Addis Ababa Institute of Technology

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Comparison of Pseudo-Static and Dynamic Response Analysis of Sibilu Dam
(Addis Ababa University, 1979) Getachew, Fantahun; Haile, Messele(PhD)
Dynamic loads induced by earthquakes are often major factors in the design of earth dams. Earthquake induced stresses are major factors in determining the angles of the dam slopes and significantly influence the selection of materials, the zoning of the dam, and the construction method. Awareness about more rigorous seismic stability analysis is also growing during recent years. In Ethiopia dams are being constructed for various purposes. The analysis and design of dams has been carried out by taking many factors in to account. Among these factors earthquake effect is considered mainly for major dams. One of these dams is the Sibilu Dam, which is under design for the Addis Ababa water supply. Until the present, in Ethiopia, seismic effect is commonly considered by the pseudo-static analysis method. But representation of the complex, transient and dynamic effects of earthquake shaking by constant pseudo-static forces is obviously not accurate. In this thesis an attempt was made to compare the pseudo-static and dynamic response analysis by taking the Sibilu Dam as a case study. The main purpose of the study is to show the shortcomings of the pseudo-static analysis method as compared to the dynamic response analysis when applied to the analysis of earth/ rock fill dams. The thesis is organized as follows: initially a background is given on seismicity and seismic hazards in general and Ethiopia in particular. The second chapter covers summary of previous works related to this study. In the third chapter some description is given about the Sibilu Dam, the dam under the case study. In chapter four, the definition of the expected seismic excitation for the dam site is presented. The historical records of earthquake events are collected and geotechnical data of the dam site are reviewed 2 paying special attention to the location of active faults. The obtained data set is analyzed to give the required earthquake parameter for two different return periods. In fifth chapter, the pseudo-static slope stability analysis is done with the conventional limit equilibrium method by using the design ground motion as an input. The analysis is performed for the upstream and down stream slopes of the dam by varying the possible critical cases. In chapter six, analysis and design is done based on permissible deformation. The dynamic response analysis is done by varying the material behavior. Non-linearity is considered by the Equivalent Linear Method. Finally, comparison of the different analysis methods is made and conclusions and recommendations are drawn.
Simulation of Flight Following System
(Addis Ababa University, 1989-06) Mathewos, Essatu; Klous, Kissig (PhD)
The simulation of the flight following system i6 primarily chosen in the interest of Ethiopian Airlines need to implement the system to replace the currently used flight following system which is based on verbal communication between aircraft and ground control people. The first section of this paper discusses the components of data communication system, aspects and objective of data communication system. The second section laid the emphasis on the fundamental communication concepts parallel transmission, serial transmission and the different types of serial transmission. The theory behind the simulation is basically based on the different types of transmission modes. The third section build the foundation for the characteristics of data transmission, direction of information flow: simplex, half-duplex and full duplex and finally rate of transmiesion effect on data transmission. In section 4 the different coding technology and structures are presented. A unique feature of the paper is section 5 protocol. There are sections on identifying and defining a problem in data communication specially for good understanding between a sender and a receiver.
Experimental Verification of Image Perturbation Theory as Applied to the Accuracy of Area Measurement
(Addis Ababa University, 1992-02) Hailu, Getacbew; Mullisa, Girma(PhD)
photosensitive array, with inter-element spacing of & = 3cm is described. A mathematical formulation of perturbation applied to length & area measurement and contour detection is reviewed and presented. A description of the proposed experimental system is given. An area measurement error is defined and applied to the projected object images. It is found that static images (no perturbation) produces considerable error. It is then found that the applJlcation of a one dimensional sinusoidal image perturbation greatly reduces the area measurement error, while triangular image perturbation is optimum and theoretically results in zero error. Some practical applications of tbe system are suggested.
