1,751 research outputs found
A New Method for Short Multivariate Fuzzy Time Series Based on Genetic Algorithm and Fuzzy Clustering
Forecasting activities play an important role in our daily life. In recent years, fuzzy time series (FTS) methods were developed to deal with forecasting problems. FTS attracted researchers because of its ability to predict the future values in some critical situations where most standard forecasting models are doubtfully applicable or produce bad fittings. However, some critical issues in FTS are still open; these issues are often subjective and affect the accuracy of forecasting. In this paper, we focus on improving the accuracy of FTS forecasting methods. The new method integrates the fuzzy clustering and genetic algorithm with FTS to reduce subjectivity and improve its accuracy. In the new method, the genetic algorithm is responsible for selecting the proper model. Also, the fuzzy clustering algorithm is responsible for fuzzifying the historical data, based on its membership degrees to each cluster, and using these memberships to defuzzify the results. This method provides better forecasting accuracy when compared with other extant researches
Virtual platforms for heritage preservation in the Middle East: the case of medieval Cairo
Much of the effort in VH is directed towards accurate representation of historic structures, objects or artefacts. There is little attention is paid, however, to the human aspects of city life, the intangible heritage to which people can actually relate. Digital models of historic buildings and spaces only give a sense of precision. Yet, rituals, human attitude and cultural traditions remained a gap in current research and advanced technology in heritage visualization. Virtual Heritage Environments (VHE) suffer from the lack of ‘thematic interactivity’ due to the limited cultural content and engaging modules largely used in photorealistic video gaming systems. In order to approach virtual fidelity and accurate reproduction of historic environments, this paper reports on a research process to investigate and incorporate a Cultural-feed into digital platforms of Virtual Heritage. In doing so, the paper focuses on the Middle East in general and Medieval Cairo in particular. It discusses conceptual and practical framework for the development of virtual heritage platforms as a research, educational and engagement tool that brings historic spaces and buildings back to the recognition of the public eye of the ordinary user. It analyses current practices and projects of the virtual heritage technologies and reports on field work that took place in Islamic Cairo with Five Start-Up entrepreneurs
Contested heritage: an analysis of the physical transformation of Derry/Londonderry’s siege monument
Transformations of Derry/Londonderry’s medieval city walls during the twentieth century have shaped an urbanism of segregated settlements within a city of religious confrontation. The heritage of military blockades, peace lines and watchtowers imposed upon the city’s Walls has influenced the disintegration of public space and created areas of no man’s land around the peripheries of the monument. The aim of this paper is to examine physical transformation and trace the consequences of urban planning regarding the historic city Walls. This change includes the shifting of residential settlements in the Bogside/Fountain areas and the movement of Protestant settlements towards the Waterside of Derry/Londonderry. The history and heritage of the Walls are analysed by focusing on four periods: 1600, when the first medieval walls were constructed; the housing crisis of 1948; the 1968 urban area plan and the beginning of the ‘Troubles’; and the present day. This analysis offers an understanding of the spatial relationships between enclaves and the monument over key moments of conflict and political change. The paper reveals that the manifestations of the Walls have aided in the further division of religiously segregated communities in Derry/Londonderry
3D Engineered Peripheral Nerve: Towards A New Era of Patient-Specific Nerve Repair Solutions
Reconstruction of peripheral nerve injuries (PNIs) with substance loss remains challenging because of limited treatment solutions and unsatisfactory patient outcomes. Currently, nerve autografting is the first-line management choice for bridging critical-sized nerve defects. The procedure, however, is often complicated by donor site morbidity and paucity of nerve tissue, raising a quest for better alternatives. The application of other treatment surrogates, such as nerve guides remains questionable, and inefficient in irreducible nerve gaps. More importantly, these strategies lack customization for personalized patient therapy, which is a significant drawback of these nerve repair options. This negatively impacts the fascicle-to-fascicle regeneration process, critical to restoring the physiological axonal pathway of the disrupted nerve. Recently, the use of additive manufacturing (AM) technologies has offered major advancements to the bioengineering solutions for PNI therapy. These techniques aim to reinstate the native nerve fascicle pathway using biomimetic approaches, thereby augmenting end-organ innervation. AM-based approaches, such as 3D