Feature recognition & tool path generation for 5 axis STEP-NC machining of free form / irregular contoured surfaces

This research paper presents a five step algorithm to generate tool paths for machining Free form / Irregular Contoured Surface(s) (FICS) by adopting STEP-NC (AP-238) format. In the first step, a parametrized CAD model with FICS is created or imported in UG-NX6.0 CAD package. The second step recognizes the features and calculates a Closeness Index (CI) by comparing them with the B-Splines / Bezier surfaces. The third step utilizes the CI and extracts the necessary data to formulate the blending functions for identified features. In the fourth step Z-level 5 axis tool paths are generated by adopting flat and ball end mill cutters. Finally, in the fifth step, tool paths are integrated with STEP-NC format and validated. All these steps are discussed and explained through a validated industrial component

Limitations and opportunities for wire length prediction in gigascale integration

Wires have become a major source of bottleneck in current VLSI designs, and wire length prediction is therefore essential to overcome these bottlenecks. Wire length prediction is broadly classified into two types: macroscopic prediction, which is the prediction of wire length distribution, and microscopic prediction, which is the prediction of individual wire lengths. The objective of this thesis is to develop a clear understanding of limitations to both macroscopic and microscopic a priori, post-placement, pre-routing wire length predictions, and thereby develop better wire length prediction models. Investigations carried out to understand the limitations to macroscopic prediction reveal that, in a given design (i) the variability of the wire length distribution increases with length and (ii) the use of Rent s rule with a constant Rent s exponent p, to calculate the terminal count of a given block size, limits the accuracy of the results from a macroscopic model. Therefore, a new model for the parameter p is developed to more accurately reflect the terminal count of a given block size in placement, and using this, a new more accurate macroscopic model is developed. In addition, a model to predict the variability is also incorporated into the macroscopic model. Studies to understand limitations to microscopic prediction reveal that (i) only a fraction of the wires in a given design are predictable, and these are mostly from shorter nets with smaller degrees and (ii) the current microscopic prediction models are built based on the assumption that a single metric could be used to accurately predict the individual length of all the wires in a design. In this thesis, an alternative microscopic model is developed for the predicting the shorter wires based on a hypothesis that there are multiple metrics that influence the length of the wires. Three different metrics are developed and fitted into a heuristic classification tree framework to provide a unified and more accurate microscopic model.Ph.D.Committee Chair: Dr. Jeff Davis; Committee Member: Dr. James D. Meindl; Committee Member: Dr. Paul Kohl; Committee Member: Dr. Scott Wills; Committee Member: Dr. Sung Kyu Li

A Study Of Small Non-Coding RNAs Of Salmonella Enterica Subspecies Enterica Serovar Typhi In Biofilm Development

Salmonella Typhi adalah Gram-negatif bakteria dan patogen khusus bagi manusia yang menyebabkan demam kepialu. Ia merupakan masalah kesihatan yang serius di negara-negara yang kurang membangun dan sedang membangun termasuk Malaysia Salmonella Typhi is a Gram-negative bacteria and human-specific pathogen which causes Typhoid fever. It is a major health problem in under-developed and developing countries including Malaysi

Integration of CAD/tool path data for 5-axis STEP-NC machining of free form/irrregular controured surfaces.

This research paper presents the work on feature recognition, tool path data generation and integration with STEP-NC (AP-238 format) for features having Free form/Irregular Contoured Surfaces(s) (FICS). Initially, the FICS features are modelled/imported in UG CAD package and a closeness index is generated. This is done by comparing the FICS features with basic B-Spines/Bezier curves/surfaces. Then blending functions are caculated by adopting convolution theorem. Based on the blending functions, contour offsett tool paths are generated and simulated for 5 axis milling environment. Finally, the tool path (CL) data is integrated with STEP-NC (AP-238) format. The tool path algorithm and STEP-NC data is tested with various industrial parts through an automated UFUNC plugin

An Exploration of the Feasibility of FPGA Implementation of Face Recognition Using Eigenfaces

Biometric identification has been a major force since 1990\u27s. There are different types of approaches for it; one of the most significant approaches is face recognition. Over the past two decades, face recognition techniques have improved significantly, the main focus being the development of efficient algorithm. The state of art algorithms with good recognition rate are implemented using programming languages such as C++, JAVA and MATLAB, these requires a fast and computationally efficient hardware such as workstations. If the face recognition algorithms could be written in a Hardware Description Language, they could be implemented in an FPGA. In this thesis we have choose the eigenfaces algorithm, since it is simple and very efficient, this algorithm is first solved analytically, and then the architecture is designed for FPGA implementation. We then develop the Verilog module for each of these modules and test their functionality using a Verilog Simulator and finally we discuss the feasibility of FPGA implementation. Implementing the face recognition technology in an FPGA would mean that they would require relatively low power and the size is drastically reduced when compared to the workstations. They would also be much faster and efficient, since they are specifically designed for face recognition

A STUDY OF B. ED. STUDENT TEACHERS\u27 ATTITUDES TOWARDS DIGITAL LIBRARIES IN MADURAI DISTRICT.

