scholarly journals An Exploratory Approach to Manipulating Dynamic Stability: Investigating the Role of Visual Control during a Precision Foot Placement Task

2016 ◽  
Vol 16 (12) ◽  
pp. 1361
Author(s):  
Russell Kennedy ◽  
Dr. Michael Cinelli
Keyword(s):  
Dynamic Stability ◽  
Visual Control ◽  
Foot Placement ◽  
Exploratory Approach

Pondok Pesantren Sebagai Lembaga Pendidikan Alternatif

KUTTAB ◽  
2017 ◽  
Vol 1 (1) ◽  
pp. 50-57
Author(s):  
Salman Zahidi
Keyword(s):  
Cultural Identity ◽  
Boarding Schools ◽  
Islamic Education ◽  
Educational Institutions ◽  
Learning Models ◽  
Literature Study ◽  
Exploratory Approach ◽  
The Times ◽  
Modern Era

Ali Bin Abi Talib once said that children should be educated in accordance with the  development of the times. The Ali bin Abi Talib’s statement could be considered as his attention more to the development of human civilization. For that reason, there should be studies focused on the role of educational institutions in facing the challenges of the times. On this stand, the writer raises the existence of pesantren (Islamic boarding schools) for being considered to have been able to survive amid the onslaught of civilization increasingly obscuring cultural identity. In addition, this study also aims to identify and discuss the role of pesantren in the modern era. This is a literature study using a descriptive and exploratory approach. It can be concluded that pesantren are non-formal Islamic educational institutions. Pesantren have permanent and distictive methods and learning models. The purpose of pesantren education is the same as Islamic education in general, instilling a sense of virtue, familiarizing themselves with courtesy, preparing for a holy, sincere and honest life entirely. Pesantren could be seen from three aspects: (a) pesantren that are seen from facilities and infrastructures, (b) pesantren that are seen from disciplines taught, and (c) pesantren that are seen from the fields of knowledge.

scholarly journals The effect of external lateral stabilization on the use of foot placement to control mediolateral stability in walking and running

2019 ◽  
Author(s):  
Mohammadreza Mahaki ◽  
Sjoerd M Bruijn ◽  
Jaap H. van Dieën
Keyword(s):  
Young Adults ◽  
Repeated Measures ◽  
Main Mechanism ◽  
Step Width ◽  
Normal Walking ◽  
Kinematic Data ◽  
Foot Placement ◽  
Mediolateral Stability

It is still unclear how humans control mediolateral (ML) stability in walking and even more so for running. Here, foot placement strategy as a main mechanism to control ML stability was compared between walking and running. Moreover, to verify the role of foot placement as a means to control ML stability in both modes of locomotion, this study investigated the effect of external lateral stabilization on foot placement control. Ten young adults participated in this study. Kinematic data of the trunk (T6) and feet were recorded during walking and running on a treadmill in normal and stabilized conditions. Correlation between ML trunk CoM state and subsequent ML foot placement, step width, and step width variability were assessed. Paired t-tests (either SPM1d or normal) were used to compare aforementioned parameters between normal walking and running. Two-way repeated measures ANOVAs (either SPM1d or normal) were used to test for effects of walking vs. running and of normal vs. stabilized condition. We found a stronger correlation between ML trunk CoM state and ML foot placement and significantly higher step width and step width variability in walking than in running. The correlation between ML trunk CoM state and ML foot placement, step width, and step width variability were significantly decreased by external lateral stabilization in walking and running, and this reduction was stronger in walking than in running. We conclude that ML foot placement is coordinated to ML trunk CoM state to stabilize both walking and running and this coordination is stronger in walking than in running.

scholarly journals The effect of external lateral stabilization on the control of mediolateral stability in walking and running

2019 ◽  
Author(s):  
Mohammadreza Mahaki ◽  
Sjoerd M Bruijn ◽  
Jaap H. van Dieën
Keyword(s):  
Young Adults ◽  
Repeated Measures ◽  
Main Mechanism ◽  
Step Width ◽  
Normal Walking ◽  
Kinematic Data ◽  
Foot Placement ◽  
Mediolateral Stability