bioprinting, are capable of biofabricating 3D engineered nerve graft scaffolds in a patient-specific manner with high precision. Moreover, realistic in vitro models of peripheral nerve tissues that represent the physiologically and functionally relevant environment of human organs could also be developed. However, the technology is still nascent and faces major translational hurdles. In this review, we spotlighted the clinical burden of PNIs and most up-to-date treatment to address nerve gaps. Next, a summarized illustration of the nerve ultrastructure that guides research solutions is discussed. This is followed by a contrast of the existing bioengineering strategies used to repair peripheral nerve discontinuities. In addition, we elaborated on the most recent advances in 3D printing (3DP) and biofabrication applications in peripheral nerve modeling and engineering. Finally, the major challenges that limit the evolution of the field along with their possible solutions are also critically analyzed
Sunflower oil-based hyperbranched alkyd/spherical ZnO nanocomposite modeling for mechanical and anticorrosive applications
Approaches for designing advanced nanomaterials with hyperbranched architectures and lack of volatile organic content (VOC) have attracted considerable attention. In this study, eco-friendly hyperbranched alkyd resins for mechanical and anticorrosive coatings with high solid content were successfully synthesized based on sunflower oil (SFO) via a polyesterification approach. These resins are characterized by energy-efficient polymer synthesis, lack of gelation properties, high functionality, and low viscosity. A chemical precipitation process was used to fabricate zinc oxide (ZnO) spherical nanostructures with controlled diameters and morphologies. A series of conformal, novel, low-cost SFO-based hyperbranched alkyd/spherical ZnO nanocomposites were fabricated through an ex situ method. Various nanofiller concentrations were distributed to establish synergetic effects on the micro-nano binary scale performance of the materials. The features of the nanocomposites, including the molecular weight, acid and hydroxyl values of the prepared alkyd resins, were concomitantly assessed through various standard tests. The nanocomposites were also subjected to various tests to determine their surface adhesion and mechanical properties, such as impact, T-bending, crosscut, and abrasion resistance tests. Furthermore, the physico-mechanical properties, anticorrosive behavior, thermal stabilities and cellular cytotoxicities of the fabricated materials were assessed. The anticorrosive features of the nanocomposites were investigated through salt spray tests in 5 wt% NaCl. The results indicate that well-dispersed ZnO nanospheres (0.5%) in the interior of the hyperbranched alkyd matrix improve the durability and anticorrosive attributes of the composites; thus, they exhibit potential applications in eco-friendly surface coatings
Measurements of Flux and Dose Distributions of Neutrons in Graphite Matinees Using LR-115 Nuclear Track Detector
Histological and Histochemical Studies on the Ampulla of the Deferent Duct of Donkey (Equus asinus)
The present study was performed on the ampulla of the deferent duct of 24 sexually mature apparently healthy male donkeys (5 to 7 years) distributed over the four seasons of the year. The ampullary glands were branched tubulo-alveolar in type which they were opened in a central lumen. The luminal and the glandular epithelium were formed of principal and basal cells. Singly scattered rod- shaped cells were observed among the principal cells. PAS positive reactivity was observed in the surface and the glandular epithelium of the ampulla ductus deferentis. Only the luminal contents and the secretory materials attached to the apical border of the principal cells, showed positive reactivity for alcian blue. The present study presents the first description of the ampulla ductus deferentis of donkey. In addition to, it acts as a reservoir for sperms it had a secretory function for neutral and acid mucopolysaccharid
Histological and Morphometrical Studies on the Ampulla of the Deferent Duct of Donkey (Equus Asinus) in Different Seasons
The objective of this study is to describe the histological and histochemical structure of the ampulla ductus defrentis during different seasons of the year. The experiment was carried out on the ampulla of the deferent duct of 24 sexually mature apparently healthy male donkeys (5 to 7 years) distributed over the four seasons of the year. Both the lamina epithelialis and the epithelium lining the ampullary glands of the donkey showed highly significant (P < 0.01) seasonal variations. The interstitial tissue/ glandular tissue ratio of the ampullary glands showed as seasonal variations. The glandular epithelium of the ampullary glands of donkey had strong PAS positive reaction. This reaction decreased gradually during summer and autumn to reach its minimal amount during winter. In conclusions, the ampullary glands of donkey appeared more active during spring and this activity decreased gradually during the summer and autumn to reach it lowest activity during winter
Mass Spectrometric study of Molecular Ions of Methylphenol Isomers using Electron Impact Technique
- …