Modeling and querying uncertain data for activity recognition systems using PostgreSQL

2012 Summer.Includes bibliographical references.Activity Recognition (AR) systems interpret events in video streams by identifying actions and objects and combining these descriptors into events. Relational databases can be used to model AR systems by describing the entities and relationships between entities. This thesis presents a relational data model for storing the actions and objects extracted from video streams. Since AR is a sequential labeling task, where a system labels images from video streams, errors will be produced because the interpretation process is not always temporally consistent with the world. This thesis proposes a PostgreSQL function that uses the Viterbi algorithm to temporally smooth labels over sequences of images and to identify track windows, or sequential images that share the same actions and objects. The experiment design tests the effects that the number of sequential images, label count, and data size has on execution time for identifying track windows. The results from these experiments show that label count is the dominant factor in the execution time

Sesame-Style Decomposition of KS-DFT Molecular Dynamics for Direct Interrogation of Nuclear Models

A common paradigm used in the construction of equations of state is to decompose the thermodynamics into a superposition of three terms: a static-lattice cold curve, a contribution from the thermal motion of the nuclei, and a contribution from the thermal excitation of the electrons. While statistical mechanical models for crystals provide tractable framework for the nuclear contribution in the solid phase, much less is understood about the nuclear contribution above the melt temperature ($C_v^{(\text{nuc})}\approx 3R$) and how it should transition to the high-temperature limit ($C_v^{(\text{nuc})} \sim \frac{3}{2}R$). In this work, we describe an algorithm for extracting both the thermal nuclear and thermal electronic contributions from quantum molecular dynamics (QMD). We then use the VASP QMD package to probe thermal nuclear behavior of liquid aluminum at normal density to compare the results to semi-empirical models -- the Johnson generic model, the Chisolm high-temperature liquid model, and the CRIS model.Comment: 6 pages, 4 figures, APS Shock Compression of Condensed Matter Conference Proceedings 201

BACK STRESS AND ASSISTANCE EXERCISES IN WEIGHTLIFTING

The purpose of this study was to test the suitability of selected assistance exercises to strengthen the low back for the Olympic lifts in high level weightlifters. Four subjects were filmed by a five-camera Motion Analysis system operating at 120Hz completing both of the Olympic lifts (Snatch and Clean) and four assistance exercises (Romanian Oeadlift (ROL), Bent-over Row (BOR), Clean Pull Oeadlift (CPO), and Good Morning (GM)). Peak Erector Spinae Force (ESF) and L5/S1 compressive and shear force (L5/S1 CF and L5/S1 SF respectively) were calculated via a top-down inverse dynamics model. Comparisons between the lifts were made using a one-way ANOVA with repeated measures. It was found that the CPO produced higher ESF than the Snatch but this exercise also produced very high L5/S 1 CF and L5/S1 SF. The Clean also displayed a higher ESF than the Snatch. When normalising the data to bar weight, the BOR and GM was shown to potentially produce high ESF but coaches should consider the possibility for these exercises to produce low back injury

Diesel Engine Startup Characterization with Pure Component and Conventional Navy Fuels

In an effort to diminish the energy consumption of the Department of the Navy, strict energy goals have been implemented, to include the use of renewable fuels. Many of the renewable fuels that are currently being evaluated by the Department of the Navy are pure component or only have a few components of hydrocarbons. In order to determine and compare the startup performance of pure component, renewable fuels and conventional Navy fuels, three pure component fuels and standard naval aviation fuel were tested in a single-cylinder diesel engine, varying compression ratio and air-fuel equivalence ratio. It was found that startup performance is improved from any three of the following: decreasing air-fuel equivalence ratio, increasing compression ratio, and finally, increasing cetane number. Additionally, startup performance was affected by the density and bulk modulus of each of the tested fuels

A comparison of methods to calculate the optimal load for maximal power output in the power clean

