physical requirement

2011 ◽  
Keyword(s):  
Physical Requirement

scholarly journals The Role of Motor Learning on Measures of Physical Requirements and Motor Variability During Repetitive Screwing

2019 ◽  
Vol 16 (7) ◽  
pp. 1231 ◽  
Author(s):  
Tessy Luger ◽  
Robert Seibt ◽  
Monika Rieger ◽  
Benjamin Steinhilber
Keyword(s):  
Muscle Activation ◽  
Biceps Brachii ◽  
Extensor Digitorum ◽  
Body Parts ◽  
Triceps Brachii ◽  
Experimental Conditions ◽  
Motor Variability ◽  
Physical Requirement ◽  
Flexor Carpi Radialis ◽  
Arm Muscles

We investigated whether physical requirements and motor variability decreased over days in novices during a repetitive screwing task. Fifty-seven subjects performed one hour of repetitive screwing and fastening on three days, separated by 2–7 days. The average physical requirement and relative cycle-to-cycle variability (coefficient of variation, i.e., CV) were calculated from continuous recordings of electromyography of four arm muscles (biceps brachii, triceps brachii, flexor carpi radialis, extensor digitorum), forearm acceleration, and electrocardiography. Muscle activity levels, heart rate, and forearm acceleration decreased from day 1 to day 2 (range: ~4% to ~20%) and/or 3 (range: ~4% to ~28%). Not all muscles showed a similar pattern. Activity of the extensor digitorum and biceps brachii decreased already between days 1 and 2 (range: ~6% to ~13%), whereas activity of the flexor carpi radialis and triceps brachii decreased between days 1 and 3 (range: ~13% to ~20%). No changes in physical requirement were detected between days 2 and 3. Relative motor variability did not change across days, except that variability of forearm acceleration increased from day 1 to 3 (~5%). This study found consistent changes in physical requirements and indicated that several arm muscles show earlier decreases of muscular activity, like the extensor digitorum, compared to other body parts, like the flexor carpi radialis. Moreover, movement strategies may develop differently than muscle activation strategies, based on the different developments of physical requirements and motor variability. The development of physical requirements in industrial tasks is part of daily living and starts at task onset, highlighting the importance of task familiarization and the randomization of experimental conditions in scientific studies.

scholarly journals ANÁLISE DA CARGA DE TRABALHO FÍSICO EM ATIVIDADES DE IMPLANTAÇÃO FLORESTAL EM ÁREAS DECLIVOSAS

FLORESTA ◽  
2012 ◽  
Vol 42 (2) ◽  
pp. 241
Author(s):  
Nilton César Fiedler ◽  
Ronie Silva Juvanhol ◽  
Elizabeth Neire da Silva Oliveira Paula ◽  
Saulo Boldrini Gonçalves ◽  
Flavio Cipriano de Assis Carmo ◽  
...  
Keyword(s):  
Well Being ◽  
Physical Work ◽  
The South ◽  
Physical Demands ◽  
Espírito Santo ◽  
Physical Requirement ◽  
Cardiac Frequency ◽  
Light Activity ◽  
Espirito Santo

