11 research outputs found
Buckling strength of compressed columns using design rules and nonlinear stability analysis
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Analysis of flow around high speed irregularly shaped bodies using numerical simulations
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The optimal design of school desks depending on the height and weight of students
No full textBackground: The subject of this research is the creation of an optimal school bench design with the aim of determining the most favorable posture of students while sitting, taking into account the relevant ergonometric and biomechanical characteristics of the human body. For the proposed model of the school bench which allows adjusting the different slopes of its surface, the corresponding computer model of the student and the table was first created, and then biomechanical and RULA analysis was performed in order to determine the maximum load in the lumbar part. Next, for each test subject of given weight, it was necessary to determine the amount of maximum load in lumbar zone L3/L4 for different slope angles and to determine the critical angles at which the maximum permissible load of 3400 N is reached.
Methods: The analysis is performed on a total of 5 subjects of the same height (180 cm) and various weights (60, 70, 80, 90, 100 kg). The task is to determine at which weight and at what angle of the workbench with standard height will not exceed the permissible loads of the spine, specifically referring to the L4/L5 vertebrae whose stresses should not exceed 3400 N. The CATIA software package (Dassault Systèmes, Vélizy-Villacoublay, France) is used for the analysis. By knowing the anthropometric and work environment data with ergonomic design and analysis, the following analyzes were made: biomechanical analysis, rapid upper limb assessment (RULA) and carry analysis (an option from CATIA software).
Results: The proposed school bench design allows for flexible adjustments to its worktop, that is, changing its tilt. This allows students of different body masses to have an optimal position at work that does not compromise their maximum permissible load in the L4/L5 spinal column (3400N).
Conclusions: The proposed ergonomic design of the desk will result in students being adequately positioned during their activities at school with the minimal risk of permanent deviations and other health problems
Influence of school backpacks on spinal column load in primary school students
No full textBackground: The problem of heavy school bags is a global problem recognized in many countries in Europe and the world, including in Bosnia and Herzegovina. In addition to poor posture habits, "sedentary lifestyles" and insufficient physical activity, school bags is one of the main causes of low back pain and deformity in pupils. The recommendation of the World Health Organization (WHO) is that the weight of the school bag should not exceed 10% of the student\u27s weight. However, in practice these limitations are far from reality with the obvious problems caused by too heavy bags. The aim of the paper is to identify and analyze the backbone load caused by the overweight school backpacks in real school work conditions and eliminate them by creating new solutions that are in line with ergonomic and biomechanical principles, as well as the recommendation given by WHO.
Methods: The research included first grade primary school students at the age of seven, including their parents. The research began by interviewing parents with relevant questions, as well as measuring the students’ height and weight and the weight of their school backpacks. The analysis was performed in CATIA v5 software package (Dassault Systèmes, Vélizy-Villacoublay, France) using its advanced biomechanical modules. By knowing the anthropometric and work environment data with ergonomic design and analysis, the biomechanical analysis, rapid upper limb assessment (RULA) and carry analysis were performed.
Results: The conducted survey showed that 84% of students walk from home to school nineteen minutes on average and that 77% of them carry their school backpacks independently. Based on the measurements, it has been shown that, on average, the weight of the school backpacks is well above the WHO recommendation. A study conducted on a representative sample of students confirmed the relation between fatigue and spinal pain caused by carrying a heavy school bag. Computer analysis showed excessive loads on the spinal segment of L4/L5 that were outside the normal range of 3,400 N.
Conclusions: A simulated computer analysis using RULA and biomechanical analysis with calculations of maximum loads in the lumbar segment of students found that school backpacks carried by students were too heavy for their age and well beyond the normal limits and WHO recommendations. The analysis showed that it is necessary to reduce the weight of the bag by about 30%
Biomechanical analysis of three-point shot in basketball
No full textBackground: A precise three-point shot (3S) is considered a key parameter of success in a basketball game, and therefore the factors that affect its success have always attracted the attention of researchers.
Aim: The aim of this research was a biomechanical-mathematical analysis of 3S in basketball, in order to determine the key parameters for performing a 3S.
Results: The research shows a model of shooting a basketball player from the central position of the shot with 6.75 m. The modeling led to the conclusion that the height of the throw, the speed and the angle of the throw of the ball have a positive and direct relationship with the angle at which the ball falls into the basket when it comes to a shot for three points.
Conclusion: The height of the throw, the speed and the angle of the ball have a positive and direct relationship with the angle at which the ball hits the basket when it comes to a shot for three points. Anthropometric characteristics of the player, such as the length of the arm, and the height of the player, directly lead to a positive relationship with the throwing angle
Beowulf : a written or an oral poem?
No full text'Beowulf' has long been considered a written poem,
and it is my intention to suggest that it may in fact be
of oral origins. The work of Milman Parry and Albert
Bates Lord on the Homeric poems has shown fairly
conclusively that the 'Iliad' and the 'Odyssey' have
been misunderstood for centuries. By comparing these
epics with twentieth century Yugoslav songs, Parry and
Lord discovered that Homer was most likely an oral singer
of the same style as the Yugoslav guslar, Avdo Međedović.
Such a discovery, strengthening as it does Parry's a priori
thesis, had enormous implications in literary studies, since
the way was now open for the re-examination of other older
works of unknown origin. So, in 1953,Francis P. Magoun
wrote an essay called 'The Oral-Formulaic Character of
Anglo-Saxon Narrative Poetry', in which he suggested the
oral nature of 'Beowulf'. But since then speculation on
the creative typology of the poem has become inconclusive,
inconsistent, and confused. I intend to show how the work
of Homeric scholars, especially of Parry and Lord, is
culturally and creatively relevant to Old English studies,
and in this way to suggest the orality of 'Beowulf'.
Oral poetry is the product of non-literate cultures
in which man is closer to the objective world than in what
Marshall McLuhan calls print cultures. Oral poetry is
near to myth and ritual, and has not yet reached the
state of discourse or logos The word as a symbolic
representation of the thing has not over-ridden the
ontology of the universe as an animistic and humanly
comprehensible sphere of energy. Besides these
mythological implications which first invested the singer
with shamanistic powers and then with the honour of both
describing and prescribing for his society, oral poetry
served the purpose of entertainment and relied on a close transaction between bard and audience. A print culture
relies on a different relationship, one that is more
impersonal and which emphasizes the split between thought
and action. Typed words in a book exist as a sort of
currency between author and reader, but are in themselves
inert. Spoken words are, by contrast, a living commerce
between singer and audience; there is no time lag, tone
lag, or intention lag between performance and delivery.
So, oral poetry may be said to close the void between
thought and action since the two are brought together.
There is no crystallization or suspension of the word as
there is in a print culture. The considerations of an
oral poetry must therefore be radically different from
those of written poetry, since the creation and expression
and artistic environment in a non-literate culture are
unique
