Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "reaction forces" wg kryterium: Temat

  Lista filtrów

Dostawca treści

Podbaza

Wyrównaj
Wyświetlanie 1-25 z 29
Tytuł:
An alternative scheme for determination of joint reaction forces in human multibody models
Alternatywny sposób wyznaczania reakcji w stawach wieloczłonowych modeli ciała człowieka
Autorzy:
Blajer, W.
Czaplicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/279332.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
human body modeling
dynamic analysis
joint reaction forces
Opis:
Multibody models are commonly used in the analysis of human movements. The dynamic formulations often use minimal sets of generalized coordinates, and joint reactions (non-working reactions of model-intrinsic constraints) are excluded from evidence. A separate modeling effort is then required to determine joint reactions, and the arising numerical procedures are computationally arduous. In this paper, a novel efficient approach to the determination of joint reactions is developed, which naturally assists the minimal-form formulations of human body dynamics. The proposed scheme does not involve matrix inversion, and as such it is well suited for both symbolic manipulations and computer implementations. The method is illustrated with a seven-segment planar model of a human body. Some results from the inverse dynamics simulation of somersaults on a trampoline are reported.
Wieloczłonowe modele ciała człowieka są powszechnie wykorzystywane do analizy czynności motorycznych. Dla sformułowań dynamiki tych modeli stosowane są zwykle niezależne współrzędne uogólnione, co powoduje, że reakcje w połączeniach (idealne reakcje więzów wewnętrznych) są eliminowane na wstępnym etapie modelowania. Dla ich określenia wymagane są dodatkowe procedury modelowania matematycznego, a generowane tą drogą zależności charakteryzują się niską efektywnością numeryczną. W niniejszej pracy proponowane jest nieco inne podejście do wyznaczania reakcji w stawach, w sposób naturalny skojarzone z minimalno-wymiarowym formułowaniem dynamiki wieloczłonowych modeli ciała człowieka. Proponowane sformułowania nic wymagają odwracania macierzy, są tym samym efektywne zarówno dla wyprowadzeń symbolicznych, jak i zastosowań numerycznych. Metoda zilustrowana jest za pomocą siedmioczłonowego płaskiego modelu ciała człowieka. Prezentowane są wybrane wyniki obliczeń numerycznych odnoszące się do symulacji dynamicznej odwrotnej sportowca wykonującego salto na trampolinie.
Źródło:
Journal of Theoretical and Applied Mechanics; 2005, 43, 4; 813-824
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of ground reaction forces during the Basic Step on the Core Board platform at various levels of stability
Autorzy:
Karczewska, M.
Madej, A.
Sadowska, A.
Mastalerz, A.
Urbanik, Cz.
Powiązania:
https://bibliotekanauki.pl/articles/306441.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fitness
biomechanika
siła reakcji podłoża
Core Board
ground reaction forces
Opis:
Purpose: The aim of this paper was to examine and compare the changes of ground reaction forces observed during the Basic Step on the Core Board fitness device at various levels of stability. Material and method: The study involved 10 female students. Participants stepped on and off the Core Board 10 times at 3 levels of stability. After completing a series of steps, the Core Board’s stability was modified and the participant repeated the whole series. The measurement platform to examine three components of the reaction force (horizontal in the sagittal and frontal planes, and vertical) was used. Results: The ground reaction force (GRF) observed on the Core Board, in the vertical and horizontal components is higher at all three levels of stability than on the platform without the device. Significant differences in GRF were observed in the horizontal component in the frontal plane (Fz) at all three levels of mobility as well as in impulse, measured on platforms with the device. Conclusion: The results on the Core Board training device present highest horizontal ground reaction forces in frontal plane at the highest level of Core Board mobility and this showing little medio-lateral stability and a more reactive way of movement regulation of the participants. As a consequence of the force patterns found it may be suggested that fitness training concepts should focus more possibly higher strains on the locomotor system most likely caused by changed ground reaction force patterns, an idea that has to be further analyzed with more complex measurement approaches.