Esta pesquisa teve o objetivo de avaliar a carga de trabalho físico em atividades de implantação florestal em áreas declivosas no sul do Espírito Santo e propor uma reorganização ergonômica para melhoria dos níveis de saúde, bem-estar e satisfação dos trabalhadores. A carga de trabalho físico foi avaliada por intermédio do levantamento da frequência cardíaca, com o uso de monitores de frequência cardíaca nas atividades de construção de cercas, roçada manual, capina química, marcação de covas, coroamento, coveamento manual, enchimento de covas, adubação pré-plantio e plantio. A maior exigência física no trabalho foi verificada na atividade de coveamento manual (125 bpm), sendo esta classificada como moderadamente pesada. A menor exigência física no trabalho foi observada na atividade de adubação pré-plantio, com frequência cardíaca média de 87 bpm, sendo classificada como atividade leve. Foram verificadas diferenças significativas entre as atividades de implantação (médias da carga cardiovascular) pelo teste de Scott-Knott ao nível de 5%, e a necessidade de reorganizar o ambiente de trabalho com inserção de pausas orientadas.Palavras-chave:  Ergonomia florestal; frequência cardíaca; plantio florestal; fisiologia do trabalho florestal. AbstractAnalysis of the load of physical work in activities of forest implementation insteepareas.This research had the objective to evaluate the load of physical work in activities of forest implementation in steep areas in the south of the Espírito Santo, Brazil and to propose an ergonomic reorganization for improvement of the levels of health, well-being and satisfaction of the workers. The load of physical work was evaluated by the survey of the cardiac frequency with the use of monitors of cardiac frequency in the activities of construction of fencing, manual mowing, weeding chemical, marking of graves, weeding, manual pit, filling of pits, adubation pre-planting and planting. The biggest physical requirement in the work was verified in the activity of manual pit (125 bpm), being classified as moderately heavy activity. The lower physical demands at work were observed in adubation pre-planting, frequently average cardiopath of 87 bpm, being classified as light activity. Significant differences had been verified enter the averages of the cardiovascular load and necessity to reorganize the environment of work with insertion of target pauses.Keywords: Forestry ergonomics; cardiac frequency; forestry activities; physiology of forest work.

Comparative Research on Different Solutions of a High-Performance Thin-Film Polarizing Beam Splitter

2012 ◽  
Vol 580 ◽  
pp. 134-140
Author(s):  
Kai Yong Yang ◽  
Hong Chang Zhao ◽  
Yun Feng Jia ◽  
Su Yong Wu
Keyword(s):  
Thin Film ◽  
Robust Design ◽  
High Performance ◽  
Beam Splitter ◽  
Dual Frequency ◽  
Physical Requirement ◽  
Optical Films ◽  
Frequency Laser ◽  
Production Errors ◽  
Polarizing Beam Splitter

In the process of fabricating an ultra-high precision thin-film polarizing beam splitter (PBS), which is the key element in a new kind of Y-shaped cavity dual-frequency laser, low production yield is a serious problem. Based on the robust design method by controlling sensitivity of optical films to production errors, response characteristics to production errors of different kinds of PBSs are comparatively studied. By experimental study of robust design, essential determinant of sensitivity of PBSs to production errors is found to be the physical requirement that the propagation angle should be larger than the critical angle of total reflection of the interface between the substrate and outer space. By fulfilling the physical requirement, optimum incidence angle has been found by repeated robust design on different incidence angles, and a high-performance thin-film PBS with low sensitivity to production errors has been designed. The coating structure of the obtained PBS is simple and it is easy to be batch manufactured, which will make a positive impact on fabrication, engineering and application of the new Y-shaped cavity dual-frequency laser.

The structure of linear relativistic wave equations. I

1950 ◽  
Vol 202 (1069) ◽  
pp. 284-300 ◽  
Keyword(s):  
Wave Equation ◽  
Wave Equations ◽  
Total Spin ◽  
Relativistic Wave Equations ◽  
Relativistic Wave ◽  
Arithmetical Progression ◽  
Physical Requirement ◽  
Complete Determination

The structure of linear relativistic wave equations of the form ( iα µ ∂ µ - X ) ψ = 0 is discussed. In general, such equations describe particles with a spectrum of mass and spin values. It is proved that the physical requirement that all particle states can be unambiguously specified by the momentum, mass, spin and charge, leads to a complete determination of the eigenvalues of the total spin. These must form an arithmetical progression S H , S H — 1, S H — 2, ..., terminating at 0, 1/2 or 1. A coupling diagram is associated with every wave equation and necessary restrictions on the shape of the diagram are worked out. There results a useful reduction in the number of mathematical possibilities.

