Prior knowledge and information-seeking behavior of PhD and MA students     

Mahmood Khosrowjerdi  Mohammad IranshahiAuthor vitae 《Library & information science research》2011,33(4):331-335

Information seeking and its dimensions have been analyzed and measured in different disciplines and contexts and the relationships to other variables, such as gender, task, knowledge, personality, experience, and expertise, have been measured by researchers and have yielded helpful results. In this study, the relationships between information-seeking behavior and prior knowledge of graduate (MA and PhD) students at Tehran University were tested and analyzed. Results show positive and strong relationships between these two variables. Moreover, some dimensions of information-seeking behavior and some aspects of prior knowledge (expertise, familiarity, and past experience) had positive and significant relationships.  相似文献   

Life Cycle Management Considerations of Remotely Sensed Geospatial Data and Documentation for Long Term Preservation     

Mohammad Khayat  Steven J. Kempler 《Journal of Map & Geography Libraries》2015,11(3):271-288

As geospatial missions age, one of the challenges for the usability of data is the availability of relevant and updated metadata with sufficient documentation that can be used by future generations of users to gain knowledge from the original data. Given that remote sensing data undergo many intermediate processing steps, for example, an understanding of the exact algorithms employed and the quality of that data produced could be key considerations for these users. As interest in global climate data is increasing, documentation about older data, their origins, and their provenance are valuable to first-time users attempting to perform historical climate research or comparative analysis of global change. Incomplete or missing documentation could be what stands in the way of a new researcher attempting to use the data. Therefore, preservation of documentation and related metadata is sometimes just as critical as the preservation of the original observational data. The Goddard Earth Sciences–Data and Information Service Center (GES DISC), a NASA Earth science Distributed Active Archive Center (DAAC) that falls under the management structure of the Earth Science Data and Information System (ESDIS), is actively pursuing the preservation of all necessary artifacts needed by future users.

In this article, we will detail the data custodial planning and the data lifecycle process developed for content preservation, and our implementation of a Preservation System to safeguard documents and associated artifacts from legacy (older) missions, as well as detail lessons learned regarding access rights and confidentiality of information issues. We also elaborate on key points that made our preservation effort successful; the primary points being drafting of a governing baseline for historical data preservation from satellite missions and using the historical baseline as a guide to content filtering of what documents to preserve. The Preservation System currently archives documentation content for High Resolution Dynamics Limb Sounder (HIRDLS), Upper Atmosphere Research Satellite (UARS), Total Ozone Mapping Spectrometer (TOMS) mission data, and the 1960s era Nimbus mission. Documentation from other missions like the Tropical Rainfall Measuring Mission (TRMM), the Ozone Monitoring Instrument (OMI), and the Atmospheric Infra-Red Sounder (AIRS) are also slated to be added to this repository, as well as other mission datasets to be preserved at the GES DISC.  相似文献   

Kolkhoung (Pistacia khinjuk) Hull Oil and Kernel Oil as Antioxidative Vegetable Oils with High Oxidative Stability ?and Nutritional Value     

Maryam Asnaashari  Seyed Mohammad Bagher Hashemi  Hamed Mahdavian Mehr  Seyed Hossein Asadi Yousefabad 《Food Technology and Biotechnology》2015,53(1):81-86

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Jones,Christopher (2015) Networked learning. Springer (Berlin) isbn 978‐3‐319‐01934‐5 249 pp £90 boards (ebook £72) http://www.springer.com/us/book/9783319019338          下载免费PDF全文

Mohammad Ali Salmani Nodoushan 《British journal of educational technology : journal of the Council for Educational Technology》2015,46(6):E31-E32

This book is largely about how people connect with each other and with digital technologies, and how this affects their learning. It reviews existing literature on networked learning and describes the role of universities and academics in that approach. Jones's book targets anyone interested in learning technology, and— if you are in that group—I recommend that you borrow a copy for a while. Mohammad Ali Salmani Nodoushan  相似文献   

Teacher empowerment as an important component of job satisfaction: a comparative study of teachers’ perspectives in Al-Farwaniya District,Kuwait     

Wafaa Salem Al-Yaseen  Mohammad Yousef Al-Musaileem 《Compare》2015,45(6):863-885

The present comparative study investigates the perceptions of male and female teachers regarding the relationship between empowerment and job satisfaction. The study aims to look at factors that empower teachers and lead to job satisfaction from teachers’ perspectives. For that purpose, teachers were selected from three educational levels (primary, middle and secondary) in Al-Farwaniya District in the State of Kuwait. A total of 231 teachers from the Al-Farwaniya School District responded to a questionnaire. Both t-test and one-way ANOVA were applied. Data analysis reveals a lack of job empowerment and a high degree of dissatisfaction among teachers. The study concludes with several suggestions including opening up a dialogue with teachers in order to understand their problems and needs and involving them in the process of decision-making and change.  相似文献   

Live-streaming: Time-lapse video evidence of novel streamer formation mechanism and varying viscosity     

Mazeyar Parvinzadeh Gashti  Julien Bellavance  Otini Kroukamp  Gideon Wolfaardt  Seyed Mohammad Taghavi  Jesse Greener 《Biomicrofluidics》2015,9(4)

