Shrinkage Estimation in Multilevel Normal Models

This review traces the evolution of theory that started when Charles Stein in 1955 [In Proc. 3rd Berkeley Sympos. Math. Statist. Probab. I (1956) 197--206, Univ. California Press] showed that using each separate sample mean from $k\ge3$ Normal populations to estimate its own population mean $\mu_i$ can be improved upon uniformly for every possible $\mu=(\mu_1,...,\mu_k)'$. The dominating estimators, referred to here as being "Model-I minimax," can be found by shrinking the sample means toward any constant vector. Admissible minimax shrinkage estimators were derived by Stein and others as posterior means based on a random effects model, "Model-II" here, wherein the $\mu_i$ values have their own distributions. Section 2 centers on Figure 2, which organizes a wide class of priors on the unknown Level-II hyperparameters that have been proved to yield admissible Model-I minimax shrinkage estimators in the "equal variance case." Putting a flat prior on the Level-II variance is unique in this class for its scale-invariance and for its conjugacy, and it induces Stein's harmonic prior (SHP) on $\mu_i$.Comment: Published in at http://dx.doi.org/10.1214/11-STS363 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Engineering analysis and test results of the pre-stage planetary gear trains for wrist rotation and pitch assembly and azimuth and elevation assembly of the extendable stiff arm manipulator kit assembly

In order to improve the performance capability of the Extendable Stiff Arm Manipulator (ESAM) it was necessary to increase the overall gear ratio by a factor of approximately four. This is accomplished with minimum effect to existing hardware by the interposition of a planetary gear transmission between the respective drive motors and the harmonic drive transmissions. The engineering analysis in support of this design approach and the subsequent no-load test results are reported

ICE encounter operations

The operations encompassing the International Cometary Explorer's (ICE) encounter with the Comet Giacobini-Zinner on September 11, 1985 are documented. The ICE mission presented new challenges for the Deep Space Network (DSN) 64 meter subnetwork. Because of poor telemetry link margin predicted for Giacobini-Zinner (GZ) encounter, supplemental support by the Japanese Institute for Space and Astronautical Sciences 64-meter antenna at Usuda, Japan and the 305-meter Arecibo Radio Observatory in Puerto Rico was required. To improve the 64 meter subnetwork telemetry performance the following were also implemented: (1) Real time antenna array of 64 meter and 34 meter at a single complex and the required performance testing; and (2) Nonreal time antenna array of two complexes was implemented as a backup in the event of ground or spacecraft failure

The NASA digital VGH program, early results

Data from airline digital flight data recorders provides relevant statistical data for estimating fatigue life consumption of the current airliner fleet and for design criteria updating for future designs. The data indicates real operating effects due to the autopilot, i.e., gust response frequency peak increase by 2 or 3 times, and the existence of the low frequency low amplitude limit cycle motion in altitude hold. The extension of more data types for ground operations is considered. Onboard processing of simple data types is also considered

String-Like Lagrangians from a Generalized Geometry

This note will use Hitchin's generalized geometry and a model of axionic gravity developed by Warren Siegel in the mid-nineties to show that the construction of Lagrangians based on the inner product arising from the pairing of a vector and its dual can lead naturally to the low-energy Lagrangian of the bosonic string.Comment: Conclusions basically unchanged, but presentation streamlined significantly. Published versio

Goal events in football: an investigation into how football performance is impacted in a given time-period preceding a goal event

Football has evolved into a fast-paced, time-constrained sport. Over the last two decades match analysis has become a useful tool to utilize objective information that can subsequently improve performance. Defined as the ball successfully crossing the goal line, goal events are the ultimate objective of the sport. Goal events are arguably fundamental to a team’s success in football, thereby understanding the physical and technical performance in periods preceding these moments can play a pivotal role in obtaining consistency. The present study aimed to identify key aspects of football performance that may predict goal outcomes. Physical and technical performance data were collected from one professional team in their opening ten matches of their 2021/22 season. Performance indicators were analysed across offensive (goal-scoring) and defensive (goal-conceding) outcomes, as well as playing position. The data collected in the full-match, as well as the 5 minutes preceding a goal event were analysed statistically. Passing frequency, penalty area entries and shooting accuracy were most prominent in goal-scoring (p<0.05) whilst passing accuracy, crossing accuracy, sprint count and tackling success were seen to be pertinent to goal-conceding (p<0.05). The present study also confirmed significant differences for scored and conceded goals in relation to positional physical performance. A team’s ability to keep custody of the ball whilst penetrating the opposing teams most vulnerable areas of the pitch was found to relate to goal-conceding and goal-scoring, respectively. Across playing position given goal events seemed to be a consequence of differing match demands. The key performance indicators explored in this investigation highlighted what most often contributes to positive and negative match events, instead of simply what implicates winning and losing

How Much Care Do the Aged Receive from Their Children? A Bimodal Picture of Contact and Assistance

This paper presents some preliminary findings about contact between the aged and their children based on a new survey of the aged and their children, entitled The Hebrew Rehabilitation Center for the Aged-NBER (HRC-NBER) Child Survey. Data on extended families is quite limited. The HRC-NBER Child Survey represents one of the few attempts to collect economic and demographic data on the elderly and their children. While these data will be used in future,research to test structural models of the living arrangements, the purposes of the current paper are to describe the survey and to examine contact between the elderly and their children. While our findings are preliminary and will be updated and expanded as we receive more data, it appears that a significant minority of the elderly, many of whom need assistance with the activities of daily living, have either no children or have only limited contact with their children. Contact between children and the vulnerable elderly appears to be less than that between children and the nonvulnerable elderly, and the amount of contact between children and the institutionalized elderly seems the least of all. In addition, although many of the parents in our data are very poor, financial support from children to parents, other than in the form of shared housing, is uncommon. The impression given by these data is that many of the elderly are very well cared for by their children, while a significant minority either have no children or have no children who provide significant time or care. Some of the findings for this sample are striking: (1) over a fifth of the elderly have no children. (2) over one half of the elderly either do not have a daughter or do not have a daughter who lives within an hour of them. (3) over half of single elderly males and females and over two fifths of vulnerable single elderly males and females live completely alone. (4) of the elderly who have children, fewer than a quarter live with their children. (5) a small fraction of elderly with children hear from them at most on a yearly basis. (6) almost 10 percent of the children of the elderly have at most yearly contact. (7) financial assistance from children to the elderly, even in cases where the elderly are quite poor, is extremely rare. (8) in a typical month over a quarter of elderly who have children do not physically spend time with their children.