Towards a scalability model for wireless mesh networks

Zenzeleni mesh network is a wireless ad-hoc mesh network that provides voice services using public analogue telephones to the Mankosi community in the Eastern Cape Province. We would like to improve on the network infrastructure by upgrading the mesh routers and introducing low-end smartphones onto the network; and offer both data and voice over Internet protocol services. However, before deploying resources, it is imperative to identify the maximum number of mesh nodes, clients and simultaneous voice over internet protocol calls that can be supported by the mesh network while maintaining acceptable quality of service levels. Absence of such data might lead to financial risk and time depletion when setting up an optimal network. Bolstering the claim are investigations that report drop in quality levels as network density and hop count escalate. As current investigations mostly yield capacity models to predict per-node throughput with increasing hop count, we propose experiments to devise a scalability model to quantify scalability of mesh networks in this paper. We recommend experimental implementations at simulation level in Network Simulator-3 moving on to testbeds built using WiBed, and then finally take results to the field.Telkom, Cisco, Aria Technologies, THRIP, CONFINEDepartment of HE and Training approved lis

A randomized controlled trial to examine the posttreatment efficacy of neurofeedback, behavior therapy, and pharmacology on ADHD measures

Objective: To examine the efficacy of neurofeedback (NF), behavior therapy (BT), and pharmacology (PH) on the improvement of ADHD-related symptoms. Method: Fifty-nine children with ADHD (M = 8.80 years, SD = 1.92 years) were randomly assigned to one of the three treatments in a pre/post assessment design. Mother- and teacher-rated ADHD scales and children were assessed using The Integrated Visual and Auditory Continuous Performance Test (IVA/CPT). Results: The three treatments were effective on the IVA/CPT, but with different trends. BT and especially NF achieved improvement on response control and attention, and PH mainly in visual attention. On the rating scales, BT improved all measures, and NF and PH had a minor but interesting influence. Conclusion: From a global perspective, behavior therapy had the most extensive results, but PH had the greatest capacity to improve overall attention. NF was able to improve both control response and inattention. Clinical implications are discussed.Plan Nacional i+d+i PSI2008–06008-C02–0

Clustered Multi-layer Multi-protocol Wireless Mesh Networks

Wireless Mesh Networks (WMNs) have emerged as an alternative option to the wired networks in areas where wired deployment is unfeasible and/or costly. They have been widely adopted in community networks as these networks are mostly built within “not for profit” projects and do not require enterprise class investment which can lead to inefficient network architectures and routing protocol designs. B.A.T.M.A.N-ADV has been designed as a simple routing protocol that adheres to lightweight equipment requirements of wireless mesh deployment in the rural areas of the developing countries. However, it is built around a flat WMN topology which is challenged with scalability, security and implementation issues; which can limit WMN growth and services expansion. This paper proposes and evaluates the performance of a new multi-layer, multi-protocol WMN architecture that addresses B.A.T.M.A.N-ADV scalability issues by borrowing from wired networks their clustering model and building around the B.A.T.M.A.N Experimental (BMX6) protocol to introduce layer2 tunnelling through a cloud of layer3 routers.Telkom, Cisco, Aria Technologies, THRIPDepartment of HE and Training approved lis

A participatory design for a billing system: A South African case study of a community based telephony system

This paper describes the role participatory design can play in developing and implementing an information and communication technology for development project in a rural area. It shows how the process of co-designing an artifact can reflect and shape social development. A case study was conducted in the Mankosi Community in the Eastern Cape with the aim of designing and implementing a billing system for an existing community-owned telephony system, by accommodating the community’s requirements. Relevant criteria had to be considered for this telephony system based on voice over Internet Protocol with the possibility of ‘break-out’ calls to external networks. Different payment modalities were explored that would allow for a transparent method of both collecting money and applying the collected funds to achieve the project’s sustainability. A participative methodology with future users and operators of the network—using scenarios and prototypes to illustrate the implementation—informed the design of the billing system. Data was collected by means of unstructured interviews and focus group discussions. Qualitative data was analyzed using a qualitative content analysis tool. The community indicated that a billing system, based on both vouchers and prepaid service, would satisfy their needs.Telkom, Cisco, Aria Technologies, THRIPDepartment of HE and Training approved lis

