Fair Coexistence of Scheduled and Random Access Wireless Networks: Unlicensed LTE/WiFi

We study the fair coexistence of scheduled and random access transmitters sharing the same frequency channel. Interest in coexistence is topical due to the need for emerging unlicensed LTE technologies to coexist fairly with WiFi. However, this interest is not confined to LTE/WiFi as coexistence is likely to become increasingly commonplace in IoT networks and beyond 5G. In this article we show that mixing scheduled and random access incurs and inherent throughput/delay cost, the cost of heterogeneity. We derive the joint proportional fair rate allocation, which casts useful light on current LTE/WiFi discussions. We present experimental results on inter-technology detection and consider the impact of imperfect carrier sensing.Comment: 14 pages, 8 figures, journa

Electro-precipitation of magnetite nanoparticles: an electrochemical study

Nanoparticles of magnetites (Fe3O4) are synthesized with a new process based on electro-precipitation in ethanol medium. A mechanism pathway is proposed consisting of a Fe(OH)3 precipitation followed by the reduction of iron hydroxide to magnetite in the presence of hydroxyl ions which are enerated at the cathode

Complementarity between human capital and trade in regional technological progress

The effect of openness and trade orientation on economic growth remains a highly contentious issue. Trade facilitates knowledge diffusion and the adoption of more advanced and efficient technologies which faster total factor productivity (TFP) growth and, hence, per capita income. New technologies that diffuse by trade require a sufficiently qualified labour force to adapt them into the domestic productive environment. Thus, openness and human capital accumulation will lead to TFP growth, and the larger the complementarity between both variables the higher TFP growth. The paper discusses the implications of these assumptions and tests their empirical validity using a pool of data for the industrial sector in the Spanish regions in a period in which both the stock of human capital and openness experienced a not able improvement. Key words: trade, human capital, technological progress and regions. JEL category: C23, D24, O33.

Complementarity between human capital and trade in regional technological progress

The effect of openness and trade orientation on economic growth remains a highly contentious issue in the literature. Trade facilitates the spread of knowledge and the adoption of more advanced and efficient technologies, which hastens total factor productivity (TFP) growth and, hence, per capita income. New technologies that spread through trade require a sufficiently skilled labour force to adapt them to the domestic productive environment. Thus, openness and human capital accumulation will lead to TFP growth and the greater the complementarity between both variables, the higher the TFP growth. This paper discusses the implications of these assumptions and tests their empirical validity, using a pool of data for manufacturing industry in Spanish regions in a period in which both the stock of human capital and openness experienced a notable increase.technological progress, industry, human capital, trade

Selection of personnel in Puerto Rico.

Thesis (M.A.)--Boston Universit

Transitioning to Housing First: Perceptions of the Role of the Rehabilitation Counselor in Serving Homeless Individuals with Disabilities in Puerto Rico

Since the 1980s, the federal government has developed strategies to eradicate homelessness in the US and its territories. The introduction of evidence-based practices like the Housing First Model helped decrease the number of people living homeless. Still, it continues to be a public health problem, especially among chronically homeless individuals, defined broadly as people with disabilities and substance abuse problems experiencing homelessness. Rehabilitation counselors are professionals specialized in serving individuals with disabilities. However, their role in programs identified as Housing First was unclear. Thus, the study aimed to identify service providers\u27 views, opinions, knowledge, and experiences about the role of rehabilitation counselors, the chronic homeless population, and the implementation process of the Pathways Housing First model in Puerto Rico. The process included two different data collection strategies: in-depth interviews to explore the experiences of key informants and a review of documents depicting the procedures and job descriptions related to the model. The sample included coordinators, administrators, clinical and case managers from four permanent housing programs at the two Continuum of Care systems on the island. The results were compared with additional information gathered from different sources to identify similarities. Results showed rehabilitation counselors were unknown to most service providers, who were not aware of their professional skills and capabilities. Furthermore, in many instances, the staff confused rehabilitation counselors with addictions counselors. In contrast, results showed service providers knew about the Housing First model and agreed with its fundamental principles, values, and notions about the homeless population. Still, some participants expressed reservations about the model\u27s effectiveness on the island due to environmental factors such as lack of sufficient support services, poor accessibility to services, and the local government’s insufficient support to programs working on behalf of the homeless population. The participants\u27 experiences were consistent with those of other professionals transitioning to a housing first approach to service. Still, to effectively implement the model, community-based organizations, service providers, and local government officials need to promote continuity of service, a shared public policy, and an open mind to address homelessness in Puerto Rico

Thwarting Selfish Behavior in 802.11 WLANs

The 802.11e standard enables user configuration of several MAC parameters, making WLANs vulnerable to users that selfishly configure these parameters to gain throughput. In this paper we propose a novel distributed algorithm to thwart such selfish behavior. The key idea of the algorithm is for honest stations to react, upon detecting a selfish station, by using a more aggressive configuration that penalizes this station. We show that the proposed algorithm guarantees global stability while providing good response times. By conducting a game theoretic analysis of the algorithm based on repeated games, we also show its effectiveness against selfish stations. Simulation results confirm that the proposed algorithm optimizes throughput performance while discouraging selfish behavior. We also present an experimental prototype of the proposed algorithm demonstrating that it can be implemented on commodity hardware.Comment: 14 pages, 7 figures, journa