Research
Experimental Study and Verification of Wear for Glass Reinforced Polymer using ANSYS
The current design/manufacturing field looking for value added/engineering projects. In this study, an attempt has been aimed to predict the wear of the sliding surfaces in the development stage it self which will be results in the increase of durability of the components. The wear for a polymer-polymer sliding surface contact in dry condition can be obtained by creating simulation. There are two inputs required for determining the wear volume loss over its usage time. One is the nodal pressure value at the contact area for small sliding steps which can be calculated by subjecting the geometrical model to the finite element analysis. ANSYS was used as finite element tool. Another one is the friction coefficient which can be obtained by custom designed experiments. For the calculation of friction coefficient, prototype to be subjected to unlubricated pin-on-disc experimental setup. The wear rate can be calculated by graph by plotting between pressure and cycles. Swiveling of mirror over the base resulted in the wear. By the above techniques, the wear loss and reliability of the rear mirror can be predicted.
Acceleration Analysis of 3DOF Parallel Manipulators
This paper presents a new approach to the velocity and acceleration analyses 3DOF parallel manipulators. Building on the definition of the „acceleration motor‟, the forward and inverse velocity and acceleration equations are formulated such that the relevant analysis can be integrated under a unified framework that is based on the generalized Jacobian. A new Hessian matrix of serial kinematic chains (or limbs) is developed in an explicit and compact form using Lie brackets. This idea is then extended to cover parallel manipulators by considering the loop closure constraints. A 3- PRS parallel manipulator with coupled translational and rotational motion capabilities is analyzed to illustrate the generality and effectiveness of this approach.
Total Productive Maintenance: A Case Study in Manufacturing Industry
The purpose of this paper is to evaluate the contributions of total productive maintenance (TPM) initiatives towards improving manufacturing performance in Ethiopian malt manufacturing industry. The correlations between various TPM implementation dimensions and manufacturing performance improvements have been evaluated and validated by employing overall equipment effectiveness (OEE) in boiler plant. The research focuses upon the significant contributions of TPM implementation success factors like top management leadership and involvement, traditional maintenance practices and holistic TPM implementation initiatives, towards affecting improvements in manufacturing performance in the Ethiopian industry. The study establishes that focused TPM implementation over a reasonable time period can strategically contribute towards realization of significant manufacturing performance enhancements. The study highlights the strong potential of TPM implementation initiatives in affecting organizational performance improvements. The achievements of Ethiopian manufacturing organizations through proactive TPM initiatives have been evaluated and critical TPM success factors identified for enhancing the effectiveness of TPM implementation programs in the Ethiopian context.
Supplier Selection Using MCDM Method in TV Manufacturing Organization
The aim of this study was to provide an analytical tool to evaluate and select the best supplier(s)/vendor(s) in fuzzy environment for Television (TV) manufacturing organization. A hierarchy through which decision makers can bring about a comparison among the suppliers was worked out and software for the same was developed. The methodology for selection was based upon multiple criteria decision making/multiple attribute decision making (MCDM/MADM) method using technique for order preference by similarity to ideal solution (TOPSIS). MCDM approach and application of TOPSIS proved to be a powerful technique for rapid, performance evaluation, comparative assessment and selection of supplier(s). Biasness in decision making process was avoided using weights for DM’s based on their proficiency in the problem under consideration. The suppliers were evaluated and selected on the basis of criteria/attributes (quality, delivery, price, and suggestion acceptance) and weights were assigned (0.5, 0.3, 0.1, and 0.1) to them. The ranking/selection order of ten suppliers (alternatives) was determined as C4, C5, C10, C7, C2, C6, C1, C8, C9, and C3. Although the study concentrates on TV manufacturing organization, however the methodology can be adopted by any organization if the criteria and alternatives are clearly defined. Results have provided valuable suggestions to suppliers on how to improve each criterion so that they could bridge the gap between actual and aspired performance values in the future. The decision-aiding software was implemented in C language to automate the supplier(s) selection process.
Evaluation on BPR Implementation in Ethiopian Higher Education Institutions
This paper analyzes business process re-engineering (BPR) implementation at Ethiopian higher education institutions (EHEI’s) i.e., Mekelle University, Mekelle, and Aksum University, Aksum. It investigates the current status and effectiveness of BPR implementations at the EHEI’s. It reviews the literature relating to the hard and soft factors that cause success and failure for BPR implementations, classifies these factors into subgroups, and identifies critical success and failure factors. Finally, it explains how these factors influence the process of BPR implementation in the higher institutions. Primary data were collected by means of survey questionnaires from academic staff members and interviews with the academics core process owners. One hundred sixty survey questionnaires were distributed to Mekelle (110) and Aksum (50) universities. All the questionnaires were filled and properly received from both universities. The respondents for the survey were all academic staff members from all departments and posts (technical assistant, graduate assistant, assistant lecturer, lecturers and professors). The findings of the research show that the institutions’ performance is not effective in terms communicating and accomplishing the goals and objectives of BPR. The current progress of BPR in the institutions is also at low level. The findings also show that effective utilization of resources, having BPR motivated by customer demands, good information exchange and flow, continuous performance improvement, using technology as enabler not as solution, developing and communicating clear written goals and objectives, proper alignment of BPR strategy with the corporate strategy, using progress evaluation are the most important factors that enable BPR implementation to be successful, whereas lack of employee training, unrealistic report to outsiders that hide actual progress of BPR implementation, management frustration with slow business results, lack of management deter
A Cultural Algorithm for the Two Variable Integer Programming Problem
A specific implementation of cultural algorithm is presented here for solving the following two variable integer programming problem with n constraints: Maximize or Minimizeare signed integers. A cultural algorithm consists of a population component almost identical to that of the genetic algorithm and, in addition, a knowledge component called the belief space. As the integer programming problem is a constrained optimization problem, the constraints including nonnegativity and integer restrictions are availed as the knowledge component and used to build the belief space.
Ergonomics Assessment of Passenger Seats of Mini-Buses in Ethiopia
A descriptive survey was conducted on an ergonomics assessment of passenger seats of minibus around Mekelle city, Ethiopia (Africa). The basic research questions which answered by this study are (i) to what extent the locally manufactured passenger seats of minibuses are comfortable to the passengers around Mekelle city? (ii) is there significant difference between the dimensions of locally manufactured passenger seats of minibus and the body dimensions of passengers around Mekelle city? (iii) are the passengers around Mekelle city aware of the comfort of passenger seats of minibus?. One hundred forty four passengers with ages ranging from 18 years to 63 years in the subjective evaluation and another one hundred forty four passengers with ages ranging from 18 years to 60 years in the objective evaluation participated in the study. In the subjective evaluation, passengers were asked to evaluate the dimensions and comfort of seats of minibus. Six anthropometric dimensions from one hundred forty four passengers and the dimensions of the locally fabricated seats in thirty minibuses were measured for the objective evaluation. The data collected was analyzed using descriptive statistics such as means, standard deviations, fifth, fiftieth and ninety fifth percentiles for the seat dimensions and passengers’ body dimensions were calculated using Excel Microsoft Package. Moreover, the data obtained from the passenger’s body dimensions was compared with the relevant dimensions of the seats using independent samples t-test (2-tailed) and chi-square test at 95 percent level of confidence. The results showed a degree of mismatch between the passengers’ body dimensions and the seat dimensions. This may be an indication that the dimensions of locally manufactured passenger seats of minibus and passengers’ anthropometric dimensions are at variant. It was thus concluded that the anthropometric dimensions of the passengers were not employed in the design and manufacturing of t
