Achieving robust design through statistical effect screening

This work proposes a method for statistical effect screening to identify design parameters of a numerical simulation that are influential to performance while simultaneously being robust to epistemic uncertainty introduced by calibration variables. Design parameters are controlled by the analyst, but the optimal design is often uncertain, while calibration variables are introduced by modeling choices. We argue that uncertainty introduced by design parameters and calibration variables should be treated differently, despite potential interactions between the two sets. Herein, a robustness criterion is embedded in our effect screening to guarantee the influence of design parameters, irrespective of values used for calibration variables. The Morris screening method is utilized to explore the design space, while robustness to uncertainty is quantified in the context of info‐gap decision theory. The proposed method is applied to the National Aeronautics and Space Administration Multidisciplinary Uncertainty Quantification Challenge Problem, which is a black‐box code for aeronautic flight guidance that requires 35 input parameters. The application demonstrates that a large number of variables can be handled without formulating simplifying assumptions about the potential coupling between calibration variables and design parameters. Because of the computational efficiency of the Morris screening method, we conclude that the analysis can be applied to even larger‐dimensional problems. (Approved for unlimited, public release on October 9, 2013, LA‐UR‐13‐27839, Unclassified.) Copyright © 2015 John Wiley & Sons, Ltd.     

Change Agent Competencies for Information Technology Project Managers.

In the past few years, the project management (PM) profession has grown exponentially. Yet recent studies in the information technology (IT) sector have found that the use of PM methodologies alone does not guarantee project success. In fact, IT project success is seen to rely on the ability of project managers to be agents of change (i.e., individuals who lead organizational change efforts), a traditional role of practitioners of organization development and change. This article identifies the knowledge, skills, and competencies that are common to organization development (OD) practitioners and project managers, as represented by 6 principles or competencies that OD and PM change methods snare: communication, teamwork, process management, leadership, training, and continuous learning. The importance of these 6 principles in developing professional project managers as effective agents of change is explored with the intent of finding means to improve upon current IT project success rates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detecting back irrelevant responding on the Personality Assessment Inventory in a psychiatric inpatient setting.

The present studies focus on strategies for detecting back irrelevant responding (BIR) on the Personality Assessment Inventory (PAI; L. C. Morey, 1991). Moderate BIR levels can greatly affect the clinical scales of the PAI. Further, the PAI's Inconsistency and Infrequency validity scales are less than optimal for detecting BIR. L. C. Morey and C. J. Hopwood (2004) developed an alternative strategy for detecting BIR that involves comparison of 2 scales from the PAI short-form with the same 2 scales from the PAI full-instrument. The present study examines how different BIR levels affect the clinical, treatment, and interpersonal scales of the PAI in 2 psychiatric inpatient samples. The effectiveness of various strategies for detecting BIR in an inpatient setting is also discussed. Consistent with previous research, moderate rates of BIR impacted several PAI scales in a meaningful way. The Inconsistency and Infrequency validity scales of the PAI were relatively ineffective for detecting low-to-moderate BIR levels. Conversely, the short-form full-instrument comparison strategy was much more sensitive to BIR. Finally, a new BIR detection indicator is presented that improves sensitivity rates for detecting all BIR levels in an acute setting. The implications of these results for detecting BIR in inpatient settings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expository Text Comprehension in the Primary Grade Classroom.

This study investigates the effectiveness of an instructional program designed to teach 2nd graders how to comprehend compare-contrast expository text. Along with introducing new content (animal classification), the program emphasizes text structure via clue words, a sequence of questions, and a graphic organizer, and via the close analysis of specially constructed exemplar paragraphs. The authors compared the program with (a) more traditional instruction that focused only on the new content and (b) a no instruction control; 128 7- and 8-year-olds participated. Classroom teachers provided the instruction. The program improved students' ability to comprehend compare-contrast texts. Students were able to demonstrate transfer to uninstructed compare-contrast texts though not to text structures other than compare-contrast. Moreover, the text structure instruction did not detract from their ability to learn new content. The results provide evidence, heretofore lacking, that explicit instruction in comprehension is feasible and effective as early as the 2nd grade. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

DYNAMIC BEHAVIOR OF PERIODIC FEEDBACK CONTROL SYSTEMS

Periodic feedback is a control strategy implemented by fast zero-average oscillations in the parameters of the control law. It is well known that time invariant feedback control offers no means for zeros relocation. Periodic feedback allows zeros relocation in an asymptotic sense, resulting in improved closed loop characteristics, such as increased gain margins.     

