73 research outputs found
Parallel Coupled Wide Pass-Band Filter with Dual Square Complementary Split Ring Resonator and Defected Ground Structure
No full textIn this work, a novel design for obtaining wider pass-band was proposed using dual-square complementary split ring resonator and squared symmetrical defected ground structure. Parallel coupling was also amalgamated which helps to achieve wider band-width. Ideally, microwave filters were designed to have high return loss, diminutive insertion loss, coordinated impedance and stable frequency selectivity to avert redundant signal interference in the spectrum. The proposed structure provides excellent selectivity of -46 dB and -28 dB at the lower and upper cut-off frequencies respectively. Defected ground structure (DGS) improved the return loss of this work and insertion loss of nearly zero dB was obtained. The prototype was designed using ANSOFT HFSS 13.0 where centre frequency was maintained at 4.97 GHz. With reference to other filter techniques, better results were obtained in terms of return loss, insertion loss, selectivity, pass-band stretch, fractional band-width and Q-facto
Improved coupling based wide pass-band filter with double square complementary split ring resonator
No full textHeat Transfer Modification in a Particle-Laden Turbulent Channel Flow: For externally heated particles
No full textHeat transfer in multiphase flows plays an important role in many industrial applications. For instance, particle-based solar receivers utilize the high absorptivity and heat capacity of dispersed phase in a carrier fluid to improve efficiency and heat transfer. This dispersed phase generally consists of a large number of small particles. It is, therefore, difficult to completely resolve such flows considering their finite size. Usually, these particles are so small, that they can be treated as point particles. This considerably reduces the computational effort, while preserving the essential characteristics of the particle-laden flows. In this thesis, the focus is on heat transfer modulation in a particle-laden turbulent channel flow using direct numerical simulations. In flows with temperature gradients (for example, channel flow between hot and cold wall), particles absorb heat from hotter regions and release heat to colder regions, thereby enhancing heat transfer through particle feedback flux. On the other hand, presence of particles leads to decay in turbulence resulting in lower turbulent heat transfer. The interplay of this two phenomena can either increase or decrease the overall heat transfer based on Stokes number and thermal Stokes number (ratio of thermal response time to characteristic time scale of the flow).To investigate the heat transfer modulation in particle-laden channel flow, the existing DNS code developed by Boersma [5] has been modified to include particle transport and heat transfer. The point-particle approach with two way coupling is implemented using trilinear interpolation scheme and 3 rd order Runge-Kutta time marching scheme. The implemented code is validated using the results from literature [20] for a flow with no external heating.With the developed code, cases with no external source term and external source term with different optical thickness of the fluid have been analyzed. In order to focus only on the fluid-particle interaction, the effect of gravity is neglected and the flow is considered to be incompressible. It has been observed from these simulations that particles play an important role in modulation of heat transfer in such flows. Mean temperature profiles, heat flux mechanisms, temperature variance and budgets of temperature variance are studied extensively in order to understand the underlying phenomenon. It is found that the particle feedback heat transfer is the dominating mode in particle-laden flows
SPINAL ACCESSORY NERVE: ANATOMICAL VARIATIONS AND ITS SIGNIFICANCE DURING NECK DISSECTION IN HEAD AND NECK CANCER
No full textSpinal accessory nerve plexus includes the spinal accessory nerve with all its Intra- and extracranial connections to other nerves. Neck dissection is an important technique for the treatment of cervical lymph node metastasis in patients with head and neck cancer. Due to the adverse effects of radical neck dissection, a progressively more conservative functional neck dissection including preservation of the spinal accessory nerve is no longer an exception. Iatrogenic injury to the spinal accessory nerve can have medico-legal implications. Despite the presence of many described techniques to locate the nerve, it still remains vulnerable to damage during neck dissection due to its variations in the course and relations with other structures. Since the introduction of functional neck dissection, various modi?cations have been made to reduce the adverse effects of radical neck dissection. This paper describes the variations of the spinal accessory nerve in the neck and surgical significance which will guide head and neck oncosurgeons in imbibing adequate knowledge and using efficient techniques during surgical neck dissections
A Static Feature Selection-based Android Malware Detection Using Machine Learning Techniques
No full textCROSS COUPLED BAND-PASS FILTER USING DUAL SQUARE COMPLEMENTARY SPLIT RING RESONATOR FOR WIRELESS COMMUNICATION
No full textA Survey on Offensive AI Within Cybersecurity
Get PDFArtificial Intelligence (AI) has witnessed major growth and integration across various domains. As AI systems become increasingly prevalent, they also become targets for threat actors to manipulate their functionality for malicious purposes. This survey paper on offensive AI will comprehensively cover various aspects related to attacks against and using AI systems. It will delve into the impact of offensive AI practices on different domains, including consumer, enterprise, and public digital infrastructure. The paper will explore adversarial machine learning, attacks against AI models, infrastructure, and interfaces, along with offensive techniques like information gathering, social engineering, and weaponized AI. Additionally, it will discuss the consequences and implications of offensive AI, presenting case studies, insights, and avenues for further research
