Miracle-dz/UniFAR-FTUs huggingface dataset:
Phase control of magnetic susceptibility in multiferroic composites

This work reports on measurements of magnetic permeability using simultaneous excitation of the laminate multiferroic composites by the combined alternating magnetic and electric fields at the resonant frequency. Especially interesting effects were observed when the phase between the electric and magnetic fields was varied. Initial studies of the multiferroics at dual excitation have recently been published, however they have different focus than the results described here.
Design of LDPC Codes for Unequal ISI Channels

In this paper, we design an irregular low-density parity-check (LDPC) codes for unequal inter-symbol interference channels based on the modified extrinsic information transfer chart. During transmission, each LDPC codeword will be divided and transmitted to the different channels. The aim of this scheme is to avoid transmitting the whole codeword in a high error rate channel. The simulation results show that the proposed code optimized for both PR1 and PR2 channels can achieve a 0.2 coding gain over the codes designed specifically for each individual channel. When this simple code is applied to a perpendicular channel with these two targets, the coding gains of the proposed code is about 0.08 dB at the frame error rate of $10^{-3}$ .
Práticas e comportamentos de liderança na gestão dos recursos humanos escolares

In today’s globalized and complex world, human capital draws focus in leadership-related areas in educational institutions and the related human resource management. Therefore, we should recognize the perceptions of teachers and staff regarding the practices and behavior related to principals’ leadership skills. As its methodological framework, this mixed-nature research examined a case study focusing on the second and third cycles of basic education in a middle school situated in the archipelago of the Autonomous Region of Madeira. The Leadership Practice Inventory (LPI) Observer questionnaire by Kouzes and Posner was administered to the school’s teachers and staff. Content analysis focused on the School Educational Project and the Annual School Action Plan. In conclusion, respondents opined that an effective principal should emphasize leadership practices involving notions such as “Enable Others to Act” and “Encourage the Heart”.
Modelling and analysing neuronal and epidemiological dynamics on structured static and dynamic networks

Many of the technological, social and biological systems we observe and partake in in our everyday lives can be described as networks of interacting elements. Network- based research can then be performed to improve our understanding about the structural features of such complex networks, the behaviour of processes occurring within such complex networks, and the interaction between the two. During my PhD I have considered neuronal and epidemiological dynamics occurring on complex networks, with the main aim of improving model realism by incorporating spatial or local structure whilst maintaining model tractability. In total I have considered three network-based research projects which are included in this thesis in chronological order. This thesis begins with an introduction to the study of complex networks and processes occurring on complex networks. Comparisons are drawn between the approaches of neuroscience and epidemiology-based network studies, including consideration of the difficulties regarding modelling local spatial structure. Chapter 2 considers an existing model describing the activity-dependent growth and development of a network of excitatory and inhibitory neurons embedded in space. A systematic investigation of the effects of various spatial arrangements of neurons on the resultant electrical dynamics finds that increased spatial proximity between inhibitory neurons leads to oscillatory dynamics. Chapter 3 utilises the edge-based compartmental modelling approach. Existing research is extended to derive and validate equations describing the evolution of a susceptible-infected-recovered (SIR) epidemic process occurring on a dual-layer multiplex network incorporating heterogeneity in the structure, type and duration of connections between individuals. Chapter 4 considers pairwise models describing the SIR epidemic process and derives and validates analytic expressions for the epidemic threshold, an improvement on existing results. This thesis concludes with a discussion of the research contained in Chapters 2-4, including suggestions for improvements and future research ideas.
Typologies and Multidimensional Nature of Computer Use for Classroom Instruction in Secondary Education

Computer technology has proved essential in all sectors of human endeavours such as in industry and business. As a consequence, education has been the main beneficiary of the emergence of the microcomputer being used in financial management, administration and progressively in the classroom for instruction. The experimental phase on the benefits of computer technology for instruction is maturing. This paper explores through reviewing literature the various ways computers have been used in the classroom for instruction and through a pilot study, determine the dimensions of computer use with the help of factor analysis. In the pilot study, a sample of 71 respondents provided usable data. This paper helps us to understand: (a) what is meant by “technology/computer use” in the context of classroom instruction, the view that underpins a user’s actual use of technology; (b) the “evident” or “actual usage” of technology in the classroom for instruction; and (c) the possible dimensions of this use. It is deemed important to bring a common understanding of computer use with respect to information and communication technology integration in pedagogy.
Korean EFL Teachers’ Beliefs of Cooperative Learning: With a Focus on Classroom Practice