Design of Electrical Networks Through Computer-Aidedoptimization Techniques
(Addis Ababa University, 1993-06) Zewde, Solomon; Mullisa, Girma(PhD)
The objective of the study reported in this thesis has been to develop a unified algorithm for the computer-aided design of a wide range of electrical network configurations. While the design has been based on well-known techniques established earlier by other researchers, the present work has made significant contributions in simplifying the uses of nodal equation formulation method, graph theoretic concepts and topological formulas, as well as applications of a modified least p-th Taylor method, component damping techniques, sensitivity analyses and related design concepts. The basic computer-aided design approachfor a selected network was realized byfirst generating a voltage gain transfer function from the network connectivity details. Information concerning the gradient vector necessary in the course of an optimization process was then derived through a direct method of sensitivity analysis, without performing the normally needed first orderpartial differentiations. Comparison of a transfer function against desired response was preceded by sampling of the latter at selected frequency points and the whole adjustment was eventually automated via the least p-th Taylor method of optimization. It has been established that this approach avoided the time consuming calculation of a Hessian matrix that is usually required for performing network optimization. Convergence properties of the least p-th Taylor method were improved through a use of Fletcher's modification of the classicalLevenberg-Marquardt method together with component damping techniques. The concept of dynamic memory allocation has also been exploited. The resulting computer-aided network design technique was therefore efficient in terms of both processing time and memory requirements and the entire package has been termed as a Pascal program for optimal network design or P-POND. The algorithm has beenfully tested in its usefor designing both passive and active network types by specifying initial network parameters and input-output relations.
(7,3) Maximum - Length Binary Cycle Code Applied to Single Channel Digital Communication System for Error Correction
(Addis Ababa University, 1996-06) snegash, Yohanne; Alemu, Ketema(phD)
This paper presents the design and hardware implementation of the (7,3) maximum-length binary cyclic code applied to a single channel communication system. In hardware implementation of the system a PC with a data acquisition board with time <- sharing for interfacing the analog signals. A 12-bit digital output of the PC is divided into blocks of 3-bits for processing by the channel encoder The implementation of the system is carried out using shift registers and logic gates. A sinusoidal input waveform is applied to the system input and a circuit designed with a combination of D-type flip-flops and logic gates is used to introduce the effects of a single-random-error and a double-adjacent-burst error to observe the performance of the system. The code resulted in good performance in correcting a single-random-error and a double-adjacent-burst-error.
Neural Network Implementation of Character Recognition
(Addis Ababa University, 1998-05) Bireda, Tezazu; Adugna, Eneyew(PhD)
Artificial neural networks, as they are usually called, currently gained much popularity in the design of "intelligent" machines and in programs which are used for automatic pattern recognition as pattern classifiers. In contrast to symbolic-oriented methods in artificial intelligence (Al), artificial neural networks are computing systems that use mathematical algorithms and "imitate" the way the brain, the biological neural network, functions. They are made up of a number of simple, highly connected non linear processing elements and process information by their dynamic state response to external inputs. They are characterized by the ability to learn and generalize, massive parallelism which gives rise to greater speed on computers with parallel processors or on a dedicated analogue VLSI circuit chip, tolerance to significant erroneous data or network fault, and some models exhibit self organization in the learning phase giving optimum network architecture. Their greatest asset compared to other recognition methods, however, is their ability to learn and generalize. In this paper a feed-forward Back Propagation Network (BPN) architecture, which is one of the several network architectures available, is implemented to recognize printed multifont alpha-numeric (English and Amharic or Geez) characters and its performance is investigated. The network model has three layers and is trained in a supervised training mode. In the research, two independent sets of pattern classes of characters were formed each pattern class having four training and two testing sample character patterns. The first set deals with randomly selected pattern classes and the second set deals with very similar pattern classes. And in both sets of training and testing schemes, the relative recognition performance of the network is evaluated. The network recognition rate or performance, only for the test patterns, in percentage for the first set is about 85% and for the second set is about 67%. The overall recognition rate accounting tests with both the training and test patterns is 93% for the first set and 87% for the second. When the test patterns from these two sets were corrupted with noise, the recognition performance of both sets degraded steadily. Test was also made with tilted test patterns on the first set and the performance was unaffected up to a tilt angle of 4.4 degrees from the vertical. A steady improvement in performance was observed as the dimension of the input pattern vectors, the number of training patterns in a pattern class, and network size were increased.
