Off line simulation system of machining processes     

Ibrahim M. Deiab  Stephen C. Veldhuis 《Journal of The Franklin Institute》2007,344(5):565-576

The primary objective for modeling of machining processes is to develop a predictive capability of machining performance in order to facilitate effective planning of machining operations. This capability leads to faster implementation, higher performance, quality at a lower cost. This comes about due to improved selection of machining parameters, optimal fixture design and the avoidance of tool failure. The simulation system presented simultaneously considers the effect of cutter geometry, the cutter's initial position errors, workpiece geometry, machine tool dynamics, and workpiece/fixture system dynamics on the machining process.The integration of all of the above in one model provides an off-line tool to simulate and optimize the machining parameters and the fixture configuration cutting both lead and production time. The modular nature of the simulation system presented allows for the study of many different machining processes. The cutting forces in this system are modeled using a mechanistic approach. NURBS curves and surfaces are utilized for the geometric modeling and simulation of the machining process. While a finite element method is used to model and analyze the workpiece/fixture dynamics. Two case studies are presented to demonstrate the practical application of the presented simulation. The first case presents the optimization of the fixture configuration of a generic automotive component. While the second case presents the results of simulations performed on a novel mill/grind machining process. This process is a combination of face milling and grinding in one operation. Some simulated results are presented along with experimental validation.  相似文献   

Optimization of fuzzy model using genetic algorithm for process control application     

Rubiyah Yusof  Ribhan Zafira Abdul Rahman  Marzuki Khalid  Mohd Faisal Ibrahim 《Journal of The Franklin Institute》2011,348(7):1717-1737

A technique for the modeling of nonlinear control processes using fuzzy modeling approach based on the Takagi-Sugeno fuzzy model with a combination of genetic algorithm and recursive least square is proposed. This paper discusses the identification of the parameters at the antecedent and consequent parts of the fuzzy model. For the antecedent fuzzy parameters, genetic algorithm is used to tune them while at the consequent part, recursive least squares approach is used to identify the system parameters. This approach is applied to a process control rig with three subsystems: a heating element, a heat exchanger and a compartment tank. Experimental results show that the proposed approach provides better modeling when compared with Takagi Sugeno fuzzy modeling technique and the linear modeling approach.  相似文献   

Factors affecting attitudes and intentions towards knowledge sharing in the Dubai Police Force     

Ibrahim Seba  Jennifer Rowley  Sian Lambert 《International Journal of Information Management》2012

This study contributes to the limited research base on knowledge sharing in public sector organisations, specifically police forces, and organisations in the Middle East through a case study investigation into the factors that affect knowledge sharing in the Dubai Police Force. A questionnaire-based survey was conducted with staff in key departments in the Dubai Police Force. Informed by the literature and by interviews conducted in a previous phase, the core of the questionnaire was a bank of Likert-style questions covering the dependent variables intention to knowledge share, and attitude towards knowledge sharing, and the independent variables, trust, organisational structure, leadership, reward, time, and information technology. Data was analysed using structured equation modelling, in order to test the measurement model using confirmatory factor analysis, and to test the structural model. The structural model suggests a strong relationship between attitude to knowledge sharing, and intention to share knowledge. Hypotheses regarding the influence of leadership, trust, organisational structure, time, and information technology on attitude to knowledge sharing were upheld. Rewards did not to influence attitude to knowledge sharing. Recommendations are offered for practice and further research.  相似文献   

Evaluating research performance of research institutes within Malaysian universities: an alternative assessment framework     

Ta  Goh Choo  Halim  Sharina Abdul  Azman  Norzaini  Komoo  Ibrahim  Mokhtar  Mazlin 《Tertiary Education and Management》2021,27(4):331-349

Tertiary Education and Management - Evaluation of research performance has significantly increased in importance, particularly in many emerging higher education systems. In Malaysia, the Malaysian...  相似文献   

Optimal sizing of piezo-actuators for minimum-deflection design of frames under uncertain loads     

Sarp Adali  Ibrahim S. Sadek  James M. Sloss 《Journal of The Franklin Institute》2007,344(5):698-710