Capillary LC-MS for high sensitivity metabolomic analysis of single islets of Langerhans

Reversed-phase, packed capillary liquid chromatography interfaced by electrospray ionization to mass spectrometry was explored as an analytical method for determination of metabolites in microscale tissue samples using single islets of Langerhans as a model system. With the use of a 75 microm inner diameter column coupled to a quadrupole ion trap mass spectrometer in full scan mode, detection limits of 0.1-33 fmol were achieved for glycoloytic and tricarboxylic acid cycle metabolites. Reproducible processing of islets for analysis with little loss of metabolites was performed by rapid freezing followed by methanol-water extraction. The method yielded 20 microL of extract of which just 15 nL was injected suggesting the potential for performing multiple assays on the same islet. Approximately 200 presumed metabolites could be detected, of which 22 were identified by matching retention times and MS/MS spectra to standards. Relative standard deviations for peak detection was from 7 to 18% and was unaffected by storage for up to 11 days. The method was used to detect changes in metabolism associated with increasing extracellular islet glucose concentration from 3 to 20 mM yielding results largely consistent with known metabolism of islets. Because most previous studies of islet metabolism have only observed a few compounds at once and require far more tissue, this measurement method represents a significant advance for studies of metabolism of islets and other microscale samples.     

Microglial FABP4-UCP2 Axis Modulates Neuroinflammation and Cognitive Decline in Obese Mice

The microglial fatty-acid-binding protein 4-uncoupling protein 2 (FABP4-UCP2) axis is a key regulator of neuroinflammation in high-fat-diet (HFD)-fed animals, indicating a role for FABP4 in brain immune response. We hypothesized that the FABP4-UCP2 axis is involved in regulating diet-induced cognitive decline. We tested cognitive function in mice lacking microglial FABP4 (AKO mice). Fifteen-week-old male AKO and wild-type (WT) mice were maintained on 60% HFD or normal chow (NC) for 12 weeks. Body composition was measured using EchoMRI. Locomotor activity, working memory, and spatial memory were assessed using behavioral tests (open field, T-maze, and Barnes maze, respectively). Hippocampal microgliosis was assessed via immunohistochemical staining. An inflammatory cytokine panel was assayed using hippocampal tissue. Real-time RT-PCR was performed to measure microglial UCP2 mRNA expression. Our data support that loss of FABP4 prevents cognitive decline in vivo. HFD-fed WT mice exhibited impaired long- and short-term memory, in contrast with HFD-fed AKO mice. HFD-fed WT mice had an increase in hippocampal inflammatory cytokine expression (IFNγ, IL-1β, IL-5, IL-6, KC/GRO(CXCL1), IL-10, and TNFα) and microgliosis, and decreased microglial UCP2 expression. HFD-fed AKO mice had decreased hippocampal inflammatory cytokine expression and microgliosis and increased microglial UCP2 expression compared to HFD-fed WT mice. Collectively, our work supports the idea that the FABP4-UCP2 axis represents a potential therapeutic target in preventing diet-induced cognitive decline.     

Knowledge and beliefs regarding the consequences of cigarette smoking and their relationships to smoking status in a biracial sample.

198 men and 413 women responded to random telephone surveys in Fargo, North Dakota and Memphis, Tennessee. Each S was given the Smoking Attitudes Survey, which assesses generalized health beliefs and health-related problems associated with smoking. Ss' knowledge of smoking-associated diseases and diseases not associated with smoking was also assessed. Stepwise regression analysis of composite knowledge scores revealed 4 predictors of the health consequences of smoking: education, race, smoking status, and income. Smokers reported less knowledge and less concern about health consequences of smoking, were more likely to be male, and were more concerned about health consequences of cholesterol. The best predictor of smokers who had never attempted cessation was their greater concern over weight control, compared with smokers with a history of smoking-cessation attempts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stochastic colored Petri net models of flexible manufacturing systems: Material handling systems and machining

This paper presents an overview of SCPN theory, a set of three generic SCPN submodels, a behavior-preserving methodology for combining those submodels into a larger model, and a combined model. The three submodels include a machine with failures, repairs, and limited I/O buffers, and two types of conveyor submodels—a simple conveyor segment and a conveyor segment at a machine.