Photometric measurements of surface characteristics of echo i satellite final report

Photometric measurements of Echo I satellite surface characteristic

Ground-based photometric surveillance of the passive geodetic satellite

Ground-based photometry of Passive Geodetic Earth Orbiting Satellite /PAGEOS

Inefficiencies in the Cache Hierarchy: A Sensitivity Study of Cacheline Size with Mobile Workloads

With the rising number of cores in mobile devices, the cache hierarchy in mobile application processors gets deeper, and the cache size gets bigger. However, the cacheline size remained relatively constant over the last decade in mobile application processors. In this work, we investigate whether the cacheline size in mobile application processors is due for a refresh, by looking at inefficiencies in the cache hierarchy which tend to be exacerbated when increasing the cacheline size: false sharing and cacheline utilization. Firstly, we look at false sharing, which is more likely to arise at larger cacheline sizes and can severely impact performance. False sharing occurs when non-shared data structures, mapped onto the same cacheline, are being accessed by threads running on different cores, causing avoidable invalidations and subsequent misses. False sharing has been found in various places such as scientific workloads and real applications. We find that whilst increasing the cacheline size does increase false sharing, it still is negligible when compared to known cases of false sharing in scientific workloads, due to the limited level of thread-level parallelism in mobile workloads. Secondly, we look at cacheline utilization which measures the number of bytes in a cacheline actually used by the processor. This effect has been investigated under various names for a multitude of server and desktop applications. As a low cacheline utilization implies that very little of the fetched cachelines was used by the processor, this causes waste in bandwidth and energy in moving data across the memory hierarchy. The energy cost associated with data movements is much higher compared to logic operations, increasing the need for cache efficiency, especially in the case of an energy-constrained platform like a mobile device. We find that the cacheline utilization of mobile workloads is low in general, decreasing when increasing the cacheline size. When increasing the cacheline size from 64 bytes to 128 bytes, the number of misses will be reduced by 10%-30%, depending on the workload. However, because of the low cacheline utilization, this more than doubles the amount of unused traffic to the L1 caches. Using the cacheline utilization as a metric in this way, illustrates an important point. If a change in cacheline size would only be assessed on its local effects, we find that this change in cacheline size will only have advantages as the miss rate decreases. However, at system level, this change will increase the stress on the bus and increase the amount of wasted energy due to unused traffic. Using cacheline utilization as a metric underscores the need for system-level research when changing characteristics of the cache hierarchy

Strong interaction of a turbulent spot with a shock-induced separation bubble

Direct numerical simulations have been conducted to study the passage of a turbulent spot through a shock-induced separation bubble. Localized blowing is used to trip the boundary layer well upstream of the shock impingement, leading to mature turbulent spots at impingement, with a length comparable to the length of the separation zone. Interactions are simulated at free stream Mach numbers of two and four, for isothermal (hot) wall boundary conditions. The core of the spot is seen to tunnel through the separation bubble, leading to a transient reattachment of the flow. Recovery times are long due to the influence of the calmed region behind the spot. The propagation speed of the trailing interface of the spot decreases during the interaction and a substantial increase in the lateral spreading of the spot was observed. A conceptual model based on the growth of the lateral shear layer near the wingtips of the spot is used to explain the change in lateral growth rat

Training scholars in dissemination and implementation research for cancer prevention and control: A mentored approach

Abstract Background As the field of D&I (dissemination and implementation) science grows to meet the need for more effective and timely applications of research findings in routine practice, the demand for formalized training programs has increased concurrently. The Mentored Training for Dissemination and Implementation Research in Cancer (MT-DIRC) Program aims to build capacity in the cancer control D&I research workforce, especially among early career researchers. This paper outlines the various components of the program and reports results of systematic evaluations to ascertain its effectiveness. Methods Essential features of the program include selection of early career fellows or more experienced investigators with a focus relevant to cancer control transitioning to a D&I research focus, a 5-day intensive training institute, ongoing peer and senior mentoring, mentored planning and work on a D&I research proposal or project, limited pilot funding, and training and ongoing improvement activities for mentors. The core faculty and staff members of the MT-DIRC program gathered baseline and ongoing evaluation data regarding D&I skill acquisition and mentoring competency through participant surveys and analyzed it by iterative collective reflection. Results A majority (79%) of fellows are female, assistant professors (55%); 59% are in allied health disciplines, and 48% focus on cancer prevention research. Forty-three D&I research competencies were assessed; all improved from baseline to 6 and 18 months. These effects were apparent across beginner, intermediate, and advanced initial D&I competency levels and across the competency domains. Mentoring competency was rated very highly by the fellows––higher than rated by the mentors themselves. The importance of different mentoring activities, as rated by the fellows, was generally congruent with their satisfaction with the activities, with the exception of relatively greater satisfaction with the degree of emotional support and relatively lower satisfaction for skill building and opportunity initially. Conclusions These first years of MT-DIRC demonstrated the program’s ability to attract, engage, and improve fellows’ competencies and skills and implement a multicomponent mentoring program that was well received. This account of the program can serve as a basis for potential replication and evolution of this model in training future D&I science researchers

The Isolation of an Actinomycetes-Like Organism from Root Canals

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67354/2/10.1177_00220345410200030301.pd

Quantifying black carbon deposition over the Greenland ice sheet from forest fires in Canada

Black carbon (BC) concentrations observed in 22 snowpits sampled in the northwest sector of the Greenland ice sheet in April 2014 have allowed us to identify a strong and widespread BC aerosol deposition event, which was dated to have accumulated in the pits from two snow storms between 27 July and 2 August 2013. This event comprises a significant portion (57% on average across all pits) of total BC deposition over 10 months (July 2013 to April 2014). Here we link this deposition event to forest fires burning in Canada during summer 2013 using modeling and remote sensing tools. Aerosols were detected by both the Cloud‐Aerosol Lidar with Orthogonal Polarization (on board CALIPSO) and Moderate Resolution Imaging Spectroradiometer (Aqua) instruments during transport between Canada and Greenland. We use high‐resolution regional chemical transport modeling (WRF‐Chem) combined with high‐resolution fire emissions (FINNv1.5) to study aerosol emissions, transport, and deposition during this event. The model captures the timing of the BC deposition event and shows that fires in Canada were the main source of deposited BC. However, the model underpredicts BC deposition compared to measurements at all sites by a factor of 2–100. Underprediction of modeled BC deposition originates from uncertainties in fire emissions and model treatment of wet removal of aerosols. Improvements in model descriptions of precipitation scavenging and emissions from wildfires are needed to correctly predict deposition, which is critical for determining the climate impacts of aerosols that originate from fires