Źródło:
Acta of Bioengineering and Biomechanics; 2016, 18, 4; 63-70
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of the vertical component of ground reaction force during gait of healthy people and people with Parkinson’s disease
Autorzy:
Tymińska, Karolina
Derlatka, Marcin
Powiązania:
https://bibliotekanauki.pl/chapters/2215318.pdf
Data publikacji:
2022
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
Parkinson’s disease
ground reaction forces
human gait
statistical analysis
Opis:
One of the symptoms of Parkinson’s disease is an abnormal gait cycle. Locomotion becomes slower, less sure, and gait very often leads to falls. This paper analyses the vertical component of the ground reaction force and pressure force for healthy subjects and those with Parkinson’s disease. The data used in the paper comes from the physionet.org website and includes the results of tests that were conducted with Ultraf lex Computer Dyno Graphy system Infronic insoles. The dataset contains recorded ground reaction forces during gait of 164 people, including 71 healthy people and 93 people with Parkinson’s disease at varying degrees of disease severity as determined by the Hoehn-Yahr scale. The analysis showed statistically significant differences (α ≤ 0.05) between the highest value and the local minimum of the vertical component of the ground reaction force. The course of the vertical component of the ground reaction force changed with increasing disease progression, characteristic gait phases disappeared, and the foot contacted the ground in a different way during the heel strike phase. This is due to the development of an abnormal gait pattern, which protects against falls and helps to maintain independence for longer. Gait testing and analysis of the vertical component of the ground reaction force can help to detect the disease earlier and therefore to implement treatment more quickly, resulting in a slower onset of symptoms.
Źródło:
Advances in biomedical engineering; 85-97
9788367185400
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Próba stworzenia kryteriów oceny funkcji chodu z wykorzystaniem platformy PDM-S
An attempt to create criteria for the assessment of gait function by means of the PDM-S platform
Autorzy:
Jaszczur, I.
Koprowski, P.
Wrzosek, Z.
Powiązania:
https://bibliotekanauki.pl/articles/261387.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Wydział Podstawowych Problemów Techniki. Katedra Inżynierii Biomedycznej
Tematy:
chód
platforma dynamometryczna
siła reakcji podłoża
gait
dynamometric platform
ground reaction forces
Opis:
Chód, jako podstawowa forma lokomocji, jest przedmiotem zainteresowań i wielu opracowań, począwszy od patologii chodu po sport wyczynowy. Badaniu podlegają różne aspekty chodu, takie jak np.: długość i częstotliwość kroków, analiza fazy podparcia i wymachu, przebieg sił reakcji podłoża, charakterystyka kinematyki stawów. Szczegółowymi zagadnieniami analizy chodu są: kinematyka, kinetyka, dynamiczna elektromiografia oraz ocena kosztów energetycznych. W niniejszej pracy zaprezentowana została próba stworzenia kryteriów oceny funkcji chodu za pomocą platformy dynamograficznej PDM-S, z uwzględnieniem wpływu masy ciała. Utworzony wzorzec, w dalszym etapie, może posłużyć do badań nad wpływem treningu lub nad ubytkami sprawności, wynikającymi z przyczyn patologicznych.
Many researchers are interested in gait as the primary form of transportation. Various aspects of gait can be analyzed as e.g. length and frequency of steps, support and swing phase, the course of ground reaction forces, joint kinematics. Specific issues relating to gait are among others: kinematics, kinetics, dynamic electromyography and assessment of energy costs. In this paper, an attempt to create criteria for the assessment of gait function by means of the PDM-S platform, with influence of body weight, will be presented. The obtained pattern can be used for further examination on the effects of training or pathological changes of locomotory system.
Źródło:
Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna; 2013, 19, 1; 24-31
1234-5563
Pojawia się w:
Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of minimalist and conventional sports shoes and lower limbs dominance on running gait
Autorzy:
Jandova, S.
Volf, P.
Vaverka, F.
Powiązania:
https://bibliotekanauki.pl/articles/307459.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
analiza kinematyczna
siły reakcji podłoża
bieganie
laterality
kinematic analysis
ground reaction forces
running
Opis:
Purpose: The aim of this study was to determine how minimalist running shoes (MRS), conventional running shoes (CRS) and the dominance of lower limbs influence the running gait. Methods: Trained recreational runners (N = 13) who have been engaged in regulary running for more than one year were participants in this study. They were experienced with using MRS and CRS for more than half year and they used both types of shoes. An in-shoe pressure measuring system (Pedar-X®, Novel, Munich, Germany) was used to monitor plantar pressure and vertical force and the temporal parameters when running in MRS and CRS during the stance phase, the swing phase and over one stride. Results: Running in CRS significantly prolonged stance, swing and stride phases by 2–11% compared to MRS. In contrast, when running in MRS significantly larger values of maximum pressure (9–14%) and maximum vertical force (3–7%) than in CRS were found. Conclusions: For this reason, running in MRS could be recommended to recreational runners only with care. The effect of limb dominance on temporal characteristics was detected when running in CRS. Significantly longer stance phase for dominant limb is associated with a shorter swing. The kinematics variables were significantly higher for dominant limb than for non-dominat limb when running in MRS and CRS (by 12–23%).
