a. Demonstrate the center of gravity by balancing a yardstick on two fingers. b. Challenge students to balance a pen or pencil lengthwise on a finger. As students shift object back & forth, ask them why they are doing that If necessary, explain their action is helping them find the center of gravity 3. Challenge students to follow written directions for building “Balancing Bob” model 4. After building “Balancing Bob”, go test him out on the taut fishing line.
However, the benefits gained from visual feedback of the COP during quiet standing are still under debate [7, 8]. Kilby et al. reported that the real-time visual feedback of neither the COP nor the COM affected the postural motion of healthy adults during quiet standing ; in other words, neither the COP nor the COM velocities changed when conditions were altered between a pres- ence and lack of augmented visual feedback. In addition, the participants in the study of Lakhani et al. showed no postural stability learning effects when visual feedback training was using either as a vertical projection of the COM onto the ground (i.e., the center of gravity (COG)) or the COP during quiet standing . In fact, under no feedback conditions did the root mean square values of the COP or COG change between the pre-training and post-training sessions.
In this work, the factors influencing on acceleration and braking performance such as coefficient of adhesion, location of center of gravity (C.G), tyre pressure, and rolling resistance are studied experimentally, acceleration and braking performance of the vehicle is calculated with the help of governing equations. In the following section the details of the experimental results obtained for the above parameters are discussed.
Facility location selection is one effort in optimizing the transportation of goods.The selection of locations will result in savings on transportation costs. The distance factor to the destinations is calculated to decrease transportation costs as low as possible. In this research will be used Center of Gravity method.The calculation of Center of Gravity method involves the volume of goods to be transported from one point to another, regional coordinates and transportation costs. From this calculation will be known location of provincial level hazardous waste collection in East Java. In addition, a warehouse for this province level collection will be designed also conduct a risk identification for the construction of a provincial level hazardous waste collection in East Java.
Abstract: The center of gravity (CG) of the human body is a hypothetical point around which the force of gravity appears to act. CG need not lie within the physical bounds of an object. Human beings do not remain fixed in the anatomical position and the precise location of the CG changes constantly with every new position of the body and limbs. CG plays an important role in maintaining balance, equilibrium, and breaking inertia during the performance of a sports technique. Purpose of this study is to discover the pattern and make the comparison of CG height and CG velocity changes in the execution of frequently used soccer kicks within and between the kicks by the male players. Five male players played for the Bangladesh National Football teams were selected as subject and their age was between 16-19 years. A Cannon EOS7D with the capacity of 55 f/sec camera placed on sagittal plane at the backside of the kick 5.00 meters away and at 1.13 meter of height to capture kicking actions of the players on Coronal/Frontal plane. The best frame was selected out of 3 trials. 2D motion Analysis Software Kinovea 0.8.25 was employed for the quantitative analysis of the video clips. Changing of the CG height position in percentage was studied in three different phases i.e. Ground contact, Ball contact, and Follow-through in reference to erect standing CG height of the players. In addition, CG velocity changes were also studied in ball contact and follow-through phases. This study demonstrates that the male soccer players demonstrate inconsistency in CG height reduction in performing all three phases (Ground Contact, Ball Contact, & Follow-through) in all selected five kicks (Push Pass, Instep Kick, Lofted Kick, Chip Shot, and In-swerve Kick), but highest reductions have been located in the ball contact phase of all the kicks. Players change CG height in the same manner among the five selected kicks in each of the phases distinctly. Players experience CG height drop in Instep Kick differently between ball contact and ground contact phases. Players display higher mean CG velocity in ball contact phase than follow-through phase in Push Pass but remaining other kicks exhibit opposite actions. Players display CG velocity in all selected soccer kicks in the same manner at ball contact and follow-through phases. Players change CG velocity differently between Push Pass and Instep Kick, In-swerve Kick, Lofted Kick at follow-through phase.
The purpose of this paper is to propose a new multi stage algorithm for the recognition of isolated characters. It was similar work done before using only the center of gravity (This paper is extended version of “A fast recognition system for isolated printed characters using center of gravity”, LAP LAMBERT Academic Publishing 2011, ISBN: 978-3- 8465-0002-6), but here we add using principal axis in order to make the algorithm rotation invariant. In my previous work which is published in LAP LAMBERT, I face a big problem that when the character is rotated I can’t recognize the character. So this adds constrain on the document to be well oriented but here I use the principal axis in order to unify the orientation of the character set and the characters in the scanned document. The algorithm can be applied for any isolated character such as Latin, Chinese, Japanese, and Arabic characters but it has been applied in this paper for Arabic characters. The approach uses normalized and isolated characters of the same size and extracts an image signa- ture based on the center of gravity of the character after making the character principal axis vertical, and then the system compares these values to a set of signatures for typical characters of the set. The system then provides the closeness of match to all other characters in the set.
