A Phenomenological Investigation of African American Counselor Education Students' Challenging Experiences     

Malik S. Henfield  Hongryun Woo  Ahmad Washington 《Counselor Education & Supervision》2013,52(2):122-136

This study explored 11 African American doctoral students’ perceptions of challenging experiences in counselor education programs. The authors identified the following themes using critical race theory: feelings of isolation, peer disconnection, and faculty misunderstandings and disrespect. Implications for counselor education programs and policies are discussed.  相似文献   

Adaptive T–S fuzzy controller using reinforcement learning based on Lyapunov stability     

A. Aziz Khater  Ahmad M. El-Nagar  Mohammad El-Bardini  Nabila M. El-Rabaie 《Journal of The Franklin Institute》2018,355(14):6390-6415

In this paper, an adaptive Takagi–Sugeno (T–S) fuzzy controller based on reinforcement learning for controlling the nonlinear dynamical systems is proposed. The parameters of the T–S fuzzy system are learned using the reinforcement learning based on the actor-critic method. This on-line learning algorithm improves the controller performance over the time, which it learns from its own faults through the reinforcement signal from the external environment and tries to reinforce the T–S fuzzy system parameters to converge. The updating parameters are developed using the Lyapunov stability criterion. The proposed controller is faster in learning than the T–S fuzzy that parameters learned using the gradient descent method under the same conditions. Moreover, it is able to handle the load changes and the system uncertainties. The test is carried out based on two mathematical models. In addition, the proposed controller is applied practically for controlling a direct current (DC) shunt machine. The results indicate that the response of the proposed controller has a good performance compared with other controllers.  相似文献   

Probabilistic fuzzy logic controller for uncertain nonlinear systems     

Omar Shaheen  Ahmad M. El-Nagar  Mohammad El-Bardini  Nabila M. El-Rabaie 《Journal of The Franklin Institute》2018,355(3):1088-1106

This paper proposes a probabilistic fuzzy proportional - integral (PFPI) controller for controlling uncertain nonlinear systems. Firstly, the probabilistic fuzzy logic system (PFLS) improves the capability of the ordinary fuzzy logic system (FLS) to overcome various uncertainties in the controlled dynamical systems by integrating the probability method into the fuzzy logic system. Moreover, the input/output relationship for the proposed PFPI controller is derived. The resulting structure is equivalent to nonlinear PI controller and the equivalent gains for the proposed PFPI controller are a nonlinear function of input variables. These gains are changed as the input variables changed. The sufficient conditions for the proposed PFPI controller, which achieve the bounded-input bounded-output (BIBO) stability are obtained based on the small gain theorem. Finally, the obtained results indicate that the PFPI controller is able to reduce the effect of the system uncertainties compared with the fuzzy PI (FPI) controller.  相似文献   

The impact of organizational factors on management information system success: An investigation in the Iran's agricultural extension providers     

Abdolmotalleb Rezaei  Ali Asadi  Ahmad Rezvanfar  Hajar Hassanshahi 《International Information and Library Review》2009,41(3):163-172

Information system success has been widely discussed in the past two decades. As systems and technologies are being improved and developed, discussions on their effectiveness and evaluation on their success have been continuously debated by researchers, scholars and practitioners throughout the years. Besides the major concern of IS effectiveness, factors influencing IS effectiveness are also important. One of these factors is the organizational factor. Using perceptual measures, this study aims to investigate the influence of organizational factors on MIS success. Survey questionnaires were gathered from 132 Extension Managers from Iran's Agricultural Extension Providers. Seven items were identified to influence MIS success. They are IS department structure, top management support, management style, managerial IT knowledge, goal alignment, resources allocation and IS infrastructure. The study also identified five MIS success dimensions; systems quality, information quality, perceived Ease of use, organizational impact and individual impact. The study found that the MIS success variables are significantly and highly correlated. The study also found all the organizational factors are significantly correlated to the five IS success factors investigated; the system quality, information quality, perceived ease of use, organizational impact and individual impact. Multiple regression analyses also found goal alignment as the highest predictor of IS success, followed by IS department structure, IS infrastructure and management style.  相似文献   

试析维吾尔族人生礼仪的文化内涵   总被引：1，自引：0，他引：1  

卡沙依丁·艾合买提 《喀什师范学院学报》2009,30(4):36-39

对维吾尔族人生礼仪作简要的介绍,进而分析其中所体现出的维吾尔人的社会伦理观、吉祥数崇拜观、生死观念,以及贯穿于各人生礼仪之中的人际馈赠关系。  相似文献   

Characterization of wall dispersive and attenuative effects on UWB radar signals     

Ali Muqaibel  Ahmad Safaai-Jazi 《Journal of The Franklin Institute》2008,345(6):640-658