Prefabrication of Structural Elements: A CaseStudy
(Addis Ababa University, 1998-06) Bulto, Gutema; Adamu, Asnake (PhD)
The back-log of housing units in Ethiopia was so immense that all efforts made by the Government and inhabitants could not wipe out the shortage of housing in the early 1980s. To promote the building industry and to alleviate the housing shortage prefabrication technology was introduced. The Prefabricated Building Parts Production Enterprise (PBPPE), which makes use of IMS precast concrete system (a patent of the Institute for Testing Materials for prestressed concrete), was established in 1984 with a technical assistance from the former Yugoslavia. The objectives of the enterprise are to promote the building industry through mass production of precast concrete elements, to alleviate the shortage of housing and to reduce the construction cost. Since its foundation the enterprise has carried out the production of building parts and the erection of residential and public buildings. The IMS framework of precast concrete constitutes one of the widely applied industrialized building technology, because it provides for cost-effective mass production of buildings. In the research work, a review of the experiences of other countries and a comprehensive literature survey on prefabrication was conducted. Then, the Ethiopian experience in the use of precast concrete especially the IMS system was assessed. The use and development of the IMS precast system were found slow and far below our expectation. To identify the sole cause that contributed to this effect, a sample survey was carried out and from the analysis of the survey conclusions were drawn. After a thorough evaluation of the existing modules, to demonstrate the flexibility and the possible modification to the existing modules of the IMS system, a proposal was made for a G+1 dwelling building. Comparative analysis between the existing and the proposed modules was made and recommendations were forwarded. The study also considers the application of precast concrete to other special structures. Finally, conclusions and recommendations were forwarded to promote the development of the IMS system. Essentially, great efforts should be done to disseminate technical information through brochures, manuals, design guidelines and advertisement to support the industrialization of the building industry in Ethiopia.
Design and Realization of an Audio Frequency Filter Unit for Shortwave Communication System Using TMS320CSO DSP Kit
(Addis Ababa University, 1998-12) Mengesha, Seble; Haferkorn, Habil P(PhD)
Causes that may affect the quality of shortwave data communication over radio are presented. Designing an audio-frequency filter unit, other than the filters exist in the transceiver, is considered as one solution to improve the quality of this shortwave data communication. Among the different data communication modes exist in the communication system, the CW (continuous wave), RTTY (Radio teletype) and AMTOR (amateur teleprinting over radio) types are selected to test the performance of the designed filter unit. The filter unit is of FIR digital filter type which the impulse response coefficients are obtained using the Kaiser Window design technique. The DSK (digital signal processor starter kit) assembler and debugger are used to develop the assembly code so as to realize and implement the filter on TMS320C50 digital signal processor. The magnitude response of the resulting filter unit is estimated by a spectrum analyzer. Finally, the designed filter unit is tested in an Amateur Radio Communication System.
Establishing Water Release Rules for Koka Reservoir for Wet Seasons.
