NRU :: Browsing by Author "Ogao, Patrick"

Browsing by Author "Ogao, Patrick"

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An Algorithm for Geo-Spatial Objects Adjustment
(Advances in Geomatics Research (, 2015) Wadembere, Ismail; Ogao, Patrick
GIS practitioners always integrate geo-spatial data from different sources using map-overlay operations in order to make decisions and solve queries that deal with multiple layers. But they are always faced with openings and overlaps among objects that form features in thematically same datasets resulting into slivers (unwanted small objects) and danglings (unwanted intersections, polylines, and end points). Most GIS users end up running clean and build algorithms that just remove unwanted objects but not achieving perfect merging originally intended with main reason being lack of geometrical object based algorithm that can be used to update and adjust spatial objects to eliminate discrepancies caused by geometry differences between features of thematically similar data. We present an algorithm for manipulating geometries of geospatial objects that make up datasets basing on spatial points as the simplest geometrical primitive. Our approach makes it possible to represent high level spatial geometrical shapes using points and allows for more comprehensive handling of all shapes still maintaining the simplicity of working with the point primitive. Representation of spatial geometry shapes comprising of spatial points, polylines, and polygons using spatial point primitive geometry is achieved by scanning all the spatial dataset, observing the different geometry shapes and topology that exist, then representation all shapes using points and primary attribute in form of text. The algorithm carries out shape transformation of objects so that all openings and overlaps between objects making up dataset are eliminated so that geo-processing, modeling, and analysis utilize the properly integrated datasets. The algorithm can be applied in spatial data management like geometrical alignment and sharing environments like spatial data infrastructure.
Classifying Desirable Features of Software Visualization Tools for Corrective Maintenance
(ACM symposium on Software visualization, 2008) Sensalire, Mariam; Ogao, Patrick; Telea, Alexandru
We provide an evaluation of 15 software visualization tools applicable to corrective maintenance. The tasks supported as well as the techniques used are presented and graded based on the support level. By analyzing user acceptation of current tools, we aim to help developers to select what to consider, avoid or improve in their next releases. Tool users can also recognize what to broadly expect (and what not) from such tools, thereby supporting an informed choice for the tools evaluated here and for similar tools.
Energy Consumption in Cloud Computing Environments
(2017) Mosoti Derdus, Kenga; Omwenga, Vincent .; Ogao, Patrick
Datacentres are becoming indispensable infrastructure for supporting the services offered by cloud computing. Unfortunately, they consume a great deal of energy accounting for 3% of global electrical energy consumption. The effect of this is that, cloud providers experience high operating costs, which leading to increased Total Cost of Ownership (TCO) of datacentre infrastructure. Moreover, there is increased carbon dioxide emissions that affects the universe. This paper presents a survey on the various ways in which energy is consumed in datacentre infrastructure. The factors that influence energy consumption within a datacentre is presented as well.
Enterprise Resource Planning (ERP) System Implementation: A case for User participation
(Procedia Technology, 2013) Matende, Samwel; Ogao, Patrick
The introduction of an information system such as Enterprise Resource Planning (ERP) system in an organization brings with it changes on how users work. An ERP system cuts across the different functional units of an organization and therefore if not properly managed during its implementation may lead to resistance from the users. The different streams of research on ERP systems have mainly been on ERP adoption, success measurement, and critical success factors (CSFs). There is a paucity of studies on user participation and the contribution of users towards the successful implementation of ERP systems. This paper reviews literature on ERP implementation with an aim of building a case for involving users in this implementation.
Evaluation of Software Visualization Tools: Lessons Learned
(IEEE, 2009) Sensalire, Mariam; Ogao, Patrick; Telea, Alexandru
Many software visualization (SoftVis) tools are continuously being developed by both researchers as well as software development companies. In order to determine if the developed tools are effective in helping their target users, it is desirable that they are exposed to a proper evaluation. Despite this, there is still lack of a general guideline on how these evaluations should be carried out and many of the tool developers perform very limited or no evaluation of their tools. Each person that carries out one evaluation, however, has experiences which, if shared, can guide future evaluators. This paper presents the lessons learned from evaluating over 20 SoftVis tools with over 90 users in five different studies spread on a period of over two years. The lessons covered include the selection of the tools, tasks, as well as evaluation participants. Other discussed points are related to the duration of the evaluation experiment, its location, the procedure followed when carrying out the experiment, as well as motivation of the participants. Finally, an analysis of the lessons learned is shown with the hope that these lessons will be of some assistance to future SoftVis tool evaluators.
