排序方式： 共有43条查询结果，搜索用时 140 毫秒
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This paper proposes an adaptive scheme of designing sliding mode control (SMC) for affine class of multi-input multi-output (MIMO) nonlinear systems with uncertainty in the systems dynamics and control distribution gain. The proposed adaptive SMC does not require any a priori knowledge of the uncertainty bounds and therefore offers significant advantages over the non-adaptive schemes of SMC design. The closed loop stability conditions are derived based on Lyapunov theory. The effectiveness of the proposed approach is demonstrated via simulations considering an example of a two-link robot manipulator and has been found to be satisfactory. 相似文献
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Salmanzadeh A Kittur H Sano MB C Roberts P Schmelz EM Davalos RV 《Biomicrofluidics》2012,6(2):24104-2410413
Ovarian cancer is the leading cause of death from gynecological malignancies in women. The primary challenge is the detection of the cancer at an early stage, since this drastically increases the survival rate. In this study we investigated the dielectrophoretic responses of progressive stages of mouse ovarian surface epithelial (MOSE) cells, as well as mouse fibroblast and macrophage cell lines, utilizing contactless dielectrophoresis (cDEP). cDEP is a relatively new cell manipulation technique that has addressed some of the challenges of conventional dielectrophoretic methods. To evaluate our microfluidic device performance, we computationally studied the effects of altering various geometrical parameters, such as the size and arrangement of insulating structures, on dielectrophoretic and drag forces. We found that the trapping voltage of MOSE cells increases as the cells progress from a non-tumorigenic, benign cell to a tumorigenic, malignant phenotype. Additionally, all MOSE cells display unique behavior compared to fibroblasts and macrophages, representing normal and inflammatory cells found in the peritoneal fluid. Based on these findings, we predict that cDEP can be utilized for isolation of ovarian cancer cells from peritoneal fluid as an early cancer detection tool. 相似文献
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Navid Vafamand Mohammad Hassan Asemani Alireza Khayatian 《Journal of The Franklin Institute》2017,354(14):5854-5876
In this paper, a novel technique for Takagi–Sugeno (TS) model-based robust L1 controller design of nonlinear systems is proposed. Two synthesis methods based on quadratic and non-quadratic Lyapunov functions are considered. To design the robust stabilizing controller, a new approach for deriving sufficient conditions associated with the L1 performance criterion in terms of strict linear matrix inequality is proposed. This novel technique results in less pre-chosen scalar design variables and calculation burden. Furthermore, deriving the controller synthesis conditions via a non-quadratic Lyapunov function (NQLF) relaxes the obtained conditions. Therefore, the proposed approaches not only efficiently minimize the effect of persistent bounded disturbance, but also are applicable for wider classes of TS systems. Furthermore, some new lemmas are proposed to facilitate strict LMI formulation and to provide more degrees of freedom. Finally, several numerical and practical examples are presented to show the merits of this paper. 相似文献
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Ali Bikmoradi Mats Brommels Alireza Shoghli Davoud Khorasani Zavareh Italo Masiello 《Higher Education》2009,57(4):417-427
In Iran, restructuring of medical education and the health care delivery system in 1985 resulted in a rapid shift from elite
to mass education, ultimately leading to an increase in the number of medical schools, faculties, and programs and as well
as some complications. This study aimed to investigate views on academic culture, values, and routines held by faculty members.