Local ownership, exercise of ownership and moving from passive to active entitlement: a practice-led inquiry on a rural community network

In this paper, we aim to shed light on local ownership from a double practical and theoretical perspective, and examine its meaning as well as the factors that are bound to influence its development in community based interventions. The questions we intend to answer are: How can 'local ownership' be defined in a way that facilitates its investigation in CI practice, and enables at the same time its theoretical examination and relation with other CI key conceptual constructs? What key factors contribute to fostering local ownership in CI initiatives, taking the case of an externally initiated rural community network? To answer these questions, the paper reports on a study which assessed the development of local ownership in a rural community network in South Africa and singled out the factors found to delineate the development of a sense of ownership in local people, as well as driving the exercise of ownership towards autonomous local action. Based on a detailed analysis of the development of community ownership in this project, and in constant dialogue with the community informatics and social science literature, the paper makes three key contributions to CI theory and practice, as well as more specifically to future practice in community networks: An operational definition of local ownership and a conceptual model which highlights relations to other constructs such as responsibility, power and control and emphasises the role of local ownership in moving from passive to active entitlement towards community assets or CI interventions An empirical analysis of the development of local ownership in a community network in rural South Africa, highlighting the critical factors that led to fostering ownership An examination and critical discussion of factors that are positively related with the development of ownership, carried out in dialogue with CI scholarship and highlighting the bearing of and relations with other critical constructs in CI research, such as participation, empowerment, and capacity building These contributions come at a critical stage in community informatics development as a discipline, in which, we argue, a more solid and critical engagement with theory is required to firmly establish its place and the premises for dialogue with other sociotechnical disciplines.Web of Scienc

Co-designing a billing system for voice services in rural South Africa: Lessons learned

Access to information and communication technologies re- mains una ordable for many in rural areas despite recent progress in providing voice services to remote communities. The sustainability of alternative technical solutions is a chal- lenge, which can be addressed when local knowledge is taken into account during the design process. This research re- ects on the process of co-designing a billing system for voice services provided by a Community Network in rural South Africa. Several payment methods were explored with users and operators of the Community Network, focusing on the legal, nancial, technical and social feasibility - as well as constraints - of each method. Those methods that suited the community's needs were implemented and tested with stakeholders. The process revealed factors embedded in the provision of voice services by traditional voice operators in South Africa that prevent economically poor and illiterate users from fully bene ting from voice services. Solutions to these factors were explored with users and were implemented as a billing system. The system is currently being deployed in a rural South African community. Both the problems experienced and solutions proposed may inform similar ini- tiatives.Telkom, Cisco, Aria Technologies, THRIP, FIR

Unmasking community trust issues in rural field work

The principal objective of this paper is to describe the au thor's fieldwork and research in a remote rural area of South Africa, where a Village Telco is deployed to provide Voice over Internet Protocol on a wireless mesh network. The users' social environment was evaluated to understand trust issues associated with the adoption of the network. Qualita-tive measures such as contextual inquiry, participant obser-vation, focus group and individual interviews were used during data collection. Focus group discussions were held with community members involved with the planning of ways in which to sustain the network. Involving the community gave them a sense of commitment and ownership of the network. To maintain the network, different solutions were proposed. One of these was a billing system for the use of the network. This will be designed to meet users' needs and should also be transparent so that the community will trust it. A prototype is being developed, with input from the community, using open source software to address their requirements.Telkom, Cisco, Aria Technologies, THRIPWeb of Scienc

Evaluación del impacto ambiental y económico generado por el aprovechamiento de llantas usadas en el desarrollo vial de nivel local en la ciudad de Bogotá D.C..