Food Safety Solution Using Block Chain Technology
(EasyChair, 2020) Kibet, Vincent; Mburu, Lucy; Ogao, Patrick
Block chain technology is a modern technology that is digital based and has a provision for storage of information of products that cannot later be hacked neither manipulated. Block chain technology is a technology that looks forward to bringing transformational features that will impact food industries. From the year 2009 when block chain technology was founded, its applications have had a wide range of applications including the food industry. It is clear from its description that this technology will impact and transform the entire food sector by enhancing safety. The ability of block chain technology to hold and provide information on food products will enable consumer protection from harmful food products that may result in foodborne illnesses. There have been increased cases of food insecurity as a result of a lack of awareness of information about the food being consumed. This paper will consider using block chain technology as a tool for food safety. This can be effectively achieved with the help of a quick response code. Implementation of QR code on block chain technology will make it possible to track information about food products throughout their life, thereby, providing relevant and necessary information on food products before they are consumed. This will make it highly effective in using block chain technology to improve food safety levels globally.
Geometry Adjustment for Geospatial Data Integration
(WORLDCOMP’10 Conference, 2010) Wadembere, Ismail; Ogao, Patrick
As many mapping organizations are updating geospatial databases with new data about our rapidly changing world, there are challenges of how to effectively and quickly to adjust the geometries so that there are no openings and overlaps due to variation between different versions of same data and neighboring features. The paper describes an approach of geospatial geometry adjustment basing on paradigm of point as being the simplest and smallest spatial primitive to manipulate and to define all geospatial data. Every unique identifiable spatial instance in form of point is given an identifier and it is this that is manipulated during geometry adjustment to transfer updates from the source/reference data to the data set being adjusted. This approach solves the issue of slivers and dangling which are always created during data merging and differences that are always brought into databases due to variations in data capture, storage, and manipulation.
Geometry Updating for Geospatial Data Integration
(International Archives of Photogrammetry and Remote Sensing, 2010) Wadembere, Ismail; Ogao, Patrick
Lots of geospatial data has been collected within the last decades due to advances in digital spatial data capturing technologies and this has brought in different versions of the same data sets. Although various spatial and mapping organizations are updating and revising geospatial databases with new data/information about our rapidly changing environment; there are challenges of how to effectively and quickly update and adjust the geometries so that there are no sliver and dangling issues as a result of opening and overlaps due to variation between different versions of same data. This is vital in geospatial data updating and management in geosystems and databases. The paper describes an approach of geospatial geometry updating and adjustment basing on paradigm of point as being the simplest and smallest spatial primitive to handle and that it can be manipulated to define all geospatial data elements. It integrates methodologies from both earth sciences and computer science. Every unique identifiable spatial instance in form of point is given an identifier and it is this that is manipulated during geometry adjustment to transfer updates from the source/reference data to the data set being updated/adjusted. This approach solves the issue of silvers and dangling which are always created during data merging and the differences that are always brought into databases due to variations in data capture, storage, and manipulation approaches.
Model-Based Analysis of Adoption Factors for Software Visualization Tools in Corrective Maintenance
(2010) Sensalire, Mariam; Ogao, Patrick; Telea, Alexandru
Several classification models exist for software visualization (SoftVis) tools. Such models can be used to compare the features provided by several tools to the requirements of a given use case, in the process of selecting optimally fitting tools. However, it is not easy to predict how such models will perform when used to predict the adoption of SoftVis tools at large, especially for tools which were not considered during the model design. Here, we consider an existing classification model that aims to provide generic guidelines for comparing SoftVis tools for corrective maintenance (CM) based of their features perceived as desirable by users. Although this model explicitly captures several such features, it is not evident that tools that fit the model will be found effective by users in practice. This paper tests the above hypothesis by presenting a comparative evaluation of four software visualization (SoftVis) tools used in CM. The tools were selected to fit well the desirable criteria captured by the model under evaluation. Four independent groups of professional software devel- opers participated in the evaluation, each group using a different tool to solve the same CM task on a real-world code base under typical industry conditions. The results show matches between the features described by the model as highly desirable and and those observed in practice to be essential for tool acceptance, e.g. IDE integration, extended search capabilities, multiple views, scalability, and the need for both dynamic and static visualizations; weakly relevant features, e.g. the commercial tool status; and features which do not influence acceptance, e.g. 3D and anima- tion. Besides showing the correlation between the classification model and observed practice, our study further refines the model’s criteria seen as important for industrial acceptance of software visualization tools.
