http://dr.lib.sjp.ac.lk/handle/123456789/7038 Thu, 23 Apr 2026 10:57:08 GMT 2026-04-23T10:57:08Z http://dr.lib.sjp.ac.lk/handle/123456789/7805 Intelligent System for High Resolution Computed Tomography (HRCT) Image Analysis: A concept Chandrasena, S.; Subasinghe, A. Sun, 01 Jan 2017 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/7805 2017-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/7097 Joint Assignment of Power, Routing, and Spectrum in Static Flexible-Grid Networks Yan, Li; Agrell, Erik; Dharmaweera, M.N; Wymeersch, Henk Attached; This paper proposes a novel network planning strategy to jointly allocate physical layer resources together with the routing and spectrum assignment in transparent nonlinear flexible-grid optical networks with static traffic demands. The physical layer resources, such as power spectral density, modulation format, and carrier frequency, are optimized for each connection. By linearizing the Gaussian noise model, both an optimal formulation and a low complexity decomposition heuristic are proposed. Our methods minimize the spectrum usage of networks, while satisfying requirements on the throughput and quality of transmission. Compared with existing schemes that allocate a uniform power spectral density to all connections, our proposed methods relax this constraint and, thus, utilize network resources more efficiently. Numerical results show that by optimizing the power spectral density per connection, the spectrum usage can be reduced by around 20% over uniform power spectral density schemes. Sun, 01 Jan 2017 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/7097 2017-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/7095 Improving numerical sea ice predictions in the Arctic Ocean by data assimilation using satellite observations Mudunkotuwa, D.Y.; De Silva, L.W.A.; Yamaguchi, H. Attached; This study focuses on improving sea ice predictions in the Arctic Ocean by introducing data assimilation into an ice-ocean coupled Ice-POM model that is used to predict sea ice conditions in the Arctic sea routes. Ocean part of the model used in this study is based on the Princeton Ocean Model (POM). The ice model considers discrete characteristics of ice along the ice edge. The model domain consists of the Arctic Ocean, Greenland-Iceland-Norwegian (GIN) seas and the Northern Atlantic Ocean. The model grid is with 25km horizontal resolution. An improved nudging method that takes the observation errors into account is used in this study. Observation errors are varied in accordance with the season and the location. Sea ice concentration, sea ice thickness and sea ice velocity are assimilated simultaneously. Assimilation improved ocean and ice conditions significantly. This is evident from the changes in sea ice extent, sea ice thickness and ocean salinity. Sun, 01 Jan 2017 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/7095 2017-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/7094 An approach to deal with free riders in assessed group work. A case study in an undergraduate engineering program Mudunkotuwa, D.Y.; Samarasekara, G.N.; Nandapala, K.; Priyadarshani, K.A.M. Attached; Group work are an essential component of engineering education programs. It is a challenge to assess individual contributions in a group work assessment. General approach is to provide an identical grade to all the group members. However, the problem with this approach is that of free riders, who benefits but contributes less than their fair share of the tasks in the group work. To overcome this issue a novel approach was employed. Two group assessments were considered in the analysis. After each assessment, the group was asked to submit a single report with a chapter on individual contributions. Students were asked to indicate the percentage of contribution from each member clearly specifying individual contribution. Students were asked to provide strong justification when two group members were given the same contribution percentage. Based on a questioner consisting of open-ended and multiple answer questions, 167 student feedback statements received. These statements were used to investigate the fairness and acceptability of the employed method. Majority of (94%) students were satisfied with the percentage of contribution received from the group and 80% stated that it is fair to be evaluated by peers. Students have commended the method to be evaluated by peers since peers know the best about how each member have performed. Those who stated that the method is unfair, raised the difficulties of assigning a unique percentage for each member and requested to assign the same marks to several students. With this revision authors propose the usage of aforementioned method to avoid free riders Sun, 01 Jan 2017 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/7094 2017-01-01T00:00:00Z