Carrier Density and Plasma Frequency of Aluminum Nanofilms

In this work, the prerequisite and mode of electromagnetic response of Al nanofilms to electromagnetic wave field was suggested.Reflectance, transmittance in infrared region and carrier density of the films was measured. With the carrier density of the films, the dependence of their plasma frequencies on the film thickness was obtained. On the other hand, the dependence of absorptance on the frequency of electromagnetic wave field was set up by using the measured reflectance and transmittance,which provided plasma frequency-film thickness relation as well. Similarity of both plasma frequency-film thickness relations proved plasma resonance as a mode of electromagnetic response in Al nanofilms.     

Soft quasi-maximum-likelihood detection for multiple-antenna wireless channels

The paper addresses soft maximum-likelihood (ML) detection for multiple-antenna wireless communication channels. We propose a soft quasi-ML detector that maximizes the log-likelihood function by deploying a semi-definite relaxation (SDR). Given perfect channel state information at the receiver, the quasi-ML SDR detector closely approximates the performance of the optimal ML detector in both coded and uncoded multiple-input, multiple-output (MIMO) channels with quadrature phase-shift keying (QPSK) modulation and frequency-flat Rayleigh fading. The complexity of the quasi-ML SDR detector is much less than that of the optimal ML detector, thus offering more favorable performance/complexity characteristics. In contrast to the existing sphere decoder, the new quasi-ML detector enjoys guaranteed polynomial worst-case complexity. The two detectors exhibit quite comparable performance in a variety of ergodic QPSK MIMO channels, but the complexity of the quasi-ML detector scales better with increasing number of transmit and receive antennas, especially in the region of low signal-to-noise ratio (SNR).     

FULL-RCMA: a high utilization EPON

This paper proposes an alternate solution for Ethernet passive optical networks. Our solution uses a novel protocol named full utilization local loop request contention multiple-access protocol to efficiently provide communications in passive optical networks. We study the physical layer implementation, as well as medium access control (MAC) layer protocol performance to illustrate the feasibility and benefit of our solution. The performance studies show that the MAC protocol is capable of offering 95% channel utilization under heavy load conditions. The performance results also indicate that delivery of multimedia traffic with a high quality-of-service can be achieved with our solution.     

Understanding the emotional aspects of escalation of commitment: The role of negative affect.

Despite the importance of understanding the emotional aspects of organizational decision making, prior research has paid scant attention to the role of emotion in escalation of commitment. This article attempts to fill this gap by examining the relationship between negative affect and escalation of commitment. Results showed that regardless of whether negative affect was measured as a dispositional trait (Neuroticism) in Studies 1 and 2 or as a transient mood state in Study 3, it was negatively correlated with escalation tendency when one was personally responsible for a prior decision. This pattern of results is consistent with the predictions derived from the coping perspective, suggesting that people seek to escape from the unpleasant emotions that are associated with escalation situations. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Multi-objective module placement for 3-D system-on-package

System-on-package (SOP) is a viable alternative to system-on-chip (SOC) for meeting the rigorous requirements of today's mixed-signal system integration. Thermal integrity is arguably the most crucial issue in three-dimensional (3-D) SOP due to the compact nature of the 3-D integration. In addition, the power supply noise issue becomes more serious as the supply voltage continues to decrease while the number of active devices consuming power increases. We propose a 3-D module and decap (decoupling capacitance) placement algorithm that evenly distributes the thermal profile and reduces the power supply noise. In addition, we allocate white spaces around the modules that require decaps to suppress the power supply noise while minimizing the area overhead. In our experimentation, we achieve improvements in both maximum temperature and decap amount with only small increase in area, wirelength, and runtime.     

On equal-gain combining for acquisition of time-hopping ultra-wideband signals

The acquisition of ultra-wideband (UWB) signals is a potential bottleneck for system throughput in a packet-based network employing UWB signaling format in the physical layer. The problem is mainly due to the low received signal power and the fine time resolution which forces the acquisition system to process the signal over long periods of time before getting a reliable estimate of the timing of the signal. Hence, there is a need to develop more efficient acquisition schemes by taking into account the signal and channel characteristics. In this paper, we investigate two approaches, the square-and-integrate and the integrate-and-square, which collect the energy in the multipaths by performing equal-gain combining (EGC) to improve the acquisition performance. We define the hit set as the set of hypothesized phases which can guarantee adequate system performance after acquisition, and also study the effect of the EGC window length on the acquisition performance.     

