let $pounds$ be the category of locally compact abelian groups and $a,cin pounds$. in this paper, we define component extensions of $a$ by $c$ and show that the set of all component extensions of $a$ by $c$ forms a subgroup of $ext(c,a)$ whenever $a$ is a connected group. we establish conditions under which the component extensions split and determine lca groups which are component projective. ...

The purpose of this study was to investigate the influence of gender and somatotypes on single-leg upright standing postural stability in children. A total of 709 healthy children from different schools were recruited to measure the anthropometric somatotypes and the mean radius of center of pressure (COP) on a force platform with their eyes open and eyes closed. The results were that (a) girls...

A free action α of a group G on a row-finite directed graph E induces an action α∗ on its Cuntz-Krieger C ∗-algebra C∗(E), and a recent theorem of Kumjian and Pask says that the crossed product C∗(E) ×α∗ G is stably isomorphic to the C∗-algebra C∗(E/G) of the quotient graph. We prove an analogue for free actions of Ore semigroups. The main ingredients are a new generalisation of a theorem of Gr...

Ninety-five years after Kretschmer’s original publication the concept of somatotype in psychiatry remains controversial. The aim of the current study was to compare the somatotype of patients with bipolar I disorder and sex-matched mentally healthy controls using an objective method of somatotyping and predefined inclusion and exclusion criteria. 67 bipolar I patients (26 males, 41 females) and...

A method of generating a practically unlimited number of quasigroups of a (theoretically) arbitrary order using the computer algebra system Maple 7 is presented. This problem is crucial to cryptography and its solution permits to implement practical quasigroup-based endomorphic cryptosystems. The order of a quasigroup usually equals the number of characters of the alphabet used for recording bo...

A group in which every element commutes with its endomorphic images is called an E-group. If p is a prime number, a p-group G which is an E-group is called a pE-group. Every abelian group is obviously an E-group. We prove that every 2-generator E-group is abelian and that all 3-generator E-groups are nilpotent of class at most 2. It is also proved that every infinite 3-generator E-group is abel...

Aggregates are a significant feature of asphalt mixtures, which significantly affect the volumetric properties and mechanical performance. Layers concrete consist mixture fine aggregates, coarse fillers mixed with penetration grade asphalt. The pavement layer (asphalt concrete) has several types: wear surface layer, intermediate foundation layer. experimental research method gradation testing u...