SRM

The simplicity of photovoltaic motors makes them ideal candidates for fully autonomous applications requiring thousands of operating hours without maintenance, like water pumping. Photovoltaic motors use photovoltaic cells optically commutated by a shutter driven by the motor rotor to convert light energy into mechanical energy, without the need of any brushes or other power electronics. With the decrease of photovoltaic cells price, photovoltaic motors could be more affordable and reliable than conventional systems, and therefore particularly well suited for off-grid applications.  The concept has been patented under various forms, but the scientific literature is so far very scarce. In this article, we attempt to classify photovoltaic motors, and to explain in details their physical working principle. Then we compare the different architectures by defining two pre-design factors linked to the system maximal output power. Finally, we report first experimental results on a photovoltaic switched reluctance motor (PV SRM) prototype using a 6/4 switched reluctance machine and 12 photovoltaic cells.

Supply chain management (SCM) involves various activities that deal with transforming raw materials into finished products. SCM focuses on maximising value to the customer through providing quality materials at a lower price. Although SCM has been in existence for over 80 years, it was mainly associated with Large Enterprises (LEs) while SMEs were ignored. Recently, however, SCM has become popular among SMEs due to the benefits it offers such as decreased lead times, improvement in customer responsiveness, increased productivity, sales and firm profitability. Despite SCM popularity, there is a shortage of literature, especially in the food manufacturing sector in Tanzania. Previous researchers mainly focused on SCM of raw agricultural products. Furthermore, the literature on SME and SCM in Tanzania remains scarce.
The main purpose of this research was to assess the factors affecting the implementation of SCM in food manufacturing SMEs in Dar es Salaam Tanzania. The study adopted a qualitative design; 13 semi-structured interviews were held with SCM experts. The findings reveal that SCM implementation within these firms needs development. The factors that limit effective SCM implementation in Tanzania are low knowledge concerning supply chain(SC), ineffective management, unsophisticated technologies and weak SSR. The study recommends SMEs to improve their relationship with suppliers. Also, SMEs have to invest in the latest technologies to reduce lead times, maximise productivity, and become agile. Support from the government in the form of training and financial aid is also imperative for SMEs to improve SCM implementation

The paper deals with the problem of speed and position estimation in SRM drive equipped with hysteresis band current controller. Instead of measured current the observer utilize reference current. The voltage is calculated from switching on-time. A speed observer structure which uses estimated back EMF and current of each phase is presented. The shaft position is integrated from estimated speed signal. Observer uses a simplified 1­-dimensional nonlinear equation set instead of 2-dimensional.

Supply chain management (SCM) involves various activities that deal with transforming raw materials into finished products. SCM focuses on maximising value to the customer through providing quality materials at a lower price. Although SCM has been in existence for over 80 years, it was mainly associated with Large Enterprises (LEs) while SMEs were ignored. Recently, however, SCM has become popular among SMEs due to the benefits it offers such as decreased lead times, improvement in customer responsiveness, increased productivity, sales and firm profitability. Despite SCM popularity, there is a shortage of literature, especially in the food manufacturing sector in Tanzania. Previous researchers mainly focused on SCM of raw agricultural products. Furthermore, the literature on SME and SCM in Tanzania remains scarce. The main purpose of this research was to assess the factors affecting the implementation of SCM in food manufacturing SMEs in Dar es Salaam Tanzania. The study adopted a q...

—Different methods have been proposed for torque ripple control in Switch Reluctance motor (SRM). In order to overcome this problem, some of the methods are based on changing in the structure and the geometry of the motor and others are performed by using control methods. This paper describes the structure and principles of operation in SRM and then introduces some controlling methods for these motors. Some methods are studied for SRM toque ripple reduction and after that an optimum methods is suggested by authors according to the results which have been obtained in laboratory.

