Mixed control of uncertain jumping time-delay systems     

Magdi S. Mahmoud  Fouad M. AL-Sunni  Yan Shi   《Journal of The Franklin Institute》2008,345(5):536-552

In this paper, we investigate a class of linear continuous-time systems with Markovian jump parameters. An integral part of the system dynamics is a delayed state with time-varying and bounded delays. The jumping parameters are modeled as a continuous-time, discrete-state Markov process. Employing norm-bounded parametric uncertainties and utilizing the second-method of Lyapunov, we examine the problem of designing a mixed controller which minimizes a quadratic performance measure while satisfying a prescribed -norm bound on the closed-loop system. It is established that sufficient conditions for the existence of the mixed controller and the associated performance upper bound could be cast in the form of linear matrix inequalities.  相似文献   

A new active R bandpass filter     

Ahmed M. Soliman  Mahmoud Fawzy 《Journal of The Franklin Institute》1978,306(2):159-163

A new active R filter which realizes a second order bandpass transfer function is given. The network employs only resistors and two operational amplifiers. Sensitivities to all passive and active circuit components are very low. Design equations are given and experimental results are also included.  相似文献   

Academic Journals Plagued by Bogus Impact Factors     

Mehdi Dadkhah  Glenn Borchardt  Mohammad Lagzian  Giorgio Bianciardi 《Publishing Research Quarterly》2017,33(2):183-187

The current status of academic publishing is worrying. Cybercriminals are now targeting academic audiences, making it necessary to inform both editors and authors about such issues. The latest involves bogus impact factors, which are challenging scholarly publishing. Legitimate impact factors are used by authors and editors to get a general idea of the audience, if any, for a particular piece or journal. The bogus metrics only add confusion in support of the cybercrimes of their initiators. In this paper, we discuss bogus impact factors, victim countries, and try to clarify the phenomena for both authors and editors.  相似文献   

Inclusive assessment for linguistically diverse learners in higher education     

Amrita Kaur  Mohammad Noman  Hasniza Nordin 《Assessment & Evaluation in Higher Education》2017,42(5):756-771

As classrooms become increasingly diverse in higher education, educators are emphasising inclusive practices in teaching and learning to accommodate the needs of diverse learners. There is also an emerging need for an inclusive approach in assessment for accessibility, opportunity, relevance and engagement. This study, using design-based research guidelines with student–faculty partnership, designed, developed, implemented and evaluated contextually sensitive assessment protocol as inclusive and fair assessment. Data from students’ reflections and face-to-face interviews with open-ended questions suggested that, despite concerns such as potential bias, time and accommodation challenges, such assessment practices can make valuable contributions in creating a positive learning environment, improving relatedness and self-esteem and motivating and engaging students for better effort and effective learning. Implications for higher education practitioners with diverse learners are discussed.  相似文献   

Investigation and evaluation of ultrasound reactor for reduction of fungi from sewage     

Dehghani MH  Mahvi AH  Jahed GR  Sheikhi R 《Journal of Zhejiang University. Science. B》2007,8(7):493-497

The objective of the investigation was to study the application of ultrasound reactor technology （USRT） as a disinfectant for reduction of fungi from sewage effluent. Fungi are carbon heterotrophs that require preformed organic compounds as carbon sources. USRT is an attractive means to improve water quality because of the system simplicity and no production of toxic by-products. An ultrasound reactor produces strong cavitation in aqueous solution causing shock waves and reactive free radicals by the violent collapse of the cavitation bubble. These effects should contribute to the physical disruption of microbial structures and inactivation of organisms. There was significant reduction in fungal growth, with decreased fungal growth with increasing USRT. In this study, ultrasound irradiation at a frequency of 42 kHz was used to expose suspensions of fungi to evaluate the disinfection efficacy of the ultrasound reactor. Also, this study showed that in this system more than 99% reduction of sewage fungi was achieved after 60 min.  相似文献   

Publishing in predatory open access journals: Authors' perspectives     

Mohammad Salehi  Mohammad Soltani  Hadis Tamleh  Shohreh Teimournezhad 《Learned Publishing》2020,33(2):89-95

The proliferation of predatory or bogus journals has been recognized as a threat to academic research, and this study was conducted to discover the experiences of authors published in these journals. Eighty authors who had published in journals identified as predatory were surveyed. We asked how the authors learnt about these journals, what they thought about the reputation of the journals, their experiences of peer review and the quality of feedback provided, and whether publication was driven by PhD or job requirements. Our results showed that a third of authors discovered the journals by web searches or responding to email invitations. Over half said the reputation and name of the journal were important in selecting a journal, although a third admitted that the journal they published in did not have a good reputation. The main reason for selecting the journals was the promise of fast publication (31.2% respondents). Only half of the respondents said that publication was driven by PhD or job requirements. Just over a third reported that peer review was good or excellent, and only 17.5% said that peer review was poor or non‐existent – over 70% thought they had received good feedback from the journals. Although the research was somewhat limited, it does indicate general satisfaction with the journals in which the authors published. Fast publication coupled with good feedback and encouragement to submit can make publishing in predatory journals so tempting that few authors can resist.  相似文献   

The study of the success indicators for pre-implementation activities of Iran's E-Government development projects     