OBIA-based Monitoring of Riparian Vegetation Applied to the Identification of Degraded Acacia Xanthophloea along Lake Nakuru, Kenya.
(HAL Open Science, 2018) Osio, Anne; Lefèvre, Sébastien; Ogao, Patrick; Ayugi, Samson
The Lake Nakuru (Kenya) faces flooding since 2010, thus interfering with the growth of riparian vegetation, and requiring automated image analysis to monitor the effect of flooding on the Lake Nakuru Riparian Reserve vegetation species. The vegetation specie that was affected by the flooding lake is Acacia Xanthophloea, i.e. a habitat and feed for many animal species within the National Park. In this study, we explore how an OBIA methodology can provide riparian vegetation classification, thus easing the detection of degraded Acacia Xanthophloea spp. Our study shows that: i) from a thematic point of view, GEOBIA was able to identify Acacia Xanthophloea from Landsat satellite imagery, and comparing the resulting classification maps allows us to achieve monitoring of this specie through time; ii) from a software point of view, it might be necessary to involve several different tools (both proprietary or open source) since there is still some missing functionalities in the existing GEOBIA software solutions.
Overcoming Object Misalignment in Geo-Spatial Datasets
(Journal of Geographic Information System, 2014) Wadembere, Ismail; Ogao, Patrick
In integrating geo-spatial datasets, sometimes layers are unable to perfectly overlay each other. In most cases, the cause of misalignment is the cartographic variation of objects forming features in the datasets. Either this could be due to actual changes on ground, collection, or storage approaches used leading to overlapping or openings between features. In this paper, we present an alignment method that uses adjustment algorithms to update the geometry of features within a dataset or complementary adjacent datasets so that they can align to achieve perfect integration. The method identifies every unique spatial instance in datasets and their spatial points that define all their geometry; the differences are compared and used to compute the alignment parameters. This provides a uniform geo-spatial features’ alignment taking into consideration changes in the different datasets being integrated without affecting the topology and attributes.
PSO of Neural Networks to Predict Busy Times of Cellular Traffic for Assignment to TV Idle Channels by Cognitive Radio
(IEEE, 2013) Ojenge, Winston; Afullo, Thomas; Ogao, Patrick; Okello Odongo, William
Kenya has identified radio spectrum as a key driver in its development. Yet, globally, radio spectrum is inefficiently utilized due to ITU’s static spectrum allocation. In Kenya, mobile operators are running short of bandwidth due to deployment of 4G services, which enable superfast mobile broadband/internet. In the USA and UK, FCC and Ofcom, respectively, have made effort to allow opportunistic ‘poaching’ of licensed spectrum as long as communication of licensed user is not interfered with. This has focused research on use of cognitive radio, which would use its sensor networks to establish which TV channels are idle in order to allocate them temporarily to cellular networks. Enabling the cognitive radio to predict which channels shall lie idle at what times introduces better planning and more temporally-efficient allocation. This study explores the viability of predicting the times of mobile telephony traffic jam for a mobile service operator with poor QoS rating within a cell of perennial mobile traffic jam in order to explore whether those times can map well with the TV spectrum holes. The times of the TV spectrum holes shall be determined in a later study.
The Quality of Kenyan University Websites: A Study for the Re-engineering of the Masinde Muliro University Website
(Journal of e-Learning and Knowledge Society, 2013) Ochieng Ojino, Ronald; Mich, Luisa; Ogao, Patrick; Karume, Simon Maina
With the increasing uptake of websites by universities, competition is no longer limited to physical campuses but has also shifted online, where each university seeks to create a high quality website. Online promotion and communication is even more important for African universities, which are spread on large territories, as it presents an opportunity for them to promote their existence and achievements, collaborate with other institutions, and deliver online education to students. Challenges facing Africa’s higher education institutions include: cultural differences, funding problems, language issues, and governance problems. In this paper we present the results of the evaluation of the website quality of three representative Kenyan universities. The study is based on an evaluation framework derived from a meta-model based on 7 dimensions. An in-depth evaluation was carried out using surveys, inspective analysis and automated tools. Results highlighted a number of critical issues and gave important suggestions for the improvement of the Masinde Muliro University (MMUST) website.