Źródło:
Acta of Bioengineering and Biomechanics; 2018, 20, 3; 3-9
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integral method (IM) as a quantitative and objective method to supplement the GMFCS classification of gait in children with cerebral palsy (CP)
Autorzy:
Dziuba, A.
Bober, T.
Kobel-Buys, K.
Stempień, M.
Powiązania:
https://bibliotekanauki.pl/articles/306450.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
children walking
cerebral palsy
ground reaction forces
chód dziecka
porażenie mózgowe
reakcja podłoża
Opis:
Gait analysis is an objective tool for the clinical assessment of locomotor activity in children with cerebral palsy (CP). Correct diagnosis and properly planned rehabilitation are necessary for enhanced motor functions in persons suffering from cerebral palsy. Orthoses, orthopedic operations, medications and physiotherapy are the most common treatments. However, there is still a lack of objective methods for assessing motor behavior and monitoring the progress of recovery. The aim of the study was to use the ground reaction force patterns generated during walking to create the Integral Method (IM), which could become an objective tool that could supplement the functional classification of CP children based on the Gross Motor Function Classification System (GMFCS). A total of 15 healthy children and 34 children with CP who walk independently participated in the study. A Kistler force plate and GRFintegral software were used. Of the 34 measurements based on the IM for CP children, 17 matched the level assigned by the GMFCS, 2 children were assigned a higher level, and 15 were assigned a lower level. Pearson’s correlation coefficient between the IM and the GMFCS was moderate (r = 0.61, p ≤ 0.01). Asymmetry was found in 11 cases. The IM supplements the GMFCS and is an objective and quantitative assessment of motor abilities. The method allows for the detection of asymmetry, diagnosis of the improvement of gait pattern and assessment of foot support technique. With the appropriate software, the IM provides pediatricians, neurologists, orthopedists, surgeons and physiotherapists with a simple and fast way to assess gait.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 2; 105-111
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Differences in pediatric vertical ground reaction force between planovalgus and neutrally aligned feet
Autorzy:
Pauk, J
Szymul, J.
Powiązania:
https://bibliotekanauki.pl/articles/306708.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
force platforms
planovalgus
neutrally aligned feet
ground reaction forces
stopa
chód dziecka
biomechanika
Opis:
Ground reaction forces (GRF) reflect the force history of human body contact with the ground. The purpose of this study was to explore human gait abnormalities due to planovalgus by comparing vertical GRF data between individuals with planovalgus and those with neutrally aligned feet. Second we estimated associations between various measurements and vertical GRF parameters in a pediatric population. Boys and girls between the ages of 4 and 18 years (72 planovalgus feet and 74 neutrally aligned feet) took part in this study. Ground reaction forces were recorded by two Kistler platforms and normalized to body weight. Comparison of vertical GRF between planovalgus and neutrally aligned feet suggests that the first and the second peaks of vertical force (Fz1, Fz2) are most affected by planovalgus. The results also indicate that neutrally aligned feet display a different ground reaction force pattern than planovalgus, and that differences between boys and girls may be observed. The shape of the vertical GRF curve can help in clinical interpretation of abnormal gait.
Źródło:
Acta of Bioengineering and Biomechanics; 2014, 16, 2; 95-101
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza obciążeń w step aerobics na podstawie literatury
Analysis of loads in step aerobics - literature review
Autorzy:
Błażkiewicz, M.
Kowalczyk, P.
Powiązania:
https://bibliotekanauki.pl/articles/99179.pdf
Data publikacji:
2008
Wydawca:
Politechnika Śląska. Katedra Biomechatroniki
Tematy:
biomechanika
step aerobics
basic step
siła reakcji podłoża
obciążenie
biomechanics
ground reaction forces
load
Opis:
Step aerobics jest jedną z bardziej popularnych form rekreacji ruchowej. Uważa się, że podwyższenie wysokości stopnia, lub zaaplikowanie w choreografii kroków typu high-impact zwiększa poziom trudności i intensywność zajęć, a w konsekwencji bardziej obciąża układ ruchu, co często prowadzi do kontuzji. Siła reakcji podłoża jest jedną ze zmiennych, która dostarcza informacji o obciążeniach. Niniejsza praca zawiera podsumowanie wyników, podawanych w literaturze, dotyczących zmian sił reakcji podłoża podczas najczęściej wykonywanych kroków aerobikowych.
