Multiscale, Multiphysics Numerical Modeling of Fusion Welding with Experimental Characterization and Validation

Various physical interfacial phenomena occur during the process of welding and influence the final properties of welded structures. As the features of such interfaces depend on physics that resolve at different spatial scales, a multiscale and multiphysics numerical modeling approach is necessary. In a collaborative research project Modeling of Interface Evolution in Advanced Welding, a novel strategy of model linking is employed in a multiscale, multiphysics computational framework for fusion welding. We only directly link numerical models that are on neighboring spatial scales instead of trying to link all submodels directly together through all available spatial scales. This strategy ensures that the numerical models assist one another via smooth data transfer, avoiding the huge difficulty raised by forcing models to attempt communication over many spatial scales. Experimental activities contribute to the modeling work by providing valuable input parameters and validation data. Representative examples of the results of modeling, linking and characterization are presented.     

On the Cumulative Distribution of Outgoing Quality: A New Criterion for Sampling Plans

A procedure is developed for designing rectifying sampling plans by attributes with a predetermined upper bound on the outgoing quality of the lots. These plans are derived so that the upper bound is satisfied with specified minimum probability regardless of the value of the process average. In addition, the average outgoing quality limit (AOQL) criterion is evaluated with respect to the probability bound concept. Computational procedures are presented that allow the design of sampling plans with user specified upper bounds with designated minimum probability 1 – α. A table is presented for determining sampling plans for the use of 1 – α = .95.     

Some Implications of Interactive Graphic Computer Systems for Data Analysis and Statistics

“Current facilities for computing, display, and real time interaction have developed substantially beyond our understanding of how to use them effectively in data analysis. Current limitations in data analysis technology are mainly in explicating and organizing the science of data analysis and of defining and implementing the necessary associated computer software.

“From the statistical side of the discipline must come: broader, more permissive, empirically oriented concepts and theories; more inclusive and realistic classifications of objectives; more effective and coherent classifications of useful techniques; research toward more empirically informative techniques that will provide both exposure and summarization; more understanding and research on techniques of reforming and re-expressing variables; deeper insight into the psychology of graphs, pictures and output formats in general, both for interaction and for communication; progress toward standardized data structures of great flexibility and comprehensiveness.

“From the computing side of the discipline is required software to provide: convenience with flexibility, simple and effective bookkeeping and history keeping, adequate editing, effective means for treating output as input, more flexible and general graphical presentations, and a variety of means to facilitate real time interaction.

“Though some progress is being made on many of these needs, the technology of data analysis is still in its infancy.” (Tukey and Wilk, 1966)

John Tukey and Martin Wilk have described what, they feel are the future needs in data analysis and statistics in the following terms.     

Fault detection using transient machine signals

This paper describes the development and testing of a strategy for vibration-based online detection of faults in a particular class of machinery. This machinery is defined by two basic characteristics that preclude it from the application of standard online condition monitoring systems. The first characteristic is the absence of historical fault data. The second characteristic is that the machine is in a constant state of transient operation. An example of such a machine is the swing machinery of an electromechanical excavator. The monitoring strategy presented here employs an anomaly detection scheme together with various methods of signal processing and feature extraction. Experiments are carried out using a laboratory apparatus to show the how various configurations of the system are able to detect different types of faults. The results indicate that this approach is effective and merits further investigation.     

Effects of acute and 14-day coenzyme Q10 supplementation on exercise performance in both trained and untrained individuals

Background

To determine whether acute (single dose) and/or chronic (14-days) supplementation of CoQ10 will improve anaerobic and/or aerobic exercise performance by increasing plasma and muscle CoQ10 concentrations within trained and untrained individuals.

Methods

Twenty-two aerobically trained and nineteen untrained male and female subjects (26.1 ± 7.6 yrs, 172 ± 8.7 cm, 73.5 ± 17 kg, and 21.2 ± 7.0%) were randomized to ingest in a double-blind manner either 100 mg of a dextrose placebo (CON) or a fast-melt CoQ10 supplement (CoQ10) twice a day for 14-days. On the first day of supplementation, subjects donated fasting blood samples and a muscle biopsy. Subjects were then given 200 mg of the placebo or the CoQ10 supplement. Sixty minutes following supplement ingestion, subjects completed an isokinetic knee extension endurance test, a 30-second wingate anaerobic capacity test, and a maximal cardiopulmonary graded exercise test interspersed with 30-minutes of recovery. Additional blood samples were taken immediately following each exercise test and a second muscle biopsy sample was taken following the final exercise test. Subjects consumed twice daily (morning and night), 100 mg of either supplement for a period of 14-days, and then returned to the lab to complete the same battery of tests. Data was analyzed using repeated measures ANOVA with an alpha of 0.05.

Results

Plasma CoQ10 levels were significantly increased following 2 weeks of CoQ10 supplementation (p < 0.001); while a trend for higher muscle CoQ10 levels was observed after acute CoQ10 ingestion (p = 0.098). A trend for lower serum superoxide dismutase (SOD) was observed following acute supplementation with CoQ10 (p = 0.06), whereas serum malondialdehyde (MDA) tended to be significantly higher (p < 0.05). Following acute ingestion of CoQ10, plasma CoQ10 levels were significantly correlated to muscle CoQ10 levels; maximal oxygen consumption; and treadmill time to exhaustion. A trend for increased time to exhaustion was observed following 2 weeks of CoQ10 supplementation (p = 0.06).

Conclusion

Acute supplementation with CoQ10 resulted in higher muscle CoQ10 concentration, lower serum SOD oxidative stress, and higher MDA levels during and following exercise. Chronic CoQ10 supplementation increased plasma CoQ10 concentrations and tended to increase time to exhaustion. Results indicate that acute and chronic supplementation of CoQ10 may affect acute and/or chronic responses to various types of exercise.     

从大都市到多中心都市

巨型城市区域：一个新现象 多中心巨型城市区域（MCR：mega-cityregion）作为一个全新的现象,正在当今世界上高度城市化的地区出现。它的出现经历了一个从中心大城市到邻近小城市的漫长扩散过程。这些小城市或新或旧。虽然戈特曼（Jean Gottmann）早在1961年就已在其关于都市带的先驱研究中最早界定美国高度城市化的东北海岸为巨型城市区域．     

Narrative text analysis of Kentucky tractor fatality reports

Narrative information in fatality investigation reports contains data elements not routinely analyzed with coded occupational injury surveillance data. A narrative text analysis of 69 Kentucky Fatality Assessment and Control Evaluation (FACE) agricultural tractor fatality reports from 1994 to 2004 was performed. The FACE reports were developed using the National Institute for Occupational Safety and Health, Division of Safety Research-recommended FACE report format that incorporates Haddon's matrix. Haddon's matrix separates the fatal incident into three event phases and is used to develop points of intervention based on human, organizational, and environmental factors. A multivariate logistic regression analysis for association between identified exposure variables and the outcomes of interest was undertaken. The operation of a tractor with an attached bucket, muddy terrain, and being thrown from the tractor were independent risk factors for being declared "dead at the scene". A tractor rollover and operation of a tractor on a slope were independent risk factors for being "crushed" by a tractor. Narrative text analysis of FACE fatality investigation reports is a valuable tool for the identification of additional factors contributing to tractor fatalities that can inform farm safety training, identify new areas for agricultural interventions, and support the development of new agricultural engineering strategies.