Use of GA-Optimized NN to Predict DVB-T2 Receiver Spectrum Holes to Accommodate Burden GSM Voice Calls
(International Journal of Simulation--Systems, Science & Technology, 2015) Ojenge, Winston; Okelo-Odongo, William; Ogao, Patrick
Cognitive radio enables opportunistic utilization of under-used spectrum for networks that are overwhelmed. In Nairobi city, mobile telephony networks are overwhelmed while broadcast TV channels lie idle in some parts. Research in cognitive radio concentrates on point-to-point communication and successfully conducts transmitter sensing in order to establish spectrum holes. However, in broadcast communication such as terrestrial TV, transmitter detection is inefficient, as transmitter signals may be present yet that licensed channel is not tuned-into by TV receivers, rendering those frequencies essentially idle. Our paper describes an attempt to use a novel remote technique to detect, model and predict which DVB-T2 channels are not tuned-into by any TV receiver during the worst mobile traffic jam time, within an overwhelmed mobile cell. An MLP that was GA-optimized to an MSE of 0.0046245 indicated predictability of TV-viewing and predicted Channel 514 MHz as being idle during the 5.00-5.03 pm jam time slot.
User participation in ERP Implementation: A Case-based Study
(International Journal of Computer Applications Technology and Research, 2015) Matende, Samwel; Ogao, Patrick; Nabukenya, Josephine
Information Systems (IS), such as Enterprise Resource Planning (ERP) systems, are being developed and used in organizations to achieve their business goals and to enhance organizational effectiveness. The effect of user participation on successful systems development and implementation of ERP systems continues to be an area of interest to researchers. Common understanding has been that extensive user participation is not only important, but absolutely essential to system success. Even with this understanding of user participation as one of the critical factor in successful IS development and implementation, empirical studies have been unable to conclusively link user participation to systems success. This paper uses a private university as a case study to examine the role played by user participation in the implementation of an ERP system. In order to achieve its objective, this study adopted a mixed method where both qualitative and quantitative approaches were used in the collection of data. The results of the study reveal that user participation has a positive impact on the likelihood of ERP system success, user participation by choice is the best, user participation leads to better understanding of system requirements, the more participation the more the satisfied the users are, and participation builds support for the system during implementation. From our results we conclude that user participation in ERP system implementation is critical for successful implementation.
Virtual Machine Customization Using Resource Using Prediction for Efficient Utilization of Resources in IaaS Public Clouds
(Journal of Information Technology and Computer Science, 2021) Kenga, Derdus; Omwenga, Vincent; Ogao, Patrick
The main cause of energy wastage in cloud data centres is the low level of server utilization. Low server utilization is a consequence of allocating more resources than required for running applications. For instance, in Infrastructure as a Service (IaaS) public clouds, cloud service providers (CSPs) deliver computing resources in the form of virtual machines (VMs) templates, which the cloud users have to choose from. More often, inexperienced cloud users tend to choose bigger VMs than their application requirements. To address the problem of inefficient resources utilization, the existing approaches focus on VM allocation and migration, which only leads to physical machine (PM) level optimization. Other approaches use horizontal auto-scaling, which is not a visible solution in the case of IaaS public cloud. In this paper, we propose an approach of customizing user VM’s size to match the resources requirements of their application workloads based on an analysis of real backend traces collected from a VM in a production data centre. In this approach, a VM is given fixed size resources that match applications workload demands and any demand that exceeds the fixed resource allocation is predicted and handled through vertical VM auto-scaling. In this approach, energy consumption by PMs is reduced through efficient resource utilization. Experimental results obtained from a simulation on CloudSim Plus using GWA-T-13 Materna real backend traces shows that data center energy consumption can be reduced via efficient resource utilization
Visualizing Object Oriented Software: Towards a Point of Reference for Developing Tools for Industry
(IEEE, 2007) Sensalire, Mariam; Ogao, Patrick
Developing a software visualization tool that gets high acceptability in the industry or research community would imply success for that particular tool. In the past, many tools have been developed within the academic arena with many more currently being developed. The rate of commercial success for the developed tools however does not match their development rate. In this paper the views of expert programmers are sought on what should be incorporated in a software visualization tool. These views are sought after exposing the programmers to three tools and allowing them to use the tools for a period of time. The results from the observations show that many of the desires of the expert programmers are not catered for in the currently existing tools. The potential need for a point of reference for developing tools for Industry is also discussed.

Browsing by Author "Ogao, Patrick"

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