Noble Gas Clusters and Nanoplasmas in High Harmonic Generation

We report a study of high harmonic generation from noble gas clusters of xenon atoms in a gas jet. Harmonic spectra were investigated as a function of backing pressure, showing spectral shifts due to the nanoplasma electrons in the clusters. At certain value of laser intensity this process may oppose the effect of the well-known ionization-induced blueshift. In addition, these cluster-induced harmonic redshifts may give the possibility to estimate cluster density and cluster size in the laser-gas jet interaction range.Comment: 5 pages, 4 figure

Cluster size distributions in gas jets for different nozzle geometries

Cluster size distributions were investigated in case of different nozzle geometries in argon and xenon using Rayleigh scattering diagnostics. Different nozzle geometries result in different behaviour, therefore both spatial- and temporal cluster size distributions were studied to obtain a well-characterized cluster target. It is shown that the generally used Hagena scaling can result in a significant deviation from the observed data and the behaviour cannot be described by a single material condensation parameter. The results along with the nanoplasma model applied to the data of previous high harmonic generation experiments allow the independent measurement of cluster size and cluster density.Comment: 7 pages, 6 figure

On transitioning from type-1 to interval type-2 fuzzy logic systems

Capturing the uncertainty arising from system noise has been a core feature of fuzzy logic systems (FLSs) for many years. This paper builds on previous work and explores the methodological transition of type-l (Tl) to interval type-2 fuzzy sets (IT2 FSs) for given "levels" of uncertainty. Specifically, we propose to transition from Tl to IT2 FLSs through varying the size of the Footprint Of Uncertainty (FOU) of their respective FSs while maintaining the original FS shape (e.g., triangular) and keeping the size of the FOU over the FS as constant as possible. The latter is important as it enables the systematic relating of FOU size to levels of uncertainty and vice versa, while the former enables an intuitive comparison between the Tl and T2 FSs. The effectiveness of the proposed method is demonstrated through a series of experiments using the well-known Mackey-Glass (MG) time series prediction problem. The results are compared with the results of the IT2 FS creation method introduced in [1] which follows a similar methodology as the proposed approach but does not maintain the membership function (MF) shape

Improved uncertainty capture for nonsingleton fuzzy systems

In non-singleton fuzzy logic systems (NSFLSs), input uncertainties are modelled with input fuzzy sets in order to capture input uncertainty (e.g., sensor noise). The performance of NSFLSs in handling such uncertainties depends on both: the appropriate modelling in the input fuzzy sets of the uncertainties present in the system’s inputs, and on how the input fuzzy sets (and their inherent model of uncertainty) interact with the antecedent and thus affect the inference within the remainder of the NSFLS. This paper proposes a novel development on the latter. Specifically, an alteration to the standard composition method of type-1 fuzzy relations is proposed, and applied to build a new type of NSFLS. The proposed approach is based on employing the centroid of the intersection of input and antecedent sets as origin of the firing degree, rather than the traditional maximum of their intersection, thus making the NSFLS more sensitive to changes in the input’s uncertainty characteristics. The traditional and novel approach to NSFLSs are experimentally compared for two well-known problems of Mackey-Glass and Lorenz chaotic time series predictions, where the NSFLSs’ inputs have been perturbed with different levels of Gaussian noise. Experiments are repeated for system training under noisy and noise-free conditions. Analyses of the results show that the new method outperforms the traditional approach. Moreover, it is shown that while formally more complex, in practice, the new method has no significant computational overhead compared to the standard approach

Changes under the hood - a new type of non-singleton fuzzy logic system

A major asset of fuzzy logic systems is dealing with uncertainties arising in their various applications, thus it is important to make them achieve this task as effectively and comprehensively as possible. While singleton fuzzy logic systems provide some capacity to deal with such uncertainty aspects, non-singleton fuzzy logic systems (NSFLSs) have further enhanced this capacity, particularly in handling input uncertainties. This paper proposes a novel approach to NSFLSs, which further develops this potential by changing the method of handling input fuzzy sets within the inference engine. While the standard approach is getting the maximum of the intersection between input’s and antecedent’s fuzzy sets (in the ”pre-filtering” stage), it is proposed to employ the centroid of the intersection as the basis of each rule’s firing degree. The motivation is to capture the interaction of input and antecedent fuzzy sets with high fidelity, thus making NSFLSs more sensitive to the input’s uncertainty information. The testbed is the common problem of Mackey-Glass time series prediction in the presence of input noise. Analyses of the results show that the new method outperforms the standard approach (by reducing the prediction error) and has potential for a more efficient uncertainty handling in NSFLS applications

Contrasting singleton type-1 and interval type-2 non-singleton type-1 fuzzy logic systems