Abstract: The purpose of the study was to analysis of the technique of set shot while attempting free throws with the performance, in relation with time to perform the course and displacement of center of gravity. Sixty National level male basketball players of three different height groups i.e. Group I: 5’5’’ to 5’8’’,Group II: 5’9” to 6’ and Group III: 6’ 1” to 6’4”,(20 in each group) were selected as subjects for the study. The data was obtained from two given positions (i) Moment of stance in set shot and (ii) Moment of release of ball in set shot. Total ten attempts were given and the successful shots marked as score out of ten as criterion measure of performance. Four Digital Video cameras Sony 2100 series were used in order to register the technique of set shot while attempting set shot. The films were analyzed by using standard motion analyzer. With regard to purpose of the study techniques of product moment correlation and analysis of variance were applied. In order to check the significance, level of significance was set at 0.05. It was found that there is significant relationship between the time to perform the course and the performance in set shot of different height group players in basketball and there is no significant relationship found between the displacement of center of gravity and the performance of set shot of different height group players in basketball and therefore, the selected variable puts no impact on the performance of set shot. It was also concluded that Time to perform the course had lowest impact (7%) in the performance. Further it was concluded that displacement of center of gravity was significantly different in first group (5’5’’ to 5’8’’) from the other two groups.
Remember, the lateral center of pressure is the one point where the aerodynamics forces act. In the illustrations, all the wind can then be treated as a single force acting through the center of pressure. This force acting at a distance away (d) from the CG creates a moment that either stabilizes or destabilizes the rocket. It is best to build a rocket with its fins as far as possible to the rear. The farther behind the center of gravity the center of pressure is placed, the stronger and more precise will be the restoring forces on the model and it will fly straighter with less wobbling and side-to-side motion, which robs the rocket of energy. Fins usually should not be placed forward of the center of gravity on a model because this will add to instability. If fins are added forward of the center of gravity, be certain the center of pressure remains behind the center of gravity. Students can also test the stability of a rocket with precision experimentally through the use of the swing test or the use of a wind tunnel.(Directions for building a wind tunnel may be found in Estes The Classic Collection, Technical Report TR-5, “Building a Wind Tunnel”). The simplest, least expensive method is the swing test.
(1) Type A1 clinical signs: pelvis lateral to thoracic concave and outward projection; trunk imbalance, center of gravity in thoracic convex side, thoracic convex side leg bearing; If the pelvis does not move laterally, the sternum tends to move laterally to the thoracic concave. The rib protrusion on the back of the chest is longer, and the protrusion on the same side of the waist is also seen. X-ray features: single long thoracic curve (top vertebra in T19-T11) involved the upper segment of lumbar curve, L3 in the thoracic convex side was inclined, L4 in the horizontal or inclined to the thoracic convex side, L5 in the horizontal position; TP, T1 in the thoracic convex side, the entire spine in the CSL side; may be accompanied by proximal thoracic curve (top vertebra in T2-T4).
and then polygon is concave polygon (Fig. 3(b)). The convex polygon is divided into triangles with small enough area by the center of gravity coordinates and the adjacent two Cip. The concave polygon connects the center of gravity coordinates with each Cip, and a half-fold deployment method is used to locate virtual repair nodes.
Today, researchers exploit hybrid craft more than they used to be. The main reason is that they need to high speed as well as extra portability. For instance, a famous hybrid craft is named Hysucat, was designed through the combination of catamaran and hydrofoil. Catamarans, a type of multihull boats, have always considered by designers because of their simultaneous supply of high speed and stability. These boats hold high drag despite more wetted surface as well. By using hydrofoil the wetted surface reduces, and then the drag of boat will decline. Meanwhile, sketches in the layout of hydrofoil processes notice to weight and center of gravity. This paper investigated application of hydrofoil in the high speed catamaran with considering different conditions in terms of center of gravity and load conditions. The model has exploited in the three states of loading (partial, ballast and over) and two centers of gravity for each diverse weight. Hence, nine series tests in towing tank have been carried out on the model boat in scale 1 ratio to 11.43. Eventually, results were computed to full scale boat by Froude number and ITTC model. According to the test results, usage of the hydrofoil brings about 50% drag reduction.
Measures used to assess balance included the Dynamic Gait Index (DGI), Functional Reach Test (FRT), and the Limits of stability (LOS) test on the Neurocom Balance Master. The DGI is a clinical measure that evaluates an individual’s balance while performing tasks with a mov- ing base of support (BOS). The DGI is able to detect small, but clinically relevant, changes in fall risk in pa- tients with TBI.  Three subtests of the DGI have been found to have significant correlations with sub- jective complaints of balance impairments in patients with mTBI. These include “gait with vertical head turns”, “gait with horizontal head turns” and “gait and pivot turn”.  The FRT is a clinical measure used to evaluate an individual’s ability to displace their center of gravity (COG) forward without losing their balance. No psychometric properties have been specifically established for TBI. However, excellent reliability and high validity was shown in individuals with subacute stroke by Outermans et al. . A cut-off score <15 cm for increased fall risk post stroke has been established as well . The FRT was taken under three conditions: reaching forward with palms together (FRTb), right hand only (FRTr), and left hand only (FRTl).
