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- ItemOpen AccessInformation Systems Development as an Activity(Computer Supported Cooperative Work, 2002-03) KORPELA, MIKKO; MURSU, ANJA; SORIYAN, H.A.. Intbrrnation systems development (ISD) is analysed in this paper as a systemic work activity, using Activity Analysis and Development (ActAD) as the theoretical fl'amework. ISD is regarded here as the process by which some collectivc work activity is lacilitated by new informationtechnological means through analysis, design, irnplementation, introduction and sustained support, as well as process management. It is a temporary, boundary-crnssing activity which draws its actors. means, rules, etc. from two sidcs typically a software company and the IS user olganization. ISD is analysed as a part of a network of activities. too, aror.rnd software development and a computersupported use activity. A theoretical tramework and a pragmatic checklist are presented for studying ISD activities. It is argued that the activity-theoretical tiamework provides a theoretically lbunded but detailed and practicable procedure tbr studying ISD as a work activity in context.
- ItemOpen AccessAn adaptive bio-inspired optimisation model based on the foraging behaviour of a social spider(cogent OA, 2019-11) otor, samera; akinyemi, bodunde; aladesanmi, temitope; aderounmu, ganiyuExisting bio-inspired models are challenged with premature convergence among others.In this paper,an adaptive social spider colony optimization model based on the foraging behaviour of social spider was proposed as an optimisation problem. The algorithm mimics the prey capture behaviour of the social spider in which, the spider senses the presence of the prey through vibrations transmitted along the web thread. Spiders are the search agents while the web is the search space of the optimization problem.The natural or biological phenomenon of vibration was modeled using wave theory while optimization theory was considered in optimizing the objective function of the optimisation problem. This objective function was considered to be the frequency of vibration of the spiders and the prey as this is the function that enables the spider differentiates the vibration of the prey from that of neighbouring spider sand therefore forages maximally. To address the parameter tuning problem, the searchpatternwascontrolledbythepositionofthepreyforconvergence.The proposed model was tested for convergence using several benchmark functions with different characteristics to evaluate its performance and results compared to an existing state of the arts’ spider algorithm. Results showed that the proposed model performed better by searching the optimum solution of the benchmark functions used to test the model
- ItemOpen AccessBi-directional Shape Correspondences (BSC)(Abdulrahman Ibraheem, 2014-11) Abdulrahman, IbraheemWe propose Bidirectional Shape Correspondence (BSC) as a possible improvement on the famous shape contexts (SC) framework. Our proposals derive from the observation that the SC framework enforces a one-to-one correspondence between sample points, and that this leads to two possible drawbacks. First, this denies the framework the opportunity to effect advantageous many-to-many matching between points on the two shapes being compared. Second, this calls for the Hungarian algorithm which unfortunately usurps cubic time. While the dynamic-space-warping dynamic programming algorithm has provided a standard solution to the first problem above, it demands quintic time for general multi-contour shapes, and w times quadratic time for the special case of single-contour shapes, even after an heuristic search window of width w has been chosen. Therefore, in this work, we propose a simple method for computing "many-to-many" correspondences for the class of all 2-d shapes in quadratic time. Our approach is to explicitly let each point on the first shape choose a best match on the second shape, and vice versa. Along the way, we also propose the use of data-clustering techniques for dealing with the outliers problem, and, from another viewpoint, it turns out that this clustering can be seen as an autonomous, rather than pre-computed, sampling of shape boundary.
- ItemOpen AccessSoftware Performance Quality Evaluation of MINPHIS Architecture using ATAM(2010-05) Gambo, Ishaya; Achimugu, Philip; Soriyan, AbimbolaSoftware architecture evaluation plays an important role in the validation of quality models of software systems. This paper is based on the research carried out where the Architecture Trade-off Analysis Method (ATAM) was used. ATAM was chosen and used because it provides insight into the way quality attributes are mapped onto architecture and also shows the trade-offs existing between the identified quality and others. The evaluation was based on the developed Software Architecture Scenario-Based Performance Quality Model (SASPUM). The paper presents the results of the analysis with ATAM by providing the set of scenarios and their prioritization from brainstorming, the utility tree, the risks discovered and non-risk documented; the sensitivity points and trade-off points found. The evaluation supports the fact that performance can be identified as a software quality attribute, which is part of the execution model of software system determined by the architecture of the software system, and that is suitable for software architectural evaluation.
- ItemOpen AccessA Load Balancing Policy for Distributed Web Service(Scientific Research, 2010-01) Eludiora, Safiriyu Ijiyemi; Aderounmu, Ganiyu A.; Abiona, Olatunde; Oluwatope, Ayodeji; Onime, Clement E.; Kehinde, L. O.he proliferation of web services; and users appeal for high scalability, availability and reliability of web servers to provide rapid response and high throughput for the Clients’ requests occurring at anytime. Distributed Web Servers (DWSs) provide an effective solution for improving the quality of web services. This paper addresses un-regulated jobs/tasks migration among the servers. Considering distributed web services with several servers running, a lot of bandwidth is wasted due to unnecessary job migration. Having considered bandwidth optimization, it is important to develop a policy that will address the bandwidth consumption while loads/tasks are being transferred among the servers. The goal of this work is to regulate this movement to minimize bandwidth consumption. From literatures, little or no attention was given to this problem, making it difficult to implement some of these policies/schemes in bandwidth scarce environment. Our policy “Cooperative Adaptive Symmetrical Initiated Dynamic/Diffusion (CASID)” was developed using Java Development Environment (JADE) a middle ware service oriented environment which is agent-based. The software was used to simulate events (jobs distribution) on the servers. With no job transfer allowed when all servers are busy, any over loaded server process jobs internally to completion. We achieved this by having two different agents; static cognitive agents and dynamic cognitive agents. The results were compared with the existing schemes. CASID policy outperforms PLB scheme in terms of response time and system throughput.