Mechanics-Based Modeling Approach for Rapid Prediction of Low Velocity Impact Damage in Composite Laminates

A mechanics-based modeling approach is developed to rapidly predict damage in polymer matrix composites resulting from a low velocity impact event. The approach is incorporated into a computer code that provides an efficient means to assess the damage resistance for a range of material systems, layup configurations, and impact scenarios. It is envisioned that the developed approach will aid in early design and analysis of composite structures where sizing and layup decisions must be made, and evaluating the feasibility of a large number of laminate configurations using numerical approaches such as finite element analysis (FEA) is prohibitively expensive. Therefore, the goal of the modeling approach is to predict the impact damage size given the laminate configuration and impact scenario. This information can then be used to determine the residual strength of the material. To be useful in such a context, the tool is designed to run quickly (<2 minutes) to allow a large number of design cases to be investigated. The results presented demonstrate that the model is capable of efficiently predicting low velocity impact damage size, shape, and location within an acceptable accuracy suitable for preliminary design and analysis of composite structures

The Need For Participation In Open And Distance Education: The Open University Malaysia Experience

This paper provides an overview of adult learner participation in open and distance education by focusing participation needs based on selected socio-demographic variables such as age, years of working experience and monthly income. The related study involved a sample of 454 Open University Malaysia students from a number of learning centres located in different parts of the country. The study found that adult learners are generally below the age of 39, relatively not affluent, have less than 20 years of work experience and have a high need for participation. The highest need is professional advancement, followed closely by cognitive interest, and communication improvement while the lowest reported need is escapism/social stimulation. Age and work experience exhibited negative regression coefficients, indicating inverse associations with participation need. These results are comparable to the findings of previous research on the role of age, work experience and monthly income as factors determining participation in adult higher education

The conduct of science practical for working adults in an ODL setting

Laboratory practical play an important role in the teaching and learning of science and engineering courses. They are indispensable in elucidating and verifying the fundamental scientific principles taught in the class-room. By reinforcing the fundamental concepts and laws through laboratory experiments, practical sessions facilitate the learning process and widen the student’s understanding of science and engineering. Achievement of scientific proficiency cannot be achieved without laboratory practical experience. Besides, they also promote critical skills such as report writing, data handling, and the ability to interpret and evaluate evidence. In this paper, we review the science practical sessions for working adults in the context of open and distance learning. We share our experiences and discuss how the practical science sessions were conducted successfully nationwide to cater to the needs of adult learners enrolled in the Bachelor of Education (Science) programme at Open University Malaysia. Besides this, we will also elaborate on some of the pertinent issues and challenges that were faced in conducting these practical sessions over the last 8 years. (Abstract by authors

An Energy Efficient and High Speed Image Compression System Using Stationary Wavelet Transform

Image compression is one of the interesting domains nowadays in all areas of research. Everybody working with huge of amount of data in their daily life. In-order to deal with such huge amount of data, there is a need to store and compress the data. So there is a need to develop a system to compress and store the data. JPEG 2000 is a system to achieve this object. In this paper an area efficient and high speed JPEG2000 architecture has been developed to compress the image data. To implement JPEG2000 system, here a transform called stationary wavelet transform has been used. Stationary wavelet transform reduces the bottlenecks existing in the wavelet transform. Stationary wavelet transform avoids the problem of invariance-translation of the already existing discrete wavelet transform. The proposed stationary wavelet transform based JPEG2000 improves the speed and efficiency of power compared to the discrete wavelet transform based JPEG2000. Many image compression applications such as tele-medicine, satellite imaging, medical imaging require high-speed, low power compression techniques with small chip area. This paper has an analysis on the speed of JPEG2000 using stationary wavelet transform and it will be compared theoretically and practically with the JPEG2000 using discrete wavelet transform. The amount of information missing in the test image usually been very small when compared to the DWT based JPEG2000.The MSE and PSNR values proved to be better when compared to the DWT based JPEG2000. The proposed SWT based JPEG2000 compresses and decompresses the image at a faster rate than the DWT based JPEG2000.Finally the design will be implemented in XILINX Virtex-4 FPGA Kit. .The power consumption of the proposed method proved to be 290mW compared to other types of compression techniques

Comparative Study of PID Based VMC and Fuzzy Logic Controllers for Flyback Converter

In this paper performance of flyback converter by using PID controller and Fuzzy controller are studied, compared and analyzed. The above study is done for 200W, 230V A.C input 48V DC output. Design of fuzzy controller is based on the heuristic knowledge of converter behaviour, and tuning of fuzzy inference requires some expertise to minimize unproductive trial and error. The design of PID control is based on the frequency response of the converter. For the DC-DC converters, the performance of the fuzzy controller was superior in some respects to that of the PID controller. The fuzzy controller is easily to develop, they cover a wide range of operating conditions, and they are more readily customizable in natural language terms. Simulation is done in Matlab environment to show the performance variations of above mentioned converters using both Fuzzy & PID controllers

Comparison between simultaneous versus staged bilateral total knee arthroplasty: a prospective, randomized, controlled study

Background: Bilateral total knee arthroplasty (TKA) is a common procedure nowadays. Although, staging of surgery is a subject of debate. We conducted a study to compare safety and functional outcomes of simultaneous and staged bilateral TKA.Methods: Our study includes total 70 patients of symptomatic severe bilateral osteoarthritis, underwent simultaneous or staged bilateral TKA during 2015 to 2019. 35 patients were randomly allotted for each procedure. The postoperative evaluations were done according to Knee Society Score at one, three, six and 12 months and yearly thereafter for 2 years following a simultaneous bilateral TKA (group A) and the second procedure in the staged bilateral TKA (group B).  In the staged group, the patients were followed at monthly intervals until the second procedure. The categorical variables were statistically significant when p value &lt;0.05.Results: As compared to staged procedure (group B), estimated blood loss was significantly less in simultaneous TKA (group A). Although, blood transfusion rate was significantly high in group A. The length of hospital stay was significantly shorter in group A. Overall complication rate (inpatient and/or 90 days readmission) was not significantly higher in group A. Knee infection rate was significantly lower in simultaneous TKA group. There was no revision of surgery and no mortality in any of our study group within 2 years of follow-up.Conclusions: Simultaneous bilateral TKA is safe and cost-effective procedure with acceptable complication rates for bilateral symptomatic end stage knee osteoarthritis

Performance Assessment of Polyphase Sequences Using Cyclic Algorithm

Polyphase Sequences (known as P1, P2, Px, Frank) exist for a square integer length with good auto correlation properties are helpful in the several applications. Unlike the Barker and Binary Sequences which exist for certain length and exhibits a maximum of two digit merit factor. The Integrated Sidelobe level (ISL) is often used to define excellence of the autocorrelation properties of given Polyphase sequence. In this paper, we present the application of Cyclic Algorithm named CA which minimizes the ISL (Integrated Sidelobe Level) related metric which in turn improve the Merit factor to a greater extent is main thing in applications like RADAR, SONAR and communications. To illustrate the performance of the P1, P2, Px, Frank sequences when cyclic Algorithm is applied. we presented a number of examples for integer lengths. CA(Px) sequence exhibits the good Merit Factor among all the Polyphase sequences that are considered