Step aerobics classes are offered at many gyms and fitness centers. The step aerobics is distinguished from other forms of aerobics exercise by its use of an elevated platform (the step). The height can be tailored to individual taste by inserting risers under the step. The main objective of the paper is description of human movement and vertical ground reaction forces during common steps in a simple choreography on the base of the various articles.
Źródło:
Aktualne Problemy Biomechaniki; 2008, 2; 13-18
1898-763X
Pojawia się w:
Aktualne Problemy Biomechaniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Examination of the effect of psychophysical factors on the quality of human gait recognition
Autorzy:
Derlatka, M.
Powiązania:
https://bibliotekanauki.pl/articles/386380.pdf
Data publikacji:
2014
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
human gait recognition
ground reaction forces
classification
rozpoznawanie chodu człowieka
siła reakcji podłoża
klasyfikacja
Opis:
The paper presents an analysis concerning the influence of selected psychophysical parameters on the quality of human gait recognition. The following factors have been taken into account: body height (BH), body weight (BW), the emotional condition of the respondent, the physical condition of the respondent, previous injuries or dysfunctions of the locomotive system. The study was based on data measuring the ground reaction forces (GRF) among 179 participants (3 315 gait cycles). Based on the classification, some kind of confusion matrix were established. On the basis of the data included in the matrix, it was concluded that the wrong classification was most affected by the similar weight of two confused people. It was also noted, that people of the same gender and similar BH were confused most often. On the other hand, previous body injuries and dysfunctions of the motor system were the factors facilitating the recognition of people. The results obtained will allow for the design of more accurate biometric systems in the future.
Źródło:
Acta Mechanica et Automatica; 2014, 8, 4; 194-198
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of modified muscle morphology and activity pattern on the results of musculoskeletal system modelling in cerebral palsy patient
Autorzy:
Ogrodnik, J.
Piszczatowski, Sz.
Powiązania:
https://bibliotekanauki.pl/articles/306659.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
układ mięśniowo-szkieletowy
mięśnie
porażenie mózgowe
musculoskeletal model
muscle
cerebral palsy
joint reaction forces
Opis:
Purpose: The aim of the present study was to evaluate the influence of modified morphological parameters of the muscle model and excitation pattern on the results of musculoskeletal system numerical simulation in a cerebral palsy patient. Methods: The modelling of the musculoskeletal system was performed in the AnyBody Modelling System. The standard model (MoCap) was subjected to modifications consisting of changes in morphological parameters and excitation patterns of selected muscles. The research was conducted with the use of data of a 14-year-old cerebral palsy patient. Results: A reduction of morphological parameters (variant MI) caused a decrease in the value of active force generated by the muscle with changed geometry, and as a consequence the changes in active force generated by other muscles. A simulation of the abnormal excitation pattern (MII variant) resulted in the muscle’s additional activity during its lengthening. The simultaneous modification of the muscle morphology and excitation pattern (MIII variant) points to the interdependence of both types of muscle model changes. A significant increase in the value of the reaction force in the hip joint was observed as a consequence of modification of the hip abductor activity. Conclusions: The morphological parameters and the excitation pattern of modelled muscles have a significant influence on the results of numerical simulation of the musculoskeletal system functioning.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 3; 63-75
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reference values of spatiotemporal parameters, joint angles, ground reaction forces, and plantar pressure distribution during normal gait in young women
Autorzy:
Fryzowicz, A.
Murawa, M.
Kabaciński, J.
Rzepnicka, A.
Dworak, L. B.
Powiązania:
https://bibliotekanauki.pl/articles/307416.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kobieta
kinematyka
biomechanika chodu
pedobarografia
women
kinematics
ground reaction forces
gait biomechanics
pedobarography
reference data
Opis:
The aim of this study was to establish the reference values of spatiotemporal parameters, joint angles, ground reaction forces and plantar pressure distribution collected simultaneously on the same measurement path during normal gait in a homogenous group of young, healthy women. Methods: The studied group consisted of 28 healthy women aged 21 years on average. The motion capture system BTS Smart-D, 2 AMTI force platforms and Footscan pedobarographic platform were used in this research. The 14-metre measurement path and the 6-metre distance that examined women had to walk through before entering the measurement area ensured that a natural gait pattern was recorded. Statistical analysis was performed to evaluate differences between right and left lower extremities. Results: The applied method enabled collecting several parameters regarding normal female gait biomechanics such as: spatiotemporal parameters, angle-time characteristics as well as range of motion of pelvis, hip, knee and ankle joints in gait cycle, force-time characteristics and peaks of ground reaction force components in stance phase, peak pressure and time of loading of defined foot regions in stance phase. Conclusions: The results may be used by clinicians, physiotherapists or researchers as a reference in diagnosing gait disorders or evaluating patient’s walking pattern. In recent literature there are some disparities in gait parameters reference values even regarding similar research groups. These differences may arise from distinct method, slower or faster gait, other laboratory environment etc. This should be considered and more than one source of normative values should be checked when searching for reference data.