(Addis Ababa University, 1998-12) Shemeles, Paulos; Seleshi, Yilma (PhD)
Koka is the only single Reservoir found in the Upper Awash River Basin being utilised both for Hydropower and Irrigation uses. The current maximum capacity of the reservoir is estimated at 1,000 million rrr'. Up to the inlet to the Reservoir, the Upper Awash River Basin drains a catchment area close to 11,300 Km2. A number of important schemes found at the flood prone areas, downstream of the reservoir, are in need of a workable operation rule for Koka which can give them some protection against flooding during wet seasons. In this research an operation rule curve is established. The operation rule curve is established in such a way that all important variables for the hydropower operation and flood control are optimised subject to the constraints. Linear programming in MS-FORTRAN language is used to develop the optimisation model for Koka reservoir operation. The dry season water requirements of downstream irrigation schemes are implicitly guaranteed since the optimised rule curve will ultimately lead to a full storage at the end of every wet season which is desirable by those schemes. Emphasis was also given on the flexibility of the model to allow adaptive operation rules responding to the changing constraints and boundary conditions which are quite noticeable in the Koka reservoir system. The Real-Time operation procedure is formulated to be used in conjunction with the established rule-curve to enable the reservoir operators to make decisions, regarding releases for various purposes, in a considerably shorter period of time (e.g.,daily) using the current hydrometeorological information. The most important component in Real-Time reservoir operation is the Rainfall-Runoff model. These models enables, for a known rainfall, to predict the expected runoff which is an important information for the Real-Time operation of the reservoir and for assessing the possibility of flood hazards well in advance of its catastrophic consequences. It is, however, unfortunate that most models are data intensive that the scarcity of data is the major bottleneck in using them. In this research, a rainfall-runoff model is established employing the SCS
Coding and Transmission of Non Uniform Alphabets
(Addis Ababa University, 1998-12) Kassahun, Yohannes; Ayele, Hailu (PhD)
Two algorithms are developed in such a way that the decoding and encoding times for Huffinan encoding scheme are minimized. Algorithm One is tested for compression and decompression of text files, while Algorithm Two is tested for compression and decompression of any form of file, real time text transmission, and compression and decompression of bitmap graphics files. Programs used in the implementation of the developed algorithms in the above mentioned applications are presented. Results of the implementations are also included.
Evaluation of Approximate Methods for the Design of Biaxiall Y Loaded Reinforced Concrete Columns
(Addis Ababa University, 1999-05) Desta, Tefera; Chane, Bayou(PhD)
The ultimate capacity of reinforced concrete sections under normal force and biaxial bending moments can be represented by a three dimensional interaction surface in terms of the normal force and biaxial moments. The surface can be conveniently represented by a family of curves either on a plane of constant normal force relating the two moment components or as interaction diagram on a plane of constant angle relating the normal force and the resultant of the two moment components. However, the curves can not be described by exact and closed form mathematical expressions due to a wide variety of parameters involved in the determination of ultimate biaxial moment capacity of crosssections with normal force. Thus the systematic generation of such curves to be used for design involves obtaining sufficient number of suitable points by iteration which normally requires use of computer programs. In the absence of such facilities, the use of approximate methods becomes mandatory. There are different approximate methods adopted in different codes for the design of biaxially loaded reinforced concrete columns and the purpose of this thesis work is to assess and evaluate the proximity of some of these approximate methods with the exact solution. The approximate methods evaluated include those recommended by EBCS-2 [1), CPllO [2,3) and ACI [4,5).