Examining the role of Duration of illness on the level of mental disability in Obsessive Compulsive Disorder
Get PDFRecent literature considers duration of illness (DI) and duration of untreatedillness (DUI) as important factors influencing outcome in many psychiatric conditions. The aimof the present article is to analyze the relationship between DI and DUI, and pharmacologicalresponse in the different psychiatric disorders with particular emphasis on neurodegenerativeaspects. An updated review of the current literature was conducted through PubMed in orderto compare different studies focused on DI and DUI, and treatment response in major psychosesand in depressive/anxiety disorders. A significant body of evidence shows that a prolongedDI and DUI is associated with brain abnormalities and poor treatment response, particularly inschizophrenia. Nevertheless, an increasing number of studies point toward a similar conclusionin mood and anxiety disorders as well, even though fewer studies have been published in thisfield. The present study was undertaken to assess and compare the disability in patients with obsessive compulsive disorder (OCD) using Indian Disability Evaluation Assessment Scale (IDEAS). Results indicated Significant disabilityin work and global score was seen in patients of obsessive-compulsive disorder with duration of illness >5 yr. it was concluded that these illnesses affect all areas of daily functioning leading to greaterdisability, and thus increasing the burden on the family, pose greater challenge for therehabilitation of patients and their inclusion in the mainstream of the family and society. Furtherstudies on a larger sample need to be done to confirm the finding.
Keywords: obsessive-compulsive disorder, Indian Disability Evaluation Assessment Scale, duration of illness, disability
GemV: A Validated Micro-architecture Vulnerability Estimation Tool
Get PDFabstract: Several decades of transistor technology scaling has brought the threat of soft errors to modern embedded processors. Several techniques have been proposed to protect these systems from soft errors. However, their effectiveness in protecting the computation cannot be ascertained without accurate and quantitative estimation of system reliability. Vulnerability -- a metric that defines the probability of system-failure (reliability) through analytical models -- is the most effective mechanism for our current estimation and early design space exploration needs. Previous vulnerability estimation tools are based around the Sim-Alpha simulator which has been to shown to have several limitations. In this thesis, I present gemV: an accurate and comprehensive vulnerability estimation tool based on gem5. Gem5 is a popular cycle-accurate micro-architectural simulator that can model several different processor models in close to real hardware form. GemV can be used for fast and early design space exploration and also evaluate the protection afforded by commodity processors. gemV is comprehensive, since it models almost all sequential components of the processor. gemV is accurate because of fine-grain vulnerability tracking, accurate vulnerability modeling of squashed instructions, and accurate vulnerability modeling of shared data structures in gem5. gemV has been thoroughly validated against extensive fault injection experiments and achieves a 97\% accuracy with 95\% confidence. A micro-architect can use gemV to discover micro-architectural variants of a processor that minimize vulnerability for allowed performance penalty. A software developer can use gemV to explore the performance-vulnerability trade-off by choosing different algorithms and compiler optimizations, while the system designer can use gemV to explore the performance-vulnerability trade-offs of choosing different Insruction Set Architectures (ISA).Dissertation/ThesisMasters Thesis Computer Science 201
Crossroads --- A Time-Sensitive Autonomous Intersection Management Technique
Get PDFabstract: For autonomous vehicles, intelligent autonomous intersection management will be required for safe and efficient operation. In order to achieve safe operation despite uncertainties in vehicle trajectory, intersection management techniques must consider a safety buffer around the vehicles. For truly safe operation, an extra buffer space should be added to account for the network and computational delay caused by communication with the Intersection Manager (IM). However, modeling the worst-case computation and network delay as additional buffer around the vehicle degrades the throughput of the intersection. To avoid this problem, AIM, a popular state-of-the-art IM, adopts a query-based approach in which the vehicle requests to enter at a certain arrival time dictated by its current velocity and distance to the intersection, and the IM replies yes/no. Although this solution does not degrade the position uncertainty, it ultimately results in poor intersection throughput. We present Crossroads, a time-sensitive programming method to program the interface of a vehicle and the IM. Without requiring additional buffer to account for the effect of network and computational delay, Crossroads enables efficient intersection management. Test results on a 1/10 scale model of intersection using TRAXXAS RC cars demonstrates that our Crossroads approach obviates the need for large buffers to accommodate for the network and computation delay, and can reduce the average wait time for the vehicles at a single-lane intersection by 24%. To compare Crossroads with previous approaches, we perform extensive Matlab simulations, and find that Crossroads achieves on average 1.62X higher throughput than a simple VT-IM with extra safety buffer, and 1.36X better than AIM.Dissertation/ThesisMasters Thesis Engineering 201
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