Flank wear measurement by a threshold independent method with sub-pixel accuracy

This paper presents an image processing procedure to detect and measure the tool flank wear area. Unlike the traditional thresholding-based methods, a rough-to-fine strategy is considered in this paper whereby a binary image is first obtained and used to find the candidate wear bottom edge points; then a threshold-independent edge detection method based on moment invariance is employed for more robust determination of the wear edge with sub-pixel accuracy. To shorten computation time, a critical area is initially defined and the subsequent procedure is confined to processing this area as the region of interest. Images from three types of inserts, A30N, AC325 and ACZ350 under different cutting conditions are captured with the similar illumination conditions after milling. The measured results obtained with the proposed method from these images are compared with those obtained by direct manual measurement with a toolmaker's microscope and a method based totally on binary image contour detection. The proposed method is shown to be effective and suitable for the unmanned measurement of flank wear.     

Characterisation of ‘Hadley’ grains by confocal microscopy

This work forms part of an exploratory study to investigate the use of fluorescent laser scanning confocal microscopy (LSCM) for imaging pores and voids in hardened mortar and concrete. The study has revealed the suitability of the technique for the characterisation of hollow shell (Hadley) hydration grains (these are grains that contain a void within the original boundary of the cement grain). It was found that Hadley grains could be imaged using fluorescent light techniques, subsequent to their impregnation by epoxy resin doped with a fluorescent dye. Prior to this work, it was not clear whether hollow grains were impregnated due to connections with capillary pores, or if they had been impregnated due to connections with damage caused during surface preparation (i.e. micro-cracks or deep surface scratches). However using the 3D LSCM imaging technique it was observed that connections between Hadley grains and hardened cement paste (HCP) capillary pores did exist, in different forms, at depths well below the surface providing ‘conduits’ along which resin was able to flow and impregnate the hollow grains. Other aspects of imaging Hadley grains are also described, such as the sectioning of ‘tips’ of larger grains often taken as separate smaller pores or grains in 2D images.     

Simulating dust accumulation

Dust accumulation is a common natural phenomenon. Modeling of dust accumulation, however, has not been well studied. We present a technique to model the amount of dust that settles on object surfaces based on the properties of surfaces and the geometry of objects. Since many researchers have studied the scattering of light by air-borne dust, we do not consider it here. We illustrate our techniques with images of dusty objects rendered using our dust texture module within Rayshade 4.0.6, a public domain ray tracer     

Gi-mediated stimulation of type II adenylyl cyclase is augmented by Gq-coupled receptor activation and phorbol ester treatment

Synergism between Gs- and Gi- or Gq-dependent signaling pathways has been demonstrated in the stimulation of type II adenylyl cyclase (AC-II). Provision of activated alpha s is known to allow numerous Gi-coupled receptors to stimulate AC-II and to potentiate the responses to Gq-coupled receptors. To explore possible interactions between Gi- and Gq-coupled receptors that are independent of alpha s, the activity of AC-II was determined after the activation of Gi- and Gq-regulated pathways. Human embryonic kidney 293 cells were transiently cotransfected with cDNAs encoding AC-II and various G-protein-coupled receptors. Agonist-bound Gi-coupled receptors (including the formyl peptide, dopamine-D2, and delta-opioid receptors) stimulated AC-II activity in the absence of activated alpha s, provided that the cells were treated with 100 nM phorbol 12-myristate 13-acetate. Activation of protein kinase C (PKC) thus appears to relieve the requirement for the presence of activated alpha s. Stimulation of PKC via Gq-coupled receptors also allowed Gi-coupled receptors to activate AC-II. Coexpression of the m1 muscarinic receptor with the dopamine-D2 receptor permitted dopamine to stimulate AC-II in the presence of carbachol. The phorbol ester-permissive and alpha s-independent stimulation was mediated by G-protein beta gamma subunits because it was blocked by the beta gamma scavengers alpha t and beta-adrenergic receptor kinase. These results show that AC-II can efficiently integrate signals generated by Gq- and Gi-coupled receptors via a mechanism that is independent of Gs.