Vibration Characteristics of Buildings in Addis Ababa
(Addis Ababa University, 1999-06) Kebede, Tadesse; Halle, Messele (PhD)
Dynamic loading acting on structural systems may result from several sources such as wind and vehicular motions, etc. The type of dynamic input, which is of greatest importance to the structural engineer undoubtedly is the one that is induced by earthquakes. Buildings constructed in Seismic Zones are subjected to earthquake ground motion in addition to other types of loads. If one tries to generate response spectrum curves of a structure for different recorded ground motions, large variations will be obseIVed in both the response spectral values and the shape of the spectrum curves. These variations depend on many factors, such as magnitude, source, and variation in geological formation along the path, local site condition and the nature of the building. The recent trend of increasing height and scale of building structures accelerated the research and investigation activities in the area of Earthquake Engineering, with the aim to get rational and safe earthquake resistant design criteria. Consequently, one n of the current problems in evaluating earthquake response of a building is how 1D find out period of vibration of a building. Recent developments in the techniques for measuring period of vibration of building have permitted us 1D obtain important experimental information reganling the dynamic behavior of a building during earthquakes. The fundamental period of buildings can be obtained by one of the following methods: - 1) Microtremor measurements: here ambient building vibrations are measured by using microtremors. These ambient VIbrations called microtremors operate at a very low strain level. Properly interpreted, microtremors give the fundamental period of vibration of the building. 2) Code Method -or-Equivalent Static Analysis: this gives an approximate formula that can be used to determine the first mode period of a building. 3) Dynamic Analysis: is a sophisticated level of analysis available for finding period of vibration of buildings, that employs Dynamic Time-History Analysis or Response Spectral Analysis. III The comparison of experimental results with the results obtained by empirical formulas and dynaJnic analysis will facilitate the engineers' understanding of the an a lysis and design of building structures subject to dyn amic loading. In the "Introduction", the background and the purpose of this study are described. In the second chapter Period of vibration of selected buildings are determined by u s ing Microtremor. In the third chapter Period of vibration of buildings a re determined by using the Code Method. In the fourth ch apter periods of buildings are determined by using Dynamic Analysis. In the fifth chapter Comparison of results obtained by Microtremor, CodeMethod and Dynamic Analysis are done. In the last chapter, Conclusion was made ba sed on the results obtained.
Biodiesel Production Optimization and Quality Assessment Using Jatropha Curcas Oil And Ethanol Alcohol
(Addis Ababa University, 2001) Demissie, Biniyam; Alemu, Demiss (PhD)
Concern over high transportation fuel costs, trade deficits, depleting resources, energy security, and mounting evidence of global climate change has led to re-investigation of fossil fuel alternatives. For this reason Ethiopian Ministry of Water and Energy has started promoting bio-energy as a means to transform the nation’s abundant renewable biomass resources into cost competitive, high power biofuels and products. Biodiesel offers one renewable fuel option that can be produced from non edible vegetable oil sources. Fortunately Ethiopia has many opportunities for biodiesel production. The country´s favorable climatic condition for the cultivation of non edible vegetable oil bearing plants and the abundance of ethanol alcohol produced from the byproduct of local sugar factories gave the country a great advantage in producing biodiesel and get a little relief from petroleum related problems. However, the effort made to introduce the technology and take the most out of it is so low to force policy makers and encourage local and foreign businessmen towards the production of biodiesel using local resources. Therefore this research tries to fill this gap. The main purpose of this research is therefore to develop a biodiesel production technique from Jatropha oil (Jatropha curcas Linnaeus) and a locally produced ethanol alcohol. Special attention was paid to the optimization of base-catalyzed transesterification for converting fatty acid ethyl ester (FAEE). The crude Jatropha oil used in the transesterification contained 5.01 mg KOH/g of acid and after neutralization it was possible to bring down the acid value to 1.35 mg KOH/g. Inorder to determine the optimum condition for tranestefication of Jatopha oil using ethanol and caustic soda as input, 16 experiments varyings ethanol-to-oil molar ratio (6:-9:1) and reaction temperature (55, 65, 70, and 78 oC). Reaction time, mixing intensity, and catalyst concentration was fixed to 3 hrs, 600 rpm, and 1.5 % by weight of the oil respectively. The optimum conditions found for transesterification were an ethanol-to-oil molar ratio of 9:1 and a reaction temperature of 70 0C. At the optimum condition obtained a FAEE conversion of 80 % v/v was achieved. The resulting Jatropha biodiesel has, a density of 0.86 g/ml, viscosity of 4.13 mm2/s, acid value of 0.71 mg KOH/g, and flash point of 173 0C satisfing ASTM D6751-02 and EN 14214 biodiesel standards. The production proces developed in this work will be used in production of a small scale plant withh capcity of 300 liter per day.
