On the Enhancement of the Localization of Autonomous Mobile Platforms

The focus of many industrial and research entities on achieving full robotic autonomy increased in the past few years. In order to achieve full robotic autonomy, a fundamental problem is the localization, which is the ability of a mobile platform to determine its position and orientation in the environment. In this thesis, several problems related to the localization of autonomous platforms are addressed, namely, visual odometry accuracy and robustness; uncertainty estimation in odometries; and accurate multi-sensor fusion-based localization. Beside localization, the control of mobile manipulators is also tackled in this thesis. First, a generic image processing pipeline is proposed which, when integrated with a feature-based Visual Odometry (VO), can enhance robustness, accuracy and reduce the accumulation of errors (drift) in the pose estimation. Afterwards, since odometries (e.g. wheel odometry, LiDAR odometry, or VO) suffer from drift errors due to integration, and because such errors need to be quantified in order to achieve accurate localization through multi-sensor fusion schemes (e.g. extended or unscented kalman filters). A covariance estimation algorithm is proposed, which estimates the uncertainty of odometry measurements using another sensor which does not rely on integration. Furthermore, optimization-based multi-sensor fusion techniques are known to achieve better localization results compared to filtering techniques, but with higher computational cost. Consequently, an efficient and generic multi-sensor fusion scheme, based on Moving Horizon Estimation (MHE), is developed. The proposed multi-sensor fusion scheme: is capable of operating with any number of sensors; and considers different sensors measurements rates, missing measurements, and outliers. Moreover, the proposed multi-sensor scheme is based on a multi-threading architecture, in order to reduce its computational cost, making it more feasible for practical applications. Finally, the main purpose of achieving accurate localization is navigation. Hence, the last part of this thesis focuses on developing a stabilization controller of a 10-DOF mobile manipulator based on Model Predictive Control (MPC). All of the aforementioned works are validated using numerical simulations; real data from: EU Long-term Dataset, KITTI Dataset, TUM Dataset; and/or experimental sequences using an omni-directional mobile robot. The results show the efficacy and importance of each part of the proposed work

Production and characterization of antimicrobial active substance from some macroalgae collected from Abu- Qir bay (Alexandria) Egypt

The antimicrobial activity of three different macroalgal species [Jania rubens (Linnaeus) Lamouroux; Ulva fasciata Delile and Sargassum vulgare C. Agardh] belonging to Rhodophyta, Chlorophyta and Phaeophyceae, respectively, were collected seasonally in 2007 to 2008 from Abu-Qir bay (Alexandria, Egypt). The different macroalgal species were tested against pathogenic microbes such as Bacillus subtilis, Staphylococcus aureus and Streptococcus aureus as gram-positive bacteria, Escherichia coli, Salmonella typhi and Klebsiella pneumoniae as gram-negative bacteria and one yeast strain, Candida albicans. The influence of sampling season on the antimicrobial activity of the collected seaweeds showed strong activity in spring followed by winter, summer and autumn, respectively. However, the strongest antimicrobial activity was recorded in 70% acetone extract of U. fasciata collected during winter against all the tested microorganisms. This extract was purified using column chromatography (CC) and thin layer chromatography (TLC). The nature of this purified antimicrobial material was detected using different chemical analysis (UV, IR,1H NMR and MS) which indicated that it is an aromatic compound and has different active groups (-NH2, -C=O, -NO2, phenyl ring and -CH3). The molecular weight of the compound was determined (662) and its structure was characterized as a derivative of phthalate ester [(E)-1-(10-acetamido-2-nitrodec-9-enyl) 2-(10-acetamido-2-nitrodecyl) 4-methylphthalate]. This is the first evidence of the isolation of phthalate esters derivative from green seaweeds (U. fasciata) that has broad antimicrobial activity.Key words: Antimicrobial, pathogenic microbes, season, seaweeds

Starlike and convex functions of complex order involving generalized multiplier transformations

summary:We investigate the starlike, convex and close-to-convex functions of complex order involving generalized multiplier transformations by means of the Hadamard product

In vitro screening of antimicrobial activity of extracts of some macroalgae collected from Abu-Qir bay Alexandria, Egypt

Ethanol, methanol and acetone extracts of nine marine macroalgae (Rhodophyta, Chlorophyta and Phaeophyta) from Abu-Qir bay (Alexandria, Egypt) were evaluated for antimicrobial activity by agar well diffusion methods against pathogenic microbes (Bacillus subtilis, Staphylococcus aureus and Streptococcus aureus as gram-positive bacteria, and (Escherichia coli, Salmonella typhi and Klebsiella pneumoniae as gram-negative bacteria) and one yeast strain Candida albicans. All pathogenic microorganisms were obtained from Culture Collection of Botany Department, Faculty of Science, Tanta University. The best results were obtained by acetone extracts with inhibition activity (36.7%), followed by the methanol extracts (32.9%), and then ethanol extracts (30.2%) for all tested microorganisms. The tested species of Chlorophyta were the most active followed by Rhodophyta and Phaeophyta. The most active seaweeds was Ulva fasciata (chlorophyceae) against all tested microorganisms.Key words: Seaweeds, antimicrobial activity, extracts, pathogenic microbes

Clinical and echocardiographic evaluation of patients undergoing total leaflets preservation during mitral valve replacement; Does it make a difference?