Źródło:
Acta of Bioengineering and Biomechanics; 2018, 20, 1; 49-57
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Foot mechanics in young women are altered after walking in high-heeled shoes
Autorzy:
Winiarski, S.
Rutkowska-Kucharska, A.
Zostawa, P.
Uścinowicz-Zostawa, N.
Klich, S.
Powiązania:
https://bibliotekanauki.pl/articles/307334.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
analiza chodu
reakcja podłoża
stopa
gait analysis
high-heeled shoes
ground reaction forces
foot rockers
foot deformities
Opis:
Nowadays, fashion has caused that many young women are wearing high-heeled shoes. Therefore, the aim of this study was to examine the effects of long-term walking in high-heeled shoes on the foot mechanics during barefoot gait. Methods: Forty-three young women (22 ± 2.1 years) divided into two groups participated in this retrospective cohort study. The first group was composed of women who frequently wear high-heeled footwear. The second, infrequent wearers group, consisted of women who preferred flat-heeled shoes. Measurements of gait parameters were recorded for barefoot gait. A motion analysis system and two force plates were used in order to evaluate the lower-limb rocker mechanism, transverse foot arch height and parameters of ground reaction force. Results: Walking in high-heeled shoes modified barefoot foot mechanics, which manifested itself in a shorter duration (by ca. 4%) of the first and second rocker and a significantly longer duration (by 5%) of the third rocker phase as well as a substantial reduction in height of the transverse foot arch (by around 50%) in women habitually walking in high-heeled shoes. A significantly shorter relative duration of the third rocker (44.3% of cycle time) and greater value of the vertical component of ground reaction force (114.7% BW) in the third rocker phase were found in the group of women habitually walking in high-heeled shoes. Conclusions: The mechanism of foot rolling, with flattened foot arch, and significantly higher values of the vertical component of ground reaction force and shorter time might lead to overload in lowerlimb joints in young women.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 3; 107-113
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of the contact forces between the hexapod legs and the ground during walking in the tripod gait
Autorzy:
Grzelczyk, D.
Stańczyk, B.
Awrejcewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/128022.pdf
Data publikacji:
2016
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
multi-legged robot
six-legged robot
hexapod
tripod gait
contact forces
reaction forces
robot sześcionożny
tripod kroczący
siły kontaktowe
siła reakcji
Opis:
The paper is devoted to the dynamical modelling of the hexapod robot walking on a flat and hard ground. The main goal is to determine time series of reaction forces acting on individual legs of the robot during tripod gait often used both by the six-legged insects as well as mobile walking robots found in engineering applications. The movement of the considered robot is realized by the kinematic excitation of its legs using the so-called Central Pattern Generator (CPG) method. The paper demonstrates that there are different contact forces and overload acting on the robot, resulting from different models working as a CPG. The mentioned forces belong to the important issues that should be taken into account when the robot locomotion on the unknown terrain is planned.
Źródło:
Vibrations in Physical Systems; 2016, 27; 107-114
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic Simulation of a Hydraulic Excavator to Determine the Joint Reaction Forces of Boom, Stick, Bucket, and Driving Forces of Hydraulic Cylinders
Dynamiczna symulacja koparki hydraulicznej w celu określenia sił reakcji na przegub, wysięgnik, ramienia, łyżkę oraz sił napędowych cylindrów hydraulicznych
Autorzy:
Nguyen, Dang Tan
Powiązania:
https://bibliotekanauki.pl/articles/318155.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
dynamic simulation
excavator design
joint reaction forces
driving forces
maximum tension
symulacja dynamiczna
projektowanie koparek
siły reakcji na przegub
siły napędowe
maksymalne napięcie
Opis:
To optimize the dimensions of the boom, stick of the hydraulic excavator and select the suitable hydraulic bucket, stick, and boom cylinders, the designer must determine the joint reaction forces and driving forces. These forces always alter in an excavator's working cycle. They are conventionally calculated by mathematical method. This conventional method is complicated and challenging to determine the maximum reaction forces, which can break the stick and boom. This article builds a 3D model and simulates a working cycle of the hydraulic excavator to find the reaction force diagrams of boom and stick as well as driving forces of hydraulic cylinders by using computer software PTC Creo Parametric. Based on these results, the designer easily calculates the maximum tensions of the dimensions of boom and stick in a working cycle to optimize their dimensions as well as selects suitable hydraulic cylinders.
