Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : box


An Improve Differential Box Counting Method to Estimate Fractal Dimension

N.M.G. Alsaidi; W.J. Abdulaal

Engineering and Technology Journal, 2015, Volume 33, Issue 4, Pages 714-722

The mathematical concept that used to measure the complexity of the fractal sets is known as fractal dimension. It is considered as a global feature for fractal images. Many methods have been proposed to estimate this value according to object nature. Differential Box Counting method is one of the most important methods used to estimate the dimension of gray scale image. In this paper, we proposed a new method based on the aggregate gray level values in the image. The results of the experiments show an improvement over the traditional DBC method.

Improving Keystream Generation for Sosemanuk Stream Cipher Using Twofish Block Cipher

Rana S. Mohammed; Shant K. Avakian

Engineering and Technology Journal, 2009, Volume 27, Issue 10, Pages 1976-1991

This paper will introduce two proposal algorithms (Snowfish 1) and the
(Snowfish 2) to improve the Sosemanuk stream cipher algorithm by benefiting from
the efficient properties of the Twofish block cipher and also use its key schedule, keydependent
Sbox to increase the security, randomness and try to avoid the guess and
determine attack of Sosemanuk. These two proposals use Twofish algorithm rather
than Serpent algorithm which was used in the Sosemanuk and also they use keydependent
Sbox rather than static Sbox. They are similar in the same key length (128
to 256 bit), IV length (128 bit), LFSR length, FSM functions and output
transformation.
In this paper will make a comparison between Snowfish 1, Snowfish 2 and
Sosemanuk algorithms by using the tests of randomness, the structural tests and the
complexity of the algorithm. These tests give results that show the two proposed
algorithms have good results in increasing the security and randomness compared
with Sosemanuk algorithm.

The Production of Self-Compacting Concrete with Normal Cement Content

Luma A. G. Al- Rawi; Tariq S. Al-Attar; Shakir A. Al-Mishhadani

Engineering and Technology Journal, 2009, Volume 27, Issue 2, Pages 310-320

The main object of this work is to evaluate the possibility for using reasonable cement
content and fine materials to reduce costs of expensive chemical admixtures needed for the
manufacturing of self-compacting concrete (SCC). In this work, three values of cement content
are used (rich, medium and lean mixes) with cement content of 400, 300 and 250 kg/m3
respectively . Two maximum aggregate sizes of (10 and 20mm) for each cement content are
used. The powder content material is (cementations + filler ) is maintained constant (500kg/m3)
while the W/cm ratio ranges from 0.43 to 0.68. 10% Reactive Metakaolin Class N is used as a
partial replacement by weight of cement. On the other hand, limestone dust was used as a
partial replacement by weight of the powder content Tests were carried out on all mixes to
obtain the properties of fresh concrete in terms of viscosity and stability. The results showed that
increasing the percentage of filler (limestone dust) from 20% in rich mixes to50% in lean mixes
of the total weight of the powder content reduces the amount of cement in SCC without
significant effect on the fresh properties of the SCC mixes. This conclusion is significant from
the economical point of view. The mechanical properties of hardened SCC mixes are also
assessed. (compressive strength, modulus of elasticity ). The results obtained from this work
show that it is possible to produce SCC with different levels of cement content (250 to400kg/m3)
using local available materials which satisfy the requirements of this type of concrete .The test
data collected indicate that these materials can be used in the manufacturing of economical SCC.