Damaged watermarks detection in frequency domain as a primary method for video concealment

This paper deals with video transmission over lossy communication networks. The main idea is to develop video concealment method for information losses and errors correction. At the beginning, three main groups of video concealment methods, divided by encoder/decoder collaboration, are briefly described. The modified algorithm based on the detection and filtration of damaged watermark blocks encapsulated to the transmitted video was developed. Finally, the efficiency of developed algorithm is presented in experimental part of this paper

Change in sagittal profile after implantation of anchored interbody cage in the surgical procedure for degenerative cervical spine disease

Background. The aim of this study was to verify the relationship between changes in the segmental sagittal profile (SSP) and changes in the global sagittal profile (GSP) after anterior cervical discectomy with anchored cage implantation (ACDF). Study design. Prospective study with 2-year follow-up. Methods. This study includes 104 patients after 1-level or 2-level ACDF operated between the May 2013 and March 2016. SSP was evaluated by Cobb angle measurement of operated motion segment (CobbS) and GSP was evaluated by Cobb angle measurement in C2-C7 segments (CobbG). Both SSP and GSP were measured pre- and postoperatively within a 24 months follow-up period. The influence of factors such as age, gender, number of treated segments and osteoporosis was evaluated using t-tests. The correlation between SSP and GSP changes was assessed by Pearson's correlation coefficient. Results. In the early postoperative period after 1-level ACDF, there was a significantly greater increase in CobbS compared to that of the 2-level ACDF (P=0.0149). Male patients experienced a significant decrease of CobbG during the first 6 months after surgery as well as patients with osteoporosis within 12 months after ACDF. After ACDF the SSP change weakly correlated with the GSP change. Conclusion. SSP change after 1- or 2-level ACDF correlates mostly weakly with GSP change. Male gender and osteoporosis were identified as risk factors for global lordotisation following ACDF

Structural Health Monitoring of Helicopter Fuselage

The helicopter design is a challenging experience for fatigue concern as it is subjected to a very wide range of low- and high-frequency load cycles per flight, much more than a fixed wing aircraft. Structural Health Monitoring (SHM) seems to have capability in helping to reduce the maintenance and operational costs, which are about 25 percent of the direct operating cost of the helicopter, thus playing an important role especially in the case of the ageing helicopters. In fact, the damage tolerant design approach makes the fatigue resistance evaluation not only a safety issue but also a maintenance related concern. The work presented in this paper is a part of an international research project HECTOR (HElicopter fuselage Crack moniToring and prognosis through On-board sensoR network), founded by the European Defense Agency (EDA) and supported by 10 EDA Member States: Cyprus, France, Germany, Greece, Hungary, Italy, Poland, Slovakia, Slovenia and Spain

Computational modelling of inorganic solids

This report covers papers published in the period 2005–2007 on the application of computational modelling to solids. The main areas of application chosen for review are zeolites, metal oxides (particularly those with properties of industrial importance), minerals and nanostructures