Mohammad Sharifi  Amir Manian 《Government Information Quarterly》2010

E-Government and E-Government development project studies have been conducted in most industrialized societies, as well as in Iran. Due to their nature and structure, E-Government development projects have numerous political, social, and economic impacts on society. Given the incorporation of significant capital, human resources, information, and political commitments, these projects are considered quite vital to society. Following the systematic pre-implementation activities of E-Government development projects is critical for the success of such projects; ignoring such issues leads to various problems during E-Government project implementation. This research aims to explore and detect the success indicators for pre-implementation activities of E-Government development projects, evaluate the validity of these indicators, and investigate the indicators' status in the Fuel Smart Card Project. The researcher has also provided some suggestions on the successful implementation of E-Government development projects.  相似文献   

Hydro-Alcoholic Cinnamon Extract, Enhances Glucose Transporter Isotype-4 Translocation from Intracellular Compartments into the Cytoplasmic Membrane of C2C12 Myotubes     

Abdorrahim Absalan  Javad Mohiti-Ardakani  Hossein Hadinedoushan  Mohammad Ali Khalili 《Indian journal of clinical biochemistry : IJCB》2012,27(4):351-356

Cinnamon has been used as an anti-diabetic agent for centuries but only in recent few years its mechanism of action has been under investigation. Previous studies showed that cinnamon might exert its anti-diabetic effect via increasing glucose transporter isotype-4 (GLUT4) gene and glycoprotein contents in fat cells. To study if hydro-alcoholic cinnamon extract (HACE) enhances GLUT4 translocation from intracellular compartments of nuclear or endoplasmic reticulum membranes (N/ER) into the cytoplasmic membrane (CM). C2C12 myoblastic cell line were seeded in DMEM plus 20 % FBS and differentiated to myotubes using 2 % horse serum. After myotubes formation, 100 or 1,000 μg/ml HACE, as intervention, and as control 1 % DMSO were added for 3 h. Cells were washed and homogenized followed by ultracentrifuge fractionation, protein separation by SDS-PAGE and GLUT4 detection using semi-quantitative Western blotting. Data analysis was done by two-independent samples t test for comparison of mean ± SD of GLUT4 percent in categories. GLUT4 contents were higher in CM of groups 100 and 1,000 μg/ml HACE and lower in 1 % DMSO treated myotubes (CI = 0.95, P < 0.05). For N/ER reverse results were obtained (CI = 0.95, P < 0.05). As our results have shown HACE induces GLUT4 translocation from intra-cell into cell surface. We conclude that cinnamon maybe a choice of type-2 diabetes mellitus treatment because its extract enhances GLUT4 contents in CM where it facilitates glucose entrance into the cell. However it is necessary to trace the signaling pathways which are activated by HACE in muscular tissue.  相似文献   

Tensions experienced by teachers and their views of support for pupils with autism spectrum disorders in mainstream schools     

Mahmoud M. Emam 《欧洲特需教育杂志》2013,28(4):407-422

The number of pupils with autism spectrum disorders (ASD) who receive their education in mainstream schools in the UK has increased considerably over the last 10 years. Despite this increase, teachers and other support staff face a number of challenges in order to ensure that these inclusive arrangements bring maximum benefits to the children themselves, their parents and the school community as a whole. In this study we explore some of the tensions that teachers in mainstream schools may experience, many of which reflect the unique problems that the inclusion of pupils with ASD can present. In addition, we explore how these tensions may shape their views of support arrangements for those pupils. We observed 17 pupils with ASD ranging from 7 to 16 years, all of whom were placed in a regular class in one of eight mainstream schools on a full‐time basis, and carried out interviews with their teachers, teaching assistants (TAs) and special educational needs coordinator. Findings suggest that tensions reported by school staff are inherently shaped by the ASD‐related manifestations, particularly those pertaining to their difficulties in social and emotional understanding. These tensions determine the quality of the transactions and interactions between the teachers and the pupils with ASD. Based on these tensions, teachers form their views of the type of support that is needed for those pupils. Evidence from the data suggests that, in order for these tensions to be kept at manageable proportions, teachers rely heavily on the TA, whose role in working closely with the pupil is perceived as being indispensable. Building on the study’s findings, we suggest a generic conceptualization for the successful inclusion of pupils with ASD, which is grounded in the systems theory perspective of the relationship between the teachers and these children.  相似文献   

Non-Descender and All-Cap Arabic Writing     

Mohammad Ali Yaghan 《Al-Masaq: Islam & the Medieval Mediterranean》2018,30(2):166-190

Contrary to the common belief of Arabic language users that the Arabic writing system has descenders as an inherent quality, some historical examples demonstrate that there were some artistic attempts to create non-descender, all-cap calligraphic systems, but they have never been studied as a phenomenon. This article draws attention to the existence of these examples, and analyses and classifies them according to their form.

The article begins with an analysis of the current Arabic writing system in terms of descenders, differentiating between artistic and functional writing, defining the need for harmonious balance in artistic writing, and demonstrating that descenders do disrupt the balance in Arabic writing, which could be considered as an ascender-system.

Then, historical examples of the non-descender system are introduced, categorised into four visual stages, and the descender handling for each stage is described; all-capital letter examples are then introduced.

Finally, some historical texts describing the beauty of calligraphy in this specific system of writing are analysed.

Abbreviations: MET: The Metropolitan Museum of Art, www.metmuseum.org; LACMA: The Los Angeles County Museum of Art, www.lacma.org; No. : Accession Number  相似文献