Maestría en Desarrollo Sostenible y Medio Ambiente, Facultad de Ciencias Contables, Económicas y Administrativas.El crecimiento demográfico en Bogotá ha incrementado la afectación de manera negativa directa o indirectamente de diversos recursos en la ejecución de obras que promuevan el desarrollo de las ciudades, tales como intervención de malla vial, proyectos habitacionales entre otros; de lo anterior se deriva un alto pasivo ambiental relacionado con las actividades de extracción de materiales de construcción en los cerros orientales. Por otro lado el crecimiento del parque automotor en la ciudad de Bogotá ha traído entre otras consecuencias el incremento de la generación de llantas usadas; conllevando a que se presenten deficiencias y dificultades en la gestión de este tipo de residuo convirtiéndose en una problemática de índole ambiental para varios sectores de la ciudad; en la actualidad el 25% de la generación total de llantas usadas de la ciudad son gestionadas de manera correcta lo que repercute en que el porcentaje restante sean dispuestas en espacio público generando con esto exposición de las comunidades vecinas a riesgos como incendio, proliferación de vectores transmisores de enfermedades y detrimento de la seguridad pública, un nivel bajo comparada con lo que ocurre en otros países, en EEUU por ejemplo, se recicla aproximadamente el 90% de las llantas usadas. Teniendo en cuenta que existe legislación aplicable a la gestión de este tipo de residuo (Llantas usadas) la demanda de productos o subproductos derivados del aprovechamiento de este aún es insuficiente por cuanto es importante analizar alternativas de uso en otras aplicaciones a las ya contempladas en la normativa vigente

Estudio baropodométrico en pacientes tratados mediante artroplastia total de rodilla

La patología artrósica de la rodilla condiciona una disminución de la carga del miembro afecto y un patrón de apoyo con predominio generalmente del arco externo. El propósito de este estudio es determinar si existe una modificación significativa de este patrón tras la implantación de una artroplastia total de rodilla (ATR) primaria, recogiendo las presiones plantares de ambos pies mediante baropodometría electrónica previamente y 4 meses tras la cirugía, tanto en estática como en dinámica. Así, se analizan las presiones plantares de 30 pacientes, 21 mujeres y 9 hombres, intervenidos de ATR primaria en el Hospital Universitario Doctor Peset entre los años 2013 y 2015. También se ha determinado si existe una corrección del eje anatómico tras la cirugía. Utilizando test no paramétricos (test de Wilcoxon para datos apareados, U de Mann-Whitney), observamos una modificación significativa de dicho ángulo desde valores medianos de 1.2º de varo a 4.9º de valgo en el postoperatorio, una disminución mediana de la presión plantar en ambos pies y una redistribución de la carga axial, aumentando en el miembro intervenido. Concluimos que, 4 meses tras la cirugía, se produce una tendencia a la “normalización” de la pisada en pacientes en los que se ha implantado una ATR, condicionado tanto por la mejora del dolor y la funcionalidad como por la realineación del eje.Knee osteoarthritis determines a decrease of the load of the affected limb and a pattern usually dominance of external support plantar arc. The purpose of this study is to determine whether a significant change in this pattern is? after implantation of a primary total knee arthroplasty (TKA), measuring plantar pressures in both feet by electronic baropodometry previously and 4 months after surgery, in static and dynamic. Plantar pressures of 30 patients are analyzed, who underwent primary TKA at the University Hospital Doctor Peset between 2013 and 2015. In addition, it has also been determined if there is a correction on the anatomical axis after surgery. Using nonparametric test (Wilcoxon test for paired data, U Mann Whitney), we observed a significant change in the angle from median values of 1.2º varus to 4.9º valgus postoperatively, a median decrease of plantar pressure in both feet and a redistribution of axial load, increasing in the operated limb. We conclude that, 4 months after surgery, there is a tendency to “normalization” of the tread in patients undergoing TKA. This is conditioned by improving pain and function as axis realignment occurs

Guía de la Cooperación Española para la incorporación de las TIC en las intervenciones de Salud en la Cooperación para el Desarrollo

El objetivo de esta guía es aportar herramientas y ejemplos reales para lograr aprovechar el potencial que ofrecen las nuevas tecnologías para fortalecer los sistemas de salud de los países socios, línea prioritaria de la cooperación española dentro de la estrategia de salud