In the pre-test stage, the examinee had to stand on the power plate of the posturography while barefooted and with their hands on their sides . Furthermore, to prevent disturbance and disorder in the vestibular system, they were asked to look straight ahead and do not move their heads . In all the stages of Sensory Organization Test (SOT), the variables of alignment and displacement of center of gravity were measured. This test assesses the role of proprioception, vestibular, and sight information in controlling posture, which has six conditions for manipulating sensory data. Each test condition lasts 20 seconds with 10 seconds interval between the tests. In the break time, the next stage in SOT was explained to the examinee. During all stages of the test, no feedback was given. Each sensory condition was repeated for three times and the mean for kinetic variables in the three tests were considered .
In the present research, a comparison is made among results of various (polynomial, Yeoh, Arruda-Boyce, and Ogden) hyperelasticity models that may be candidate for simulation of the traumatic brain injuries, for the first time. A simultaneous comparison is made between results of the traditional spherical finite element model and results of the realistic MRI-based finite element model reconstructed by the authors. CATIA geometry modeling, HYPERMESH and ANSYS finite element modeling and solvers, and LS-DYNA dynamic modeling code are employed in the present research. A pair of experimental results is employed to evaluate accuracy of the peak pressures and accelerations of center of gravity of the brain predicted by the mentioned four hyperelasticity models for the two finite element models. Comparing with both experimental results confirms that employing Arruda-Boyce or Ogden models may lead to inaccurate or even erroneous results. Comparisons made with the experimental results of accelerations of the center of gravity of the brain and pressure results of the coup and countercoup regions lead to an identical conclusion that the models may be ordered with respect to the accuracy as: the polynomial model, Yeoh model, Arruda-Boyce model, and Ogden model. The traumatic head impact injury criteria reveal that the polynomial model has to be used with care due to underestimation of the injuries level and the acceleration and that the pressure criteria predict severe injuries for the considered simulation data.
This information was important in our fin design, as we had to bring the center of pressure down below the center of gravity. Our center of pressure ended up being 7 cm from the bottom of the rocket. The larger the fins, the further down the rocket the center of pressure would be pulled. Our recovery system brought our center of gravity higher up on the rocket, resulting in an increase of stability. When performing our stability test, our rocket did extremely well at straightening itself out.
For one goods, there often have several loading methods and reinforcing methods. So, it’s necessary to select a best one. Generally, the loading scheme which has a higher usage of vehicle load capacity, lower out-of-gauge grade and the overweight grade of the goods, lower center-of-gravity height of a loaded wagon as well as lesser interfe- rence to the transport, and the reinforcing scheme which is simple and convenient to operate as well as economic in material usage, are the optimal ones.
From the point of view of the transfer track of the economic center of gravity in Hebei Province, the movement track of the economic center of gravity in Hebei Province fluctuates from 2004 to 2017, but generally moves along the direction of southeast-northeast-southwest-southeast. At the same time, this also reflects that the economic development of Hebei Province presents an unbalanced development situation, and the development gap between the internal cities, especially between the eastern and western cities is gradually widening. Therefore, in the future economic development, Hebei Province should pay attention to improving the regional economic openness and industrial structure to gradually improve the regional economic development model, to promote the overall development of regional economy.
For readers like this reviewer, who do not read Germany fluently, the translation of Joachim Radkau’s Nature and Power: A Global History of the Environment is a major event. This is probably the best available overview of the changing human relationship with the biosphere: a subject whose historiographical and political significance is becoming more and more evident. The book’s center of gravity is in Europe; nevertheless, its reach is global and this will make it particularly attractive to those who (again like this reviewer) approach environmental history with world history questions in mind rather than as specialists in environmental history. For the specialists, Radkau’s book will offer a wonderful, sometimes contrary, but astonishingly rich overview of many of the central themes of environmental history. It also offers a sustained and erudite discussion of the difficulties and the importance of seeing environmental history in a more unified way over the whole sweep of human history.
Of all the species in the animal kingdom, only birds and man habitually use a bipedal gait. Even the larger primates use a quadripedal ambulation mode for most of their activity. When the weight of the body is being borne on both legs, the center of gravity is centered between the two hips and its force is exerted equally on both hips. Under these loading conditions, the weight of the body excluding the weight of both legs is supported equally on the femoral heads, and the resultant vectors are vertical.