Individual safety performance in the construction industry: development and validation of two short scales

In the current research a short measure of safety performance is developed for use in the construction industry and the relationships between different components of safety performance and safety outcomes (e.g., occupational injuries and work-related pain) are explored within the construction context. This research consists of two field studies. In the first, comprehensive measures of safety compliance and safety participation were shortened and modified to be appropriate for use in construction. Evidence of reliability and validity is provided. Both safety compliance and safety participation were negatively related to occupational injuries, yet these two correlations were not statistically different. In the second study, we investigated the relationships between these two components of safety performance and work-related pain frequency, in addition to replicating Study 1. Safety compliance had a stronger negative relationship with pain than safety participation. Implications for research are discussed.     

CAC-OLSR: Extending OLSR to Provide Admission Control in Wireless Mesh Networks

This work presents an admission control mechanism for multi-hop wireless mesh networks based on the IEEE 802.11 standard and the OLSR routing protocol. This mechanism, called CAC-OLSR, aims at ensuring that traffic flows with quality of service (QoS) requirements, especially voice and video, are only admitted in the mesh network if it has available resources in order to provide flow requirements. In addition, QoS requirements of previously admitted traffic flows cannot be violated. The proposal was evaluated with NS-2 and Evalvid simulations.     

Locomotor activity rhythms in dogs vary with age and cognitive status.

Beagle dogs exhibited diurnal patterns of locomotor activity that varied as a function of age, cognitive status, and housing environment. Aged dogs housed in an indoor facility showed a delayed onset of activity following lights on and displayed shorter bouts of activity, with more rest periods during the day, compared with young dogs. Cognitively impaired aged dogs were more active and showed a delayed peak of activity compared with unimpaired aged dogs. Housing in continuous light did not disrupt activity rhythms. The effect of age was less prominent in dogs housed in an indoor/outdoor facility. This suggests that bright sunlight and natural light-dark transitions are better able to consolidate and synchronize the activity rhythms of the dogs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improving TCP performance over wireless networks at the link layer

We present the transport unaware link improvement protocol (TULIP), which dramatically improves the performance of TCP over lossy wireless links, without competing with or modifying the transport- or network-layer protocols. TULIP is tailored for the half-duplex radio links available with today's commercial radios and provides a MAC acceleration feature applicable to collision-avoidance MAC protocols (e.g., IEEE 802.11) to improve throughput. TULIP's timers rely on a maximum propagation delay over the link, rather than performing a round-trip time estimate of the channel delay. The protocol does not require a base station and keeps no TCP state. TULIP is exceptionally robust when bit error rates are high; it maintains high goodput, i.e., only those packets which are in fact dropped on the wireless link are retransmitted and then only when necessary. The performance of TULIP is compared against the performance of the Snoop protocol (a TCP-aware approach) and TCP without link-level retransmission support. The results of simulation experiments using the actual code of the Snoop protocol show that TULIP achieves higher throughput, lower packet delay, and smaller delay variance. This revised version was published online in June 2006 with corrections to the Cover Date.     

Transient response of premixed methane flames

The response of premixed methane-air flames to transient strain and local variations in equivalence ratio is studied during isolated interactions between a line-vortex pair and a V-flame. The temporal evolution of OH and CH is measured with planar laser-induced fluorescence for N₂-diluted flames with equivalence ratios ranging from 0.8 to 1.2. One-dimensional laminar flame calculations are used to simulate the flame response to unsteady strain and variations in reactant composition. When the reactant composition of the vortex pair and the V-flame are identical, the measurements and predictions show that the peak mole fractions of OH and CH decay monotonically in lean, stoichiometric, and rich flames. We also investigate the effects of a vortex pair with a leaner composition than the V-flame. In a stoichiometric flame, the leaner vortex enhances the decay of both OH and CH. In a rich flame, we observe an abrupt increase in OH-LIF signal and a disappearance of CH-LIF signal that are consistent with a previous experimental investigation. Our results indicate that the previously observed OH burst and CH breakage were caused by a difference in the equivalence ratios of the vortex pair and the main reactant flow. A numerical study shows that N₂ dilution enhances the response of premixed flames to unsteady strain and variations in stoichiometry. Reaction-path and sensitivity analyses indicate that the peak OH and CH mole fractions exhibit significant sensitivity to the main branching reaction, H + O₂ ↔ OH + O. The sensitivity of OH and CH to this and other reactions is enhanced by N₂ dilution. As a result, N₂-diluted flames provide a good test case for studying the reliability of chemical kinetic and transport models.     

创新的ADC结构在速度和功耗上取得进展

Xignal Technologies（混合信号IC开发商）（Munich，德国）在连续时间△∑式A／D转换技术上取得突破，可为在高采样速率条件下需要高动态范围的空间有限的应用，比如下一代便携式超声波仪器，提供高速、低功耗的A／D转换。     

Using simulation to improve synchronous flow in pinion manufacturing

The quality of Management decision-making is greatly improved when a good animation of the manufacturing operation clearly shows how everything is going to work.

This paper describes the use of one of the best current animation tools, namely Witness 7 from AT&T ISTEL, applied to the decision to modify a current operation.

The paper describes how the simulation analysis played an important role in assuring that the management decision was correct.     

IT2000: A critical appraisal of Singapore's state-wide strategic planning process for information technology

In April 1992, the Singapore Government announced its information technology (IT) vision and plan for the next 15 years to turn Singapore into ‘an intelligent island’, providing a strategic regional switching centre for expertise, goods, services and information. At the heart of this plan is a national information infrastructure that would capitalize on information as a key factor of production and an important ingredient for enhancing the quality of life of its people. Code named ‘IT2000’, the plan was developed by 60 senior managers at the National Computer Board in 1991 with participation and inputs from about 200 business and industry leaders, domain experts and academics. This paper describes the background of Singapore's drive into the information age, the IT2000 planning process, the roles of various participants and the main recommendations of the plan. An evaluation of IT2000 is made in terms of its objectives, its unanticipated results and its impacts on industry participants. Implications and lessons are drawn for strategic IT planning at the national or sectoral level.