Tikrit Journal of Engineering Sciences

Cloud computing is a new technology that provide to consumers dramatically scalable and
virtualized resources, bandwidth, software and hardware on demand. However, cloud computing
introduces serious security problems. One of these major security concerns is the management of
access and identities of different entities involved in such environment. This paper proposes a new
system for Identity and Access Management (IAM) based on combining the techniques of Identity-Based
Cryptography (IBC) and security mediated cryptography with the Trusted Cloud (TC) to facilitate the
secure management and access control for cloud computing. IBC is an interesting choice for IAM as it
significantly reduces the key management complexity. On the other hand, mediated cryptography
enables system administrators to achieve access control in a fine grained manner, while a TC can
provide a Single Sign On (SSO) ability to users. The paper also presents results of the developed
prototype implementation of the proposed IAM system.

In this study, high strength concrete of 75 MPa compressive strength was investigated. The
experimental program was designed to study the effect of fibers and hybrid fibers (steel and
polypropylene fibers) on the fresh (workability and wet density) and hardened properties
(compressive strength, splitting strength, flexural strength and dry density) of high strength
concrete. Results show that decreases in slump flow of all concrete mixtures containing steel,
polypropylene and hybrid fibers compared with control mix (0% fiber). Hybrid high strength
concrete with steel and polypropylene fibers showed superior compressive, splitting, flexural
strengths over the others concrete without or with single fibers content. The test results
indicate that the maximum increase in compressive and flexural strengths are obtains with the
hybridization ratio (70%steel + 30% polypropylene) and were equal to 14.54% and 23.34%
respectively, compared with the control mix. While, the maximum increase in splitting tensile
strength with (100% steel fiber + 0 polypropylene) is 21.19%.

This paper describes the design of adaptive finite impulse response (FIR)filter with least mean square
(LMS) algorithm by which we can reduce the narrow band jamming impacting the performance spread
spectrum communication system (SSS).Simulation results shows that the jamming is rejected and the
output signals free from error.

Partially-encased composite beam-columns subjected to axial compressive and transverse
loads were analyzed using a proposed analytical method, finite element modeling and
international approaches, including ACI-318, AISC-LRFD and Eurocode4. In addition,
flexural stiffness (EI) was predicted using the recommended formulas in ACI-318 and EC4.
The results were compared with experimental data to verify of the reliability of these results.
The analysis proved that the proposed method could be used for design the partiallyencased
beam-columns. Research results also indicate that this method gives much close
solution to experimental data. The behavior and deformation shape of specimens were
close to those found using FEM. The predicted EI from EC4 was reliable in calculating the
bending moment using the proposed method while a significant difference in deflection
values was pronounced using predicted EI from ACI formula. From calculations, it was
found that the ACI-318 approach is accurate and reliable in the design of partially-encased
beam-columns.

In order to perform any simulated work like using MATLAB Simulink for a salient pole
synchronous machine the direct-axis (d-axis) synchronous reactance xd and quadrature-axis
(q-axis) synchronous reactance xq ((q-d) axis) and other parameters must be calculated .In
this paper many tests has been made practically to calculate these parameters with the aid of
using slip test and sudden short circuit test using data acquisition card. These parameters
have been calculated successfully for the used salient pole machine.

This paper aims to design a proportional-integral-derivative(PID)controller to be configured on field
programmable gate arrays(FPGAs) using Embedded Design Techniques(EDTs). Soft-core processor
system is built using Integrated Software Environment (ISE 10.1)supplied by Xilinx and configured on
Spartan 3E slice. The system is programmed by C language to act as PID controller .Trapezoidal rule is
used for integration and finite difference method is used for derivative calculation .The designed
controller is connected to a Matlab /Simulink of a DC motor model to check its functionality.

Thermal insulation of buildings takes more of researchers' interest because of different
economical and ecological considerations. Thermal insulation of walls is a principal part of
thermal insulation system for any building.
This paper includes production of four types of no-slump concrete including, normal weight
concrete, semi-lightweight concrete, no-fines concrete and lightweight concrete. Their
properties including, density, compressive strength and absorption were studded and their
thermal conductivity were calculated. Concrete oven-dry densities range was 1664.2-2141.6
kg/m3, compressive strength was 5.3-15.7 N/mm2, absorption was 6.3-16.7 % and their thermal
conductivity was 0.576-1.047 W/m.K. In addition, the research includes production two types of
concrete masonry units (CMU) from each type of concrete and studies their properties including,
compressive strength and absorption. The overall heat transfer coefficient for each type was
calculated. The results show that the reduction in concrete density by 22% results a reduction in
overall heat transfer coefficient for CMU by about 28% for CMU type I and 15% for CMU type II,
the results also show that the change in cavities sizes and their arrangements into CMU
reduces the overall heat transfer coefficient between 11-28% depends on concrete density. The
combination between the two strategies results to optimum reduction in overall heat transfer
coefficient of about 36%.

This paper presents the role of digital image processing (DIP) for the investigation of
effectively and actually irrigated areas through the signature of vegetative growth; The
techniques of digital image processing for remotely sensed images including subsetting,
enhancement, stacking, and vegetation index calculation determining the real irrigated areas in
NorthAl-jazeera irrigation project. Landsat ETM+ (Enhanced Thematic Mapper) images were
obtained, which captured in 7/4/1999, 3/6/2000, 13/6/2001 and 19/4/2002. ERDAS IMAGINE
9.1 software was used for the purposes of digital image processing and for Normalized
Difference Vegetation Index calculation (NDVI).The study showed the planted and not planted
field units and the level of vegetative growth from NDVI values.

In any stressed power system, Identification of the weakest bus and transmission lines is very
important for planning and operation to prevent voltage collapse which leads to total blackout of
the whole system. The aim of the paper is to use a technique to determine the weakest buses of
the power system. Increasing load in power system could lead to the event of voltage collapse
which implies the contingency in the system. Increasing load and line outage contingencies are
ranked so that the line which highly affects the system could be identified. This paper proposes
to utilize an established index called FVSI (Fast Voltage Stability Index) to identify the sensitive
lines and critical line outages in the system. Test system of this paper is the KRPS-30-Bus-
132kV. The contingency ranking process can be conducted by computing the line stability index
of each line for a particular Increasing load and for line outage contingency. The contingency
which is ranked the highest implies that it contributed to the system instability.