A nation-wide survey conducted in six public medical schools in Iran. The research findings show weak organizational culture
and values, together with routine behaviors sensed as a negative and low satisfaction with academic leadership. The research
evidence suggests bureaucracy, politicization, conservativeness, and centralization as common features of medical schools
in Iran and also suggests suitable supervisory skills to tackle the tension between governmental management and academic leadership
with cultural changes, the creation of new values, and adoption more efficient routines. 相似文献
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Farzad Ashrafi Hafez Mohammadhassanzadeh Farhad Shokraneh Ali Valinejadi Karim Johari Nazanin Saemi Alireza Zali Niloofar Mohaghegh Hassan Ashayeri 《Health information and libraries journal》2012,29(4):323-332
Objective: The purpose of this study is to analyse Iranian scientific publications in the neuroscience subfields by librarians and neuroscientists, using Science Citation Index Expanded (SCIE) via Web of Science data over the period, 2002–2008. Methods: Data were retrieved from the SCIE. Data were collected from the ‘subject area’ of the database and classified by neuroscience experts into 14 subfields. To identify the citation patterns, we applied the ‘impact factor’ and the ‘number of publication’. Data were also analysed using HISTCITE, Excel 2007 and SPSS. Results: Seven hundred and thirty‐four papers have been published by Iranian between 2002 and 2008. Findings showed a growing trend of neuroscience papers in the last 3 years with most papers (264) classified in the neuropharmacology subfield. There were fewer papers in neurohistory, psychopharmacology and artificial intelligence. International contributions of authors were mostly in the neurology subfield, and ‘Collaboration Coefficient’ for the neuroscience subfields in Iran was 0.686 which is acceptable. Most international collaboration between Iranians and developed countries was from USA. Eighty‐seven percent of the published papers were in journals with the impact factor between 0 and 4; 25% of papers were published by the researchers affiliated to Tehran University of Medical Sciences. Conclusion: Progress of neuroscience in Iran is mostly seen in the neuropharmacology and the neurology subfields. Other subfields should also be considered as a research priority by health policymakers. As this study was carried out by the collaboration of librarians and neuroscientists, it has been proved valuable for both librarians and policymakers. This study may be encouraging for librarians from other developing countries. 相似文献
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Educational supplementary bibliographic relationships from FRBR point of view: A Canadian Case Study
Alireza Noruzi Clément Arsenault 《Library Collections, Acquisitions, and Technical Services》2013,37(1-2):66-72
PurposeOne of the aims of library catalogs is to clearly represent the relationships existing between two or more bibliographic entities, enabling users to make sense of these relationships. Educational bibliographic relationships are the relationships between an educational work, such as a textbook, and its related works. The main interest of this study was to understand the nature of the supplementary work-to-work bibliographic relationships among educational works and the constitution of educational bibliographic families in the Canadian context using AMICUS (the Canadian national catalog). A thorough understanding of educational bibliographic relationships is required for understanding the Functional Requirements for Bibliographic Records (FRBR) supplementary relationships.Design/methodology/approachWe studied the extent and size of educational bibliographic relationships in the bibliographic universe found in the AMICUS catalog. This is an empirical investigation into the nature and extent of educational work-to-work bibliographic relationships by examining title of works, notes and added entries in bibliographic records. The study was carried out between September 1st 2010 and December 22nd 2010 and examines educational bibliographic relationships between Canadian 2009 publications in each class of the Dewey Decimal Classification (DDC). In other words, this study poses two main questions: What is the structure of educational supplementary bibliographic relationships in Canadian publications? Do significant differences exist across the ten DDC classes?FindingsResults show that 595 works of the 2009 bibliographic records in the AMICUS catalog contain an educational supplementary bibliographic relationship. Of the Canadian publications with an educational supplementary work-to-work bibliographic relationship that were studied, the rates of educational bibliographic relationships were relatively high in the fields of Science (27%), Technology (22%), Social Sciences (20%), and Language (19%). The results of this study suggest a set of guidelines for the establishment and maintenance of educational bibliographic relationships.Originality/valueThis is the first research to examine the educational bibliographic relationships, as supplementary relationships. 相似文献
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Alireza Karimi Reza Razaghi Mahdi Navidbakhsh Toshihiro Sera Susumu Kudo 《Sports Engineering》2016,19(2):105-115
Although it might be believed that the eye only comprised a very small area of the face, its injury due to the ball impacts in different sports seems to be severe enough to entice many researchers to determine the level of injury and then attempt to minimize it. Sports-related eye injuries, especially tennis, pose a substantial and preventable problem to the eye due to the high speed of the tennis ball (69 m/s). This is why many ophthalmologists provide a wide range of information for their patients regarding the risks of eye injuries in tennis to prevent the injury to well over 100,000 eyes each year. However, so far although there are some general information regarding the injury to the human eye components due to the tennis ball impact, the details of the stresses and deformations have not been well determined. Therefore, the goal of this study was to determine the stresses and deformations of the eye components, including cornea, aqueous body, iris, ciliary body, lens, vitreous body, retina, sclera, optic nerve, extra and intraconal fats, and muscles, attributable to the tennis ball impact via a Lagrangian–Eulerian computational coupling model. Magnetic resonance imaging was employed to establish a finite element model of the human eye according to a normal human eye. The numerical results revealed the highest amount of stress in the iris (19.2 MPa), whereas the lowest one was observed in the vitreous body (1.77 Pa). The cornea also experienced the stress of 8.27 MPa which might be high enough to invoke rupture in this delicate material. In addition, the results exhibited a decreasing and increasing of the radius of curvature for the cornea and lens, respectively. Finally, the collision of the tennis ball to the eye triggered the resultant displacement of 0.045 µm in the optic nerve which may imply a non-significant injury to that. The findings of this study may have implications not only for understating the values of stresses and deformations in the human eye components but also for helping the ophthalmologists to have a more precise diagnosis about the injury position in the eye due to the tennis ball impact. 相似文献