Feasibility Study of Renewable Energy Resources for Electrification of Small Islands. A Case Study on Tana Lake Islands
(Addis Ababa University, 2002) Mekonnen, Abiyot; WoldeMariyam, WoledeGiorigs (PhD)
The energy problem of islands differs from those in mainland countries because islands need to manage their own energy supplies. The islands are good test beds for the utilization of renewable energy production and storage technologies. The present study relates the main renewable energy resources to the electrical production in the small islands in Lake Tana. The necessity to integrate some renewable energy resources is shown and various storage means are classified. Also, the needs for hydro pumping storage are proposed and investigated as a good solution for promoting to the increase of the penetration rate of renewable energies, particularly in island electrical grid interconnections. In Ethiopia there are two lakes which have Islands (Lake Tana and Lake Zeway). Among them, the island on Lake Tana (Deck Island) is the biggest Island in the country having a total population of about 7000 human residents within five villages. Due to the location of the Island is so far the task of their electrification via grid system very difficult. Kerosene is used for lighting; with diesel power generation isfor milling and pumping, leaving biomass for cooking and dry cells for radio which are being used in this Island. Nothing has been done so far in developing the renewable energy resources, such as small-scale hydro, solar, and wind energy in the Island. In this work, feasibility of renewable energy resources for electric supply system to this small Island is studied using HOMER (Hybrid Optimization Model for Electrical Renewables) software as optimization and sensitivity analysis tool. Meteorological data from National Meteorological Agency of Ethiopia and other sources, such as NASA, have been used for the estimation of solar and wind energy potentials. Electric load for the basic needs of the community, such as, for lighting, radio, television, electric baker, water pumps and flour mills, have been estimated. Primary schools and health posts are also considered as energy users for the community. As a result, based on the storage system, PV/Wind/pumped hydro hybrid system combinations is found as having a cost of energy about $0.151/kWh which is much lower than diesel generators and previously studied PV-battery hybrid systems which is estimated to cost about $0.325/KWh Key words: Wind, Solar, Hybrid, HOMER, Pumped hydro, Load Estimation 8 M.sc Thesis by Abiyot Mekonnen in Electrical power Engineering ECE DeptsAAit Table
Analysis & Development of Solid Waste Management System of Addis Ababa
(Addis Ababa University, 2002-01) Belete, Zerayakob; Kitaw, Daniel(phd)
Solid waste, which is a consequence of day-to-day activity of human kind, needs to be managed properly. Addis Ababa like other cities in developing countries, faces problems associated with poorly managed waste collection operation. This thesis deals with the city’s current solid waste management problems, collection and disposal. The city’s refuse collection operation is modeled using queuing/simulation model. Spreadsheet Monte Carlo simulation technique is used to simulate the collection activities of the vehicles. In a similar manner, the average waite time of the customer( unit volume of waste) is also simulated. The result obtained shows that the collection operation is affected by the relative location of zonal centroid with reference Repi landfill site. Based on the simulation result, vehicle performance in collection operation is also evaluated. The number of vehicles that are required to carry out the operation has been calculated. In regard to solid waste disposal, alternative models are evaluated to meet the city’s disposal need. Land filling with other disposal options is found to be better alternative. The four proposed landfill sites are modeled using linear programming technique for optimized collection/disposal operation. Energy recovery potentials of various disposal options like landfill, incineration and anaerobic digestion have been assessed. Material recovery potential of the city’s refuse is also evaluated for reprocessing. Better solid waste management option is also proposed.
