Ángel G. Andrade

Supporting the strategies to improve elders' medication compliance by providing ambient aids

In this paper, we present Ambient Information Systems (AIS) that support strategies relevant to enable elders to effectively manage their medication, such as: remind (Remind-Me AIS), guide (GUIDE-Me AIS), and motivate (CARE-Me AIS) them to medicate. We have informed the AIS design through a case study we carried out to understand elders’ deficiencies for adhering to their medication routine. As a result of the case study and the AIS design process; we identified the design issues that should be addressed when developing AIS that cope with the elders needs for living independently. Identifying these design issues is a step toward proposing design guidelines for the development of AIS for elderly. Through a heuristic evaluation, we identified several usability problems that enabled us to improve AIS characteristics, such as the intuitive mapping of the information representations and the visibility of the different AIS states.

Supporting emotional ties among mexican elders and their families living abroad

The aging of the population is a phenomenon faced by most nations, such as Mexico, where 7.5% of the population is older than 60 years, a significant proportion of whom live alone (10%). This fact is related with the ever increasing migration of one or more of their relatives, mostly to the USA. Our work aims to provide a technological solution that eases the isolation of elder people living alone in Mexico while their families are abroad. To envision and inform our design we interviewed independent old persons living alone. We propose an electronic family newspaper, through which elders and their families share information, personal reminiscences and cultural stories, and occasionally interact with each other. Through its functionality, the electronic newspaper enables elders not only to maintain close social ties, but ameliorate cognitive decline.

Performance evaluation of welch's periodogram-based energy detection for spectrum sensing

In this work, the authors present the evaluation of energy detection (ED) based on the Welchs periodogram for spectrum sensing applied to cognitive radio networks. The authors analyse the impact of the number of points in the discrete Fourier transform and the number of averaged periodograms for power density spectrum estimation on the performance of ED. The authors identify that the inclusion of these parameters in the distribution of the test statistic used to detect the presence of primary users, improves the probability of detection. However, in the presence of noise uncertainty, the improvement on the probability of detection will come at the expense of an increased probability of false alarm. With the approach considered in this work is possible to increment the probability of detection for a given and low signal-to-noise ratio, without increasing the number of samples collected from primary signal. However, to maintain a constant probability of false alarm, accurate techniques for noise variance estimation are needed, because detection-threshold value is highly dependent on the noise power present at each sensing interval.

On a Spectrum Resource Organization Strategy for Scheduling Time Reduction in Carrier Aggregated Systems

In this letter we develop an efficient method to reduce the scheduling delay in Carrier Aggregated systems. We will show that it is possible to reduce scheduling delay by organizing available resource blocks in sets. A Resource Block Organization Algorithm is designed and evaluated through simulation in a macrocellular environment. Results show that the achievable scheduling delay reduction depends on the average number of resource blocks required per user. For the specific evaluation conditions the scheduling delay due to resource assignment can be reduced on average from 4 to 8 times when compared to block by block scheduling.

A resource block organization strategy for scheduling in carrier aggregated systems

Carrier aggregation (CA) is a promising technology that will allow IMT-Advanced system candidates to achieve spectrum bandwidths of up to 100 MHz using available system resource blocks (RB), even if these are fragmented. Implementation of CA functionality is managed through the use of schedulers capable of assigning multiple RBs to a user. When each available RB is handled individually, the delay from assigning multiple RBs to each user can affect the quality of service (QoS). In this article we develop an efficient scheduling strategy to reduce spectrum resource assignment delay in systems that make use of CA. This strategy is based on an a-priory organization of available RBs in sets. Two different RB Organization Algorithms are compared. In order to evaluate the performance of the proposed strategy numerical simulation was performed using a Round Robin scheduler for the downlink of a macro-cellular environment. Results show that using the proposed strategy it is possible to reduce the delay required to assign resources to users without affecting the downlink user capacity when compared to block by block scheduling strategies proposed in literature. The benefits of using the proposed strategy are discussed as well as improvement opportunities.

Evaluation of UWB Interference at WiMax Systems Based on a Generalized Pulse Waveform

In this paper the coexistence issue between the UWB systems and Wi-Max/IEEE-802.16 systems has been investigated. The aim is to evaluate the impact that the interference resulting from a realistic UWB hot spot scenario may have on the performance of a Wi-Max/IEEE-802.16 receiver. A mathematical model is developed through which the performance of the interference power produced by the UWB hot spot can be calculated. We use a pulse waveform represented as a generalized form of Gaussian pulse family that can be used in Ultra Wide Band (UWB) impulse radio systems. This pulse waveform ensures that the UWB spectrum mask established by the Federal Communications Commission (FCC) is met. The results against which the UWB interference is assessed are also developed using the specifications of Wi-Max/IEEE-802.16 systems. Several simulations have been done to both validate the analytical results and calculate the UWB interference.

Comparing particle swarm optimization variants for a cognitive radio network

It is recognized that Static Spectrum Allocation Policy currently used in most countries has led to an inefficient use of spectrum. It means that available spectrum is underutilized over certain bands while in others remain scarce. In this context, Cognitive Radio technology is proposed to recycle bands in order to solve the problem of spectrum scarcity and use the limited spectrum resource as effectively as possible. This work presents the application and performance comparison of three variants of Particle Swarm Optimization (PSO) namely Binary Particle Swarm Optimization (BPSO), Socio Cognitive Particle Swarm Optimization (SCPSO) and Derivation 0 in a Cognitive Radio Network. We aim at maximizing the sum throughput for the number of secondary links that can be admitted in the Cognitive Radio Network in the presence of primary links under interference constraints.

Differential Evolution Multi-Objective for Optimization of Isoflux Antenna Arrays

ABSTRACT The multi-objective design of concentric ring antenna arrays for isoflux radiation for Geostationary Earth Orbit (GEO) and Medium Earth Orbit (MEO) satellites is presented in this paper. This design of concentric ring antenna arrays considers the optimization of the spacing between rings and the amplitude excitation across the antenna elements in order to generate the trade-off curves between the side lobe level (SLL) and the isoflux mask error. In order to use fewer levels of excitations to diminish the hardware complexity, a concentric excitation is considered across the antenna array. Simulation results applying a differential evolution multi-objective (DEMO) optimization method are provided in this document. Furthermore, an analysis of the trade-off curve between the SLL and the isoflux mask error is achieved.

A Pervasive System for Enabling Older Adults to Cope with Depression by Motivating them to Socialize

We report on the design of a home-based ubiquitous computing system that helps elders to prevent and reduce the onset of depression by managing their social lifestyle with the family members. We propose that through a Social Calendar, elders are encouraged to socialize by receiving invitations and suggestions generated by the system when it detects that in the last two weeks the communication patterns with one or more of their children have been altered, or that it has detected those elders may have a symptom of depression.

A Web-based system to facilitate elders communication with their families living abroad

The aging of the population is a phenomenon faced by most nations. Growing old is often accompanied of a loss of close companionship which has been shown may aggravate the cognitive impairment of elders. From a qualitative study, key issues emerged regarding unmet needs of elders communication that we propose to address with Web-based technology. We decided to create an electronic family newspaper to incorporate elders to the current social networks created by their younger relatives who already communicate through Internet applications, such as IM and e-mail. The system uses Web-based technology to make it accessible from any Web browser for those users living abroad. To serve the needs of elders and make the input of information easier, several autonomous agents help the user to interact with the system that can be accessed by any electronic display with a touch screen, such as a tablet PC.