The aim of this study was to compare three calculation methods to determine the load that maximises power output in the power clean. Five male athletes (height=179.8 10.5cms, weight 91 .8 8.8kg, power dean 1RM = 117.0 20.5kg) performed two per cleans at 10% increments from 50% to 100% of 1RM. Bar displacement data was collected using a Ballistic Measurement System (BMS) and vertical ground reaction force (VGRF) data was measured by a Kistler 9287B Force Plate. Power output was calculated for BMS (system mass), BMS (bar mass) and VGRF/BMS system mass. Optimal load was determined to be 70% for the BMS (system mass) and VGRF BMS (system mass) methods and 90% for the BMS (bar mass) method. Sports scientists should be aware of the technical issues underlying these findings due to the practical ramifications for athlete testing and training.<br /

An electromyographic comparison of neck conditioning exercises in healthy controls

The purpose of this study was to compare surface electromyography (EMG) activation levels of selected neck muscles for two common neck-training modalities (Thera-Band and Cybex). Seventeen asymptomatic subjects (eight men and nine women) with a mean age 23.4 years were recruited. EMG activation normalized to maximal voluntary isometric contraction (MVIC) was measured with subjects performing exercises with green, blue, and black Thera-Bands and 50%, 70%, and 90% of 3RM for the Cybex modality. Four variables were used to depict exercise intensity: average and peak EMG activation in the concentric and eccentric phases. Significant differences (P &lt;= 0.05) in EMG activation were evident when comparing intensities of the Cybex modality with each other and when comparing the Cybex intensities with Thera-Band intensities in most cases. Minimal differences were found among differing intensities of Thera-Band. Thera-Band exercise resulted in low-level EMG activation (range, flexion 3.8-15.7% MVIC; range, extension 20.2-34.8% MVIC); therefore, such exercise may be useful in rehabilitation programs. Cybex exercise (range, flexion 20.9-83.5% MVIC; range, extension 40.6-95.8% MVIC) may be useful for occupation-related injury prevention. However, exercise prescription should be undertaken with care as the mechanical loading on passive spinal structures is unknown.<br /

A COMPARISON OF METHODS TO CALCULATE THE OPTIMAL LOAD FOR MAXIMAL POWER OUTPUT IN THE POWER CLEAN

The aim of this study was to compare three calculation methods to determine the load that maximises power output in the power clean. Five male athletes (height=179.8 10.5cms, weight 91.8 8.8kg. power clean 1RM = 117.0 20.5kg) performed two power cleans at 10% increments from 50% to 100% of 1RM. Bar displacement data was collected using a Ballistic Measurement System (BMS) and vertical ground reaction lorce (VGRF) data was measured by a Kistler 9287B Force Plate. Power output was calculated for BMS (system mass), BMS (bar mass) and VGRF/BMS system mass. Optimal load was determined to be 70% for the BMS (system mass) and VGRF 8MS (system mass) methods and 90% for the BM3 (bar mass) method. Sports scientists should be aware of the technical issues underlying these findings due to the practical ramifications for athlete testing and training

Neck exercises compared to muscle activation during aerial combat maneuvers

Introduction: Performing specific neck strengthening exercises has been proposed to decrease the incidence of neck injury and pain in high performance combat pilots. However, there is little known about these exercises in comparison to the demands on the neck musculature in flight. Methods: Eight male non-pilots performed specific neck exercises using two different modalities (elastic band and resistance machine) at six different intensities in flexion, extension, and lateral bending. Six Royal Australian Air Force Hawk pilots flew a sortie that included combinations of three +Gz levels and four head positions. Surface electromyography (EMG) from selected neck and shoulder muscles was recorded in both activities. Results: Muscle activation levels recorded during the three elastic band exercises were similar to in-flight EMG collected at +1 Gz (15% MVIC). EMG levels elicited during the 50% resistance machine exercises were between the +3 Gz (9-40% MVIC) and +5 Gz (16-53% MVIC) ranges of muscle activations in most muscles. EMG recorded during 70% and 90% resistance machine exercises were generally higher than in-flight EMG at +5 Gz. Discussion: Elastic band exercises could possibly be useful to pilots who fly low +Gz missions while 50% resistance machine mimicked neck loads experienced by combat pilots flying high +Gz ACM. The 70% and 90% resistance machine intensities are known to optimize maximal strength but should be administered with care because of the unknown spinal loads and diminished muscle force generating capacity after exercise.<br /