Computerized AnalysisofFrames with Non-Prismatic Members
(Addis Ababa University, 2002-04) Takele, Samson; Taye, Shifferaw(PhD)
A Decision Support System on Equipment Replacement
(Addis Ababa University, 2002-06) Tecleab, Sium; Roy, R.N. (PhD)
Optimal Design for Prestressed Concrete Box Girder Brigde
(Addis Ababa University, 2002-06) HaileMichael, Samuel; Taye, Shifferaw(PhD)
This thesis concerned with optimization of simply supported prestresed concrete box girder bridge. Usually, the design of prestressed concrete bridges is done based on codes on prestressed concrete bridges. The code requirement is generally concerned with the safety of the structure in its lifetime. Apart from satisfying the code requirement, the design should be economically chosen. For a given condition, there might be a large number of alternatives that satisfy the requirements imposed by codes. But the designer must be in position to choose the one, which is optimal against certain measure of optimality. Therefore, the designers have to do some optimization to arrive at such design. The objective of this thesis work is to show how the optimal design of a prestressed concrete boxgirder bridge can be obtained. It will established a general relationship among different design variables at optimum and will recommend a simple procedure to identify an the optimum design. The presentation is divided in to six chapters. In chapter one, a detail discussion on the theory of prestressed concrete is presented. Great emphasis is given for analysis of sections for flexure both in elastic and plastic ranges. It also explains the usual trends to be followed in the design of a pre stressed concrete section under service and over loads. In chapter two, application of pre stressed concrete on bridge is discussed. Conditions favoring pre stressed concrete application for such type of structural systems Chapter three discusses about optimization theory and general formulation of an optimization problem. Emphasis will be given numerical optimization theory and techniques. Chapter four deals with the methods used to solve an optimization problem. An extended complete coverage is given on linear programming and feasible direction methods, as they will be used later in chapter six to solve an optimal design problem for box-girder bridge. In chapter five, an optimal design problem is formulated for simply supported rectangular box-girder bridge based on AASHTO 96 Code. 2 In chapter six, the optimal design problem formulated in (chapter five) is solved for 40m span bridges using a Fortran program written for the method of Feasible Direction. The program is developed for this particular purpose. Concluding remark is also given The source code of developed program along with a flow chart outlining the program logic to this work is included in an appendix.
Project Management Approach to The Establishment of Computer Assembly Plant in Ethiopia
(Addis Ababa University, 2002-06) Arefaine, Fessehatsion; Roy, R.N. (PhD)
The creation of the computer and the advancement in communication systems has led to the emergence of a new era called the information age. In the new era information is rapidly becoming the world's most valuable resources. The central part of the information technology (IT) is nothing but the computer. Due to its paramount importance the personal computer (PC) has become a part of day-to-day existence of people all over the world. As a result, the computer industry today is a trillion-dollar market. In order to narrow down the gap between the developed and developing nations, countries like Ethiopia should work hard to improve the level of their information and communication technology (ICT). These days it is realized that ICT is a proven tool that one must be equipped with in the fight against poverty and in the effort to secure sustainable economic development. ICT may be composed of four elements: computer hardware, software, communication equipment and know-how. The availability of PCs at cheaper prices and preferred designs would obviously enhance the development of ICT. It is seen that the demand for PCs in Ethiopia is increasing from time to time. But, the supply so far is from imports, with an expenditure of considerable sum of hard currency. In this regard, this thesis research attempts to analyze the feasibility of building a PC assembly plant in Ethiopia applying modern project management techniques. The research applies the method of trend analysis as well as market-buildup methods to estimate the xii present and future demand of PCs in Ethiopia. Make or buy decision analysis is carried out to indicate which components to make in-house and which ones to import form outside sources. The technology, organization and implementation plans are studied at the required depth. Finally, the financial viability of the project is analyzed with the help of appropriate software.
Prestressed Concrete Bridge Design and Construction Practices and Prospects in Ethiopia
(Addis Ababa University, 2002-07) Berhane, Beruk; Tebedge, Negussie(Prossefor)
The problems and achievements on the design and construction of prestressed concrete bridges in Ethiopia is assessed through distributing Questionnaires to be filled by professionals currently working on design and construction of bridges. A seminar is also organized to collect ideas from the participants and also to convey the basic concepts of prestressed concrete bridge design and construction. The basic concepts, principles and advantages of prestressed concrete bridge design are discussed. The different construction methods of prestressed concrete bridges with the detail of anchorages are included. Design example based on simple procedures is shown including its cost comparison with normally reinforced concrete bridge. Standard sections are prepared based on PCI (prestressed Concrete Institute) for different simply supported spans with design flow chart.

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