Time-lapse videos of growing biofilms were analyzed using a background subtraction method, which removed camouflaging effects from the heterogeneous field of view to reveal evidence of streamer formation from optically dense biofilm segments. In addition, quantitative measurements of biofilm velocity and optical density, combined with mathematical modeling, demonstrated that streamer formation occurred from mature, high-viscosity biofilms. We propose a streamer formation mechanism by sudden partial detachment, as opposed to continuous elongation as observed in other microfluidic studies. Additionally, streamer formation occurred in straight microchannels, as opposed to serpentine or pseudo-porous channels, as previously reported.  相似文献   

Three dimensional passivated-electrode insulator-based dielectrophoresis     

Diana Nakidde  Phillip Zellner  Mohammad Mehdi Alemi  Tyler Shake  Yahya Hosseini  Maria V. Riquelme  Amy Pruden  Masoud Agah 《Biomicrofluidics》2015,9(1)

In this study, a 3D passivated-electrode, insulator-based dielectrophoresis microchip (3D πDEP) is presented. This technology combines the benefits of electrode-based DEP, insulator-based DEP, and three dimensional insulating features with the goal of improving trapping efficiency of biological species at low applied signals and fostering wide frequency range operation of the microfluidic device. The 3D πDEP chips were fabricated by making 3D structures in silicon using reactive ion etching. The reusable electrodes are deposited on second glass substrate and then aligned to the microfluidic channel to capacitively couple the electric signal through a 100 μm glass slide. The 3D insulating structures generate high electric field gradients, which ultimately increases the DEP force. To demonstrate the capabilities of 3D πDEP, Staphylococcus aureus was trapped from water samples under varied electrical environments. Trapping efficiencies of 100% were obtained at flow rates as high as 350 μl/h and 70% at flow rates as high as 750 μl/h. Additionally, for live bacteria samples, 100% trapping was demonstrated over a wide frequency range from 50 to 400 kHz with an amplitude applied signal of 200 Vpp. 20% trapping of bacteria was observed at applied voltages as low as 50 Vpp. We demonstrate selective trapping of live and dead bacteria at frequencies ranging from 30 to 60 kHz at 400 Vpp with over 90% of the live bacteria trapped while most of the dead bacteria escape.  相似文献   

Type-2 fuzzy consensus control of nonlinear multi-agent systems: An LMI approach     

Ali Afaghi  Sehraneh Ghaemi  Amir Rikhtehgar Ghiasi  Mohammad Ali Badamchizadeh 《Journal of The Franklin Institute》2021,358(8):4326-4347

This paper considers a class of nonlinear fractional-order multi-agent systems (FOMASs) with time-varying delay and unknown dynamics, and a new robust adaptive control technique is proposed for cooperative control. The unknown nonlinearities of the systems are online approximated by the introduced recurrent general type-2 fuzzy neural network (RGT2FNN). The unknown nonlinear functions are estimated, simultaneously with the control process. In other words, at each sample time the parameters of the proposed RGT2FNNs are updated and then the control signals are generated. In addition to the unknown dynamics, the orders of the fractional systems are also supposed to be unknown. The biogeography-based optimization algorithm (BBO) is extended to estimate the unknown parameters of RGT2FNN and fractional-orders. A LMI based compensator is introduced to guarantee the robustness of the proposed control system. The excellent performance and effectiveness of the suggested method is verified by several simulation examples and it is compared with the other methods. It is confirmed that the introduced cooperative controller results in a desirable performance in the presence of time-varying delay, unknown dynamics, and unknown fractional-orders.  相似文献   

Robust adaptive finite-time stabilization control for a class of nonlinear switched systems based on finite-time disturbance observer     

Mohammad Javad Mirzaei  Ehsan Aslmostafa  Mostafa Asadollahi  Mohammad Ali Badamchizadeh 《Journal of The Franklin Institute》2021,358(7):3332-3352

The problem of adaptive global finite-time stabilization control for a class of nonlinear switched systems in the presence of external perturbations and arbitrary switchings has been addressed in this research study. The proposed scheme has been designed based on a finite-time estimation technique in which during the control procedure, unknown imposed perturbations are accurately estimated by means of the designed finite-time disturbance observer (FTDO). Due to the exact estimation of the external disturbances within a given finite time, the encountered complications and adversities from loss of information in the Lyapunov parameter estimation (LPE) methods have been solved which are caused by the persistent switchings in the system. Furthermore, a new solution for the problem of chattering phenomenon in nonlinear switched systems has been presented by utilizing the designed FTDO, which can counteract the malfunctioning responses of the system caused by external disturbances and unmodeled dynamics. In this paper, an acknowledged class of nonlinear switched systems has been taken into account which is in the general form of canonical structure. In addition, the established design strategy is formulated for the control of perturbed nonlinear switched systems with one and only input and assures that the system states through the finite-time convergence characteristic, reach the equilibrium point of origin. Finally, numerical simulations are carried out on a mass-spring-damper (MSD) dynamical system to indicate advantages and superior efficiency of the suggested method.  相似文献   

Restructuring the educational system in Nepal     

Dibya Deo Bhatt  Mohammad Mohsin 《Prospects》1975,5(1):96-100

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