Most applications of both type-1 and type-2 fuzzy logic systems are employing singleton fuzzification due to its simplicity and reduction in its computational speed. However, using singleton fuzzification assumes that the input data (i.e., measurements) are precise with no uncertainty associated with them. This paper explores the potential of combining the uncertainty modelling capacity of interval type-2 fuzzy sets with the simplicity of type-1 fuzzy logic systems (FLSs) by using interval type-2 fuzzy sets solely as part of the non-singleton input fuzzifier. This paper builds on previous work and uses the methodological design of the footprint of uncertainty (FOU) of interval type-2 fuzzy sets for given levels of uncertainty. We provide a detailed investigation into the ability of both types of fuzzy sets (type-1 and interval type-2) to capture and model different levels of uncertainty/noise through varying the size of the FOU of the underlying input fuzzy sets from type-1 fuzzy sets to very “wide” interval type-2 fuzzy sets as part of type-1 non-singleton FLSs using interval type-2 input fuzzy sets. By applying the study in the context of chaotic time-series prediction, we show how, as uncertainty/noise increases, interval type-2 input fuzzy sets with FOUs of increasing size become more and more viable

Pre-Excitation Studies for Rubidium-Plasma Generation

The key element in the Proton-Driven-Plasma-Wake-Field-Accelerator (AWAKE) project is the generation of highly uniform plasma from Rubidium vapor. The standard way to achieve full ionization is to use high power laser which can assure the over-barrier-ionization (OBI) along the 10 meters long active region. The Wigner-team in Budapest is investigating an alternative way of uniform plasma generation. The proposed Resonance Enhanced Multi Photon Ionization (REMPI) scheme probably can be realized by much less laser power. In the following the resonant pre-excitations of the Rb atoms are investigated, theoretically and the status report about the preparatory work on the experiment are presented.Comment: 8 pages, 6 figures, submitted to Nucl. Inst. and Meth. in Phys. Res.

Automating School Fees Transactions in Nigerian Universities and Tertiary Institutions: A Systems Engineering and System Management Approach

This project uses system engineering and system management principles to analyze the problem of transactions in Nigerian universities and tertiary institutions. System management principles shall be used to highlight the imperfections in the transaction method currently in use especially the disconnect between the bank and the institutions using their services. It will explore other payment systems available in the country. This project will provide a recommendation of how to implement a better payment option through automating the process of school payments by using a system with a cloud-based educational software at the school bursary office and through the online payment processing on the school website. The system software will enable cashiering and payment management: centralized data, automated reports, and inventory controls. It will generate automatic invoices and receipts. This system will bridge the disconnect between the bank and the school since students would not need to deposit cash directly into the school account but into their accounts and then pay with their debit cards. The system will provide debit card encryption and protection using the Secure Socket Layer technology

Technology Affordances and Curriculum Flexibility in Higher Education Blended Learning

This dissertation explores technological affordances in blended learning, their influence on the flexibility of statistics and data science curricula, and students\u27 satisfaction with learning. While blended learning is often perceived as a flexible learning approach, its correlation with flexibility lacks substantial evidence in existing literature. This study contends that technological affordances significantly impact curriculum flexibility in blended learning, an aspect currently underrepresented in blended learning educational literature. Drawing on the theoretical frameworks of Technology Affordance and Constraint Theory (TACT) and Technological, Pedagogical, and Content Knowledge (TPACK), this research investigated six hypotheses to elucidate how technological affordances and the teacher\u27s technology content knowledge influence flexibility in statistics and data science curricula and student satisfaction with learning within blended learning environments. Findings indicate that students\u27 perceptions of affordances of bi-directionality, synchronicity, and user control wield a significant and strong influence on curriculum flexibility and satisfaction with technologies in blended learning. Additionally, the study highlights that curriculum flexibility strongly impacts student satisfaction, while the technology content knowledge of the teacher does not significantly affect curriculum flexibility but does impact students\u27 satisfaction. These findings emphasize that technology transcends mere delivery tools; it serves as an integral component in the design of blended learning curricul

Lessons of Burma Campaign 1942-1945: A Case Study of General Bill Slim’s Leadership and Military Qualities

This paper examines the background, strategies, tactics and battlefield experiences and qualities of General Bill Slim, one of the greatest British General of World War II.  As a Commander of the battle fields from 1914-1958, Bill Slim’s most impressive triumphs came to limelight in India and Burma in the long war against the Japanese. This paper highlights the military qualities of General Bill Slim, he employed in his military strategies the principles of flexibility and surprise. that foreshadowed modern British Military doctrine. Thrust into a desperate situation, he orchestrated the longest retreat in British Army History in the withdrawal from Burma. The turning of the tide occurred when he turned on the Japanese when they invaded India, shattered their army and pursued them to destruction in Burma. This paper points out General Slim’s great military victories, he left a legacy of training and morale building that endures in the British Army to this day. This paper draws out lessons to be learnt from General Bill Slim’s Military Leadership Experiences by examining some of Slim’s greatest battlefield experiences and the strategies and tactics employed, Administration, Command and Control that set him apart from his counterparts. This paper has sourced both primary and secondary sources, archival materials and documents, books and journals.                                  Keywords: Leadership and Military Qualities of Commanders, Battlefield, Strategies, Tactics, Administration, Command and Control, Morale