An acoustic remote sensing method for high-precision propeller rotation and speed estimation of unmanned underwater vehicles

Author Posting. © Acoustical Society of America, 2020. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 148(6), (2020): 3942-3950, https://doi.org/10.1121/10.0002954.Understanding the dominant sources of acoustic noise in unmanned underwater vehicles (UUVs) is important for passively tracking these platforms and for designing quieter propulsion systems. This work describes how the vehicle's propeller rotation can be passively measured by the unique high frequency acoustic signature of a brushless DC motor propulsion system and compares this method to Detection of Envelope Modulation on Noise (DEMON) measurements. First, causes of high frequency tones were determined through direct measurements of two micro-UUVs and an isolated thruster at a range of speeds. From this analysis, common and dominant features of noise were established: strong tones at the motor's pulse-width modulated frequency and its second harmonic, with sideband spacings at the propeller rotation frequency multiplied by the poles of the motor. In shallow water field experiments, measuring motor noise was a superior method to the DEMON algorithm for estimating UUV speed. In negligible currents, and when the UUV turn-per-knot ratio was known, measuring motor noise produced speed predictions within the error range of the vehicle's inertial navigation system's reported speed. These findings are applicable to other vehicles that rely on brushless DC motors and can be easily integrated into passive acoustic systems for target motion analysis.This work was supported by the Office of Naval Research (Award No. N00014-17-1-2474), DARPA, the Draper Fellowship, and the National Defense Science and Engineering Graduate Fellowship Program.2021-06-2

Issues in the Treatment of Depressed Children

Basic research into the cognitive, behavioral, familial, and physiological disturbances associated with depressive disorders during childhood is reviewed. hnplications for the development of a treatment program are discussed and a comprehensive treatment model is proposed. The proposed model includes intervention strategies for the child, parents, family, and school. The child component consists of intervention strategies for the affective, cognitive, behavioral, and physiological disturbances that are evident from the existing research. The parent training component is designed to address disturbances in parenting due to cognitive disturbances and skills deficits. The family therapy component emphasizes changing interaction patterns that communicate schema-consistent maladaptive interactions. A school consultation component is proposed in which school personnel support the skills training through prompting use of the skills and reinforcement of the use of the coping skills

Effects of fatiguing constant versus alternating intensity intermittent isometric muscle actions on maximal torque and neuromuscular responses

Objective: To determine the effects of constant versus alternating applications of torque during fatiguing, intermittent isometric muscle actions of the leg extensors on maximal voluntary isometric contraction (MVIC) torque and neuromuscular responses. Methods: Sixteen subjects performed two protocols, each consisting of 50 intermittent isometric muscle actions of the leg extensors with equal average load at a constant 60% MVIC or alternating 40 then 80% (40/80%) MVIC with a work-to-rest ratio of 6-s on and 2-s off. MVIC torque as well as electromyographic signals from the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) and mechanomyographic signals from the VL were recorded pretest, immediately posttest, and 5-min posttest. Results: The results indicated that there were no time-related differences between the 60% MVIC and 40/80% MVIC protocols. The MVIC torque decreased posttest (22 to 26%) and remained depressed 5-min posttest (9%). There were decreases in electromyographic frequency (14 to 19%) and mechanomyographic frequency (23 to 24%) posttest that returned to pretest levels 5-min posttest. There were no changes in electromyographic amplitude and mechanomyogrpahic amplitude. Conclusions: These findings suggested that these neuromuscular parameters did not track the fatigue-induced changes in MVIC torque after 5-min of recovery

Effects of fatiguing constant versus alternating intensity intermittent isometric muscle actions on maximal torque and neuromuscular responses

Objective: To determine the effects of constant versus alternating applications of torque during fatiguing, intermittent isometric muscle actions of the leg extensors on maximal voluntary isometric contraction (MVIC) torque and neuromuscular responses. Methods: Sixteen subjects performed two protocols, each consisting of 50 intermittent isometric muscle actions of the leg extensors with equal average load at a constant 60% MVIC or alternating 40 then 80% (40/80%) MVIC with a work-to-rest ratio of 6-s on and 2-s off. MVIC torque as well as electromyographic signals from the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) and mechanomyographic signals from the VL were recorded pretest, immediately posttest, and 5-min posttest. Results: The results indicated that there were no time-related differences between the 60% MVIC and 40/80% MVIC protocols. The MVIC torque decreased posttest (22 to 26%) and remained depressed 5-min posttest (9%). There were decreases in electromyographic frequency (14 to 19%) and mechanomyographic frequency (23 to 24%) posttest that returned to pretest levels 5-min posttest. There were no changes in electromyographic amplitude and mechanomyogrpahic amplitude. Conclusions: These findings suggested that these neuromuscular parameters did not track the fatigue-induced changes in MVIC torque after 5-min of recovery

