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This paper evaluates two novel methods to improve frequency-domain beamforming source location in noisy and reverberant environments. Experiments have been carried out with a speaker placed in an anechoic wind tunnel behind a flow generated by a noisy fan. The first method is based on a filtering of the cross-correlation matrix between eachpair of microphones, i.e. the time-domain equivalent of the cross-spectral matrix. Indeed, as the source of interest (speaker) and the contaminating sources (fan) are far from each other, their signature in the cross-correlation functions can be separated. This method has already been validated in a reverberant environment, but the results obtained in the present case were not conclusive. Thus another method based on an eigenvalue decomposition was used to investigate the problem of high background noise in wind tunnel testings.

The effect of acoustic reflections on beamforming maps and their correction is investigated in this paper. By replacing the usual steering vector expression in the beamforming algorithm with an adapted one, the effect of reflections can be reduced. Two formulations of the steering vectors are considered. The first makes use of an experimental Green's function, which is obtained by measuring simultaneously the signal of a speaker and of a 31-channel acoustic array in a hard-walled test-section. The second formulation is based on the assumption that the reflections can be modeled by a set of monopoles located at the image source positions. This numerical model is first validated by comparing the obtained Green's function with the experimental one. Then, the beamforming algorithm is modified by using the different steering vector formulations. In addition, the deconvolution algorithm Clean-SC has been used and implemented with the different formulations. Best results in terms of location and resolution accuracy were generally obtained when using the experimental Green's function formulation.

A method to improve the quality of acoustic beamforming in reverberant environments is proposed in this paper. The processing is based on a filtering of the cross-correlation matrix of the microphone signals obtained using a microphone array. The main advantage of the proposed method is that it does not require information about the geometry of the reverberant environment and thus it can be applied to any configuration. The method is applied to the particular example of aeroacoustic testing in a hard-walled low-speed wind tunnel; however, the technique can be used in any reverberant environment. Two test cases demonstrate the technique. The first uses a speaker placed in the hard-walled working section with no wind tunnel flow. In the second test case, an airfoil is placed in a flow and acoustic beamforming maps are obtained. The acoustic maps have been improved, as the reflections observed in the conventional maps have been removed after application of the proposed method.

Background: This phase III randomized trial compared pemetrexed 500 mg/m2 (P500) with pemetrexed 900 mg/m2 (P900) to determine whether higher dosing benefits non-small-cell lung cancer (NSCLC) patients as second-line therapy. Patients and methods: Patients with locally advanced or metastatic NSCLC, previously treated with platinum-based chemotherapy, were randomly assigned to receive i.v. P500 or P900 every 3 week. Results: Accrual was terminated with 588/600 patients enrolled because an interim analysis indicated a low probability of improved survival and numerically greater toxicity on the P900 arm. P900 patients were permitted to continue treatment at P500. No statistical difference was observed between the treatment arms (P500 versus P900) for median survival {6.7 versus 6.9 months, hazard ratio [HR] = 1.0132 [95% confidence interval (CI) 0.837-1.226]}, progression-free survival [2.6 versus 2.8 months, HR = 0.9681 (95% CI 0.817-1.147)], or best overall tumor response [7.1% versus 4.3% (P = 0.1616)]. The incidence of drug-related grade 3/4 toxicity was typically <5% on both treatment arms, but was numerically higher on the P900 arm for most toxicity categories. Conclusions: P900 did not improve any efficacy measure over P500. P500 i.v. every 3 week remains the standard pemetrexed dose for second-line treatment of platinum-pretreated advanced NSCLC.

The AFSC Human Systems Division, Armstrong Laboratory, Sustained Operations Branch, (AL/CFTO), was requested by the San Antonio Air Logistics Center, Human Resources Center (SA-ALC/HRC) at Kelly AFB, TX, in May 1991 to evaluate worker attitudes during a trial transition from an 8-hour per day, 5- day work week to a 10-hour per day, 4-day work week. This Compressed Work Schedule (CWS) began September-October 1991. Worker responses to the first 30 days of the trial period were surveyed by AL/CFTO from late October through early December 1991. There were 2,265 surveys collected and 2,170 were acceptable for statistical analysis. Overall, 74.9% of the workers indicated a preference for the new work week schedule and 7.3% had no preference. Of those surveyed, 17.9% preferred their previous schedule of 8 hours per day during a 5- day work week. The intent of this 30-day interim report, and the 6-month and 1- year reports to follow, is to explore the social impact of the CWS and the demographic characteristics of those who preferred and those who did not prefer the CWS. Although the majority consistently favored the CWS, certain characteristics emerged for those who did not. For example, older employees, evening or night shift workers, single parents with children, and those who use public transportation to get to work were demographic groupings that expressed less preference for the CWS than other groupings. Surveys after 6 months and 1 year will determine if subjective responses to the new work schedule were altered. These results may help management decide upon the implementation of the CWS throughout the Kelly AFB community.