Search results for: minimisation

Authors: Edison Muzenda

Abstract:

Gauteng, as the province with the greatest industrial and population density, the economic hub of South Africa also generates the greatest amount of waste, both general and hazardous. Therefore the province has a significant need to develop and apply appropriate integrated waste management policies that ensure that waste is recognised as a serious problem and is managed in an effective integrated manner to preserve both the present and future human health and environment. This paper reflects on Gauteng-s waste outlook in particular the province-s General Waste Minimisation Plan and its Integrated Waste Management Policy. The paper also looks at general waste generation, recyclable waste streams as well as recycling and separation at source initiatives in the province. Both the quantity and nature of solid waste differs considerably across the socio-economic spectrum. People in informal settlements generate an average of 0.16 kg per person per day whereas 2 kg per day is not unusual in affluent areas. For example the amount of waste generated in Johannesburg is approximately 1.2 kg per person per day.

Keywords: General waste, generation, integrated, minimisation, recycling, separation

Authors: Edison Muzenda, Freeman Ntuli, Tsietsi Jefrey Pilusa

Abstract:

This paper highlights some interesting facts on South African-s waste situation and management strategies, in particular the Integrated Waste Management. South Africa supports a waste hierarchy by promoting cleaner production, waste minimisation, reuse, recycling and waste treatment with disposal and remediation as the last preferred options in waste management. The drivers for waste management techniques are identified as increased demand for waste service provision; increased demand for waste minimisation; recycling and recovery; land use, physical and environmental limitations; and socio-economic and demographic factors. The South African government recognizes the importance of scientific research as outlined on the white paper on Integrated Pollution and Waste Management (IP and WM) (DEAT, 2000).

Keywords: Cleaner production, demographic factors, environmental quality, integrated waste management, hierarchy, recycling

Authors: V. Joshi Manohar, P. Sujatha, K. S. R. Anjaneyulu

Abstract:

Nowadays Multilevel inverters are widely using in various applications. Modulation strategy at fundamental switching frequency like, SHEPWM is prominent technique to eliminate lower order of harmonics with less switching losses and better harmonic profile. The equations which are formed by SHE are highly nonlinear transcendental in nature, there may exist single, multiple or even no solutions for a particular MI. However, some loads such as electrical drives, it is required to operate in whole range of MI. In order to solve SHE equations for whole range of MI, intelligent techniques are well suited to solve equations so as to produce lest %THDV. Hence, this paper uses Continuous genetic algorithm for minimising harmonics. This paper also presents wavelet based analysis of harmonics. The developed algorithm is simulated and %THD from FFT analysis and Wavelet analysis are compared. MATLAB programming environment and SIMULINK models are used whenever necessary.

Keywords: Cascade H-Bridge Inverter (CHB), Continuous Genetic Algorithm (C-GA), Selective Harmonic Elimination Pulse Width Modulation (SHEPWM), Total Harmonic Distortion (%THDv), Wavelet Transform (WT).

Authors: Sunita Dhingra, Satinder Bal Gupta, Ranjit Biswas

Abstract:

Multiprocessor task scheduling is a NP-hard problem and Genetic Algorithm (GA) has been revealed as an excellent technique for finding an optimal solution. In the past, several methods have been considered for the solution of this problem based on GAs. But, all these methods consider single criteria and in the present work, minimization of the bi-criteria multiprocessor task scheduling problem has been considered which includes weighted sum of makespan & total completion time. Efficiency and effectiveness of genetic algorithm can be achieved by optimization of its different parameters such as crossover, mutation, crossover probability, selection function etc. The effects of GA parameters on minimization of bi-criteria fitness function and subsequent setting of parameters have been accomplished by central composite design (CCD) approach of response surface methodology (RSM) of Design of Experiments. The experiments have been performed with different levels of GA parameters and analysis of variance has been performed for significant parameters for minimisation of makespan and total completion time simultaneously.

Keywords: Multiprocessor task scheduling, Design of experiments, Genetic Algorithm, Makespan, Total completion time.