Conflict and democracy education in Palestine

This paper describes the conflict situations that teachers and students faced when a new problem- and case-based approach to democracy education was used in Palestine. The data for the study were six documentary cases written by teachers who participated in the three-year project, supplemented by the observations and interpretations of the author as a participant observer. The study describes how dedicated and tactful teachers generally succeeded to teach democracy in a largely undemocratic context, and shows that teaching democracy in the manner described perturbed the system, and students and teachers were faced with internal and external conflict situations. These conflict situations sometimes facilitated radical change in the knowledge, beliefs, and behavior of teachers and students. The study underscores the importance of internal cognitive and emotional conflict, in addition to external conflict, in learning, as well as draws attention to the dialectical relation between teachers’ efforts to introduce educational change and their own change and professional development.peer-reviewe

Teaching democracy for political action : on the aims of democracy education in Palestine

This paper aims to identify and explicate the aims of democracy education, and to reach some agreement on the importance of these aims. It is divided into two parts. In the first theoretical part, a brief review of the works of some scholars who examined education and democracy is conducted in order to identify some of the important aims of democracy education. Subsequently, a classification of the aims of democracy education, emphasising teaching democracy for empowerment and political involvement, is presented. In the second empirical part, a report is presented on using the Delphi technique to reach consensus among key Palestinian educators about the important aims of democracy education in Palestine. It was found that two groups of independently working educators – namely, university professors and school teachers – shared the author’s priorities for democracy education.peer-reviewe

Design of second order sliding mode observer based equivalent Back-EMF for rotor position estimation of PMSM

This study introduces a scheme to estimate rotor position by the use of an Equal electromotive force (EMF) model of a synchronous machine. This use could be substituted by a sliding-mode observer (SMO) according to an equal EMF for superior reference speed tracking. There is an algorithm of the second order sliding-mode-control (SO-SMC) in controlling speed of permanent magnet synchronous motor (PMSM). This is by the use of the proportional plus-integral PI control sliding plane. The current work discusses the PMSM, which follows field-oriented appears. In addition, there are SO-SMC laws and PI sliding plans. This paper shows that the proposed high-speed PMSM sensorless speed control is valid by MATLAB simulations

Monitoring based on time-frequency tracking of estimated harmonic series and modulation sidebands

International audienceThe installation of a Condition Monitoring System (CMS) on a mechanical machine (e.g., on a wind turbine) aims to reduce the operating costs by applying a predictive maintenance strategy. The CMS is composed of sensors acquiring signals from which system health indicators are computed and monitored. Part of those indicators are predefined depending on the monitored system kinematic and are computed by averaging large or narrow spectral bands. The averaging and the need for predefined thresholds for default detection may induce lots of false alarms while reducing the ability to detect the default early. To get precise health indicators reflecting each local meaningful spectral content, the AStrion software proposes a new data-driven monitoring strategy without any a priori on the measured signals. First, an automatic spectral analysis is applied to detect, characterize and classify the different spectral structures of the successive measured signals. These spectral structures can be either single spectral peaks, either peaks grouped in harmonic series or in modulation sidebands [1]. Second, these spectral structures are characterized by several features, including for example the number of peaks, the characteristic frequencies and the energy. This gives a snapshot of the system health at the signal acquisition time. To perform an automatic diagnosis of the system, the spectral evolution should be tracked along the time snapshots. In this paper, we propose a time tracking method based on McAulay & Quatieri algorithm [2] which has been designed originally for speech signals acquired on a continuous temporal basis. We have adapted [2] in order to account not only for single spectral peak evolution but also for the evolution of more complex structures such as harmonic series or modulation sidebands, even in the case of signals acquired on a non-regular temporal basis, as it is often the case. Moreover, an added sleep state makes the proposed method robust against nondetected spectral structures at a given time. Finally, the temporal evolution of the spectral structure features can be monitored and used as precise health indicators. The following figure is a result of the proposed method applied on real signals coming from a test bench designed in KAStrion project for simulating a wind turbine operation and for which the inner race of the main bearing has been damaged. Above, the time frequency map displays a zoom of the spectral peaks detected (around 20.000 per snapshot, represented by circles) and shows in blue the tracking from 44 to 189 operating hours of a spectral peak at 3.45 Hz. This particular peak evolves at 129 hours to become an harmonic series with more and more peaks and energy. Its energy evolution (plotted below) shows an increase which mirrors out a failure. In a following step [3], this spectral structure has been associated with the ball pass frequency of the inner ring of the main bearing. A dismantling of this bearing has confirmed the failure. This result shows the potential of the proposed data-driven method to create automatically relevant health indicators

Reach Enhancement for WDM Direct-Detection Subcarrier Modulation using Low-Complexity Two-Stage Signal-Signal Beat Interference Cancellation

We describe a novel low-complexity SSBI cancellation scheme, and experimentally investigate its performance in a 7×25 Gb/s WDM direct-detection single-sideband 16QAM Nyquistsubcarrier modulation system. The scheme achieves a doubling of the transmission reach

Simulation of the deflected cutting tool trajectory in complex surface milling

Since industry is rapidly developing, either locally or globally, manufacturers witness harder challenges due to the growing competitivity. This urges them to better consider the four factors linked to production and output: quality, quantity, cost and price, quality being of course the most important factor which constitutes their main concern. Efforts will be concentrated—in this research—on improving the quality and securing more accuracy for a machined surface in ball-end milling. Quality and precision are two essential criteria in industrial milling. However, milling errors and imperfections, duemainly to the cutting tool deflection, hinder the full achieving of these targets. Our task, all along this paper, consists in studying and realizing the simulation of the deflected cutting tool trajectory, by using the methods which are available. In a future stage, and in the frame of a deeper research, the simulation process will help to carry out the correction and the compensation of the errors resulting from the tool deflection. The corrected trajectory which is obtained by the method mirror will be sent to the machine. To achieve this goal, the next process consists—as a first step—in selecting a model of cutting forces for a ball-end mill. This allows to define—later on—the behavior of this tool, and the emergence of three methods namely the analytical model, the finite elements method, and the experimental method. It is possible to tackle the cutting forces simulation, all along the tool trajectory, while this latter is carrying out the sweeping of the part to be machined in milling and taking into consideration the cutting conditions, as well as the geography of the workpiece. A simulation of the deflected cutting tool trajectory dependent on the cutting forces has been realized

A world of lies

This article reports two worldwide studies of stereotypes about liars. These studies are carried out in 75 different countries and 43 different languages. In Study 1, participants respond to the open-ended question "How can you tell when people are lying?" In Study 2, participants complete a questionnaire about lying. These two studies reveal a dominant pan-cultural stereotype: that liars avert gaze. The authors identify other common beliefs and offer a social control interpretation

Self-efficacy enhanced in a cross-cultural context through an initiative in under-resourced schools in KwaZulu-Natal, South Africa

This paper discusses the Khanyisa Programme, an initiative in KwaZulu-Natal, South Africa, where learners from under-resourced schools are supported by teachers and high achievers in Grade 11 and 12 from a previously advantaged state school under apartheid. A qualitative, evaluative study was undertaken to identify key elements in the ongoing success of the programme and collect participant suggestions for improvement. The findings, discussed within the framework of self-efficacy theory, identified enormous gains by Khanyisa learners, leading to vastly improved career prospects