Common Radio Resource Management Policy for Multimedia Traffic in Beyond 3G Heterogeneous Wireless Systems

Beyond 3G wireless systems will be composed of a variety of Radio Access Technologies (RATs) with different, but also complementary, performance and technical characteristics. To exploit such diversity while guaranteeing the interoperability and efficient management of the different RATs, common radio resource management (CRRM) techniques need to be defined. This work proposes and evaluates a CRRM policy that simultaneously assigns to each user an adequate combination of RAT and number of radio resources within such RAT to guarantee its QoS requirements. The proposed CRRM technique is based on linear objective functions and programming tools

User QoS-based Multi-Channel Assignment Schemes under Multimedia Traffic Conditions

The implementation of multi-channel assignment policies can improve a mobile’s network performance by increasing the user throughput and reducing transmission delays. However, to define efficient distribution policies, the varying service demands and the search for user QoS fairness should be considered under multimedia traffic scenarios. In this context, this paper proposes and evaluates novel bankruptcy and utility-based multi-channel distribution schemes aimed at maximising the resource’s efficiency and guaranteeing user QoS fairness

Can gamification improve the benefits of student response systems in learning? an experimental study

Student response systems (SRSs) are becoming popular among instructors in nearly all levels of learning. The benefits of using SRSs in terms of attendance, attention, participation, or motivation have been shown in many studies. Moreover, several studies demonstrate that the use of some kind of gaming techniques in education are useful to stimulate students to learn in wider, longer, and deeper ways. This paper analyzes whether the integration of both SRSs and gaming techniques leads to better results in motivation, attention, engagement, and learning performance than SRSs alone. For this purpose, a new tool has been developed for conducting an experimental study with students from different subjects and from different academic levels. A randomized post-test-only control group analysis was conducted to evaluate the impact of the gamified SRS

Dynamic generation and attribution of revenues in a video platform

The consumption of online videos on the Internet grows every year, making it a market that increasingly generates a greater volume of income. This paper deals with a problem of great interest in this context: the allocation of the generated revenues in a video website between the website and the video creators. For this, we consider a dynamic model of the revenues generation. We will consider that revenue can come from two sources: through the pay-per-view system and through the insertion of advertisements in the videos. Then to study how to divide the revenues in a reasonable and fair way between the two parties, we consider a dynamic cooperative game that reflects the importance of each part in generating revenue. From this game, we determine how its Shapley value is and introduce other allocation rules derived from it. We provide a structure of algorithm to calculate the Shapley value and its derived rules. We show that the computational complexity of the algorithms is polynomial. Finally, we provide some illustrative examples and simulations to illustrate how the proposed allocation rules perform.Comment: 31 pages, 6 figure

Multi-Channel Radio Resource Distribution Policies in Heterogeneous Traffic Scenarios

Multi-channel operation in wireless systems has been proposed to increase user throughput and reduce transmission delays. However, multi-channel operation requires adequate resource allocation policies to guarantee user fairness and avoid channel access stagnation. The definition of such policies is particularly challenging in heterogeneous traffic scenarios where each traffic service has different quality of service requirements. In this context, this work proposes and evaluates various multichannel radio resource distribution policies designed to operate under heterogeneous traffic environments. In particular, this paper proposes the application of bankruptcy policies to guarantee user fairness, and compares their performance to other schemes. The proposed policies can also be extended to manage radio resources in heterogeneous wireless systems

Lower Success Rate of Debridement and Implant Retention in Late Acute versus Early Acute Periprosthetic Joint Infection Caused by Staphylococcus spp. Results from a Matched Cohort Study

Background Surgical debridement, antibiotics and implant retention (DAIR) is currently recommended by international guidelines for both early acute (postsurgical) and late acute (hematogenous) periprosthetic joint infections (PJIs). However, due to a different pathogenesis of infection, a different treatment strategy may be needed. Questions/purposes (1) Compared with early acute PJIs, are late acute PJIs associated with a higher risk of DAIR failure? (2) When stratified by microorganism, is the higher risk of failure in late acute PJI associated with Staphylocococcus aureus infection? (3) When analyzing patients with S. aureus infection, what factors are independently associated with DAIR failure? Methods In this multicenter observational study, early acute and late acute PJIs treated with DAIR were retrospectively evaluated and matched according to treating center, year of diagnosis, and infection-causing microorganism. If multiple matches were available, the early acute PJI diagnosed closest to the late acute PJI was selected. A total of 132 pairs were included. Treatment success was defined as a retained implant during follow-up without the need for antibiotic suppressive therapy. Results Late acute PJIs had a lower treatment success (46% [60 of 132]) compared with early acute PJIs (76% [100 of 132]), OR 3.9 [95% CI 2.3 to 6.6]; p <0.001), but the lower treatment success of late acute PJIs was only observed when caused by Staphylococcus spp (S. aureus: 34% versus 75%; p <0.001; coagulase-negative staphylococci: 46% versus 88%; p = 0.013, respectively). On multivariable analysis, late acute PJI was the only independent factor associated with an unsuccessful DAIR when caused by S. aureus (OR 4.52 [95% CI 1.79 to 11.41]; p <0.001). Conclusions Although DAIR seems to be a successful therapeutic strategy in the management of early acute PJI, its use in late acute PJI should be reconsidered when caused by Staphylococcus spp. Our results advocate the importance of isolating the causative microorganism before surgery