scholarly journals Chromosomes with Two Intact Axial Cores Are Induced by G2 Checkpoint Override: Evidence That DNA Decatenation Is not Required to Template the Chromosome Structure

1997 ◽  
Vol 136 (1) ◽  
pp. 29-43 ◽  
Author(s):  
Paul R. Andreassen ◽  
Françoise B. Lacroix ◽  
Robert L. Margolis
Keyword(s):  
Topoisomerase Ii ◽  
Chromosome Structure ◽  
Core Structure ◽  
G2 Arrest ◽  
Normal Appearance ◽  
Physical Requirement ◽  
G2 Checkpoint ◽  
Chromosome Formation ◽  
Topo Ii ◽  
Chromosome Scaffold

Here we report that DNA decatenation is not a physical requirement for the formation of mammalian chromosomes containing a two-armed chromosome scaffold. 2-aminopurine override of G2 arrest imposed by VM-26 or ICRF-193, which inhibit topoisomerase II (topo II)–dependent DNA decatenation, results in the activation of p34cdc2 kinase and entry into mitosis. After override of a VM-26–dependent checkpoint, morphologically normal compact chromosomes form with paired axial cores containing topo II and ScII. Despite its capacity to form chromosomes of normal appearance, the chromatin remains covalently complexed with topo II at continuous levels during G2 arrest with VM-26. Override of an ICRF-193 block, which inhibits topo II–dependent decatenation at an earlier step than VM-26, also generates chromosomes with two distinct, but elongated, parallel arms containing topo II and ScII. These data demonstrate that DNA decatenation is required to pass a G2 checkpoint, but not to restructure chromatin for chromosome formation. We propose that the chromosome core structure is templated during interphase, before DNA decatenation, and that condensation of the two-armed chromosome scaffold can therefore occur independently of the formation of two intact and separate DNA helices.

Towards Cyber-Physical Requirement Engineering Elicitation Tool Support

2018 ◽  
Author(s):  
Sanjaya Pandey ◽  
Subik Pokharel ◽  
Hassan Reza
Keyword(s):  
Requirement Engineering ◽  
Tool Support ◽  
Physical Requirement

scholarly journals PENGARUH KARET ALAM SIKLIK (CYCLIC NATURAL RUBBER) TERHADAP RONGGA ASPAL MODIFIKASI

2016 ◽  
Vol 12 (2) ◽  
pp. 169-176 ◽  
Author(s):  
W. Ritonga ◽  
I. Irfandi
Keyword(s):  
Natural Rubber ◽  
Modified Bitumen ◽  
Physical Requirement

Penelitian ini bertujuan untuk mengetahui pengaruh karet alam siklik terhadap rongga aspal modifikasi. Tahapan peneltian meliputi pembuatan aspal modifikasi dengan menyampur aspal murni dengan karet alam siklik, pengujian persyaratan fisik aspal, pembuatan benda uji dan pengujian marshall. Berdasarkan pengujian sifat fisik aspal diperoleh data bahwa keseluruhan aspal modifikasi memenuhi persyaratan fisik aspal. Setelah pembuatan benda uji, dilakukan pengujian marshall untuk memperoleh rongga aspal meliputi VIM, VMA dan VFA. Nilai VIM pada penambahan 0 phr, 1 phr, 2 phr, 3 phr, dan 4 phr adalah 3,65%, 5,41%, 4,27%, 3,84%, dan 2,88%. Nilai VMA sebesar 15,52%, 17,26%, 16,07%, 15,80%, dan 15,17%. Nilai VFA sebesar 76,48%, 68,72%, 73,54%, 75,76%, dan 81,34%. Diperoleh kesimpulan bahwa karet alam siklik bisa dijadikan sebagai bahan memodifikasi aspal dan berpengaruh terhadap rongga aspal.This research aimed to determine the effect of cyclic natural rubber (CNR) to cavity of modified bitumen. The steps of the research were mixing the pure bitumen with CNR, testing bitumen physical requirement, making the specimen, and testing the cavity of modified bitumen with marshall method. Testing showed that all the modified bitumen met the physical requirement. After making specimen, marshall method was used to determine the cavity of bitumen, including VIM, VMA, and VFA. VIM in addition of 0 phr, 1 phr, 2 phr, 3 phr, and 4 phr was 3,65%, 5,41%, 4,27%, 3,84%, and 2,88%. The value of VMA was 15.52%, 17.26%, 16.07%, 15.80% and 15.17%. The value of VFA was 76.48%, 68.72%, 73.54%, 75.76% and 81.34%. The conclusion of this study was CNR could be used as material for bitumen modified and had the effect on bitumen cavity.

