TECHNICAL CHARACTERISTICS OF ELITE MALE AND FEMALE DISCUS THROWERS

This study identified technical characteristics of discus throwing techniques used by elite male and female discus throwers. Fifty-seven male and fifty-two female elite discus throwers were divided into four groups based on their longest official distances. Flight distance was the major determinant of the official distance for male athletes. Flight distance and aerodynamic distance contribution to the official distance for females. Horizontal and vertical velocities of the discus at release were major determinants of the official distance for both all athletes. Increases in the horizontal and vertical velocities of the discus during different phases had different effects on the official distance for all athletes. Results provide information for technical training of discus techniques and basis for future discus throwing studies

KINEMATICS STUDY OF JUNIOR AMATEUR GOLFERS IN SINGAPORE

Qualitative tools for golf motion analysis like video and graphical overlay have provided competitive golfers in Singapore feedback on their swing. The analysis of this information tends to be subjective due to a lack of reliable quantifiable kinematics information. The authors applied the methods perlormed by Mc Laughlin and Best [1994], Robinson [1994] and Miura and Nauro [1998] on two professional players and six national age group players. Differences were found in how the two groups of players swing, in particular their setup and translation of their Center of Mass (COM) at Middle of Backswing (MBS) and Ball Impact Frame (BIF). Angle displacement of the shoulder-hip axis was studied and found to be pertinent to the kinetic link analysis. This parameter could serve as an intermediary for quantitative and qualitative analysis

OVERVIEW OF VIDEO DATA COLLECTION FOR 3-DIMENSIONAL MOTION ANALYSIS DURING THE FINAL ROUNDS OF THOMAS & UBER CUP 2000 BADMINTON CHAMPIONSHIPS

The aim of this paper is to report on the biomechanics project during the final rounds of Thomas & Uber Cup 2000 Badminton Championships. The results of three-dimensional analysis are also reported. To capture the data of world-class badminton players in competition, six synchronized video cameras were used to record video images at 50 field/second for 3-dimensional motion analysis during the Thomas & Uber Cup 2000 Badminton Championships in Malaysia. The semi-final and final matches were recorded. Some of the data was selected, analyzed and published in this paper

Subducting slab ultra-slow velocity layer coincident with silent earthquakes in southern Mexico

Great earthquakes have repeatedly occurred on the plate interface in a few shallow-dipping subduction zones where the subducting and overriding plates are strongly locked. Silent earthquakes (or slow slip events) were recently discovered at the down-dip extension of the locked zone and interact with the earthquake cycle. Here, we show that locally observed converted SP arrivals and teleseismic underside reflections that sample the top of the subducting plate in southern Mexico reveal that the ultra-slow velocity layer (USL) varies spatially (3 to 5 kilometers, with an S-wave velocity of ~2.0 to 2.7 kilometers per second). Most slow slip patches coincide with the presence of the USL, and they are bounded by the absence of the USL. The extent of the USL delineates the zone of transitional frictional behavior

Real-time information processing of environmental sensor network data using Bayesian Gaussian processes

In this article, we consider the problem faced by a sensor network operator who must infer, in real time, the value of some environmental parameter that is being monitored at discrete points in space and time by a sensor network. We describe a powerful and generic approach built upon an efficient multi-output Gaussian process that facilitates this information acquisition and processing. Our algorithm allows effective inference even with minimal domain knowledge, and we further introduce a formulation of Bayesian Monte Carlo to permit the principled management of the hyperparameters introduced by our flexible models. We demonstrate how our methods can be applied in cases where the data is delayed, intermittently missing, censored, and/or correlated. We validate our approach using data collected from three networks of weather sensors and show that it yields better inference performance than both conventional independent Gaussian processes and the Kalman filter. Finally, we show that our formalism efficiently reuses previous computations by following an online update procedure as new data sequentially arrives, and that this results in a four-fold increase in computational speed in the largest cases considered

Mechanical signatures of microbial biofilms in micropillar-embedded growth chambers

Biofilms are surface-attached communities of microorganisms embedded in an extracellular matrix and are essential for the cycling of organic matter in natural and engineered environments. They are also the leading cause of many infections, for example, those associated with chronic wounds and implanted medical devices. The extracellular matrix is a key biofilm component that determines its architecture and defines its physical properties. Herein, we used growth chambers embedded with micropillars to study the net mechanical forces (differential pressure) exerted during biofilm formation in situ. Pressure from the biofilm is transferred to the micropillars via the extracellular matrix, and reduction of major matrix components decreases the magnitude of micropillar deflections. The spatial arrangement of micropillar deflections caused by pressure differences in the different biofilm strains may potentially be used as mechanical signatures for biofilm characterization. Hence, we submit that micropillar-embedded growth chambers provide insights into the mechanical properties and dynamics of the biofilm and its matrix.Singapore. National Research Foundation (Singapore-MIT Alliance for Research and Technology (SMART)

Statistical tests for large tree-structured data

We develop a general statistical framework for the analysis and inference of large tree-structured data, with a focus on developing asymptotic goodness-of-fit tests. We first propose a consistent statistical model for binary trees, from which we develop a class of invariant tests. Using the model for binary trees, we then construct tests for general trees by using the distributional properties of the Continuum Random Tree, which arises as the invariant limit for a broad class of models for tree-structured data based on conditioned Galton–Watson processes. The test statistics for the goodness-of-fit tests are simple to compute and are asymptotically distributed as χ2 and F random variables. We illustrate our methods on an important application of detecting tumour heterogeneity in brain cancer. We use a novel approach with tree-based representations of magnetic resonance images and employ the developed tests to ascertain tumor heterogeneity between two groups of patients