Function-Based Computer Aided Conceptual Design Support Tool

Conceptual design is considered as the most critical and important phase of design process. It is the stage where product’s fundamental features are determined, large proportion of the lifecycle cost of the product is committed, and other major decisions are made, which have significant impact on the downstream design and related manufacturing processes. It is a knowledge intensive process where diverse knowledge and several years of experience are put together to design quality and cost effective products. Unfortunately, computer support systems for this phase are lagging behind compared to the currently available commercial computer aided design (CAD) tools for the later stage of design to reduce the designers workload and product development time. The overall goal of this research is to provide designers with computational tool that support conceptual design process. To achieve this goal a methodology that integrates systematic design approach with knowledge-based system is proposed in this thesis. Accordingly, a framework of computer based computational tool known as conceptual design support tool (CDST) is developed using the proposed methodology. The tool assists designers in performing functional modeling by providing standard vocabularies of functions in the form of function library, generate concepts stored in the database from previous designs, display the generated concepts on the morphology chart, combine the concepts and evaluate the concepts variants. Concepts from subsea processing equipment design have been collected and saved in the database. The tool also accepts new concepts from the designer through its knowledge acquisition system to be saved in the database for future use. In doing so, it is possible to integrate human creativity with data handling capabilities of computers to perform conceptual design more efficiently than solely manual design. The tool can also be used as a knowledge management system to preserve expert’s knowledge and train novice designers. The applicability of the proposed methodology and developed tool is illustrated and validated by using a case study and validation test conducted by independent evaluators

The impact of supply chain management practices on the organizational performance of basic metal and engineering industries in Ethiopia

Today organizations are facing different kinds of challenges as they are operating in a dynamic global market. Due to the lack of proper knowledge and skill in management, shortage of capital, weak infrastructure etc. the challenge is more intensive for organizations situated in developing countries like Ethiopia. Therefore, such organizations have to seek for alternative ways to improve their business activities in order to compete in the global market. Supply Chain Management (SCM) is one of the most effective ways that many organizations like Wall-Mart have managed to achieve best organizational performance. In the Ethiopian business context, especially in Basic Metal and Engineering Industries (BMEIs), the concept of SCM should be well understood and practiced because these industries are the backbone of other growing industries in the country. The basic objectives of this research are (1) to assess the level of implementation of SCM practices in Ethiopian BMEIs, and (2) to analyze the relationship between SCM practices and organizational performance in the same industries.M.B.L

Function-Based Computer Aided Conceptual Design Support Tool

Conceptual design is considered as the most critical and important phase of design process. It is the stage where product’s fundamental features are determined, large proportion of the lifecycle cost of the product is committed, and other major decisions are made, which have significant impact on the downstream design and related manufacturing processes. It is a knowledge intensive process where diverse knowledge and several years of experience are put together to design quality and cost effective products. Unfortunately, computer support systems for this phase are lagging behind compared to the currently available commercial computer aided design (CAD) tools for the later stage of design to reduce the designers workload and product development time. The overall goal of this research is to provide designers with computational tool that support conceptual design process. To achieve this goal a methodology that integrates systematic design approach with knowledge-based system is proposed in this thesis. Accordingly, a framework of computer based computational tool known as conceptual design support tool (CDST) is developed using the proposed methodology. The tool assists designers in performing functional modeling by providing standard vocabularies of functions in the form of function library, generate concepts stored in the database from previous designs, display the generated concepts on the morphology chart, combine the concepts and evaluate the concepts variants. Concepts from subsea processing equipment design have been collected and saved in the database. The tool also accepts new concepts from the designer through its knowledge acquisition system to be saved in the database for future use. In doing so, it is possible to integrate human creativity with data handling capabilities of computers to perform conceptual design more efficiently than solely manual design. The tool can also be used as a knowledge management system to preserve expert’s knowledge and train novice designers. The applicability of the proposed methodology and developed tool is illustrated and validated by using a case study and validation test conducted by independent evaluators

Topology Optimization of Beam Structures with Various End andLoading Conditions

Topology optimization deals with optimum material (mass) distribution within a design domain to find optimal lay-out of a structure subjected to certain boundary and loading conditions. Topology optimization can be used to address conflicting requirements, such as light weight and high-strength/stiffness design. In this paper, a simulation program to analyze topology optimization of beam structures with seven different end conditions and three types of loads (single point load, two point loads and uniformly distributed load) is developed using MATLAB code adapted from Sigmund’s 99 line topology optimization code. Furthermore, the program has been enhanced with a graphical user interface for ease of use. Using the developed system, it is possible to analyze the effect of different parameters

Improving Lifetime of Domestic Compressor Subjected To Repetitive Internal Stresses

To enhance the lifetime of a mechanical system such as compressor, parametric accelerated life testing (ALT) as a systematic reliability method is proposed. It consists of (1) a parametric ALT plan formed on BX lifetime, (2) load examination for ALT, (3) a customized parametric ALTs with design alternatives, and (4) assessment of the compressor design to secure the objective BX lifetime is fulfilled. As an experiment instance, newly designed reciprocating compressors for French-door refrigerators returned from the marketplace were investigated. The refrigerators had been making disagreeable noise and vibrations, creating the consumer to ask for replacing their refrigerators. As the vibration level of the problematic refrigerators was recorded in an anechoic chamber, the result was 0.35g. Upon closer inspection of the refrigerator, the noise originated from the reciprocating compressor where there was interference between the compressor upper shell and the stator frame. To reproduce the compressor problem from the marketplace, a parametric ALT was performed. The failure mode during the ALTs for the compressor was alike to those of the failed refrigerators from the field. As a corrective action, the stator frame in the compressor system was redesigned to increase the minimum gap between the compressor upper shell and the stator frame. During the second ALT, there were no issues. After parameter ALTs were used to develop corrective action plans, the lifetime of the compressor was reassured to have a B1 life 10 years

Intestinal parasitic infections in Western Abaya with special reference to Schistosomiasis mansoni

Abstract: A cross sectional investigation on the distribution and prevalence of intestinal parasitic infections was undertaken in Western Abaya, North Omo, in January 1995. As the area is potentially irrigable for modern agriculture, emphasis was placed to explore on the endemicity of schistosomiasis, including malacological assessments. Five percent of the whole population on 1473 people, in 16 villages of the area, were parasitologically examined for intestinal parasites. Among the intestinal parasitic infections, hookworm was demonstrated in all of the villages with prevalences ranging from 4.1% (Algie) to 75% (Wajifo). The majority of the villages (10/16=62.5%) had hookworm prevalences of over 50%. Schistosoma mansoni infections were found in 11 villages with prevalences of up to 53% with more males than females being affected (P<0.001). Infected Biomphalaria sudanica snails with infection rates of up to 2.1% at two sites of Lake Abaya were also found. The importance of the dominant, S. mansoni and hookworm infections in the potentially irrigable area of Western Abaya and feasible measures of their control are discussed. [Ethiop. J. Health Dev. 1999;13(1):21-26