Application of averaged instantaneous power spectrum for diagnostics of machinery operating under non-stationary operational conditions

Vibration analysis of machines operating under non-stationary operational conditions requires special attention. This refers to the necessity of use of order tracking algorithms together with additional advanced signal processing methods, especially when faults indicators of interest are located in resonance frequency ranges.     

Risk based management of contaminated sediments: consideration of spatial and temporal patterns in exposure modeling

This paper addresses interactions among foraging behavior, habitat preferences, site characteristics, and spatial distribution of contaminants in developing PCB exposure estimates for winter flounder at a hypothetical open water dredged material disposal site in the coastal waters of New York and New Jersey (NY-NJ). The implications of these interactions for human health risk estimates for local recreational anglers who fish for and eat flounder are described. The models implemented in this study include a spatial submodel to account for spatial and temporal characteristics of fish exposures and a probabilistic adaptation of the Gobas bioaccumulation model that accounts for temporal variation in concentrations of hydrophobic contaminants in sediment and water. We estimated the geographic distribution of a winter flounder subpopulation offshore of NY-NJ based on species biology and its vulnerability to local recreational fishing, the foraging area of individual fish, and their migration patterns. We incorporated these parameters and an estimate of differential attraction to a management site into a spatially explicit model to assess the range of exposures within the population. The output of this modeling effort, flounder PCB tissue concentrations, provided exposure point concentrations for an estimate of human health risk through ingestion of locally caught flounder. The risks obtained for the spatially nonexplicit case are as much as 1 order of magnitude higher than those obtained with explicit consideration of spatial and temporal characteristics of winter flounder foraging and seasonal migration. This practice of "defaulting" to extremely conservative estimates for exposure parameters in the face of uncertainty ill serves the decision-making process for management of contaminated sediments in general and specifically for disposal of dredged materials. Consideration of realistic spatial and temporal scales in food chain models can help support sediment management decisions by providing a quantitative expression of the confidence in risk estimates.     

Products of pertechnetate radiolysis in highly alkaline solution: structure of TcO2 x xH2O

The chemistry of technetium in certain high-level nuclear waste (HLW) tanks at the Hanford Site complicates the treatment and vitrification of HLW. A major problem is the presence, in certain tanks, of unidentified, lower-valent technetium species, which are difficult to remove from the waste by current separation processes. Radiolytic reduction of TcO4- in alkaline solutions containing selected organic compounds, approximating the conditions in HLW, was investigated to determine the classes of compounds that can be formed under these conditions. Insoluble TcO2 x xH2O is the primary radiolysis product with the majority of organic compounds investigated, including citrate, dibutyl phosphate, and aminopolycarboxylates. X-ray absorption fine structure (XAFS) measurements show that TcO2 x xH2O has a one-dimensional chain structure consisting of edge-sharing TcO6 octahedra with bridging oxide and trans water ligands. When diols, such as ethylene glycol, are present, only soluble, Tc(IV) alkoxide compounds are produced. The XAFS and UV-visible spectra of these compounds provide evidence for a binuclear structure similar to (H2EDTA)2Tc2(mu-O)2. The properties of the Tc(IV) alkoxide complexes were determined and are consistent with those observed for the soluble, lower-valent technetium complexes that complicate the treatment of HLW at the Hanford site.     

Application of a computational decision model to examine acute drug effects on human risk taking.