Environmental and Labour accounts for OECD Inter-Country Input-Output Tables 2010-2013

This report (final deliverable of project JRC/SVQ/2016/J.5/0054/OC) describes the methodology used to estimate the energy, environmental and labour accounts linked to the OECD ICIO tables and gives a short overview on the data available for the estimations. In addition, it contains the structure of the code used to for the estimations, including all concordance matrices and the data input and output formats.JRC.B.5-Circular Economy and Industrial Leadershi

Ranking Objections to Christian Theism: A Survey of Subjective Declarations and their Correlations with Expert Opinions

There have been numerous books written on the top objections to Christianity—sometimes stated as “common,” “major,” “frequent,” “every day,” “cultural,” “tough,” “difficult” objections. However, there is a dearth of behavioral studies in the literature that show how and given population ranks objections to Christianity. As such, the apologist has had to rely on expert opinions from the books that have been authored. These expert opinions are based on familiarity with the literature in the field and contact with laity from university, church, and other speaking engagements. The purpose of this study is to document trends in how people report the relative strength of objections to Christian theism.[1] We analyze whether these trends correlate with popular works of Christian apologists—our baseline for expert opinion. Further, we determine whether there are any statistically significant relationships between reported demographics, rankings, and attitudes. Summary of Results and Analysis. Subjective declarations of respondents of the questionnaire showed that most participants were either 18-24 (marginally more than 55-64 and 65-74), male (marginally more than female), had some college (marginally more than bachelor’s, master’s degrees), lived in a suburban community, or lived in the South. In comparing the expert opinion baseline with the aggregate survey ranking results, we see similar rankings between the objection that “God is unloving/immoral” and that the “Bible is not inerrant” (ranked by both as 1st and 2nd, respectively) at the higher end of the spectrum. We found that those identified as agnostic seem to have the closest potential correlation to expert opinion (baseline). The mean of their rankings produced four objections that closely approximated the baseline, one objection that was about one rank removed from the baseline, and three objections that were about two ranks from the baseline. For demographics and rankings, we found statistically significant relationships between religious identification and the objection “God does not exist” with those who identified as atheists, giving it an average ranking of 3.74 (on a scale of 1-13; 1 = highest, 13 = lowest). For demographics and attitudes, we found statistically significant relationships between religious identification and age, religious discussion importance, and attitude toward Christian theism. (See “Analysis” section.) [1] The study was done under the School of Divinity Department at Liberty University in compliance with Liberty University’s Internal Review Board (Research Ethics Office). IRB-FY21-22-12. Policy: Post-2018 Rule. Submitted 07-06-2021. Last approved 09-07-2021, no expiration date applicable

Effect of sex on torque, recovery, EMG, and MMG responses to fatigue

The purpose of the present investigation was to examine the effect of sex on maximal voluntary isometric contraction (MVIC) torque and the EMG and MMG responses as a result of fatiguing, intermittent, submaximal (65% of MVIC), isometric elbow flexion muscle contractions. Methods: Eighteen men and women performed MVIC trials before (pretest), after (posttest), and 5-min after (5-min recovery) performing 50 intermittent, submaximal isometric muscle contractions. Surface electromyographic (EMG) and mechanomyographic (MMG) signals were simultaneously recorded from the biceps brachii muscle. Results: As a result of the fatiguing workbout torque decreased similarly from pretest to posttest for both the men (24.0%) and women (23.3%). After 5-min of recovery, torque had partially recovered for the men, while torque had returned to pretest levels for the women. For both sexes, from pretest to posttest EMG mean power frequency and MMG amplitude decreased, but returned to pretest levels after 5-min of recovery. Conclusions: In the present study, there were sex-related differences in muscle fatigue that were not associated with the EMG or MMG responses

Effect of sex on torque, recovery, EMG, and MMG responses to fatigue

The purpose of the present investigation was to examine the effect of sex on maximal voluntary isometric contraction (MVIC) torque and the EMG and MMG responses as a result of fatiguing, intermittent, submaximal (65% of MVIC), isometric elbow flexion muscle contractions. Methods: Eighteen men and women performed MVIC trials before (pretest), after (posttest), and 5-min after (5-min recovery) performing 50 intermittent, submaximal isometric muscle contractions. Surface electromyographic (EMG) and mechanomyographic (MMG) signals were simultaneously recorded from the biceps brachii muscle. Results: As a result of the fatiguing workbout torque decreased similarly from pretest to posttest for both the men (24.0%) and women (23.3%). After 5-min of recovery, torque had partially recovered for the men, while torque had returned to pretest levels for the women. For both sexes, from pretest to posttest EMG mean power frequency and MMG amplitude decreased, but returned to pretest levels after 5-min of recovery. Conclusions: In the present study, there were sex-related differences in muscle fatigue that were not associated with the EMG or MMG responses