The purpose of this study is to provide some valuable insights for teachers and teacher trainers to construct and monitor effective cooperative learning (CL). For this purpose, Korean EFL teachers’ beliefs of CL implementation were explored with a focus on classroom practice. The data for this study were collected through questionnaires from a total of 247 teachers at 13 elementary and 40 secondary schools in Jeollanamdo and Gwangju, Korea. The survey was conducted from May to July of 2005 academic year, and the data were analyzed quantitatively and qualitatively. The overall findings of the survey showed that the majority of respondents had a higher-level of understanding about CL’s key concepts regardless of teaching levels or experiences, but that there existed some mixed responses concerning its classroom practice. Additionally, despite several educational benefits of adopting CL as an instructional method, quite a few teachers were revealed to avoid using CL techniques chiefly because they were not adequately prepared for using CL and therefore concerned over facing some disciplinary problems. To conclude, it is suggested that teachers have some positive views of implementing CL in terms of its beneficial traits and should be properly trained through teacher education programs, thus acquiring the knowledge necessary to use various CL techniques.
The Double Movement Ten Years After the Fall of Lehman Brothers

Abstract: Ten years after the collapse of Lehman Brothers and the sharpest moments of panic within the global—and particularly the United States banking system—a somewhat strange dynamic has appeared. While the principal agents behind the crisis have collapsed their own institutions, the markets that they dominated, and even provoked what has been called the third crisis of economic theory, their political power has not waned. This theme has been well addressed by some academics such as Philip Mirowski (2013), while it has flummoxed others. In this article, we will argue that Karl Polanyi’s theory of the “double movement” offers a coherent framework that is able to account for the history of the last ten years. Polanyi argues that different groups and members of society seek protection from the market, and that this search for protection has been the driving force between historical change. Polanyi does not ignore class; rather, he argues that different social classes can protect themselves in more or less effective ways. We argue that during the last ten years, the interests of globalized financial capital have been able to protect themselves with utmost effectiveness, while all other classes have been trammeled, often not even recognizing how or why actions are taken against the general interest.
Blended Learning Program: An Alternative Solution to Improve Students TOEFL Score

This action research aims at finding out how the blended learning can improve students toefl score. The design of this research is an action research which consists of four steps in a cycle, they are: planning, action, analysis and reflection. In planning step the reserachers did FGD which involved the students, instructors, the dean, the head of language centres and staff to discuss the problems and the alternative solution, designed the syllabus and prepared the materials. In the action step, the blended learning was implemented , 50%was in Face to Face (F2F) mode and other 50% was in information and technology (IT) mode (CALL, email, WA and SMS). The subjects were 20 students from 16 Study Programs in FKIP at the eight semester who have ever joined TOEFL but have not achieved the target score stated by the university, 477.The implementation of Blended learning was observed and analyzed as the next step. The Reflection result showed that Blended learning could improve the students TOEFL score. The students also enjoyed the activities and they believed blended learning helped them improve their TOEFL score. Therefore it is recommended that the University implement the Blended learning program as an alternative solution to solve the problem.
A SLOTTED UWB ANTIPODAL VIVALDI ANTENNA FOR MICROWAVE IMAGING APPLICATIONS

This paper presents the design of an ultra-wideband (UWB) antipodal Vivaldi antenna (APVA) for radar and microwave imaging applications. A slotted APVA design is introduced to improve the low-end bandwidth limitation frequencies as well as to enhance the gain and directivity of the antenna. The optimizations of the design offer good results by using a cost-effective substrate, fiberglass reinforced grade 4 (FR4) material. The regular APVA antenna design only presents average results of gain (4–6 dBi) and directivity (4–7 dB). However, the addition of slots on the edges of antenna is able to increase the peak value of gain and directivity up to 73.65% with 7.64 dBi and 8.92 dB, respectively. Besides, the radiation pattern of the antenna is also improved by using the slotted design where the main lobe level is larger than regular APVA design. Both antennas presented in this paper are designed in compact size of 42.8mm × 57.3 mm. The antennas are also designed to operate within the frequency range of 3.6 GHz to 10 GHz frequency.
Expanding Social Science Through Disaster Studies

Objectives. This article provides an overview of how the interdisciplinary field of disaster studies contributes to the social sciences. Methods. The following themes are explored in relation to the articles contained in the special issue: disasters are social and political phenomena that generate policy change, disasters reflect and affect democratic governance, and disasters reveal shared experience and collective identity. Results. Disaster studies bridge the social sciences theoretically and methodologically. Given the scope of disaster impacts—across social, political, economic, ecological, and infrastructure spheres—and the policy response they garner involving public, private, and civic actors, they offer a lens by which to see society and politics in a way that no other critical events can. Conclusion. Disaster studies offer important applications of social science theories and concepts that expand the field, broaden our reach as social scientists, and deepen our understanding of fundamental social processes and behaviors in meaningful ways.
Identity Testing and Lower Bounds for Read-k Oblivious Algebraic Branching Programs