A normative survey was undertaken to determine the attitudes of B.Ed. student teachers concerning the Madurai district\u27s digital library. A sample of 200 students and teachers from various colleges in the Madurai area of Tamil Nadu. The Digital Library Attitude Scale was employed in this study as a tool (DLAS). Statistical approaches such as percentage analysis, mean, and standard deviation were used to analyse the data. . In terms of gender, the findings show that there is a considerable disparity between rural and urban students\u27 attitudes toward digital libraries. When comparing male and female students in their Digital library Attitude, female students (117.96) had a greater Digital library Attitude than male students (M=106.32). The results demonstrate that there is a considerable difference between the two groups. The findings demonstrate that there is a considerable variation in Digital library Attitude with respect to locality between rural and urban students. When comparing rural and urban students in terms of their Digital library Attitude, urban students (120.96) outperform rural students (M=107.96) in terms of locality. In terms of marital status, there is a substantial difference between married and unmarried students in their Digital library Attitude. When comparing married and unmarried students\u27 Digital library Attitude, single students (116.87) had a greater degree of Digital library Attitude than married students (M=107.73).

Case Study: Analysis of Stimulated Reservoir Volume Properties Through Application of Embedded Discrete Fracture Modelling

Hydraulic fracture modelling has always been a challenging task due to the complex network of fractures that have been created in shale and unconventional reservoirs and its associated uncertainty. Primitive modelling of stimulated reservoir volume typically assumes extreme simplifications to hydraulic fractures that do not accurately model the complex dynamic properties of fracture networks. This typically results in large differences in Estimated Ultimate Recovery (EUR) predictions, rendering the history matching workflow less practicable. By applying Embedded Discrete Fracture Modelling (EDFM) in fracture modelling workflow, complex fracture networks can be explicitly modelled without a high computational cost and without the need for any fracture upscaling workflows. The proposed workflow for given field data exhibits the efficiency of the Embedded Discrete Fracture modelling workflow. The results obtained also showcases the estimated fracture network parameters and its dynamic properties for the field case. The fracture network parameters obtained are also compared against similar cases from literature. The results obtained from EDFM approach is compared against a uniform Stimulated Reservoir Volume (SRV) approach that uses porosity and permeability multipliers and the advantages of EDFM workflow are observed

Radiation damage of polymers in ultrasonic fields

Radiation damage has always been a topic of great interest in various fields of sciences. In this work, an attempt is made to probe into the effect of sub-threshold ultrasonic waves on the radiation damage created by irradiation of deuterons in polymer samples wherein the polymer samples act as model systems. Two equal volumes of radiation damage were produced in a single polymer sample wherein a standing wave of ultrasound was introduced into one. Three polymers namely, Polycarbonate, Polymethylmethacrylate and Polyvinyl chloride were used in this work. Four independent techniques were used to analyze the irradiated samples and visualize the radiation damage. Interferometric measurements give a measure of the refractive index modulation in the irradiated sample. Polymers, being transparent, do not absorb in the visible region of the electromagnetic spectrum. UV-Vis absorption spectroscopy shows absorption peaks in the visible region in irradiated polymer samples. Ion irradiation causes coloration of polymers. The light microscope is used to measure the absorption of white light by the irradiated polymers. Positron annihilation spectroscopy is used to obtain a measure of the open volume created by irradiation in polymers. A comparison between the irradiated region and the region exposed to ultrasonic waves simultaneously with irradiation in a polymer sample shows the polymer specific influence of the ultrasonic standing wave.</p

Management of Tracheo Bronchial Foreign Bodies in Children – A Retrospective Study of series of 50 cases

Abstract             This retrospective study of series of 50 cases of inhaled foreign bodies in pediatric patients in one year, deals with which the cases presented and the types of foreign body removed. Diagnostic flexible bronchoscopy aid in the diagnosis of unsuspected foreign body aspiration, or with doubtful history of foreign body aspiration without physical or X-ray signs and can proceed with definitive treatment in the same preparation without delay. Tracheotomy is indicated for foreign body that cannot be removed through glottis. A team work of anesthetist, endoscopist, and assistants are essential to ensure the safety of procedure with no compromise on availability of instruments.  Key words Tracheo Bronchial · Foreign Bodies · Children · Management