An Agent-Based Approach for Scheduling Multiple Machines

We present a new agent-based solution approach for the problem of scheduling multiple non-identical machines in the face of sequence dependent setups, job machine restrictions, batch size preferences, fixed costs of assigning jobs to machines and downstream considerations. We consider multiple objectives such as minimizing (weighted) earliness and tardiness, and minimizing job-machine assignment costs. We use an agent-based architecture called Asynchronous Team (A-Team), in which each agent encapsulates a different problem solving strategy and agents cooperate by exchanging results. Computational experiments on large instances of real-world scheduling problems show that the results obtained by this approach are significantly better than any single algorithm or the scheduler alone. This approach has been successfully implemented in an industrial scheduling system.     

Enhancement of the fuel cell performance of a high temperature proton exchange membrane fuel cell running with titanium composite polybenzimidazole-based membranes

The fuel cell performance of a composite PBI-based membrane with TiO₂ has been studied. The behaviour of the membrane has been evaluated by comparison with the fuel cell performance of other PBI-based membranes, all of which were cast from the same polymer with the same molecular weight. The PBI composite membrane incorporating TiO₂ showed the best performance and reached 1000 mW cm⁻² at 175 °C. Moreover, this new titanium composite PBI-based membrane also showed the best stability during the preliminary long-term test under our operation conditions. Thus, the slope of the increase in the ohmic resistance of the composite membrane was 0.041 mΩ cm² h⁻¹ and this is five times lower than that of the standard PBI membrane. The increased stability was due to the high phosphoric acid retention capacity - as confirmed during leaching tests, in which the Ti-based composite PBI membrane retained 5 mol of H₃PO₄/PBI r.u. whereas the PBI standard membrane only retained 1 mol H₃PO₄/PBI r.u. Taking into account the results obtained in this study, the TiO₂-PBI based membranes are good candidates as electrolytes for high temperature PEMFCs.     

The Role of Local Actors in Transforming Informal Settlements in Turkey for Sustainable Urban Development: The Ankara–Dikmen Valley Case

The question of how to create sustainable cities in developing countries is closely related to the question of how to upgrade and/or transform informal settlements in developing countries. The participation processes and the partnerships of urban actors appear as the key components in upgrading/transforming informal settlements and achieving sustainable practices in urban areas. This paper examines the relations between group of urban actors who took part in a large-scale gecekondu (urban squatter areas) transformation project in Ankara, the capital city of Turkey, known as the Dikmen Valley Environmental and Housing Transformation Project. The research points to different actors involved in this transformation process, the dynamic and often conflicting relations and interests among them. Examining the environmental problems that are created due to these relations, the research highlights how environmental concerns were overridden by the political and economic concerns via the “consensus” solutions generated. It is concluded that the decision-making groups, which are the metropolitan government units, tend to dominate the participation process by establishing coalitions with other groups such as landowners and gecekondu owners. The struggles within and between the decision-making groups are also emphasized as having a major influence on generating undesired outcomes for urban sustainability.     

Oxidation effect on templating of metal oxide nanoparticles within block copolymers

Amphiphilic norbornene-b-(norbornene dicarboxylic acid) diblock copolymers with different block ratios were prepared as templates for the incorporation of iron ions using an ion exchange protocol. The disordered arrangement of iron oxide particles within these copolymers was attributed to the oxidation of the iron ions and the strong interactions between iron oxide nanoparticles, particularly at high iron ion concentrations, which was found to affect the self-assembly of the block copolymer morphologies.     

Multiwalled carbon nanotube deposition profiles within a CVD reactor: An experimental study

A number of proposed applications of carbon nanotube (CNT) arrays require that uniform deposition of well-aligned CNTs is achieved. The CNT deposition profiles inside a chemical vapor deposition (CVD) reactor are strongly dependant on the reaction temperatures, feed gas flow rates, carrier gas flow rates and reactor geometry. In addition, objects placed in the path of the flow of feed material could affect the deposition patterns. In this paper, an experimental study aimed at achieving better control of the deposition patterns of CNTs is presented. Multiwalled CNTs were grown on a long substrate by the catalytic CVD of a xylene/ferrocene solution. The deposition patterns on the substrate were examined for different furnace temperatures, xylene/ferrocene feed rates and carrier gas flow rates. Small objects representative of electronic devices were placed at different locations on the substrate and their effect on the deposition patterns was explored. The effect of changing the height and the gap distance between these objects was also studied.     

Split-attention effects in multimedia learning environments: eye-tracking and EEG analysis

Multimedia Tools and Applications - This study aimed to evaluate the split-attention effect in multimedia learning environments via objective measurements as EEG and eye-tracking. Two different...     

Object manipulation with a variable-stiffness robotic mechanism using deep neural networks for visual semantics and load estimation

Neural Computing and Applications - In recent years, the computer vision applications in the robotics have been improved to approach human-like visual perception and scene/context understanding....