Read-k oblivious algebraic branching programs are a natural generalization of the well-studied model of read-once oblivious algebraic branching program (ABP). In this work, we give an exponential lower bound of exp (n/kO(k)) on the width of any read-k oblivious ABP computing some explicit multilinear polynomial f that is computed by a polynomial-size depth-3 circuit. We also study the polynomial identity testing (PIT) problem for this model and obtain a white-box subexponential-time PIT algorithm. The algorithm runs in time 2Õ(n1−1/2k−1) and needs white box access only to know the order in which the variables appear in the ABP.
Effect and experiment of screw locations on BGA viscoplastic fatigue life

This paper establishes a packaging module of multichip with lead-free solder ball SAC305. BGA solder ball adopt nonlinear Anand viscoplasticity constitute formula. With the change factor of five screw locations, the dangerous solder ball position and stress-strain hysteresis curve are obtained through simulation with applying thermal cycling condition and screw prestress under the IPC9701 standard. Based on Coffin-Manson equation, the fatigue life of dangerous solder ball and the trend curve of solder ball life with the screw locations are deduced. And through experiments, the conclusion of the simulation is verified.
Looking beyond national differences: Cultural consensus between Confucian and Anglo societies

National cultural research in management primarily examines cultural differences between countries. Theory and practice recommendations relating to the conduct of international business are then commonly derived from these cultural differences. We propose that attention should also be paid to the ways in which nations are culturally similar. Applying data from the GLOBE national culture model, we reveal cultural similarities across two cultural groups that are usually considered to be representative of important cultural differences. We show six Confucian societies are remarkably similar to seven Anglo societies in respect to their GLOBE culture dimensions scores. We offer support for a so far largely ignored “universal culture” approach in international management that recognizes cultural similarities and balances it with the predominant cultural differences perspective. Implications for management theory and practice are drawn. JEL Classification: M14, M16
Analysis and experiments on a novel smoothly moving low-DoF multilegged robot

SmooBot, a novel low-degree-of-freedom multilegged robot with a smoothly moving platform is proposed in the paper, which is aimed at helping people do the delivery jobs in the industrial site. Cam compensation mechanisms are applied to the robot so the platform keeps smoothly moving while the robot is walking. With the special design of the compensation mechanism, the height, velocity, and attitude of the platform almost keep constant. The motion input of the compensation mechanism shares the same continuous rotation with the mechanical legs and remain the compact structure. The cam mechanisms are designed based on the kinematics analysis of the mechanical legs. The walking simulations and prototype experiments are carried out to testify the theoretical analysis. Based on the simulation and experiment results, the enhancements of the compensation mechanisms in the platform smoothness and the energy efficiency are discussed. The study in the paper provides a new idea to enable a low-degree-of-freedom multilegged robot to have a smoothly moving platform and to carry heavy load at a high speed by using the cam compensation mechanisms.
Why Do Firms Decide To Go Public? A Case Study of Karachi Stock Exchange

This study empirically examines the motivations of going public decision. This study used pre-IPO characteristics and ex-post consequences of IPO firms to address the exceeding research objective. This study used a sample of 70 newly listed firms during 2000 to 2014 on Karachi Stock Exchange (KSE). In this study, a panel probit regression model is used to estimate the impact of fundamental factors on going public decision. The results of this analysis reveal that larger-size firms, carrying high sales growth, more profitable, industry MTB ratio, and firms related general trade industry come into sight are significant determinants. Furthermore, this study also examined ex-post consequences of IPO firms by comparing with the same pre-IPO characteristics by using ‘Wilcoxon two-sample signed rank’ test. The results of this investigation reveal that: Going public decision is used (i) to dilute ownership, risk diversification, and reduction in external monitoring (ii) to finance their future investments and expansions, and (iii) to rebalance their capital structure
On initial conditions in iterative learning control

Initial conditions, or initial resetting conditions, play a fundamental role in all kinds of iterative learning control methods. In this note, we study five different initial conditions, disclose the inherent relationship between each initial condition and corresponding learning convergence (or boundedness) property. The iterative learning control method under consideration is based on Lyapunov theory, which is suitable for plants with time-varying parametric uncertainties and local Lipschitz nonlinearities.
Some Algorithms and Paradigms for Big Data

