7,131 research outputs found
Human Center of Gravity Dynamics a New Parameter of Motor Development Functions
A study of a new parameter of human growth and development was conducted. The percentage of the height of body gravity center to the stature in supine position was measured in males and females during the period of pre-puberty (l995), young and adult puberties (1995 and 1997) and male adults (1995). The parameters measured were weight, stature and the height of the gravity center. Data were calculated in obtaining arithmetic means, standard deviations of all parameters and the percentage of gravity point height to stature. The percentages of male and female means, as well as standard deviations, were compared statistically. It was shown that in the pre-puberty group the location of the gravity center to stature was the same in percentage in males compared to females, whereas in the adult group (1987, 1995) a higher percentage was found in males. Among males (1995) differences were found in the percentages, which might have been caused by differences of body typology; the mesomorphic type showed the highest percentage, the endomorphic type showed the lowest, whereas the ectomorphic type it was in between
Cephalometric Patterns on Javanese, Bataks and Chinese Students in Jakarta
In 2000 a cephalometric survey has been done on both genders of Javanese, Bataks and Chinese students at the University of Indonesia (UI), the Indonesian Christian University (UKI) and the Christian University of Jakarta (UKRIDA) with the aim to detect their cephalometric characteristics patterns and the degree of their secular changes with their ancestors. Cephalometric parameters were measured as follows: the maximal head length (glabellaopisthocranion), the maximal head breadth (euryon-euryon), the minimal forehead breadth (frontotemporalefrontotemporale), the morphological facial height (suborbitale-gnathion), the bizygomatic breadth (zygion-zygion) and the bi-gonion breadth (gonion gonion). In addition measurements were done on facial soft tissue factors such as the nasal height (suborbitale-subnasale) the nasal breadth (alare-alare), the ear length (superaurale-subaurale) and the ear breadth (preaurale-postaurale). The results were treated statistically using t test to obtain the degree of significance. It was determined that some cephalometric characteristics have undergone secular changes but both genders of Bataks, Javanese and Chinese students seemed to depict their retainment of their respective ancestors cephalometric characteristics, consequently their cephalometric characteristic differences were still detectable
Spectral averaging techniques for Jacobi matrices
Spectral averaging techniques for one-dimensional discrete Schroedinger
operators are revisited and extended. In particular, simultaneous averaging
over several parameters is discussed. Special focus is put on proving lower
bounds on the density of the averaged spectral measures. These Wegner type
estimates are used to analyze stability properties for the spectral types of
Jacobi matrices under local perturbations
T700 power turbine rotor multiplane/multispeed balancing demonstration
Research was conducted to demonstrate the ability of influence coefficient based multispeed balancing to control rotor vibration through bending criticals. Rotor dynamic analyses were conducted of the General Electric T700 power turbine rotor. The information was used to generate expected rotor behavior for optimal considerations in designing a balance rig and a balance technique. The rotor was successfully balanced 9500 rpm. Uncontrollable coupling behavior prevented observations through the 16,000 rpm service speed. The balance technique is practical and with additional refinement it can meet production standards
Towards Informative Statistical Flow Inversion
This is the accepted version of 'Towards Informative Statistical Flow Inversion', archived originally at arXiv:0705.1939v1 [cs.NI] 14 May 2007.A problem which has recently attracted research attention is that of estimating the distribution of flow sizes in internet traffic. On high traffic links it is sometimes impossible to record every packet. Researchers have approached the problem of estimating flow lengths from sampled packet data in two separate ways. Firstly, different sampling methodologies can be tried to more accurately measure the desired system parameters. One such method is the sample-and-hold method where, if a packet is sampled, all subsequent packets in that flow are sampled. Secondly, statistical methods can be used to ``invert'' the sampled data and produce an estimate of flow lengths from a sample. In this paper we propose, implement and test two variants on the sample-and-hold method. In addition we show how the sample-and-hold method can be inverted to get an estimation of the genuine distribution of flow sizes. Experiments are carried out on real network traces to compare standard packet sampling with three variants of sample-and-hold. The methods are compared for their ability to reconstruct the genuine distribution of flow sizes in the traffic
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