Electron-induced neutron knockout from 4^{4}He

The differential cross section for electron-induced neutron knockout in the reaction 4He(e,e′n)3He has been measured for the first time with a statistical accuracy of 11%. The experiment was performed in quasielastic kinematics at a momentum transfer of 300  MeV/c and in the missing-momentum range of 25–70  MeV/c. The comparison of the data with theoretical calculations shows an impressive increase of the cross section resulting from final state interaction effects. Specifically , the p−n charge-exchange process dominates the cross section in this kinematical regime. (APS

Dynamic demand fulfillment in spare parts networks with multiple customer classes

We study real-time demand fulfillment for networks consisting of multiple local warehouses, where spare parts of expensive technical systems are kept on stock for customers with different service contracts. Each service contract specifies a maximum response time in case of a failure and hourly penalty costs for contract violations. Part requests can be fulfilled from multiple local warehouses via a regular delivery, or from an external source with ample capacity via an expensive emergency delivery. The objective is to minimize delivery cost and penalty cost by smartly allocating items from the available network stock to arriving part requests. We propose a dynamic allocation rule that belongs to the class of one-step lookahead policies. To approximate the optimal relative cost, we develop an iterative calculation scheme that estimates the expected total cost over an infinite time horizon, assuming that future demands are fulfilled according to a simple static allocation rule. In a series of numerical experiments, we compare our dynamic allocation rule with the optimal allocation rule, and a simple but widely used static allocation rule. We show that the dynamic allocation rule has a small optimality gap and that it achieves an average cost reduction of 7.9% compared to the static allocation rule on a large test bed containing problem instances of real-life size

Construct Validity of the Profile of Mood States

Objectives: The purpose of the present study was to extend the validation of the Profile of Mood States-Adolescents (POMS-A: Terry, P. C., Lane, A. M., Lane, H. J., & Keohane, L. (1999). Development and validation of a mood measure for adolescents. Journal of Sports Sciences, 17, 861-872) from adolescent to adult populations. Design: A strategy of assessing the invariance of the POMS-A factor structure among disparate samples and of testing relationships with concurrent measures was used. Methods: The POMS-A was administered to 2,549 participants from four samples: Adult athletes prior to competition (n = 621), adult student athletes in a classroom (n = 656), adolescent athletes prior to competition (n = 676), and adolescent students in a classroom (n = 596). A subset of 382 adult student athletes was used to test the criterion validity of the POMS-A. Results: Confirmatory factor analysis provided support for the factorial validity of a 24-item, six-factor model using both independent and multi-sample analyses. Relationships between POMS-A scores and previously validated measures, that were consistent with theoretical predictions, supported criterion validity. Conclusion: Supporting evidence was found that the psychometric integrity of the POMS-A extended from adolescent to adult populations