The reality of big data poses both opportunities and challenges to modern researchers. Its key features – large sample sizes, high-dimensional feature spaces, and structural complexity – enforce new paradigms upon the creation of effective yet algorithmic efficient data analysis algorithms. In this dissertation, we illustrate a few paradigms through the analysis of three new algorithms. The first two algorithms consider the problem of phase retrieval, in which we seek to recover a signal from random rank-one quadratic measurements. We first show that an adaptation of the randomized Kaczmarz method provably exhibits linear convergence so long as our sample size is linear in the signal dimension. Next, we show that the standard SDP relaxation of sparse PCA yields an algorithm that does signal recovery for sparse, model-misspecified phase retrieval with a sample complexity that scales according to the square of the sparsity parameter. Finally, our third algorithm addresses the problem of Non-Gaussian Component Analysis, in which we are trying to identify the non-Gaussian marginals of a high-dimensional distribution. We prove that our algorithm exhibits polynomial time convergence with polynomial sample complexity.
Seasonal Changes in the Prevalence of Antibiotic-Susceptible Acinetobacter calcoaceticus-baumannii Complex Isolates Result in Increased Multidrug Resistance Rates During Winter Months

Abstract Temporal analysis of Acinetobacter calcoaceticus-baumannii complex isolates in a large, US healthcare system demonstrated decreased occurrence of antibiotic-susceptible isolates between November and May, while resistant isolate occurrence was temporally stable. This resulted in 50%–100% seasonal increases of resistance rates. This work offers insight into the phenomenon of Gram-negative pathogen seasonality.
Using the loss-free resistor concept to design a simple ac-dc HB-LED driver for retrofit lamp applications

Currently acknowledged, as a rapidly emerging technology, High-Brightness Light-Emitting Diodes (HB-LEDs) are considered the true alternative to many mature technologies (i.e., incandescent bulbs, compact fluorescent lamps, etc.) due to their high efficiency, low maintenance and durability. It is evident that the HB-LED driver must be durable and efficient to achieve these advantages. Moreover, in the case of replacing incandescent bulbs, the ac-dc HB-LED driver needs to be low cost and to have a high enough Power Factor (PF) to comply with international regulations. This paper presents a new proposal to design a simple, low-cost ac-dc HB-LED driver for retrofit lamps. The proposed solution originates from a very simple concept: the use a Switching Mode Power Supply (SMPS) acting as a Loss-Free Resistor (LFR) connected in series with the mains to shape the line input current. For the proposed application, it is obvious that the LFR needs to have a very simple topology to be economical. However, efficiency cannot be ignored. This paper proposes the flyback converter working as a LFR connected in series with the mains, operating in Boundary Conduction Mode (BCM) in order to improve its efficiency. First, a static analysis of the proposed concept will be presented. A distortion analysis of the input current of the proposed ac-dc HB-LEDs driver will then be carried out to test compliance with international regulations. Finally, a 12 W experimental prototype has been built and tested in order to validate the theoretical results presented in this paper. These results show the proposed ac-dc HB-LED driver to be a low-cost, high efficiency, sinusoidal input current option for designing retrofit lamps.
Precision Positioning of Hard Disk Drives Using Piezoelectric Actuators With Passive Damping

Positioning precision is crucial to today's increasingly high-speed, high-capacity, high-data-density, and miniaturized hard disk drives (HDDs). The demand for higher bandwidth servo systems that can quickly and precisely position the read/write head on a high track density becomes more pressing. The idea of applying dual-stage actuators to track servo systems has been studied. However, the current dual-stage actuator design uses only piezoelectric patches without passive damping. In this paper, we propose a dual-stage servo system using enhanced active-passive hybrid piezoelectric actuators. The proposed actuators will improve the existing dual-stage actuators for higher precision and shock resistance, due to the incorporation of passive damping in the design. We aim to develop this hybrid servo system not only to increase the speed of track seeking but also to improve the precision of track following servos in HDDs. New piezoelectrically actuated suspensions with passive damping have been designed and fabricated. In order to evaluate positioning and track following performances for the dual-stage track servo systems, experimental efforts are carried out to investigate the damping abilities and transmissibilities of the microactuators and to implement the synthesized active-passive suspension structure using a composite nonlinear feedback controller.
A Modified Method for Jiles-Atherton Hysteresis Model and Its Application in Numerical Simulation of Devices Involving Magnetic Materials

A modified method, which combines chaos optimization method and simulated annealing algorithm, is proposed to calculate the Jiles-Atherton (J-A) model parameters. The new method is validated by comparing its computation results with measurement data. Then, the validated J-A model is used in numerical modeling of Epstein frame, and the numerical results are found to be in good agreement with measurement data.