Nowadays, switched reluctance machines (SRM) are gaining interest in the scientific community due to the advantages they offer. The SRM offers an overall efficiency similar to an induction motor of the same rating, since the friction and windage losses are comparable. Many researches have been done on SRMs, their related systems and challenges. This paper reviews the SRM structures, their advantages and disadvantages. Various SRM topologies are studied and their merits and limits are given. Additionally, the most common control strategies for SRM drives are categorized, which is followed by a summary of the researches on challenges in torque and vibration reduction.

Intervento al convegno Confcommercio-Ambrosetti I protagonisti del mercato e gli scenari per gli anni 2000 23 marzo 2019, Villa d'Este, Cernobbio


https://www.centroeuroparicerche.it/wp-content/uploads/2019/03/20190412Cernobbio_Giacche.pdf

Liliana Suárez Téllez y Blanca Ruiz Hernández
Resumen
El octavo ciclo del Seminario Repensar las Matemáticas estuvo
conformado por diez sesiones donde investigadores y profesores
de matemáticas dialogaron sobre temas relacionados con entornos
tecnológicos, formación de profesores, pensamiento aritmético,
didáctica de la estadística, estrategias didácticas y resolución de
problemas, todos ellos asociados a líneas de investigación desde
la matemática educativa. Además se trataron temas más amplios
como la investigación educativa, la evaluación, la divulgación de
la ciencia y el currículo de matemáticas. En este escrito ofrecemos
una reseña de este ciclo. La participación de investigadores y
docentes de diferentes instituciones educativas del país y el extranjero
en este proyecto es una evidencia del interés de acercar la investigación a la docencia y de reconocer a la matemática
educativa como un cuerpo de conocimientos necesario para la
mejorar la calidad de los aprendizajes de nuestros estudiantes
mediante la implementación de innovaciones educativas en nuestros
salones de clases.
Palabras clave: matemática educativa, profesionalización docente,
TIC en la docencia, investigación educativa.
http://rmie.maristas.edu.mx/pdf/RMIE_3/Resenas_No3.pdf

This paper presents a novel method of profiling the phase currents to minimize the torque ripple of a switched reluctance machine. The method is a combination of machine design and control algorithm. The minimization is accomplished in three steps: The first step is to design a machine that has symmetric torque characteristics with an extended flat portion, the second step is to find the required current profile through simulation, and the third step is the fine tuning of the profile. The simulation is done to verify the method through a coupling of the finite element-based machine model and the Matlab/Simulink-based dynamic controller model. The coupled simulation considers the nonlinearities, electrical loss, magnetic loss, and mutual coupling. Experimental verification validated the torque-ripple minimization procedure.

Nowadays power electronics circuits are embedded to most of electrical application areas. This approached offers a great control mechanism with simple and easy circuit configuration. Switched Reluctance Motor (SRM) is one of the most recent apparatus which draws a great number of researchers’ interests. Previously several attempts are made to use the power converters as driver for SRM such as Voltage Source Inverter (VSI) and bridge converters. This paper presents an analysis study of three level inverter to control the SRM. The inverter is controlled using space vector modulation SVM. The aim of this paper is to report the use the multilevel inverter to be fed into the SRM. The implementation of the multilevel inverter is abl to reduce the Total Harmonics Distortion (THD). Performance comparison are made between the multilevel and previous power electronics circuits that applied to the SRM. The simulation results have been conducted by MATLAB/SIMULINK software.

