The effect of music in managing preoperative stress for Chinese surgical patients in the operating room holding area: A controlled trial.

This study investigated the effects of music intervention on the reduction of preoperative stress in Chinese surgical patients, using a matched-pairs, pre-post design. Patients waiting in an operating room holding area were randomly assigned to music intervention (n = 33) and control (n = 33) groups. The former listened to 20 min of music of their selected choice. Pre- and posttests of arterial pressure, heart rate, respiration rate, and state and trait anxiety were obtained for both groups. After the music intervention, there were reductions in all dependent variables, with significant reductions in mean arterial pressure and state anxiety. No significant reductions were found for the control group in any of the physiological or psychological measures. The findings suggested that listening to music might be an effective method for reducing the preoperative stress of patients from different cultural and ethnic backgrounds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

EXPLORING ONCE-PER-REVOLUTION AUDIO SIGNAL VARIANCE AS A CHATTER INDICATOR

The purpose of this study is an evaluation of the statistical variance in the once-per-revolution sampled audio signal during milling as a chatter indicator. It is shown that, due to the synchronous and asynchronous nature of stable and unstable cuts, respectively, once-per-revolution sampling leads to a tight distribution of values for stable cuts, with a corresponding low variance, and a wider sample distribution for unstable cuts, with an associated high variance. A comparison of stability maps developed using: 1) analytic techniques, and 2) the variance from once-per-revolution sampled time-domain simulations is provided and good agreement is shown. Experimental agreement between the well-known Fast Fourier Transform (FFT) chatter detection method, that analyzes the content of the FFT spectrum for chatter frequencies, and the new variance-based technique is also demonstrated.     

多模式WLAN芯片的设计权衡

无线局域网(WLAN)在过去两年中已经成为高技术市场的一颗耀眼的明星。企业和家庭用户迅速地采纳了802.11b标准,该标准能通过低成本、方便使用产品来提供高达11Mbps无线以太网连接。由于多家OEM厂商在802.11b标准被最终批准之前就生产出了产品,所以在各种不同产品之间的不兼容性导致了早期令人头痛的问题,但随着用户提出要求,以及供应商遵守互操作性要求、严格执行最终标     

Design and use of a virtual heritage model to enable a comparison of active navigation of buildings and spaces with passive observation

Wide ranging and significant research in recent years has highlighted the need for greater levels of engagement with end users in planning and design of the built environment. This has been against a background of far reaching advances in IT technologies, which have facilitated the widespread use of computer modelling to present design ideas in non-traditional and non-technical formats. In the context of urban redesign and public participation, the research reported in this paper emerged from an observation that pre-rendered walkthroughs of designs have become commonplace, and that the effect on cognition and preference might be significant. For the particular case study area, it was notable that the arrangement and proximity of buildings was such that the site could arguably be best understood through navigation at human scale, as opposed to through the use of traditional drawings or plans. The research proceeded to investigate whether the active navigation of a desktop virtual model of an urban environment leads to better understanding and perception than passive observation of a walkthrough, and the methodology employed commonly available and widely used modelling packages to present a small townscape, navigable using controls commonly found in modern computer ‘games’. The technical and study based results from this research have implications for how design ideas can be best presented to clients and other end users in the future, to ensure that design processes can be more clearly informed, and to avoid problems related to the interaction and understanding of architectural information by non-experts. The study results suggest that active navigation as opposed to passive observation does not affect choice between two versions of a model. However, benefits in terms of engagement, involvement, and a demonstrated tendency for the active condition to generate stronger perceptions and sensations suggest that use of navigable models could carry benefits in terms of engagement, thus adding benefits in terms of the user and study implementation without compromising or influencing the outcome. If it were the case that an exercise was required to establish whether participants could understand layout, or to establish how participants felt about the attractiveness of a place, or the sensations which might be felt once in a space, an ability to actively navigate a space better allows participants to feel that they had experienced a simulation of what the as-built space would be like.     

新型集成电路简化嵌入式POL DC/DC转换器设计

1、背景大多数嵌入式系统都是由48V背板供电的。这个电压通常要降至较低的12V或5V中间电压,以向系统内的电路板支架供电。然而,这些电路板上的大多数分支电路或集成电路所要求的供电电压范围为0.8V至3.3V,供电电流范围为数十毫安至数十安培。结果,需要负载点(POL)DC/DC转换器将12V或5V电压降低至这些分支电路或集成电路所需的电压和电流值。     

An analytic simplification for the reconstruction problem of electrical impedance tomography

This paper introduces a new reconstruction algorithm for electrical impedance tomography. The algorithm assumes that there are two separate regions of conductivity. These regions are represented as eccentric circles. This new algorithm then solves for the location of the eccentric circles. Due to the simple geometry of the forward problem, an analytic technique using conformal mapping and separation of variables has been employed. © 2002 John Wiley & Sons, Inc. Int J Imaging Syst Technol 12, 9–15, 2002     

A directional coupler acoustooptic filter with reduced sidelobelevels

A two-waveguide directional coupler filter with an acoustically induced grating structure is proposed. The directional coupler filter has the advantage that it does not require input and output polarizers and does not require specific birefringent material properties. Since multiple acoustic waves could be applied simultaneously, this property could be used to couple both TE and TM polarizations from one waveguide to the other. This allows for filtering the required optical wavelength from both polarizations simultaneously. A notable weakness of acoustooptical filters and all mode-coupling filters is the high sidelobe levels in their optical transmission spectrum. A technique to suppress these high sidelobe levels in the proposed acoustooptic filter is presented. It is based on simultaneous application of several acoustic waves on the optical waveguide. This technique could be applied to any existing configuration of acoustooptic filters     

Improving the dispersion of surplus labor in personnel scheduling solutions

Linear programming-based heuristics for personnel tour scheduling have focused primarily upon the minimization of the workforce size (or cost) necessary to satisfy forecast demand. There are often a myriad of alternative optimal LP solutions and these solutions may differ substantially in terms of secondary criteria. An even dispersion of surplus labor, which is associated with consistent customer service and employee workload, is one of the most important of these secondary criteria.

This paper presents a two-stage preemptive goal programming (PGP) approach that enables service operations managers to provide a more even dispersion of surplus labor while maintaining low-cost solutions. The cost incurred for improved surplus dispersion is the time required to run a second mathematical programming model (in this study 1–4 min on a 386 PC). If management has already invested the resources to use LP-based scheduling methods, implementing this alternative model would result in greater consistency of employee workload and customer service.