MULTIPARTITE QUANTUM SYSTEMS: PHASES DO MATTER AFTER ALL

2006 ◽  
Vol 20 (11n13) ◽  
pp. 1877-1884 ◽  
Author(s):  
LUIS L. SÁNCHEZ-SOTO ◽  
ANDREI B. KLIMOV ◽  
HUBERT de GUISE
Keyword(s):  
Fourier Transform ◽  
Quantum Systems ◽  
Mutually Unbiased Bases ◽  
Dimensional System ◽  
Finite Fourier Transform ◽  
Diagonal Operators ◽  
Physical Requirement ◽  
Commuting Operators ◽  
Finite Dimensional ◽  
Comprehensive Theory

A comprehensive theory of phase for finite-dimensional quantum systems is developed. The only physical requirement imposed is that phase is complementary to amplitude. This complementarity is implemented by resorting to the notion of mutually unbiased bases. For a d-dimensional system, where d is a power of a prime, we explicitly construct d + 1 classes of maximally commuting operators, each one consisting of d - 1 operators. One of this class consists of diagonal operators that represent amplitudes and, by the finite Fourier transform, operators in this class are mapped to off-diagonal operators that can be appropriately interpreted as phases. The relevant example of a system of qubits is examined in detail.

scholarly journals A design of HDPE flexible spline of harmonics gear

2018 ◽  
Vol 192 ◽  
pp. 01030
Author(s):  
Pholchai Chotiprayanakul ◽  
Nattakul Khamsri ◽  
Neeracha Kumjaroen
Keyword(s):  
Planetary Gear ◽  
Gear Ratio ◽  
Gear Train ◽  
The Other ◽  
Servo Motor ◽  
Strain Wave ◽  
Important Method ◽  
Physical Requirement ◽  
Wave Drive ◽  
Small Robot

In a design of a small robot, selecting a servo-motor is the most important method in designing process. Common miniature servo motors for small robots normally use conventional gear train set or planetary gear set. Gear train and planetary gear give very low gear ratio whereas its weight is too heavy. On the other hand, Harmonic gear system, which is developed from strain wave drive gearing, gives better the highest gear ratio per weight than those two gear systems. In this paper, a plastic flexible spline gear is presented in order to replace a thin metal spline. The plastic flexible spline gear is designed under gear physical requirement and servo-motor properties. The spline thicknesses are varied in a range of 1 to 4 millimetre and simulations on strength, fatigue, and torque requirement are made to verify the designs.

Evaluation of Job Physical Requirements to Aid in the Placement of Medically Restricted Workers

1979 ◽  
Vol 23 (1) ◽  
pp. 163-167
Author(s):  
Randall A. Rabourn
Keyword(s):  
Energy Expenditure ◽  
Medical Treatment ◽  
Job Placement ◽  
Medical Department ◽  
Physical Requirement ◽  
Physical Limitations ◽  
Employee Data

This presentation describes the application of ergonomic principles by one company and its medical department to aid in the placement of medically restricted employees. Job physical requirements are systematically defined in terms of biomechanics and energy expenditure parameters as are workers' physical limitations. The job and employee data are then used to promote the safe, healthful and efficient job placement of the employee. The job physical requirement data has also been valuable in the medical treatment of workers and in workplace redesign.

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