in Bernstein (in: Halevi (ed) Advances in Cryptology\u2014CRYPTO 2009: 29th Annual International Cryptology Conference, Santa Barbara, CA, USA, August 16\u201320, 2009. Proceedings, pp 317\u2013336. Springer Berlin Heidelberg, Berlin, Heidelberg, 2009). In 2015, Cenk et al. (J Cryptogr Eng 5(4):289\u2013303, 2015) suggest new multiplication algorithms. In this paper, (a) we present a \u201ck-1\u201d-level recursion algorithm that can be used to reduce the effective number of bit operations required to multiply n-bit polynomials, and (b) we use algebraic extensions of F 2 combined with Lagrange interpolation to improve the asymptotic complexity