Improved Soft-Output RAKE Receiver for CDMA Mobile Terminals with High Data Rates

In this paper we propose a soft-output RAKE receiver for CDMA mobile terminals using low spreading factor and/or high-order modulation constellations for high data rates. Based on the outputs of theRAKE correlator fingers, the receiver produces symbol or bit metrics for soft decision decoding. The formulation of these metrics is derived analytically taking into account the multipath propagation, interfering users and channel estimation errors. Simulations show thata performance gain is achieved when low spreading factors or high-order modulation constellations are used.     

Advanced flaw production method for in-service inspection qualification mock-ups

One of the key issues in in-service inspection qualification is the representativeness of the defects used in qualification specimens. The best representativeness is achieved with realistic defects. However, present specimen production techniques have some significant weaknesses, such as unrealistic defects or additional alterations induced in the surrounding material. Specimens manufactured, for example, by weld implantation or with weld solidification defects always result in one or more extra weld interfaces. These interfaces can be detected by NDT. To overcome problems with the current specimens, a new defect manufacturing technique was developed. The new technique produces natural, representative defects without introducing additional weld metal or other unwanted alterations to the specimen.The new method enables artificial production of single, separate fatigue cracks by thermal loading. The method is based on a natural thermal fatigue damage mechanism and enables production of real cracks directly into the samples. Cracks are produced without welding or machining and without any preliminary surface treatment or artificial initiator such as a notch or a precrack. Single crack or a network of cracks can be induced into the base material, welded areas, HAZ, weld claddings, threaded areas, T-joints, etc. The location, orientation and size of produced cracks can be accurately controlled. Produced cracks can be used to simulate different types of service-induced cracks such as thermal fatigue, mechanical fatigue and stress corrosion cracks. It is shown that artificially produced thermal fatigue cracks correspond well with the real, service-induced cracks and overcome the problems of traditional qualification specimen manufacturing techniques.     

Suboptimal Exposure to Facial Expressions When Viewing Video Messages From a Small Screen: Effects on Emotion, Attention, and Memory.

The authors examined the effects of suboptimally presented facial expressions on emotional and attentional responses and memory among 39 young adults viewing video (business news) messages from a small screen. Facial electromyography (EMG) and respiratory sinus arrhythmia were used as physiological measures of emotion and attention, respectively. Several congruency priming effects were found. In particular, happy facial primes prompted increased (a) pleasure ratings, (b) orbicularis oculi EMG activity, (c) perceived trustworthiness, and (d) recognition memory for video messages with a positive emotional tone. Emotional and other responses to video messages presented on a small screen can be modified with suboptimal affective primes, but even small differences in the emotional tone of the messages should be allowed for. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

NMR imaging and differential scanning calorimetry study on drying of pine,birch, and reed pulps and their mixtures

Drying, water fractions, and water distribution were investigated for pine, birch, and reed pulps and pine–birch, pine–reed, and pine–birch–reed pulp mixtures. Gravimetrically determined drying times showed that the drying rates of the pulps decreased at two to four inflection points. Characterizations of the dried pulps by differential scanning calorimetry (DSC) showed a faster removal of free water than freezing and nonfreezing bound waters; all decreased simultaneously, however. DSC also revealed the critical water contents at which the free water and freezing bound water disappeared. The gravimetrically determined inflection points of the drying curves corresponded with the critical points determined by DSC. NMR line widths and images produced by ¹H‐NMR imaging revealed the nature and regions of the pulp drying. The constant growth rate of the NMR line widths with decreasing water content appeared to change at two inflection points, which fell approximately in the same water content regions as the inflection points of the drying curves. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 937–945, 2006     

Polymerization mechanisms and molecular weight distribution. II. AIBN-initiated polymerization of styrene at 60°C

An experimental study was carried out on the AIBN-initiated polymerization of styrene at 60°C. The kinetic rate constants were determined by the method of moments and the MWD method, which was proposed in a previous paper. The results compared favorably with the data in the literature and the MWD method was noted to yield more consistent results than the method of moments, which indicates the importance of considering the whole molecular weight distribution. The theoretical MWD was found to approximate the experimental MWD well. The chain-transfer constant to AIBN was found to be between 0.09 and 0.14.     

Efficacy of training procedures in implementing a legislated safety programme

This study examines the effect of training procedures, as measured by the results of a test, on the level of assimilation of a new safety programme in 80 Quebec companies. The Workplace Hazardous Materials Information System (WHMIS) was introduced in the province in 1989. The bipartite safety association representing the manufacturers of transportation equipment and machinery offered two types of WHMIS training services to their members: (a) 4 h employee training courses, and (b) two-day trainer training courses. Companies were free to choose from these and other services to comply with the WHMIS training requirements. A test was issued to a stratified sample of 862 employees approximately one year after the training. On average, the scores were best in plants having employees trained directly by experts from the safety association (type a). The training of internal trainers for companies produced slightly inferior learning results (type b).     

On the optimality of field-line routing in massively dense wireless multi-hop networks

We consider the load balancing problem in large wireless multi-hop networks by applying the continuum approximation. The task is to find routes, geometric curves, such that the maximal traffic load in the network is minimized. In finite fixed networks, multi-path routes generally yield a lower congestion and thus allow higher throughput. In contrast, we show that in dense wireless multi-hop networks, the optimal load balancing can be achieved by a destination based single-path routing referred to as field-line routing. This is because any routing can be transformed to the corresponding field-line routing with the same or better performance, by using as paths, the field lines of the so-called destination flow associated with the original routing. The concepts are illustrated with two examples. In the case of a unit disk with unit traffic, the maximal load of 0.389 of a multi-path routing system is reduced to 0.343 by using the field-line routing. Similar improvements are also demonstrated for the unit square.     

Numerical optimization of conduction cooled current leads for low current applications

The basic design principles of current leads for superconducting magnets are well established but HTS materials and conduction cooled systems call for new numerical methods. In this paper the design of current leads was formulated as an optimization problem. Both time integration and finite differencing were examined as possible ways to compute the temperature distribution inside the leads. Three examples about optimization of conduction cooled as well as gas cooled systems are presented. First, the design of tubular normal conducting gas cooled current leads was studied. Second, normal conducting leads cooled with a two-stage cryocooler were examined. Third, the optimization was applied to current leads consisting of HTS tapes at the low temperature end of a normal conducting bar. The study took into account the magnetic field and temperature dependent voltage-current characteristics of the anisotropic Bi-2223 material. The results are compared with traditional analytical ones and the numerical optimization is shown to be an efficient design tool for both normal conducting and HTS current leads.