Direct thrust force and flux control of a PM-linear synchronous motor using fuzzy sliding-mode observer

In this paper, a fuzzy sliding-mode observer, which uses sigmoid function for speed sensorless control of permanent-magnet linear synchronous motor (PMLSM) is proposed. Most of the observers use sign or saturation functions that need low pass filter in order to detecting back electromotive force. In this paper, the sigmoid function is used instead of discontinuous sign function to decrease undesirable chattering phenomenon. By reducing the chattering, detecting back EMF can be done directly from switching signal without any low pass filter. So the delay time because of low pass filter, in the proposed observer is eliminated. Furthermore, there is no need to compensate phase fault in position estimating. The simulation results show advantages of proposed observer over conventional ones

The Quantitative and Qualitative Study of the Effectiveness of the Problem-based Learning Approach in Teaching Research Methods

Research methods is an essential ingredient of postgraduate programs across a wide range of social science disciplines. The purpose of this study was to compare the effectiveness of problem-based learning (PBL) and lecture-based learning (LBL) approaches to teaching research methods through a mixed-methods approach in an explanatory sequential design. The quantitative data were collected following a quasi-experimental design whereby two classes of research methods in a postgraduate program randomly received either an LBL or a PBL treatment. To assess students’ academic achievement, a final exam on the course was used. The results indicated a higher academic achievement of students in the PBL class compared to LBL class. The qualitative data were gathered through a semi-structured interview to gain deeper insight into the quantitative results. The thematic analysis of the interviews showed that PBL led to deeper and more meaningful learning, increased students’ knowledge in their field of specialty, provided more enjoyable and active learning, increased the students\u27 skills in doing their thesis projects, enhanced their autonomy and independence, and also promoted their dignity and status

Shift work as an oxidative stressor

BACKGROUND: Some medical disorders have higher prevalence in shift workers than others. This study was designed to evaluate the effect of night-shift-working on total plasma antioxidant capacity, with respect to the causative role of oxidative stress in induction of some of these disorders. METHODS: Two blood samples were taken from 44 workers with a rotational shift schedule, one after their day shift and one after their night shift. The total plasma antioxidant capacity of each worker was measured through the FRAP method. The impacts of age and weight were also assessed. RESULTS: The total plasma antioxidant capacity was measured in 44 shift-workers with a mean age of 36.57 years (SD: 10.18) and mean BMI of 26.06 (SD: 4.37) after their day and night shifts. The mean reduction of total plasma antioxidant capacity after the night shift was 105.8 μmol/L (SD: 146.39). Also, a significant correlation was shown between age and weight and total plasma antioxidant capacity. Age and weight were found to be inversely related to total plasma antioxidant capacity; as age and weight increased, the total plasma antioxidant capacity decreased. CONCLUSION: Shift work can act as an oxidative stressor and may induce many medical disorders. Aging and obesity in shift workers makes them more sensitive to this hazardous effect

Intelligent adaptive multi-parameter migration model for load balancing virtualized cluster of servers