Określenie siły reakcji na przegub i siły napędowej jest warunkiem optymalizacji wymiarów wysięgnika, ramienia koparki hydraulicznej i dobrać odpowiednie hydrauliczne siłowniki łyżki, ramienia i wysięgnika. W cyklu roboczym koparki, siły te zawsze zmieniają się. Tradycyjne metody są zwykle skomplikowane i trudne do określenia maksymalnych sił reakcji, które mogą spowodować złamanie drążka i wysięgnika. W artykule zbudowano model 3D i symulowano cykl pracy koparki hydraulicznej w celu znalezienia wykresów sił reakcji wysięgnika i ramienia oraz sił napędowych cylindrów hydraulicznych za pomocą oprogramowania komputerowego PTC Creo Parametric. Na podstawie tych wyników, konstruktor w łatwy sposób oblicza maksymalne naprężenia wymiarów wysięgnika i ramienia w cyklu pracy, aby zoptymalizować ich wymiary, a także dobiera odpowiednie hydrauliczne cylindry.
Źródło:
Inżynieria Mineralna; 2020, 1, 2; 131-137
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
ALIANČNÁ BEZPEČNOSŤ V PODMIENKACH ORGANIZÁCIE DOHODY O KOLEKTÍVNEJ BEZPEČNOSTI
Autorzy:
Martin, JOŠČÁK,
Boris, Ďurkech,
Powiązania:
https://bibliotekanauki.pl/articles/891954.pdf
Data publikacji:
2018-08-13
Wydawca:
Wyższa Szkoła Bezpieczeństwa Publicznego i Indywidualnego Apeiron w Krakowie
Tematy:
collective defence
cooperative defence
collective security treaty organization (CSTO)
collective rapid deployment forces
collective rapid reaction forces
regional air defence system
regional military groupings
Opis:
This article focuses on the collective defence in the post soviet area representing by the Collective Security Treaty Organization, its structure and capability to ensure security in the area of responsibility. The article evaluates capabilities of the collective defence, collective rapid reaction forces, collective peacekeeping forces, collective air forces, regional military groupings, and regional air defence systems at main strategic defence directions.
Źródło:
Kultura Bezpieczeństwa. Nauka – Praktyka – Refleksje; 2016, 23; 90-110
2299-4033
Pojawia się w:
Kultura Bezpieczeństwa. Nauka – Praktyka – Refleksje
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic load indicators for take-off–landing sequence in blocks and attacks of elite female volleyball players
Autorzy:
Kabaciński, J.
Dworak, L. B.
Murawa, M.
Rzepnicka, A.
Powiązania:
https://bibliotekanauki.pl/articles/307295.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
siła reakcji podłoża
obciążenie dynamiczne
start
atak
biomechanika
ground reaction forces
take-off–landing
dynamic loads
blocks
attacks
volleyball
biomechanics
Opis:
Purpose: Dynamic loads during landings determined by the ground reaction forces (GRFs) may elaborate internal loads and increase the risk of overload knee injuries as a result of performing volleyball jumps many times. The study dealt with a biomechanical assessment of dynamic load indicators in female volleyball players for the motion sequence of take-off–landing in blocks and attacks. Methods: Twelve professional female volleyball players participated in the study. Blocks and attacks were filmed by two cameras. GRFs vs. time graphs were recorded with the use of a force platform. Values of dynamic load indicators in terms of the relations of peak of vertical component of GRF, build-up index of this force (BIF), and power output (P) during landing to the vGRF, BIF and P during take-off (L/T) were calculated. Results: The statistically significant ( p < 0.05) highest values of L/T indicators were found for back row attack spikes: 2.4 (vGRF), 12.2 (BIF) and 3.1 (P). In the case of blocks, slide attack spikes and attack line spikes, results of these variables were in range: 1.8÷2.1, 5.9÷7.6 and 2.1÷2.9, respectively. Conclusions: The reduction of GRFs during landings contributes to decreasing the level of the load indicators L/T which should minimize the incidence of anterior cruciate ligament and patellar tendon injuries in female volleyball players.
