Suboptimal state estimation for continuous-time nonlinear systems from discrete noisy measurements

This paper presents the derivation of the dynamical equations of a second-order filter which estimates the states of a non-linear plant on the basis of discrete noisy measurements. The filter equations contain terms involving the second-order partial derivatives of the plant and output equations. Simulation results are presented which yield a comparison of the performance of the first-versus the second-order filter when applied to a nonlinear third-order system. The results indicate that the inclusion of second-order terms can markedly improve the filter performance.     

Autoxidation of tissue lipids. II. Monocarbonyl compounds formed by the autoxidation of methyl eicosapentaenoate,methyl docosahexaenoate,and cod-liver oil

Fatty acid analysis of autoxidized cod-liver oil with a peroxide value of 192 showed significant degradation of only eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids of the linolenate family. Purified, mildly autoxidized cod-liver oil with a peroxide value of 28, methyl eicosapentaenoate, and methyl docosahexaenoate produced carbonyl patterns in agreement with the accepted mechanism for olefinic autoxidation. In all cases the major products were propanal andn-pent-2-enal as predicted, andn-hex-2-enal andn-hept-2-enal as reported in the literature for linolenate. In addition, the same cod-liver oil, which had been heated to 188C in vacuum for 1 hr to decompose completely the hydroperoxides before carbonyl analysis, showed the presence ofn-hepta-2,4-dienal as predicted.     

Task difficulty and the efficiency of muscular activity.

Hypothesized that intensity and organization of muscle activity are functions of S's expectation of difficulty of a task. Task difficulty was varied for 15 20-40 yr. old instructors and undergraduates by preparing S for holding heavy and light weights, respectively. The difficult task consisted of holding a 41-lb weight following 30 sec. of holding a 19-lb weight. The easy task was holding a 6-lb weight following 30 sec. of holding the 19-lb weight. Electrical activity of the following muscles of the right (active) arm was measured: biceps brachii, brachialis, brachioradialis, flexor carpi ulnaris, and triceps. During the holding of the middle range weight, muscle activity was lower in preparation for the heavy weight than for the light weight, but there were no significant changes in the organization of muscle activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Studies in efficiency: Muscle-action patterns in reaction time as related to GSR conditioning.

A significant interaction between degree of efficiency in reaction time and in meeting task requirements in the GSR conditioning situation was found, such that efficient Ss tended to take longer to reach criterion under instructions to relax, while there was no difference between the groups when the requirement was to solve a problem. Under the relax instructions the correlation of right- to left-arm tension with trials to successive CRs was .60; under problem instructions it was -.04. Taken together with the previous studies, these results are interpreted as support for the method of analysis implied by the concept of efficiency. They prepare the way for further tests of the hypothesis that efficiency will be related to degrees of psychopathology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A developmental study of efficiency in differential galvanic skin response conditioning.

Hypothesized that in a differential galvanic-skin-response (GSR) conditioning situation, differential sets would be increasingly effective with increasing age in producing differential rates of conditioning. The GSRs of 193 children from kindergarten and Grades 1, 2, 4, and 6 were conditioned under inhibiting and facilitating sets. Support for the hypothesis was found in a significant Grade * Set interaction. Ability to verbalize the positive-conditioned-stimulus-unconditioned-stimulus relation was also a function of the Grade * Set interaction, as well as the interaction of Grade * Successful vs Unsuccessful Conditioning. Data also indicate the importance of cognitive factors in classical conditioning paradigms with human Ss. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Francis W. Irwin (1905–1985).

Presents and obituary for Francis Irwin. For almost 60 years, Irwin devoted himself to learning, creating, and transmitting knowledge at the distinguished level worthy of a person of science and integrity. He labored assiduously to fashion a lasting contribution to his field, producing results and ideas which constitute a major addition to the structure required for a genuine science of behavior. His substantive contributions to psychophysics centered on the many changes occurring in subjects due to their experience in making the required judgments. His research also focused on methods in the psychology of motivation, and he developed his own theory of motivation, an elegant and carefully woven structure based on a clear philosophy of the nature of psychological science, relevant experimental results, and persistent confrontation of the complexities of animal and human motivation. Using the established tools of symbolic logic, as well as inventing a new operation required by an empirical science, Irwin built an inclusive theory of motivation solidly based on past data and theory. Among his many professional activities, Irwin served twice on the Board of Directors of the Eastern Psychological Association. He was also a member of the Society of Experimental Psychologists and served on its Warren Medal Committee. In addition, he had a distinguished career as an editor, editing the Journal of Experimental Psychology from 1942 to 1950 and contributed greatly to the achievement of its eminent status. Irwin died on July 8, 1985. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparitive study of monocarbonyl compounds formed during deep frying in different fats

Fresh commercial corn oil, fresh commercial lard, and hydrogenated vegetable shortening were analyzed for carbonyl compounds before and after deep frying. The frying was carried out in an apparatus with a capacity for 2000 g of oil designed to quantitatively trap the volatile materials evolved during frying and which would ordinarily escape into the atmosphere. The trapped distillate was also subjected to carbonyl analysis. Analysis of the fats and distillates showed a carbonyl pattern in essential agreement with the classical autoxidation mechanism for the different fats, i.e., the typical alkanals, alk-2-enals, and alk-2,4-dienals. The pattern correlated generally with the fatty acid composition of the fats. Comparison of the concentrations of the monocarbonyl compounds in the fats before and after frying, and in their distillates, indicated that the deodorization process which accompanies frying is effective in preventing the accumulation of the more volatile compounds formed. The less volatile products, mainly deca-2,4-dienal, were not efficiently removed. Accordingly, it was observed that the oils containing higher proportions of linoleic acid contained more residual monocarbonyl compounds after frying. Scientific Article No. A-1124, Contribution No. 3570 of the Maryland Agricultural Experiment Station.     

Potential economic benefits of lower-extremity amputation prevention strategies in diabetes

OBJECTIVE: To estimate the potential economic benefits of selected strategies from published literature--educational interventions, multidisciplinary clinics, and insurance coverage for therapeutic shoes--to reduce the incidence of lower-extremity amputation among individuals with diabetes. RESEARCH DESIGN AND METHODS: We developed a model to estimate the expected incidence and associated costs of lower-extremity amputation in a hypothetical cohort of 10,000 people with diabetes. Prevention strategies were assumed to be targeted at individuals with a history of foot ulcer, and benefits were estimated over a period of 3 years. RESULTS: The total potential economic benefits (discounted at 5%) of strategies to reduce amputation risk ranged from $2.0 to $3.0 million ($2,900 to $4,442 per person with a history of foot ulcer) over 3 years. Benefits were highest for educational interventions. Most benefits were found to accrue among individuals aged > or = 70 years. CONCLUSIONS: Strategies to reduce the risk of lower-extremity amputation may generate substantial economic benefits and should be a standard component of routine diabetes care. Benefits may best be achieved through a partnership of government, private payers, health care service providers and producers, and individuals with diabetes.