SUST Journal Systems (Sudan Univ. of Science and Technology)
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Performance Analysis of Adaptive Joint Call Admission Control to Support QoS in Heterogeneous 4G Wireless Networks
Get PDFCall admission control (CAC) is one of the basic mechanisms for ensuring high quality of service
(QoS) offered to the user in Wireless Heterogeneous Networks (HetNet). Based on the available network resources,
it estimates the impact of accepting or blocking a new session request. Many CAC algorithms have been proposed in
the literature but they were all limited by the available bandwidth. This paper analyses the bandwidth adaptation
technique for the Adaptive Joint CAC (AJCAC) algorithm; it is proposed as a solution for congestion; where the
AJCAC algorithm degrades the bandwidth of some ongoing users to make room for new incoming ones. A
restoration process must take place when the network is underutilized; where the algorithm restores the maximum
bandwidth service to the degraded users. In this paper the bandwidth degradation process was investigated and
evaluated using a system-level MatLab simulation. The results showed that as the degradation in the bandwidth
increases the adaption required in the network increases. On the other hand, degradation in the QoS results in a
decrease in the blocking probability
A New Heuristic for Scheduling Optimization of Non-Repetitive Construction Projects under Constrained Resources
Get PDFIn Sudan, the clients, contractors and consultants (stakeholders) suffer from the
elongation of project completion time, especially in the case of limited resources. This problem
results in the conflict among them, and hence leads to project delay that consequently influences
the overall project cost. To solve this problem, data from ten construction projects executed in
Khartoum state and other towns was collected, simulated and analyzed. Primavera software
program was used as a simulator tool and sixteen selected heuristics were applied to the ten
projects. Statistical and operational research tools combined with the existing heuristics, while
considering best common practices in construction industry, were used. Lindo software, as a
decision making tool, is then used to find the optimum solution, i.e., finding the minimum time
to complete the project under limited resources. The results were then evaluated and, hence,
concluded that the optimum solution of the extra needed time at its minimum possible rate (to
complete the project under limited resources) was achieved as a result of implementing the
heuristic of “minimum late start time”. This new “selected” heuristic optimizes the scheduling
time of non-repetitive projects while considering the availability of limited resources
Estimation of Petro Physical Properties in Bentiu Formation, Rakuba Sub Basin, Sudan
Get PDFThis paper focuses on estimating the petro physical characteristics as porosity, permeability and water saturation of Bantui formation. The formation is considered to be a reservoir rock in Rakuba depositional sub-basin. The properties have been estimated by analyzing and interpreting open hole logs of three wells. The raw log data were processed using Interactive Petro physics software version 3.5(IP v 3.5). Density-neutron cross plot logs was interpreted in order to estimate shale volume and porosity. The resistivity logs were corrected so that water saturation can be calculated with reasonable accuracy. Water saturation has been estimated using Archie's equation and the permeability has been calculated using Timur’s equation. As a result of applying this methodology, Bentiu’s formation porosity was found to be a good porosityas far as permeability are concerned, average porosity in Bentiu's formation 20%, permeability ranges from 0 to264 m.D, and water saturation value 100%.as final point Bentiu can be considered as a good reservoir but regrettably it is full of wate
Partial Replacement of Ordinary Portland Cement (OPC) with
Get PDFConsidering the need for low-cost construction materials in the rural areas in
Sudan, especially in Darfur, this paper examines ordinary Portland cement (OPC). The use of
as a replacement of Jebel Marrah volcanic ash in concrete. The ash is obtained from Jebel
Marrah (mountains), west of Sudan. These materials have been chemically and physically
characterized.
Concrete cubes measuring 150mm*150mm*150mm were made from four different concrete
mixes prepared by using pozzolana to replace 0%, 10%, 20% and 30% of OPC by weight.
