Numerical simulation of water flow in an axial flow pump with adjustable guide vanes

A new adjustable guide vane (AGV) is proposed in this paper. This vane can reduce hydraulic losses and improve the performance of an axial flow pump. The formula of AGV adjustment was obtained after theoretical analysis. The fluid flow inside the axial flow pump with a fixed guide vane and adjustable guide vane was simulated. The calculated Q-H curves for the fixed guide vane agreed well with the experimental ones. The results show that the attack angle and flow separation have an important contribution to the vortices which create hydraulic losses in the guide vane channel. The AGV can decrease hydraulic losses and significantly enhance the pump head and efficiency by changing the guide vane angle.     

An EMG-based muscle force monitoring system

Information about muscle forces helps us to understand human movements more completely. Recently, studies on estimating muscle forces in real-time have been directed forward; however, the previous studies have some limitations in terms of using a three-dimensional (3D) motion capture system to obtain human movements. In the present study, an electromyography (EMG)-based real-time muscle force estimation system, which is available for a variety of potential applications, was introduced with electrogoniometers. A pilot study was conducted by performing 3D motion analysis on ten subjects during sit-to-stand movement. EMG measurements were simultaneously performed on gastrocnemius medialis and tibialis anterior. To evaluate the developed system, the results from the developed system were compared with those from widely used commercially available off-line simulation software including a musculoskeletal model. Results showed that good correlation coefficients between muscle forces from the developed system and the off-line simulation were observed in gastrocnemius medialis (r = 0.718, p < 0.01) and tibialis anterior (r = 0.821, p < 0.01). However, muscle lengths and muscle forces were obtained with a maximum delay of about 100 ms. Further studies would be required to solve the delay limitation. The developed system yielded promising results, suggesting that it can be potentially used for the real-time diagnosis of muscle or interpretation of movements.     

The Ge condensation technique: A solution for planar SOI/GeOI co-integration for advanced CMOS technologies?

This paper presents a general study on the germanium (Ge) condensation technique to assess its potential, issues and applications for advanced metal oxide semiconductor field effect transistor (MOSFET) technologies. The interest in such process for fabrication of ultrathin germanium on insulator (GeOI) layers for fully depleted GeOI MOSFETs application is first described. We highlight the impact of initial silicon on insulator (SOI) substrates uniformity on the process, determined as the key parameter to be improved. Next, a global procedure is described for MOSFETs integration on Ge layers grown on 75% Ge-enriched silicon germanium on insulator (SGOI) substrates obtained by the Ge condensation technique. A third section reviews the different local Ge condensation techniques for fabrication of SOI–GeOI hybrid substrates. Interests of such substrates for SOI–GeOI planar co-integration either at the microprocessor, at the cell or at the transistor level will be discussed. Finally, the fabrication of a first 50-nm-thick SOI–GeOI hybrid substrate is described.     

A Metadata Design for Augmented Broadcasting and Testbed System Implementation

Augmented reality (AR) is a popular service in mobile devices, and many AR applications can be downloaded from app stores. As TV broadcasting has continued to integrate with the Internet, it has become an area in which the AR concept is able to reside, although in a simple form, such as an advertisement placed in the static region of a scene. There are some restrictions against TV broadcasting realizing AR since TVs are fixed devices and typically do not have GPS, geomagnetic, or acceleration sensors, which are standard equipment in mobile devices. However, the desire to experience AR on a large TV screen has triggered research and development for an ideal AR business model and service type. This paper introduces several use cases for augmented broadcasting services and also presents an augmented broadcasting metadata scheme designed for a broadcasting environment. We also verify some of the use cases and an augmented broadcasting metadata scheme in an implemented augmented broadcasting system based on a hybrid TV platform.     

Optimization of SIMOX for VLSI by electrical characterization

A comprehensive electrical characterization study which was conducted to optimize the fabrication of SIMOX substrates for VLSI is discussed. The oxygen implantation was carried out using medium-current and high-current implanters. The wafers were annealed at 1275°C and 1300°C to produce high-quality, precipitate-free material. The effect of dose, the effect of multiple implantation (by sequentially implanting and annealing), and the effect of the anneal ambient gas and the capping layer during annealing were studied. MOSFETs of various geometries with a gate oxide of ~20 nm were fabricated by a CMOS process incorporating the addition of a thin epitaxial Si layer. A general evaluation of each transistor was conducted by studying its static characteristics. The interface states, bulk traps, and carrier generation phenomena were studied. Good-quality interfaces were obtained. Better implantation control reduced contamination and suppressed deep traps below the detection limit. Multiple implantation resulted in superior material quality. as evidenced by very long generation lifetime values (> 100 μs)     

A Location-Routing Problem in Designing Optical Internet Access with WDM Systems

In this paper, we deal with a location-routing problem in designing the optical Internet with WDM systems. This problem arises from the design of broadband local access networks that deliver high-speed access service to residential subscribers. The problem is to find an optimal location of the gateway and optimal routing of traffic demands in the optical access network. We develop mixed-integer programming models for solving the location-routing problem to minimize the total cost of network elements used in the network while carrying the offered traffic. By exploiting the inherent structure of the problem, we derive two effective tabu search procedures. We present promising computational results of the proposed solution procedures.     

Effects of localized interface defects caused by hot-carrier stressin n-channel MOSFETs at low temperature

Hot-carrier stressing was carried out on 1-μm n-type MOSFETs at 77 K with fixed drain voltage V_d=5.5 V and gate voltage V_g varying from 1.5 to 6.5 V. It was found that the maximum transconductance degradation ΔG_m and threshold voltage shift ΔV_t, do not occur at the same V_g. As well, ΔK_t is very small for the V_g <V_d stress regime, becomes significant at V_g≈V_d, and then increases rapidly with increasing V_g, whereas ΔG_m has its maximum maximum in the region of maximum substrate current. The behavior is explained by the localized nature of induced defects, which is also responsible for a distortion of the transconductance curves and even a slight temporary increase in the transconductance during stress     

Improvement of SOI MOS current-mirror performances usingserial-parallel association of transistors

The serial-parallel association of SOI MOSFETs proves to be useful for increasing the breakdown voltage and the early voltage of transistor structures. This permits one to realise current mirrors with an output-to-input current ratio close to unity in the weak, moderate and strong inversion regimes of the MOSFETs