Źródło:
Acta of Bioengineering and Biomechanics; 2016, 18, 1; 41-46
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie systemu analizy ruchu BTS do określenia chwili utraty stabilności
Application of motion capture system to assess human stability loss
Autorzy:
Matuszewska, Agata
Liszkowski, Jakub
Walczak, Tomasz
Buśkiewicz, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/2201473.pdf
Data publikacji:
2019
Wydawca:
Politechnika Śląska. Katedra Biomechatroniki
Tematy:
stabilność
równowaga
siły reakcji podłoża
system analizy ruchu
ryzyko upadku
stability
balance
ground reaction forces
motion analysis system
fall risk
Opis:
W pracy przeprowadzono próbę wyznaczenia chwili utraty stabilności dla upadków z pozycji statycznej. Pozycją początkową, jaką przyjmowała osoba badana, było stanie na dwóch nogach z rękami wzdłuż tułowia. Rejestracji ruchu dokonano dzięki wykorzystaniu systemu BTS. W celu wyznaczenia chwili utraty stabilności zaproponowano i opracowano własne miary i parametry, bazujące na pomiarach wykonanych z użyciem platform dynamometrycznych oraz systemu analizy ruchu. Dla analizowanego przypadku ruchu wielkości te pozwoliły na szacunkowe wyznaczenie chwili utraty stabilności.
Assessing of human stability loss was performed at this work in case of falls from a static position. At the beginning patient takes the starting position as standing on two legs with hands along the thorax. Human motion registration was performed by using BTS system. In order to determine the instant of human stability loss the new measures and parameters were proposed, which based on measurements from force platforms and motion analysis system. These parameters allowed to assess the instant of stability loss for analyzed motion.
Źródło:
Aktualne Problemy Biomechaniki; 2019, 17; 69--76
1898-763X
Pojawia się w:
Aktualne Problemy Biomechaniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomechanical characteristics of the jump down of healthy subjects and patients with knee injuries
Autorzy:
Mielińska, A.
Czamara, A.
Szuba, Ł.
Będziński, R.
Powiązania:
https://bibliotekanauki.pl/articles/307066.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
mięśnie
siła mięśni
aktywność mięśni
prędkość
biomechanika
vertical ground reaction forces
muscle power
muscle activity
velocity
acceleration
mass centre reposition
Opis:
Purpose: The aim of this study is to investigate the drop jump performance of male patients who underwent ACLR and a control group using combined data acquisition system. Methods: A total of 28 male subjects aged 20 to 26 were studied: 22 did not show and were not diagnosed with any knee joint dysfunction (the control group) and six men who underwent ACLR of the left limb (group of patients). The control group was age, height and body mass matched. A data acquisition setup consisting of three independent modules including force platforms, position analysis system and electromyography was used. Subjects were jumping down from 0.1, 0.2, and 0.3 m step heights. The acquired signals were used to determine the ground reaction force, muscular activity, mass centre position, velocity and acceleration. Results: Statistically significant differences were found between the groups (t-test, p < 0.05) in the maximum vertical ground reaction force in the left limb for 0.2 and 0.3 m step heights. Differences in the muscle activity between the groups were found to be statistically significant (t-test, p < 0.05) before the jump, during the landing phase, and after the jump for selected muscle groups and step heights. Conclusion: Combing the three independent measurement systems provided new information on drop jump biomechanics. The distribution of loads in different muscles was not uniform across the groups. Patients allocated more energy to control their motion and seemed to protect their operated limb by shifting the bodyweight to the healthy limb.
Źródło:
Acta of Bioengineering and Biomechanics; 2015, 17, 2; 111-120
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelowanie obciążeń dynamicznych w formie przysiadów na kładkach dla pieszych
Modelling of the dynamic loads in the form of squats on footbridges
Autorzy:
Pańtak, M.