The workability of the fresh concrete mixes were evaluated using the slump test and
compacting factor test while compressive strengths of concrete cubes were evaluated at 7, 28,
and 90 days. The maximum compressive strength at all ages of testing was obtained at 20%
replacement. Workability increased with an increase in replacement percentage and the
strength of cement/ash concrete increased with curing period but decreased with increasing
ash percentage. The results obtained showed that Pozzolana can be used to partially replace
up to 20% of OPC in the production of concrete without compromising strength
Integration of SCADA, GIS, and Call Center Systems for Electrical Power Distribution Management and Planning
Get PDFIn electrical power distribution systems the traditional methods cannot detect the customer fault location in real time and respond to customer complaints at the same time of the outage of the electric power because the required information is scattered among isolated databases. In this paper the combination of Supervisory Control and Data Acquisition (SCADA) and Geographical Information System (GIS) and using SQLCMD against DBSET has been shown to solve this problem better. This paper reducing the response time of the customer waiting when they calling the agent in the call center, creating a model for the integration of real time data in SCADA system against static data in GIS to make online GIS and send data from GIS to CALL CENTER at the same time. The prototype describes the flow of the data between various systems and integrates all in one logical database that contains all data about the customers. The proposed model depends on three major sub-systems: GIS, SCADA, and Call Center systems. The GIS system is base of the model so the change and update in GIS database is available, GIS provides different features like maps, real coordinates and tables. The model contains three different databases, GIS as geo database, SCADA as the real time database and call center as customer information database, all this database will be in one logical global database that contains of spatial information tables, asset information tables, topology information tables, and operation information tables. This method has been shown to significantly improve the accuracy and efficiency of fault detection in distribution networks and to decrease the response time in call centers
Assessing the Spreading of Nile Blend Crude Oil in the Sudanese Red
Get PDFSpreading is one of the most important processes of the early stages of
oil slick transformation. Four physical forces were considered to develop spreading:
gravity, inertia, viscous and surface tension forces. In this study Fay’s analytical
approach was used to predict the spreading of Sudanese Nile Blend in the Red Sea
coastal water. These results were verified using experimentally determined data from
the measurement of the spread of Sudanese crude oil and kerosene on the surface
seawater of the Red Sea. Two different weather conditions (wind and calm weather)
were considered. The spread under calm condition was found to be slower than that
under wave action. Field data showed that Fay's theory greatly underestimates slick
growth. The spreading rate of kerosene is found to be 1.12 to 4.78 times the spreading
rate of NB crude oil. The results of NB was compared with other three crude oils
namely Arabic Light crude oil, North Sea crude oil, and Venezuela crude oil using
Fay spreading theory. The results show that spreading rate of Arabic light, North Sea
and Nile Blend are all most the same. Venezuela crude oil showed a lower spreading
rate.
Keywords: Spreading, Fay equation
Assessment of the Effect of Increasing Local Bentonite
Get PDFThis study carried out to assess the effect of increasing bentonite percentage (solid
phase) on rheological properties and filtration loss for water base drilling fluid prepared from
local bentonite (Umm Ali area). Chemical tests were carried out to assess quality of local
bentonite. In this study Carboxymethyle Cellulose CMC is used to increase viscosity and
decrease filtration loss. The major finding showed that when adding 7% of CMC and 7% of local
bentonite, the rheological properties, filter loss and yield point to plastic viscosity ratio will be
within the acceptable range of American Petroleum Institute (API) specification
Influence of Flow Characteristics on the Design of Two-Phase Horizontal Separators
No full textABSTRACT - Flouid streams produced from petroleum reservoirs reach surface as complicated mixtures consisting of multi-phase gas, oil, and water. Depending on the quantity of each phase, separators should be designed and installed to handle the mixture and separate it into pure phases for further treatment of each phase. Separators design follows calculations of sequential concepts that lead to determination of the optimum size (internal diameter and length) that provide efficient separation process at lowest cost. In this paper, the influence of flow characteristics has been studied using published calculation models. Because these models are performed through multi-step and iterated calculations which are time consuming, an algorithm and computational program has been developed to facilitate the analysis at this stage and serve as a robust computational tool for future work. Using the computational tool, the analysis results indicate significant influence of flow characteristics and separation conditions on separators design
Multiple Gross Errors Detection in Surveying Measurements Using Statistical
Get PDFMost of the surveying tasks involve the acquisition and analysis of measurements.
Such measurements are subject to random, systematic and gross errors. In practice, redundant
measurements are made to provide quality control and errors check. In qualitative analysis
and statistical evaluation, it is generally assumed that the measurements contain only random
errors and are regarded as random variables. In reality, the measurements may contain gross
and/or systematic errors. The effects of such errors are distributed over the residuals, after an
adjustment and lead to questionable results and interpretation.
For high precision applications, gross and systematic errors need to be detected prior to the
analysis. These errors should be tackled before the adjustment by means of screening. These
few remaining gross errors in the measurements can be detected after the adjustment. These
adjustment methods assume the presence of only one gross error. One of the most effective
methods that can be used in detecting multiple gross errors is the statistical quality control
method. Statistical quality control is a technique used to monitor a procedure with a goal of
making it more efficient and ensures precise results.
Statistical control charts are used to provide an operational definition of a special cause for a
given set of data. It is possible to construct multiples of sigma control limits. When all the
points on a control chart are within a multiple of sigma control limits and there are no gross
errors in the data, the process of measurements is said to be in a state of statistical control.
Otherwise, the data indicate the presence of non-random gross errors. In this research work,
different methods of statistical quality control were used. Results showed that statistical
quality control method can be used successfully and efficiently in detecting multiple gross
errors