It is still unclear how humans control mediolateral (ML) stability in walking and even more so for running. Here, foot placement strategy as a main mechanism to control ML stability was compared between walking and running. Moreover, to verify the role of foot placement as a means to control ML stability in both modes of locomotion, this study investigated the effect of external lateral stabilization on foot placement control. Ten young adults participated in this study. Kinematic data of the trunk (T6) and feet (heels) were recorded during walking and running on a treadmill in normal and stabilized conditions. Correlation between ML trunk CoM state and subsequent ML foot placement, step width, and step width variability were assessed. Paired t-tests (either SPM1d or normal) were used to compare aforementioned parameters between normal walking and running. Two-way repeated measures ANOVAs (either SPM1d or normal) were used to test for effects of walking vs. running and of normal vs. stabilized condition. We found a stronger correlation between ML trunk CoM state and ML foot placement and significantly higher step width and step width variability in walking than in running. The correlation between ML trunk CoM state and ML foot placement, step width, and step width variability were significantly decreased by external lateral stabilization in walking and running, and this reduction was stronger in walking than in running. We conclude that ML foot placement is coordinated to ML trunk CoM state to stabilize both walking and running and this coordination is stronger in walking than in running.

Modeling and Experimental Investigation of Micro-Hydrostatic Gas Thrust Bearings for Micro-Turbomachines

2005 ◽  
Author(s):  
C. J. Teo ◽  
Z. S. Spakovszky
Keyword(s):  
Dynamic Stability ◽  
High Speed ◽  
Thrust Bearing ◽  
Dynamic Instability ◽  
Axial Stiffness ◽  
Stable Operation ◽  
Essential Information ◽  
Flow Choking ◽  
Thrust Bearings

One of the major challenges for the successful operation of high-power-density micro-devices lies in the stable operation of the bearings supporting the high-speed rotating turbomachinery. Previous modeling efforts by Piekos [1], Liu et al. [2] and Spakovszky and Liu [3] have mainly focused on the operation and stability of journal bearings. However, since thrust bearings play the vital role of providing axial support and stiffness, there is a need to gain a fuller understanding of their behavior. In this work, a rigorous theory is presented to analyze the effects of compressibility in micro-flows (characterized by low Reynolds numbers and high Mach numbers) through hydrostatic thrust bearings for application to microturbomachines. The analytical model, which combines a 1-D compressible flow model with Finite-Element Analysis, serves as a useful tool for establishing operating protocols and assessing the stability characteristics of hydrostatic thrust bearings. The model is capable of predicting key steady-state performance indicators, such as bearing mass flow, axial stiffness and natural frequency as a function of the hydrostatic supply pressure and thrust bearing geometry. The model has been applied to investigate the static stability of hydrostatic thrust bearings in micro-turbine-generators, where the electrostatic attraction between the stator and rotor gives rise to a negative axial stiffness contribution and may lead to device failure. Thrust bearing operating protocols have been established for a micro-turbopump, where the bearings also serve as an annular seal preventing the leakage of pressurized liquid from the pump to the gaseous flow in the turbine. The dual role of the annular pad poses challenges in the operation of both the device and the thrust bearing. The operating protocols provide essential information for the required thrust bearing supply pressures and axial gaps required to prevent the leakage of water into the thrust bearings for various pump outlet pressures. Good agreement is observed between the model predictions and experimental results. In addition, a dynamic stability analysis is also performed, which indicates the occurrence of unstable axial oscillations due to flow choking effects in both forward and aft thrust bearings. These a-priori dynamic stability predictions were subsequently verified experimentally on a micro-turbocharger. The frequencies of unstable axial oscillations predicted using the model compare favorably to those determined experimentally, thus vindicating the validity of the model. A simple and useful dynamic stability criterion is established, where the occurrence of flow choking in both thrust bearings give rise to dynamic instability.

scholarly journals The role of binocular vision in walking

2009 ◽  
Vol 26 (1) ◽  
pp. 73-80 ◽  
Author(s):  
MARY HAYHOE ◽  
BARBARA GILLAM ◽  
KELLY CHAJKA ◽  
ELIA VECELLIO
Keyword(s):  
Binocular Vision ◽  
Monocular Vision ◽  
Stereoscopic Vision ◽  
Eye Position ◽  
Visually Guided ◽  
Extensive Investigation ◽  
Foot Placement ◽  
Walking Performance ◽  
The Difference