Najvažnija korist virtualizacije je dobivanje okruženja s ujednačenim opterećenjem kroz prenošenje (migraciju) virtualnim strojem (VM). Djelovanje usluga u skupinama (klasterima), kao što je prosječno vrijeme reakcije - Average Response Time - reducirano je inteligentnom odlukom VM o prenošenju. Prenošenje ovisi o nizu kriterija poput korištenja resursa (uporaba CPU, korištenje RAMa, korištenje mreže, itd.) i potrebe za strojevima (fizičkim (PM) i virtualnim (VM)). To je više- kriterijski problem prenošenja koji procjenjuje, komparira i sortira niz fizičkih i virtualnih strojeva (PM i VM) na osnovu parametara istaknutih u procesu prenošenja. Ali, koji parametar (parametri) ima dominantnu ulogu nad djelovanjem klastera u određenom vremenskom odjeljku? Kako možemo odrediti težinu parametara u nadolazećim vremenskim razmacima? Postojeći algoritmi prenošenja (migration algorithms) ne uzimaju u obzir težine parametara koje se mijenjaju ovisno o vremenu. Te analize pretpostavljaju fiksnu težinu za svaki parametar kroz široki raspon vremenskih intervala. To dovodi do netočnog predviđanja o traženju rješenja za svaki server. U našem se radu predstavlja novi Inteligentni i Adaptivni Multi Parametarski (IAMP) upravljač resursima na bazi prenošenja (migracije) za virtualizirane centre podataka i klastere s novom na umjetnoj neuronskoj mreži (ANN) temeljenoj analizi težina nazvanoj Error Number of Parameter Omission (ENPO). U svakom se vremenskom razmaku težina parametara ponovo izračunava te će nevažni parametri biti oslabljeni u postupku rangiranja. Obilježili smo parametre koji utječu na performansu klastera i koristili hot migration s naglaskom na skupini servera u XEN platformi virtualizacije. Eksperimentalni rezultati temeljeni na radnim opterećenjima sastavljenim od stvarnih aplikacija pokazuju da je primjenom IAMP-a moguće poboljšati rad virtualnog klaster sustava do 23 % u usporedbi s postojećim algoritmima. Što više, on brže reagira i eliminira vruće točke zbog svog potpuno dinamičkog upravljačkog algoritma.The most important benefit of virtualization is to get a load balanced environment through Virtual Machine (VM) migration. Performance of clustered services such as Average Response Time is reduced through intelligent VM migration decision. Migration depends on a variety of criteria like resource usage (CPU usage, RAM usage, Network Usage, etc.) and demand of machines (Physical (PM) and Virtual (VM)). This is a multi-criteria migration problem that evaluates, compares and sorts a set of PMs and VMs on the basis of parameters affected on migration process. But, which parameter(s) has dominant role over cluster performance in each time window? How can we determine weight of parameters over oncoming time slots? Current migration algorithms do not consider time-dependent variable weights of parameters. These studies assume fixed weight for each parameter over a wide range of time intervals. This approach leads to imprecise prediction of recourse demand of each server. Our paper presents a new Intelligent and Adaptive Multi Parameter migration-based resource manager (IAMP) for virtualized data centres and clusters with a novel Artificial Neural Network (ANN)-based weighting analysis named Error Number of Parameter Omission (ENPO). In each time slot, weight of parameters is recalculated and non-important ones will be attenuated in ranking process. We characterized the parameters affecting cluster performance and used hot migration with emphasis on cluster of servers in XEN virtualization platform. The experimental results based on workloads composed of real applications, indicate that IAMP management framework is feasible to improve the performance of the virtualized cluster system up to 23 % compared to current algorithms. Moreover, it reacts more quickly and eliminates hot spots because of its full dynamic monitoring algorithm

Preparedness of Final-year Students in Fields of Medicine, Nursing, and Midwifery Regarding Interprofessional Learning

Background & Objectives: Interprofessional learning (IPL) can create more collaborations among students of different healthcare disciplines. However, this depends on the tendency of students to learn from each other. Given the fact that the attitude of students is recognized as the major factor for the implementation and success of a program, this study aimed to determine the attitude of final-year students in fields of medicine, nursing, and midwifery of Iran University of Medical Sciences, Tehran, Iran toward the implementation of IPL. Materials and Methods: This descriptive and cross-sectional research was conducted on 200 final-year students in the fields of medicine, nursing, and midwifery, who were active in clinical settings and had work experiences in clinical environments. In this research, data were collected using the valid and reliable readiness for inter-professional learning scale (RIPLS), and subjects were selected through convenience sampling. Results: From 200 distributed scales, about 180 questionnaires (response rate=90%) were returned, 80 and 100 of which were filled by students in the fields of medicine, nursing and midwifery, respectively. According to the results, 50.6% of the respondents were female and 49.4% were male. Moreover, mean (standard deviation) total score of the evaluated students was equal to 79.8 (SD=92). Considering the obtaining of a score higher than the desired level by students (57), it could be concluded that the subjects had a positive attitude toward IPL. While the results were indicative of no significant difference between the two medicine and nursing-midwifery groups in terms of preparedness for IPL (P=0.4), there was a significant difference in the subcategory of cooperation and teamwork (P=0.001). In this regard, medical students obtained a lower score, compared to the nursing and midwifery students. Conclusion: According to the results of the study, the subjects had a proper attitude toward IPL, which itself is the most important support for the entrance of this new educational approach in student curriculums