Papers by Keyword: Movement

Abstract: In this article is determined the ratio between effective elastic characteristics of the fibrous transversally isotropic material. Fibrous uniaxial material, which consists of the isotropic elastic matrix and fiber, is in the focus of attention. It is assumed that mechanical properties of components under stretching and compression are different, notably matrix material and fiber material are multi-modular. Transverse stretching and transverse compression of composite cell are considered. Two problems for each type of strain are solved. In the first problem stresses and displacements of matrix and fiber under conditions of their common axisymmetrical deformation are determined. Subsequently similar characteristics for the cell deformation of the homogeneous transversally isotropic material as a composite are determined. Ratio between effective composite’s characteristics is solved from the conditions of equality of the axial displacements of the composite’s cell and radial displacements on its surface. The relation of the calculated ratio from volume fraction of fiber in a composite is analyzed.

Abstract: The human knee is a complex joint (the largest joint of the human body). During the different daily activities, this joint is exposed to significant loads and movements, may in some cases exceed the limit of the mechanical capacities of its components, which shows that the pathologies are quite numerous at the level of the human knee and the treatment sometimes requires surgery to either repair or implant (implant total knee prosthesis). As we know very well, the success of a total knee implant is highly dependent on the initial stability of the femoral or tibial implant and the integration of femur and tibia bone tissue with these implants in the long term. Due to the optimal distribution of mechanical stresses in the surrounding bone. It is for this reason that the search for reasonable solutions to compensate the damaged knee prosthesis and reduce the stresses in the cortical bone and spongy has become a very important research axis. In this regard, we have proposed three models of prosthesis knee joint from available literature and study the distribution of Von-Mises stresses and strains in the differents composents of knee prosthesis, know the total displacement between the model intact and model artificial of knee, 3D modeling software Solidworks 2016 is used for 3D modeling of knee prosthesis and finite element analysis software ANSYS 16.2 is used for numerical estimation of von-Mises stresses and strains. We find in this study that the maximum stresses and strains of Von Mises at the level of the tibia and tibial bone decrease, that is to say that the cement and the elastomer play a very important role in the absorption of the stresses and their minimization. On the other hand, the four knee prostheses (Model I (Ti6Al4V), Model II (CoCrMo), Model III (316L SS), Model IV (ZrO₂)) implanted by elastomer contribute significantly to the reduction of stresses in the patella bone compared to the Intact Model. In general, both models of the knee prosthesis and reinforced by a stress reduction system (cement, elastomer) gave a lower stress level in the tibia and tibial bone of a normal person compared to a healthy model. The results obtained provide a theoretical basis for choosing an appropriate surgical model.

Abstract: The precision in localization of the UBISENSE Real Time Location System was assessed for evaluating the possibility of using the system in the detection of movements and position of athletes on the field during sport performance. The system was implemented in an indoor lab space measuring 11 by 7 meters. Four sensors were installed on the roof at a height of 3 meters above floor. Various sampling rates were used with a single location tag. UBISENSE is using UWB localization technology based on the triangulation of time of arrivals of UWB pulses at the different antenna sensors. Precision varied in position and speed determination being position resolution in the range of 15 to 50 cm while speed precision was in the figure of 6% at slow actual speed of 0.18 m/s up to 20% at fast speed of 1 m/s. This was mainly due to sampling frequency in the location system. In conclusion, as long as speed of the athlete is not at stake, the position can be measured with quite good resolution and sampling frequency so to permit the evaluation of sport performances of the athlete during the exercise or activity. A very attractive feature of the system is that the athlete must be tagged with a very low-weight and quite comfortable active tag which, on the contrary to video tracking systems, doesn’t need to remain in the field of view.