In 3 previous experiments, high doses of alcohol, marijuana, and alprazolam acutely increased risky decision making by adult humans in a 2-choice (risky vs. nonrisky) laboratory task. In this study, a computational modeling analysis known as the expectancy valence model (J. R. Busemeyer & J. C. Stout, 2002) was applied to individual-participant data from these studies, for the highest administered dose of all 3 drugs and corresponding placebo doses, to determine changes in decision-making processes that may be uniquely engendered by each drug. The model includes 3 parameters: responsiveness to rewards and losses (valence or motivation); the rate of updating expectancies about the value of risky alternatives (learning/memory); and the consistency with which trial-by-trial choices match expected outcomes (sensitivity). Parameter estimates revealed 3 key outcomes: Alcohol increased responsiveness to risky rewards and decreased responsiveness to risky losses (motivation) but did not alter expectancy updating (learning/memory); both marijuana and alprazolam produced increases in risk taking that were related to learning/memory but not motivation; and alcohol and marijuana (but not alprazolam) produced more random response patterns that were less consistently related to expected outcomes on the 2 choices. No significant main effects of gender or dose by gender interactions were obtained, but 2 dose by gender interactions approached significance. These outcomes underscore the utility of using a computational modeling approach to deconstruct decision-making processes and thus better understand drug effects on risky decision making in humans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Group psychotherapy focusing on self-concept change following acquired brain injury: A pilot investigation.

Objective: The current study explored the effectiveness of a group therapy intervention that was focused specifically on self-concept changes following acquired brain injury (ABI). Method: Eighteen individuals in the postacute phase of recovery underwent a 6-week group therapy intervention and were administered a self-concept measure before and after the intervention. Results: Group members showed a significant increase (improvement) in self-concept ratings at the end of the group intervention. Conclusions: Although the results of this study suggest that this intervention may be helpful in improving self-concept following ABI, further exploration is clearly warranted. Future research is needed to investigate the impact of self-concept on emotional adjustment, participation in rehabilitation activities, and functional outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of multiplicative combination rules when the causal variables are measured with error.

Evaluates the validity of the observational method used to test multiplicative combination rules with respect to 2 measurement issues: measurement level (i.e., the effects produced by allowing monotonic transformations of the measures) and measurement error (i.e., the effects produced by using unreliable measures of the causal variables). The evaluation is based on a theoretical distinction between the structural model (the set of equations relating theoretical constructs to each other) and the measurement model (the set of equations relating the theoretical constructs to the observed measures). It is concluded that hierarchical regression analysis is inadequate for determining whether the structural model is additive or multiplicative for 2 reasons: First, an additive structural model may produce multiplicative effects through a nonlinear measurement model. Second, a multiplicative structural model may produce nondetectable multiplicative effects because of multiplicative measurement error. Some alternatives to hierarchical regression analysis are described. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparing professional and lay expectations of psychotherapy.

Compared 25 mental health professionals whose primary duties involved psychotherapy with 52 laypersons aged 18–51 yrs to determine similarities and differences in their expectations of psychotherapy. Ss were administered the Therapy Expectations Scale. Differences between the 2 groups were found in degree of expected change, importance of self in problem-solving, financial emphasis, and expected duration of psychotherapy. Similarities were found in socioenvironmental areas and in emphasis on the early years of life. Laypersons tended to appreciate the active role of the client in psychotherapy and viewed therapists as experts in problem-solving. It is suggested that greater efforts be made to educate the general public as well as individual clients about the realities of psychotherapy. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Decision theory and artificial intelligence: I. A semantics-based region analyzer

Mathematical decision theory can be combined with heuristic techniques to attack Artificial Intelligence problems. As a first example, the problem of breaking an image into meaningful regions is considered. Bayesian decision theory is seen to provide a mechanism for including problem dependent (semantic) information in a general system. Some results are presented which make the computation feasible. A programming system based on these ideas and its application to road scenes is described.     

Reality testing by schizophrenics.

Compared 15 schizophrenics with 15 controls of similar mental test status and educational background on 2 classes of elementary problems from a series of artifact testing tasks monitored by an automatic problem programing machine called the Heuristic Evaluation Problem Programmer. In terms of an index that reflects the ability to conduct the required inquiry efficiently, the groups did not differ significantly on statistical tests that employed between-Ss differences as the error variance. Repeated measures of group differences showed a small, but statistically significant, superiority for the control Ss. Intercorrelations between scores on various problem sets indicated that the tests were reliable. During the 1st 3/4 of the problem series, there was a marked inefficiency of performance in a small group of paranoid schizophrenics as compared with a group of chronic undifferentiated schizophrenics. (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)