Novel concepts and strategies in skull base reconstruction after endoscopic endonasal surgery

Recently, a variety of craniofacial approaches has been adopted to enter the skull base, among those, the endonasal endoscopic technique. An effective watertight thereafter: the reconstruction can be performed using different materials, both autologous and non-autologous, individually or combined in a multilayer fashion. The current study was focused on the development of new advanced devices and techniques, aiding in reducing postoperative CSF leak rate. Additive manufacturing allows the design of devices with tailored structural and functional features and, as well, injectable semi-IPNs and composites; therefore specific mechanical/rheological and injectability studies are valuable. Accordingly, we propose new additive-manufactured and injectable devices

Time- and frequency-asynchronous aloha for ultra narrowband communications

A low-power wide-area network (LPWAN) is a family of wireless access technologies which consume low power and cover wide areas. They are designed to operate in both licensed and unlicensed frequency bands. Among different low-power wide-area network (LPWAN) technolo-gies, long range (LoRa), Sigfox, and Narrowband Internet of Things (NB-IoT) are leading in IoT deployment in large-scale. However, Sigfox and LoRa both have advantages in terms of battery lifetime, production cost and capacity whereas lower latency and better quality of service are of-fered by Narrowband Internet of Things (NB-IoT) operating licensed cellular frequency bands. The two main approaches for reaching wide coverage with low transmission power are (i) spread spectrum, used by LoRa, and (ii) ultra-narrow band (UNB) which is used by Sigfox. This thesis work focuses on the random-access schemes for UNB based IoT networks mainly. Due to issues related to receiver synchronization, two-dimensional time-frequency ran-dom access protocol is a particularly interesting choice for UNB transmission schemes. Howev-er, UNB possess also some major constraints regarding connectivity, throughput, noise cancel-lation and so. This thesis work investigates UNB-based LPWAN uplink scenarios. The throughput perfor-mance of Time Frequency Asynchronous ALOHA (TFAA) is evaluated using MATLAB simula-tions. The main parameters include the interference threshold which depends on the robust-ness of the modulation and coding scheme, propagation exponent, distance range of the IoT devices and system load. Normalized throughput and collision probability are evaluated through simulations for different combinations of these parameters. We demonstrate that, using repeti-tions of the data packets results in a higher normalized throughput. The repetition scheme is designed in such a way that another user's packets may collide only with one of the target packets repetitions. The power levels as well as distances of a user’s all repetitions are consid-ered same. By using repetitions, reducing the distance range, and increasing the interference threshold, the normalized throughput can be maximized

Revisión sistemática del uso de los diferentes protocolos de interconexión para internet de las cosas (IoT)

Trabajo de investigaciónEl presente documento presenta una revisión sistemática acerca del uso de los diferentes protocolos de interconexión que son más destacados e interoperables para lograr la implementación de internet de las cosas (IoT) dentro de entornos empresariales y el hogar. Para la elaboración de este trabajo se implementó una metodología especializada en revisiones sistemáticas llamada metodología de Bárbara Kitchenham, desarrollada en 2004 por la autora del mismo nombre. Adicionalmente se utilizó un software especial para este tipo de trabajos llamado Start, con el que se ha extraído la información de las bases de datos IEEE y SCOPUS que nos dio como resultado un número de artículos científicos seleccionados minuciosamente bajo unos criterios de elegibilidad y calidad definidos dentro del desarrollo de la metodología.INTRODUCCIÓN JUSTIFICACIÓN 1. PLANTEAMIENTO DEL PROBLEMA 2. OBJETIVOS 3. ALCANCES Y LIMITACIONES 4. MARCO TEÓRICO 5. ESTADO DEL ARTE 6. METODOLOGÍA 7. RESULTADOS CONCLUSIONES RECOMENDACIONES REFERENCIASPregradoIngeniero de Sistema

DESIGN STRATEGIES AND ADDITIVE MANUFACTURING OF 3D CUSTOMIZED SCAFFOLDS WITH OPTIMIZED PROPERTIES FOR CRANIOFACIAL TISSUE ENGINEERING

3D customized scaffolds for craniofacial tissue engineering were designed using advanced strategies and technologies. Specifically, reverse engineering, additive manufacturing, material selection, experimental and theoretical analyses were properly integrated. The focus was on: i) design strategies of 3D customized nanocomposite scaffolds for hard tissue regeneration; ii) an engineered design of 3D additive manufactured nanocomposite scaffolds with optimized properties; iii) an approach toward the design of 3D customized scaffolds for large cranial defects

Integrated Methodologies and Technologies for the Design of Advanced Biomedical Devices

Biomedical devices with tailored properties were designed using advanced methodologies and technologies. In particular, design for additive manufacturing, reverse engineering, material selection, experimental and theoretical analyses were properly integrated. The focus was on the design of: i) 3D additively manufactured hybrid structures for cranioplasty; ii) technical solutions and customized prosthetic devices with tailored properties for skull base reconstruction after endoscopic endonasal surgery; iii) solid-lattice hybrid structures with optimized properties for biomedical applications. The feasibility of the proposed technical solutions was also assessed through virtual and physical models

Long-range and secure communication system for remote data logging monitoring of micro-grids

With the increasing renewable energy penetration in the grid system, the number of distributed generation and remote micro-grids are also increasing. While each remote micro-grid requires to have a sophisticated (secure, long range, low power and low cost) communication system for the Suspervisory Control and Data Acquision (SCADA) system, creating a research gap for devising a system with desired attributes. This research was conducted to fill that gap by implementing a low power, low cost, secure, and a long-range communication system for remote micro-grids. The literature review comprising the study of twelve wireless technologies and three wired technologies was done to achieve this. After the comparison of those technologies, LoRa communication was chosen for this purpose. Different encryption algorithms were studied, implemented, cross-checked, and finally advanced encryption algorithm was implemented to achieve the security of the communication system. An algorithm was developed to generate a unique message authentication code for each message. It enabled to identify a bit-level alteration in the message. Further, to monitor the system remotely, data was uploaded to the server. It was achieved by programming and configuring different gateways for this purpose. LoRa range was improved by implementing LoRa nodes in a mesh-network structure. A hybrid, LoRa and radio-set based system was implemented to extend its range up to 40km. Three different system topologies were designed and implemented, and the final one was recommended based upon the SG SCADA system requirements. The results of step-by-step designing and implementation of the system show that this research work has significantly contributed to develope a low-cost, secure and long-range communication system for remote micro-grids