AbstractDespite the extensive investigation of binocular and stereoscopic vision, relatively little is known about its importance in natural visually guided behavior. In this paper, we explored the role of binocular vision when walking over and around obstacles. We monitored eye position during the task as an indicator of the difference between monocular and binocular performances. We found that binocular vision clearly facilitates walking performance. Walkers were slowed by about 10% in monocular vision and raised their foot higher when stepping over obstacles. Although the location and sequence of the fixations did not change in monocular vision, the timing of the fixations relative to the actions was different. Subjects spent proportionately more time fixating the obstacles and fixated longer while guiding foot placement near an obstacle. The data are consistent with greater uncertainty in monocular vision, leading to a greater reliance on feedback in the control of the movements.

scholarly journals Visual control of foot placement when walking over rough terrain

2011 ◽  
Vol 11 (11) ◽  
pp. 915-915 ◽  
Author(s):  
J. Matthis ◽  
B. Fajen
Keyword(s):  
Visual Control ◽  
Rough Terrain ◽  
Foot Placement

scholarly journals Biomechanic and physiological factors providing the technique of goal-oriented shot actions in football

2009 ◽  
Vol 8 (3) ◽  
pp. 53-57
Author(s):  
Ye. V. Koshelskaya ◽  
V. N. Bazhenov ◽  
O. I. Buravel ◽  
L. V. Kapilevich ◽  
V. I. Andreyev
Keyword(s):  
Basic Skills ◽  
Visual Control ◽  
Technical Development ◽  
Football Players ◽  
Visual Analyzer ◽  
Physiological Factors ◽  
Equilibrium Control ◽  
Equilibrium Function

Biomechnic peculiarities of the technique of shots in football have been studied. With the aid of electromyography and stabilography, 45 men aged from 18 to 27 were examined. It has been shown that stabilographic and electromyographic characteristics of ball shooting can serve indicators of technical development of sportsmen. The technique of direct kick is formed at the stage of perfection of basic skills, while that of lateral kicks is formed at the stage of top sport mastering. In football players of high qualification, the role of the visual analyzer in equilibrium control is insignificant, while in low- and moderate-qualified players, the equilibrium function works worse without visual control.

scholarly journals The effect of external lateral stabilization on the control of mediolateral stability in walking and running

2018 ◽  
Author(s):  
Mohammadreza Mahaki ◽  
Sjoerd M Bruijn ◽  
Jaap H. van Dieën
Keyword(s):  
Active Control ◽  
Repeated Measures ◽  
Gait Cycle ◽  
Center Of Mass ◽  
Step Width ◽  
Kinematic Data ◽  
Foot Placement ◽  
Consumption Data ◽  
Mediolateral Stability

It is still unclear how humans control mediolateral (ML) stability in walking and even more so for running. Here, foot placement adjustment as a main mechanism of active control of mediolateral stability was compared between walking and running. Moreover, to verify the role of foot placement as a means of active control of ML stability and associated metabolic costs in both modes of locomotion, this study investigated the effect of external lateral stabilization on foot placement control. Ten young adults participated in this study. Kinematic data of the trunk (T6) and feet (heels) as well as breath-by-breath oxygen consumption data were recorded during walking and running on a treadmill in normal and stabilized conditions. Coordination between ML trunk Center of Mass (CoM) state and subsequent ML foot placement, step width, and step width variability were assessed. Two-way repeated measures ANOVAs (either normal or SPM1d) were used to test for effects of walking vs. running and of normal vs. stabilized locomotion. We found a stronger association between ML trunk CoM state and foot placement in walking than in running from 90-100% of the gait cycle and also a higher step width variability in walking, but no significant differences in step width. The association between trunk CoM state and foot placement was significantly decreased by external lateral stabilization in walking and running, and this reduction was stronger in walking than in running from 75-100% of gait cycle. Surprisingly, energy cost significantly increased by external lateral stabilization, which was more pronounced in running than walking. We conclude that ML foot placement is coordinated to the CoM kinematic state to stabilize both walking and running. This coordination is more tight in walking than in running and appears not to contribute substantially to the energy costs of either mode of locomotion.

scholarly journals The effect of external lateral stabilization on the control of mediolateral stability in walking and running

2019 ◽  
Author(s):  
Mohammadreza Mahaki ◽  
Sjoerd M Bruijn ◽  
Jaap H. van Dieën
Keyword(s):  
Young Adults ◽  
Repeated Measures ◽  
Main Mechanism ◽  
Step Width ◽  
Normal Walking ◽  
Kinematic Data ◽  
Foot Placement ◽  
Mediolateral Stability