Optimal piezo-actuator sizes and locations for a frame structure under bending load uncertainty are determined with the objective of minimizing the deflection under worst case of loading. The bending moments generated by the piezo-actuators are used for deflection control, i.e., to minimize the maximum deflection. The frame is subjected to a tip load which lies in an uncertainty domain with regard to its magnitude and direction. The specific uncertain loading studied in the present paper involves a load of given magnitude but of unknown direction, which should be determined to produce the highest deflection. The worst case of loading depends on the size and location of the actuators leading to a nested problem of optimization (design) and anti-optimization (uncertainty problem). Results are given for deterministic and uncertain loading conditions.  相似文献   

Cross-cultural counseling and psychotherapy: An existential-psychological approach     

Farah A. Ibrahim 《International journal for the advancement of counseling》1984,7(3):159-169

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Evaluating students experiences using a virtual learning environment: satisfaction and preferences     

Hamutoglu  Nazire Burcin  Gemikonakli  Orhan  Duman  Ibrahim  Kirksekiz  Ali  Kiyici  Mubin 《Educational technology research and development : ETR & D》2020,68(1):437-462

Educational technology research and development - Virtual learning environments (VLEs) are web-based software systems that enable students to interact with their teachers and classmates, access...  相似文献   

The need for Saudi faculty and the media for instruction in Saudi Arabian universities     

Ibrahim A. Al-Shami 《Higher Education》1983,12(3):285-296

The past three decades have witnessed rapid growth and expansion in higher education. This study attempts to throw some light on the extent to which Saudi universities have attracted national faculty to match the level of increase in students' enrollment. Another important issue which is discussed in this article is the extent to which Arabic, the national language, is used as a medium of instruction in Saudi universities.Saudi government publications, as well as some international statistical documents, have been utilized in evaluating the possibility of achieving a national faculty and the possibility of using Arabic as the medium of instruction. Practical suggestions are offered to help the higher educational system in Saudi Arabia overcome some of the current problems.  相似文献   

Preparation of counsellors in Pakistan: A proposed model     

Iffat Almas  Farah A Ibrahim 《International journal for the advancement of counseling》1985,8(4):323-327

Summary This paper proposes a comprehensive counselor preparation model within the philosophical and religious beliefs of Pakistan. A series of courses are presented to provide a cohesive and comprehensive body of knowledge to counselors to work in educational, business, health and community settings. The proposed curriculum reflects the philosophy, beliefs, and values of the country in terms of human development, life/career and educational planning. Furthermore, this model proposes a pre-service preparation to replace the current in-service preparation model for counselors.Paper presented at the Tenth International Round Table for the Advancement of Counselling (Working Group: The Training of Counsellors), University of City-Dorigny. University of Lausanne, Lausanne, Switzerland, September 5–9, 1982.  相似文献   

Learning sorting algorithms through visualization construction     

Ibrahim Cetin  Christine Andrews-Larson 《Computer Science Education》2016,26(1):27-43

Recent increased interest in computational thinking poses an important question to researchers: What are the best ways to teach fundamental computing concepts to students? Visualization is suggested as one way of supporting student learning. This mixed-method study aimed to (i) examine the effect of instruction in which students constructed visualizations on students’ programming achievement and students’ attitudes toward computer programming, and (ii) explore how this kind of instruction supports students’ learning according to their self-reported experiences in the course. The study was conducted with 58 pre-service teachers who were enrolled in their second programming class. They expect to teach information technology and computing-related courses at the primary and secondary levels. An embedded experimental model was utilized as a research design. Students in the experimental group were given instruction that required students to construct visualizations related to sorting, whereas students in the control group viewed pre-made visualizations. After the instructional intervention, eight students from each group were selected for semi-structured interviews. The results showed that the intervention based on visualization construction resulted in significantly better acquisition of sorting concepts. However, there was no significant difference between the groups with respect to students’ attitudes toward computer programming. Qualitative data analysis indicated that students in the experimental group constructed necessary abstractions through their engagement in visualization construction activities. The authors of this study argue that the students’ active engagement in the visualization construction activities explains only one side of students’ success. The other side can be explained through the instructional approach, constructionism in this case, used to design instruction. The conclusions and implications of this study can be used by researchers and instructors dealing with computational thinking.  相似文献