Mobile WiMAX system performance – simulated versus experimental results

This paper addresses the downlink performance of mobile WiMAX operating at 2.3GHz in an urban environment. The analysis includes a comparison of simulated and experimental results. Simulated packet error rate (PER) versus Signal to Noise Ratio (SNR) graphs are generated on a per link-speed basis using a fully compliant 512 carrier mobile WiMAX simulator. Experimental data is gathered using a carrier-class basestation, a mobile-WiMAX enabled laptop, and a suite of application layer logging software. An H264 AVC encoder and IP packetisation unit is used to transmit video to a mobile client. Results show strong agreement in terms of simulated and captured PER. Using this data, the downlink operating range is evaluated as a function of the Effective Isotropic Radiated Power (EIRP) and path loss exponent. Results indicate that at low EIRP (32 dBm) the expected outdoor operating range is around 200-400m. Applying the UK OFCOM regulations for licensed operation in the 2.5GHz band, downlink operation in excess of 2km can be achieved

Student experiences and perceptions of digital literacy skills development: engaging learners by design?

In the current digital environment, it is vital for learners to develop digital literacy skills. The UK?s Quality Assurance Agency for Higher Education (HE) requires graduates to demonstrate digital literacy. Employers consider these skills essential. With the high cost of HE in the UK, learners themselves also expect university courses to demonstrate relevance to the workplace. Nevertheless, some learners may not fully engage in digital literacy skills development, instead concentrating on the subject-specific content of their modules. The Faculty of Health & Social Care (FH&SC) at the UK?s Open University uses different approaches to digital literacy skills development, based on skills resources that are either ?generic? (usable by any FH&SC module) or module specific. By exploring student experiences of digital literacy skills development, we aim to understand what motivates learners to engage with the skills content of their module. We collected data from online questionnaires and interviews involving learners from three modules and present findings from an analysis of the quantitative questionnaire data, supported by qualitative interview data, where relevant. We look at learner perceptions and engagement in relation to the demographic factors gender, age, previous education, disability and financial status and whether these factors influence individual learner preferences for learning design, such as use of generic resources versus contextualisation of skills activities within the module. We aim to identify good practice in learning design and what demographic factors need to be considered to support individual learners appropriately, and so optimise engagement

A Limnological Study of Ricks Pond and the Gulpha Creek Drainage in Garland County, Arkansas

A limnological investigation of Ricks Pond and the Gulpha Creek drainage of Garland County, Arkansas was conducted between 1 June 1978, and 21 August 1978. Water samples taken from ten stations on three different dates indicated that the stream and pond systems were typical in water quality characteristics of other small, high gradient streams and impoundments in the Ouachita Mountains of Arkansas. In Ricks Pond, thermal stratification occurred along with the development of an oxygen deficient zone below a depth of one meter. Other water quality parameters indicated that Ricks Pond is a moderately productive ecosystem, with the productivity limited by the nitrogen species. The fecal coliform bacterial counts were very low, indicating no direct input of excessive amounts of fecal matter into the system during the present study. However, a Hot Springs city sewer line runs through the pond, and two manholes emerge from the pond\u27s surface. The possibility exists that this sewer line could discharge raw sewage into Ricks Pond during periods of high water. A biological investigation was also conducted in the study area, and lists of the phytoplankton, periphyton, higher aquatic vegetation, zooplankton, benthic macroinvertebrates, and fishes are presented. Twenty-seven species of fishes were collected from the Gulpha Creek drainage, and no rare or endangered forms were found. Ricks Pond is best-suited for the establishment of a put- and-take fishery for channel catfish, Ictalurus punctatus. The following recommendations were made for the establishment of such a fishery: (1) Renovation of the pond by draining and deepening it; (2) Removal of the sewer line from the pond; (3) Stocking of catchable size channel catfish at the rate of approximately 300-400 pounds per acre; (4) Periodic monitoring of the water quality

The Human and Environmental Concerns of the Ohio Train Derailment using Geographic Information Systems

The Norfolk Southern train derailment in East Palestine, Ohio poses many long term concerns for humans and the environment. Over a hundred thousand gallons of hazardous chemicals were released into the air, soil, and waterways after the train derailed and started a fire. Norfolk Southern performed a controlled burn of the chemicals after residents were told to evacuate. Was this really the best solution? Geographic Information Systems (GIS) datasets and tools can be used to get a better understanding of the impact the accident has had on the community. Overlaying datasets of waterways and cropland onto a map can help one understand the environmental impact. Additionally, datasets from the ArcGIS living atlas of household income and health insurance coverage can bring insight to humanitarian concerns. GIS is an extremely helpful tool in gathering and assessing data to further research and also to make sure the public is well informed