Powiązania:
https://bibliotekanauki.pl/articles/104642.pdf
Data publikacji:
2017
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
drgania
podatność
siły reakcji podłoża
odpowiedź dynamiczna
kładka
strop
trybuna
vibrations
susceptibility
ground reaction forces
dynamic response
footbridges
floor
stadium stand
Opis:
Konstrukcje budowlane charakteryzujące się zwiększoną podatnością dynamiczną i możliwością występowania drgań odczuwalnych przez ich użytkowników narażane są często na intencjonalne wzbudzanie drgań przez osoby wykonujące podskoki lub przysiady. Obciążenia dynamiczne tego typu wystąpić mogą m.in. na: kładkach dla pieszych, trybunach stadionowych, stropach budynków (podczas wydarzeń sportowo-rekreacyjnych, dyskotek, koncertów). W referacie przedstawiono charakterystykę obciążeń dynamicznych w formie sił reakcji podłoża generowanych podczas ciągłych, rytmicznych przysiadów wykonywanych przez jedną osobę wraz z propozycją modeli matematycznych tych obciążeń. Zaproponowane modele opracowano w oparciu o wyniki badań laboratoryjnych sił reakcji podłoża i wstępnie zweryfikowano w drodze dynamicznych analiz numerycznych oraz badań terenowych przykładowych kładek dla pieszych. Wyniki analiz i badań potwierdziły poprawność i skuteczność stosowania modeli w celu wyznaczania wartości sił reakcji podłoża powstających podczas ciągłych, rytmicznych przysiadów oraz ustalania wartości odpowiedzi dynamicznej konstrukcji.
Dynamic forces generated by moving persons can lead to excessive vibration of the long span, slender and light-weight structure such as floors, stairs, stadium stands and footbridges. These dynamic forces are generated during walking, running, jumping and rhythmical body swaying in vertical or horizontal direction etc. One of the important type of dynamic loading of a susceptible and light-weight structures can be the ground reaction forces generated during rhythmically repeated squats. In the paper the load models of the ground reaction forces generated during partial squats have been presented. Elaborated models was compared to the forces measured during laboratory tests carried out by author in wide range of frequency using force platform. Moreover, the load models were initially validated during dynamic numerical analyses and dynamic field tests of the exemplary footbridges.
Źródło:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury; 2017, 64, 3/I; 189-202
2300-5130
2300-8903
Pojawia się w:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Human-induced force reconstruction using a non-linear electrodynamic shaker applying an iterative neural network algorithm
Autorzy:
Peláez-Rodríguez, César
Magdaleno, Álvaro
Salcedo-Sanz, Sancho
Lorenzana, Antolín
Powiązania:
https://bibliotekanauki.pl/articles/27311419.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
ground reaction forces
electrodynamic shaker
artificial neural networks
forces reconstruction
iterative neural network
siły reakcji podłoża
wstrząsarka elektrodynamiczna
sztuczne sieci neuronowe
rekonstrukcja sił
sieć neuronowa iteracyjna
Opis:
An iterative neural network framework is proposed in this paper for the human-induced Ground Reaction Forces (GRF) replication with an inertial electrodynamic mass actuator (APS 400). This is a first approach to the systematization of dynamic load tests on structures in a purely objective, repeatable and pedestrian-independent basis. Therefore, an inversion-free offline algorithm based on Machine Learning techniques has been applied for the first time on an electrodynamic shaker, without requiring its inverse model to tackle the inverse problem of successful force reconstruction. The proposed approach aims to obtain the optimal drive signal to minimize the error between the experimental shaker output and the reference force signal, measured with a pair of instrumented insoles (Loadsol©) for human bouncing at different fre- quencies and amplitudes. The optimal performance, stability and convergence of the system are verified through experimental tests, achieving excellent results in both time and frequency domain.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 3; art. no. e144615
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
BEZPIECZEŃSTWO ENERGETYCZNE SPOŁECZNOŚCI LOKALNEJ
ENERGY SECURITY OF LOCAL COMMUNITIES
Autorzy:
Wieczorek, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/512990.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
Law,
Energy Security,
crisis management,
Renewable Energy Sources,
scattered energy,
Cold Fusion,
Low Energy Nuclear Reaction,
LENR,
energy supply
break threats,
non-military threats,
crisis situation,
Armed Forces reaction to natural disaster,
Military Rebuilding Units
Opis:
The publication concerns the issue of periodic energy supply breaks. The main goal of the paper is to answer the following question: how one can solve the problems of local communities connected with periodic energy supply breaks, for instance: floods, avalanches, windstorms, hurricanes, tornadoes, which result in power cuts lasting for almost a week. Secondly, this article is also dedicated to the investors, who would certainly decrease the use of energy in some urban areas, if they applied the provided solutions with regard to their investments such as huge shopping centres. What is more, the aim of this paper is to present certain legal regulations related to the crisis management concerning the use of the equipment of the Armed Forces in the case of periodic energy supply breaks.
Źródło:
Polityka i Społeczeństwo; 2017, 15, 2; 82-103 (22)
1732-9639
Pojawia się w:
Polityka i Społeczeństwo
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 29

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies