Scheduling UET-UCT tasks: branch-and-bound search in the priority space

The paper is concerned with the problem of scheduling partially ordered unit execution time tasks on parallel processors with unit communication delays and release times. Two criteria are considered, the maximum lateness and its particular case, the makespan. This problem plays an important role in scheduling theory and was originally inspired by the applications to multi-processor computer systems. It is well known that for both criteria the problem is NP-hard in the strong sense. The paper presents an implementation of the branch-and-bound method which does not partition the feasible region explicitly. The theoretical results are complemented by computational experiments.     

State and dynamic behavior of a high stiffness stewart platform-based force/torque sensor

The performance of a Stewart platform-based force/torque sensor is analyzed. The influence of sensor geometry is assessed with particular reference to the characteristic orientation angles of the arms connecting the platforms, which consist of single-axis bidirectional force transducers. Static and dynamic performance is analyzed and compared with experimental tests, © 7993 John Wiley & Sons, Inc.     

Dynamic model and experimental investigation of a pneumatic proportional pressure valve

A nonlinear dynamic model of a Honeywell Lucifer-type EPP3 J-21-U-100-10 (now Parker P3P-R) pneumatic proportional pressure valve is formulated by modeling the valve's main internal mechatronic devices in order to simulate its dynamic behavior in the time and frequency domains, for several operating conditions and different downstream loads. Mechatronic design and functionality of this valve are carefully analyzed by considering the conditions of its internal devices for each of the three standard working configurations of a three-way proportional valve. The main physical parameters introduced in formulating the dynamic model were identified by means of an experimental investigation. Finally, the experimental and simulated diagrams in the time and frequency domains are compared in order to validate the proposed model, which can be used as a general approach for modeling any pneumatic proportional pressure valve featuring a similar mechatronic design and internal structure.     

Micropatterning PEDOT:PSS layers

PEDOT:PSS is a conductive polymer that is used as electrodes in organic electronic devices, but also in neuronal probes and implantable devices. This material can also be used for building deformable electrodes in soft substrates for several sensing applications. However, this material being sensitive to several chemicals and moisture it is difficult to pattern microstructures using standard lithography techniques. This paper will review and show some techniques developed for patterning PEDOT:PSS thin films using both soft lithography, such as microcontact printing and shadow masking, and conventional lithography techniques. In addition of this review we present a new lithography technique using silicon nitride protection layer and an analysis and comparison of ICP RIE dry plasma etch rates of PEDOT:PSS with different gases.     

Managing product/process knowledge in the concurrent/simultaneous enterprise environment

Innovation is a critical factor in the success of industrial companies, and just as important is the need to get innovative products to the market quickly. Therefore, it is important to talk about ‘management of product development time’ because, under this new paradigm, companies able of ‘mastering’ the development time will launch the product into the market just spending the planned time and resources and at the real moment. This will give back to the company higher market share and faster market penetration. The main objective of the project Acceleration of Innovative Ideas into the Market (AIM) is to provide the means of stimulating the creation of innovative ideas in general, and specifically on potential product/process improvements and on problem solving. These ideas are collected throughout the extended enterprise from people involved with the products and processes; this knowledge will be further developed into innovations in a project-basis process.     

A CMOS microcoil-associated preamplifier for NMR spectroscopy

For improving sensitivity of nuclear magnetic resonance (NMR) measurements, an in-field preamplifier in a low-cost CMOS process is presented. It is based on a second-generation positive current conveyor (CCII+), with an impedance-matching output stage. The circuit has been designed with optimization of key performances, such as bandwidth, noise, and offset voltage. There have also been precautions taken against potential effect of strong magnetic field under which the circuit should operate. The designed preamplifier has a voltage gain of 15 dB and a bandwidth of 100 MHz. After fabrication of the circuit, we have carried out testing work, including in-field circuit test and characterization of MOS transistors. Under 2-T magnetic field, there have not been substantial changes in overall circuit performances compared to results obtained by post-layout simulations. For an experiment of NMR measurements with and without in-field preamplifier, the circuit is coupled with a receiver micro-coil. The experiment has been to detect protons at 85.13-MHz resonance frequency under 2-T magnetic field with water sample. The obtained results have shown a 14-dB signal-to-noise ratio improvement when the preamplifier is associated with the receiver coil.     

Study and design of resistive switching behaviors in PMMA-based conducting-bridge random-access memory (CBRAM) devices

The fabrication and the performance of PMMA resistive switching device have been studied by using FR-4 (copper), PMMA (poly methyl methacrylate) and aluminum as the active anode, the solid electrolyte and the inert cathode respectively. By etching the copper surface with the acid solution [4HNO₃ + 11H₃PO₄ (98 %) + 5CH₃COOH] at 60 °C for 2 min, a good performance of Cu/PMMA/Al device, which can switch until 2300 cycles, has been realized. The spin rate for forming the PMMA coating plays a decisive role in the performance of Cu/PMMA/Al device. The best performance of the Cu/PMMA/Al device was obtained only when the spin rate of deposition of PMMA reached 4000 rpm (low thickness).

     

Functional electrical stimulation of abdominal muscles to augment tidal volume in spinal cord injury.

Functional electrical stimulation (FES) of abdominal muscles as a method of enhancing ventilation was explored in six neurologically intact subjects and five subjects with spinal cord injury (SCI) who had levels of injury between C4 and C7. Pulmonary ventilation was augmented in both groups predominantly due to an increase in tidal volume. The average increase in tidal volume during FES for the neurologically intact group was 350 ml, while in the SCI group it was 220 ml. The FES caused active volume decreases in both the lower thorax and upper abdomen, which together appear to be the mechanism behind the increases seen in tidal volume. Therefore, the proposed method might be useful in future clinical practice. The results indicate that FES of abdominal muscles should be more thoroughly explored as a potential technique of ventilatory support in SCI. The results also point to the necessity for further studies of maintaining the condition of the chest wall in the pulmonary rehabilitation of individuals with tetraplegia.