Background: The effect of anterior and posterior leaflet preservation on left ventricular function after mitral valve replacement is still the subject of ongoing research. The objective of this study is to analyze the early outcomes of total leaflets preservation compared to posterior and non-leaflet preservation during mitral valve surgery on cardiac function and dimensions measured by echocardiography and on the clinical outcomes.Methods: This prospective cohort study recruited 155 patients who had mitral valve replacement (MVR) from April 2016 to March 2018 at Assiut University Hospital. Patients were divided into three groups according to the technique of leaflets preservation; Group I (no leaflet preservation-N-MVR), Group II (total leaflet preservation- T-MVR) and Group III (posterior leaflet preservation-P-MVR). Patients who underwent redo mitral valve replacement (MVR) or those with endocarditis and had combined coronary artery bypass grafting with the MVR were excluded from the study.Results: There were nine early deaths (6%); eight patients were in Group I (N-MVR). Causes of mortality were massive intracranial hemorrhage (n= 2) and left ventricular failure (n=6). One patient died in Group III (P-MVR) from intracranial hemorrhage (1.3%). Hospital stay was significantly longer in N-MVR group compared to T-MVR and P-MVR (10.6±2.13 days in N-MVR group; p= 0.03 and 0.011 respectively). Postoperative low cardiac output occurred in all patients in N-MVR group. Left ventricular function (ejection fraction= 61.28±6.02%) and dimensions (end-diastolic diameter= 5.18±0.69 mm, end-systolic diameter= 3.58±0.78 mm) improved significantly in total leaflets preservation group.Conclusion: Leaflet preservation during mitral valve replacement was associated with improved clinical and echocardiographic outcomes. Non-leaflets preservation increased the risk of postoperative complications and length of hospital stay. Leaflet preservation is recommended as the standard approach during mitral valve replacement

TRA-941: EFFECTIVENESS OF VARIABLE MESSAGE SIGNS IN IMPROVING THE ROAD NETWORK THROUGH ROUTE GUIDANCE

Variable Message Signs (VMS) are a means of providing valuable information to roadway users and enhancing the performance of the road network. The main objective of this research was to analyze the effectiveness of the use of VMS in improving the efficiency of the road network. This was implemented through a number of case studies under different conditions and different designs of the VMS. As this is a unique traffic guidance method to Egypt, the different factors that may affect the effectiveness of the sign to divert drivers was studied to fully understand the benefits of implementing VMS in Egypt. Traffic data was collected from five sites which are located in Giza Governorate, Egypt. At each location, the driver had the choice of two alternative routes leading to the same destination. The VMS informed the drivers that one of these routes was congested and to use an alternative route. Three different sign types were applied to identify the most effective type of VMS on drivers in Egypt. The most effective sign type was identified during the pilot study and used in the remaining sites. For each site, Traffic counts for each route was recorded for twenty minutes without the VMS and twenty minutes with the VMS applied to obtain the diversion rate of drivers Average travel times for 30 vehicles and queue lengths were also recorded before and after the application of the VMS and Queue lengths were also recorded before and after applying the VMS

Radiographic visualization of the metacarpus and phalanges in the impala (Aepyceros melampus)

Radiographic and anatomic studies of the metacarpus and phalanges were evaluated in 10 thoracic limbs of the impala (Aepyceros melampus). The metacarpi and phalanges appeared strong and smaller in both size and mass. The fused Mc3/4 appeared longer, rounded, smoother and had a flat palmar surface. The small metacarpal bones (Mc2 and Mc5) were developed and situated on the palmar aspects of the fused Mc3/4. Impala have two digits; each digit has three phalanges (ph I, ph II, ph III) and three sesamoid bones. The two proximal sesamoid bones were elongated. The distal sesamoid bone was quadrilateral in shape. Ph I and p II were much shorter and slimmer. ph III was uniquely triangular in shape. Impala possess a radiographic peculiarity; in the latero-medial radiographic view the dorsal cortex of fused Mc3/4 was thicker than the palmar. The distal epiphysis appeared rounded. The lateral and medial digits were superimposed. In the dorso-palmar view, ph I, ph II, and ph III appeared symmetrical. The proximal and distal sesamoid bones were superimposed. ph III was triangular, with numerous vascular channels. The slim, graceful legs of the impala with narrow and shorter distal segments and reduced weight of the metacarpus and phalanges may represent a distinctive structural modification necessary to facilitate the speedy movement of the impala