Advanced manufacturing technology

Manufacturing is currently undergoing a revolutionary transition with focus shifting from mass production to mass customization. This trend motivates a new generation of advanced manufacturing systems that can dynamically respond to customer orders and changing production environments. It is becoming increasingly important to develop control architectures that are reconfigurable and fault tolerant. A holonic manufacturing system (HMS) is a system of holons that can cooperate to achieve a common goal or objective. The holonic organization enables the construction of very complex systems that are efficient in the use of resources. This paper focuses on the dynamic re-configuration and task optimization of holonic manufacturing systems (HMS). The concept of dynamic virtual clustering is extended to the control process of a holarchy or holonic organization. A task-oriented clustering mechanism and a corresponding optimization algorithm are presented as an efficient approach to the holonic control in the HMS domain. The mediator-based dynamic virtual clustering mechanism is presented firstly. Then a negotiation strategy based on the contract net protocol is proposed for cooperative action among holons. Finally, a hybrid algorithm based on particle swarm optimization (PSO) and simulated annealing (SA) for holon task allocation is described to support the optimum organization of a holarchy. The hybrid algorithm combines the high speed of PSO with the powerful ability to avoid being trapped in local minimum of SA. Simulation results show that the proposed model and algorithm are effective.

In this article, we study a single-machine scheduling problem in which the processing time of a job is a nonlinear function of its basic processing time and starting time. The objectives are to minimise the makespan, the sum of weighted completion times and the sum of the kth powers of completion times. We show that the makespan minimisation problem can be solved in polynomial time. However, the total completion time and the sum of the kth powers of completion times minimisation problems can be solved in polynomial time in some cases. Besides, some useful properties are also provided for the sum of weighted completion times problem under certain conditions.

There has been growing interests in direct patterning of metallic contents on the surface of the substrate without including complex steps of the microfabrication lithography process. The direct fabrication process using electrostatic ink-jet printing can be expected to be a powerful tool for both nanotechnology research and applications such as microelectronics. The droplet ejection voltage, meniscus, cone-jet behavior, and counter electrode distance depends on the ink properties such as surface tension, viscosity, and percentage of metallic pigments. In this paper, 2-μm level needle-type electrostatic head designs for contact-less fabrication of printed electronics, composed of differently treated surface materials, have been studied and analyzed. The electrostatically actuated ink-jet heads were tested and compared for low power and high resolution on ink containing metallic nano-particle particles as pigments. The two laboratory-fabricated discrete and electrostatically actuated ink-jet heads, one made by poly di-methyl siloxane modeling process and other through micro-electrical discharge machine techniques, were compared, and their orifice outlet surface (hydrophobic and hydrophilic) condition influence has been discussed. The paper also investigates different dripping behaviors of metallic ink under the influence of counter electrode distance, voltages, and materials. The observation of droplet ejection with high-speed camera revealed that in the case of hydrophobic head, better meniscus shape and ejection was achieved even at low voltage compared to the hydrophilic head. It was also found that the less flow rate is required in hydrophobic head. Printing characteristic of the hydrophilic nozzle head was also compared with the hydrophobic head on PET substrate.

When a customer selects a product from a product family, the attributes of the components for selection are usually technical parameters instead of customer-familiar characteristics of the product. In this paper, an optimization method for components selection is proposed based on quality function deployment (QFD) to minimize the difference between the customer’s expectation and the selected product. The model is

Purpose – The principal aim of this paper is to determine the critical factors of total quality management (TQM) and to measure their effect on organizational performance of SMEs operating in Turkish textile industry. Design/methodology/approach – Data for this study was collected using a self-administered questionnaire that was distributed to 500 SMEs in textile industry in the city of Istanbul