In the crowd of institutions that claim big about offering placements to their alumni, only some are there who keep to their promises on providing the relevant and best-matched jobs to their outgoing students, All the students after completing their professional education aspire for a placement in a company of repute. SRM University, Sonepat not only prepares excellent manpower in its campus, but the university also assists and guides the students in getting their desired employments. To fulfill this purpose, SRM has collaborated with the Indian and International companies of repute which are pioneers in their fields. SRM University, Sonepat Haryana, has carved a niche for itself by providing the world of opportunities for its students after completion of their respective courses, and the university keeps on increasing number of campus selections year by year. In its endeavour to assist students in their job search after completion of courses, SRM has collaborated HCL to name a few. These all are industry leaders to which SRM provides new talent, which is honed by these companies according to their requirements. Under the biggest placement programs, these collaborated companies conduct Job fairs in the SRM campus, and select talents who can work for them; the companies offer handsome salary packages with on-the-spot offer letters to the selected candidates. The newly recruited candidates selected by these recruiters have proven their mettle so far and SRM continues to provide such talented manpower to its collaborated and other companies only to benefit the companies and for personal growth of its alumni, which ultimately becomes the reason of the growth of the nation and in turn the world. All these personality traits that these companies look for in a talented manpower that they want to hire are inculcated in SRM alumni since his/her very first day at SRM. These personality traits are passion, collaboration, entrepreneurial spirit, innovation and taking ownership, all these are thoroughly tested by these companies by conducting various skill tests before selection. The campus selections are two-way beneficial: if a candidate is hired on the spot, it is well and good; but if for some reason a candidate is not hired or is reluctant to join a company, the interview process of campus selection helps boost the confidence of the candidate making candidate's will power firm for facing interview challenges in their career plans in future. SRM has also collaborated with some startup companies who also hold job fairs in SRM campus. One of the advantages to get selected in campus is that these new startup companies even offer the newly selected candidates a partnership in the company within a few years of employment that is hardly a possibility with the already a big name or organization. That is also a positive thing that make students lean towards accepting offers by such new startups. So, all these reasons are enough on why we claim to be the top placement university. We welcome all our students to be successful in their campus selection fair and wish them a good luck in grabbing their dream job!!

What happens to a society that has too many men? In this provocative book, Valerie Hudson and Andrea den Boer argue that, historically, high male-to-female ratios often trigger domestic and international violence. Most violent crime is committed by young unmarried males ...

The paper deals with the problem of sensorless control of SRM drives. A speed control system using back EMF and position estimator is presented. The shaft position is estimated using a "global" current error. That observer robustness on motor parameter accuracy estimation is verified by simulation results.

Hou WH, Shih CL, Chou YT, Sheu CF, Lin JH, Wu HC, Hsueh IP, Hsieh CL. Development of a computerized adaptive testing system of the Fugl-Meyer motor scale in stroke patients. OBJECTIVE: To develop a computerized adaptive testing system of the Fugl-Meyer motor scale (CAT-FM) to efficiently and reliably assess motor function in patients with stroke. DESIGN: First, a simulation study was used to develop and examine the psychometric properties of the CAT-FM. Second, a field study was employed to determine the ...

This paper presents a novel method of controlling switched reluctance generators (SRGs) for maximum efficiency with active current regulation. The effect of varying the input control parameters on the efficiency of the SRG is first analyzed through exhaustive data collection through simulation and experiments. The analysis of the collected data showed that the input control parameters that minimize the dc-link current ripple also maximize the generating efficiency. A novel control strategy based on the analysis is then developed to maximize the efficiency indirectly through the control parameters that minimize the dc-link current ripple in real time while delivering the commanded generation power. The controller algorithm has been implemented with a 1-kW experimental three-phase SRG drive system charging a NiMH battery pack. Index Terms—DC-link ripple, SRG control, SRG efficiency, switched reluctance generator (SRG).

Advances in our understanding of the natural history and limited aggressive potential of many small renal masses, expanding treatment options and the integration of molecular factors into prognostic and therapeutic algorithms have stimulated renewed interest in percutaneous renal mass biopsy. A comprehensive literature review was performed using MEDLINE/PubMed to evaluate the indications, techniques, complications and efficacy of renal mass biopsy. Reported techniques of renal mass biopsy vary widely with different modes of radiographic guidance, needle size, number of cores and pathological analyses. Percutaneous renal mass biopsy with 2 or 3 cores using 18 gauge needles may improve diagnostic accuracy without increasing morbidity. Serious complications of percutaneous biopsy are rare and the minor complication rate in recent series has been less than 5%. The reported rate of technical failure of renal mass biopsy due to insufficient material was about 9% before 2001 and 5% in more...