Abstract: Mimosa Pudica (also known as Pokok Semalu) is an action plant with unique biological cell mechanism that has great potential to be explored for next generation biomechatronics devices. The motion principle of each petiole movement occurs by an organ of motion, called pulvinus. The behavior analysis of the Mimosa Pudica plant main pulvinus and petiole against external stimulations has been investigated. The response of the plant cell was observed by optical and scanning electron microscopes (SEM). External stimulation tests on Mimosa Pudica plant such as mechanical, electrical and light stimulations were conducted. Optical microscopy and SEM observations revealed the existence of red cells in the tertiary pulvinus. Mechanical stimulation results had shown a response time of approximately 2 seconds and a recovery time of 10 to 12 minutes for the leaves and 20 minutes for the petiole. Bending force of the petiole of Mimosa Pudica was also measured. The torque generated by the bending of petiole was found to increase exponentially as the pulvinus diameter increased. A torque of 30.91 g mm was generated from the bending of a petiole with 1.5 mm pulvinus diameter. The lifting potential of the Mimosa Pudica was tested using loadings with increments of 0.42 gram. The plant responded to electrical stimulation of 1.3 Ampere and displayed side effect. The light sensitivity region of Mimosa Pudica was obtained through light stimulation using a full spectrum daylight bulb, and ranges from 50 to 300 lux. Signal transmission to neighbouring structures was observed when the leaf was stimulated with threatening stimulus, with the signal speed achieving 0.8 cm/s. Movement mechanism of Mimosa Pudica is believed to be triggered by signal through receptor cells. It was found that the torque generated during petiole lifting is relatively higher than that during petiole bending.

Abstract: In order to have a proper impression of a city, observer needs to move and participate in the city’s life. One of the most important functions of the image of our surroundings is to enable orientation and guidance of movement towards a certain goal. Urban structures that are reflected through disposition and appearance of streets, through a specific landscape arrangement, and ultimately through specific dimensioning and shaping of architecture, can often help to create a place that is easy to read. The increase in vividness of a space enables easier visual identification as well as orientation in space. That type of visual stimulation is expressed through orientation reaction, which stimulates easier adjustment of the subject to a certain space. Perception is defined as the level of sensitivity to visual stimuli in space, which are often connected to the level of interest of the subject. This research aims to identify the role of reference points in terms of the subject’s movement and orientation in the process of understanding both the unknown and the known surroundings.

Abstract: Automatic cotton picker was widely used in contemporary cotton production operations, moreover, the farmers prefer to small cotton picker, and picking mechanism is the most important parts of cotton picker, therefore, the research on the movement of picking mechanism is very important. This paper introduced a new kind of the opposite-two-rows type automatic cotton picker, analyzed its operating principle, and made a theoretical derivation of the equations of motion of the picking mechanism, the obtained results can provide theoretical guidance for the design of picking mechanism of cotton picker.

Abstract: China’s rapid march toward urbanization makes sustainable building a priority at all levels of government. As decades of urbanization has led to unchecked environmental degradation, resource depletion, and growing populations without access to quality public services. Sustainable development is of paramount importance to China’s future. This paper represents green building movement opportunities and challenges in China at current time. Keywords: Green Building, Movement, Opportunity, Challenge, Rating System.

Abstract: The new wave-energy dynamoelectric equipment has small volume and its transportation is very relaxed for application in the wide ocean area etc. So it has certain competitive power and enhanced researching value. After analyzing the structure of the equipment, it is found that the displacement difference between the floater and reducing-velocity structure validates feasibility and efficiency of the equipment. In this paper, the displacement difference is mainly researched. At first, forces on the upper and lower parts are analyzed respectively. Then investigating their movements, some structural parameters are determined. At the same time, the problem that the discontinuous acceleration change of the movement of the reducing-velocity structure causes the impulsion to the whole equipment is found. In order to solve the problem, the solution that a spring is added to the connecting string is adapted. The improved equipment is checked and finally it is found feasible.

Abstract: This paper deals with kinematic analysis of a six-member mechanism. The analytical solution is based on the fundamental kinematic relations derived for this mechanism. The program MSC ADAMS was selected for the simulation modeling of mechanism. That program allows comprehensive analysis of this system using a simple modeling.

Abstract: The traditional method of the offshore caisson positioning and installing is using the barge or floating crane, but for the large caisson with 26,000 tons, the method is unable to achieve apparently. In this paper, the offshore location and installation of the large caisson with mooring line system and anchor cable system are studied. The research gets the wave and flow conditions results as well as the related and advertent items, which provide the reference for large caisson positioning and installation as well as the similar engineering construction technology.