This paper addresses the potentials of ultra-wideband (UWB) through-wall imaging radars compared with conventional narrowband systems. The challenges that limit the utilization of high precision UWB systems are examined with the aim of mitigating them. These challenges include multi-path, pulse dispersion, and antenna effects on the pulse shape due to angles of transmission and arrival. The propagation of UWB signals through walls is a crucial factor in determining the success of UWB radar technology. UWB signals, when propagating through walls, not only suffer attenuation but also distortion due to dispersive properties of the walls. This paper examines time- and frequency-domain techniques for measuring the electromagnetic properties of construction materials in the UWB frequency range. The measured parameters provide valuable insights in appreciating the capabilities and limitations of the UWB technology. Special attention is paid to time gating as a mean to extract the direct-path signal from the multi-path components. Both single-pass and multi-pass models are discussed. Multi-pass models account for the multiple reflections within the wall while the single-pass model assumes the possibility of gating out a single transmission. The partition-dependent narrowband propagation model is modified to account for the ultra-wide bandwidth of the signal. The paper illustrates the application of the modified model in indoor environments. The modified model is helpful in estimating the link power budget. It is also useful in studying the performance of UWB systems for indoor communication and positioning applications.  相似文献   

Adjustments of serum lactate dehydrogenase isoenzymes and their significance in monitoring the treatment in patients with tubercular pyothorax     

Riaz Ahmad  Mumtaz Alam  M. Faisal Siddiqui  Absar-ul Hasnain 《Indian journal of clinical biochemistry : IJCB》2008,23(2):181-185

The adjustments and diagnostic significance of polyacrylamide gel electrophoretic (PAGE) profiles of lactate dehydrogenase isoenzymes (LDH: 1.1.1.27) was evaluated in the sera and pleural fluid of patients with tubercular pyothorax. Sera and pleural fluid samples were randomly collected from 72 and 18 patients respectively at two different timings; first, when patients were admitted to the Hospital and second, after an intensive phase of treatment. Sera of 20 healthy individuals served as control. Our results demonstrate significant differences in sera LDH (sLDH) and pleural fluid LDH (pfLDH) isoenzymes. In patients the order of LDH isoenzyme in sera and pleural fluid followed: LDH−5>−4>−2>−3>−1 and LDH-5>−4>−3>−2>−1 respectively. The ranking of activity levels in control was LDH−2>−1>−3>−5>−4. In the second phase of sampling from 31 patients, values of sLDH isoenzymes showed recovery and resembled profiles of controls. Therefore, the sLDH zymograms of patients can be used as the prognostic marker, since they tend to reach the normal level during recovery signifying the effect of chemotherapy in hospitalized patients. Moreover, according to the present findings on LDH-PAGE profiles, the levels of LDH-5 and-4 rise in pyothorax patients significantly (P<0.05). This elevation along with the rise in total LDH activity may, therefore, be used in the diagnosis and monitoring of tubercular pyothorax.  相似文献   

Orthogonal Polynomials and Padé Approximation     

Faiz Ahmad 《上海大学学报(英文版)》1998,(2)

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＰａｄéａｐｐｒｏｘｉｍａｔｉｏｎｉｓａｔｙｐｅｏｆｒａｔｉｏｎａｌｆｒａｃｔｉｏｎａｐｐｒｏｘｉｍａｔｉｏｎｔｏａｆｕｎｃｔｉｏｎ．Ｌｅｔｆｂｅｒｅｐｒｅｓｅｎｔｅｄｂｙａｐｏｗｅｒｓｅｒｉｅｓｆ（ｘ）＝∑∞ｉ＝０ｃ...  相似文献   

Interpreting Cues of Goodness: Thin Sliced Judgment of Malaysians and Chinese towards Political Leaders     

Madiha A. Hashmi  Ezhar Tamam  Moniza Waheed  Abdul Muati Ahmad 《Journal of Intercultural Communication Research》2016,45(5):419-436

Thin slice studies have demonstrated that quick personality inferences of unknown others can be made fairly accurately. Utilizing focus group interviews, the current study examines thin sliced judgments and perceptions of six leaders in the context of goodness. Findings revealed that perceivers were able to form relatively accurate impressions of some leaders based on brief glimpses of nonverbal footage. Across all groups (Malaysian and Chinese) paralinguistic cues, dynamic cues and static cues were instrumental in the formation of positive perceptions of leaders in the context of goodness. These findings have implications for the areas of nonverbal behaviour, political communication, and personality judgement.  相似文献   

Conversational functions for knowledge building communities: a coding scheme for online interactions     

Stefano Cacciamani  Vittore Perrucci  Ahmad Khanlari 《Educational technology research and development : ETR & D》2018,66(6):1529-1546

The aim of this study was to develop a coding scheme rooted in the Knowledge Building model, named Conversational Functions for Knowledge Building (CF4KB), to analyze students’ interactions in an online undergraduate course. In order to develop the coding scheme, we analyzed students discourse and identified the kinds of “Conversational Functions” students performed. Connecting these identified functions with Knowledge Building Model principles, we developed the coding scheme to analyze knowledge building [In the present article, we used “Knowledge Building” to indicate the theoretical model and “knowledge building” to refer to the activity of the community members.] activity. Applying the resulting coding scheme, two independent judges coded 186 messages posted into Knowledge Forum by 26 students (5 men and 21 women) attending the online course of Educational Psychology at University of Valle d’Aosta to develop the coding scheme. The inter-coder agreements obtained were 77.3 and 78.0%, with Cohen’s K?=?0.68 and 0.66, respectively for Specific and Global Conversational Functions level. The theoretical implications and possible uses in different contexts for future inquiry of this instrument are discussed.  相似文献