It is still unclear how humans control mediolateral (ML) stability in walking and even more so for running. Here, foot placement strategy as a main mechanism to control ML stability was compared between walking and running. Moreover, to verify the role of foot placement as a means to control ML stability in both modes of locomotion, this study investigated the effect of external lateral stabilization on foot placement control. Ten young adults participated in this study. Kinematic data of the trunk (T6) and feet (heels) were recorded during walking and running on a treadmill in normal and stabilized conditions. Correlation between ML trunk CoM state and subsequent ML foot placement, step width, and step width variability were assessed. Paired t-tests (either SPM1d or normal) were used to compare aforementioned parameters between normal walking and running. Two-way repeated measures ANOVAs (either SPM1d or normal) were used to test for effects of walking vs. running and of normal vs. stabilized condition. We found a stronger correlation between ML trunk CoM state and ML foot placement and significantly higher step width and step width variability in walking than in running. The correlation between ML trunk CoM state and ML foot placement, step width, and step width variability were significantly decreased by external lateral stabilization in walking and running, and this reduction was stronger in walking than in running. We conclude that ML foot placement is coordinated to ML trunk CoM state to stabilize both walking and running and this coordination is stronger in walking than in running and independent of speed in running.

scholarly journals Jelajah Kearifan Teknologi Bangunan Arsitektur Nusantara

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Ch. Koesmartadi ◽  
D.Lindarto
Keyword(s):  
Formal Education ◽  
Construction Technique ◽  
Technology Knowledge ◽  
Architectural Space ◽  
Building Technology ◽  
Exploratory Approach

Sejauh ini pengetahuan teknologi bangunan Indonesia yang diketengahkan dalam pendidikan formal lazimnya adalah pengetahuan yang diturunkan dari pemikiran non-nusantara (notabene adalah teknologi bangunan arsitektur barat). Hal demikian memunculkan diskusi timpang (menjurus kepada beda tafsir) ketika dilakukan tindak pembahasan struktur dan konstruksi arsitektur tradisional Nusantara dengan menggunakan idiomatika teknologi bangunan tradisional Barat. Dengan focus ke-iklim-an dan ke-gempa-an yang menjadi faktor pembentuk dalam teknologi penegakkan bangunan nusantara maka tulisan ini bertujuan mengungkapkan beberapa pemikiran teknologi bangunan arsitektur nusantara yang mempunyai kebedaan dengan teknologi bangunan barat. Melalui pendekatan deskriptif eksploratif dilakukan penjelajahan dengan interpretasi normatif atas penyandingan beberapa obyek arsitektur nusantara dalam konteks teknologi bangunan nusantara. Jelajah menghasilkan temuan pengetahuan teknologi bangunan nusantara yaitu dasar pemikiran struktur konstruksi wilayah dua musim, konsekwensi ruang arsitektural nusantara, teknik konstruksi ikat dan sambungan nusantara dan keragaman titik berat serta peran konstruksi sebagai pembentuk tempat (place). Jelajah ini dimaksudkan untuk membentuk mindset pensejajaran kearifan lokal arsitektur nusantara dengan ilmu struktur konstruksi barat. Tidak ada lagi hambatan ketidak percayaan penalaran bahwa pengetahuan Arsitektur Nusantara memang nyata berbeda dengan pengetahuan Arsitektur Barat. So far, the knowledge of Indonesian building technology that is presented in formal education is usually knowledge derived from non-archipelago thinking (incidentally is the technology of western architectural building). This thus gave rise to unequal discussions (leading to different interpretations) when the discussion on the structure and construction of the traditional archipelago architecture was carried out using the idiomatic technique of Western traditional building technology. With a focus on climate and earthquake which are forming factors in the building technology of the archipelago, this paper aims to express some thoughts on archipelago architectural building technology that has a difference with western building technology. Through a descriptive exploratory approach exploration is carried out with normative interpretation of the pairing of several archipelago architectural objects in the context of archipelago building technology. The exploration resulted in the discovery of archipelago building technology knowledge, namely the rationale for the construction of the two-season region, the consequences of the archipelago architectural space, the connective construction technique and the archipelago connection and the diversity of centers of gravity and the role of construction as a place-maker. This exploration is intended to form a mindset of the alignment of the local wisdom of the archipelago architecture with the science of western construction structures. There is no longer any obstacle to distrust of reasoning that the knowledge of Nusantara Architecture is indeed different from the knowledge of Western Architecture.

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