Energy-Efficient Data Collection Method for Sensor Networks by Integrating Asymmetric Communication and Wake-Up Radio

In large-scale wireless sensor networks (WSNs), nodes close to sink nodes consume energy more quickly than other nodes due to packet forwarding. A mobile sink is a good solution to this issue, although it causes two new problems to nodes: (i) overhead of updating routing information; and (ii) increased operating time due to aperiodic query. To solve these problems, this paper proposes an energy-efficient data collection method, Sink-based Centralized transmission Scheduling (SC-Sched), by integrating asymmetric communication and wake-up radio. Specifically, each node is equipped with a low-power wake-up receiver. The sink node determines transmission scheduling, and transmits a wake-up message using a large transmission power, directly activating a pair of nodes simultaneously which will communicate with a normal transmission power. This paper further investigates how to deal with frame loss caused by fading and how to mitigate the impact of the wake-up latency of communication modules. Simulation evaluations confirm that using multiple channels effectively reduces data collection time and SC-Sched works well with a mobile sink. Compared with the conventional duty-cycling method, SC-Sched greatly reduces total energy consumption and improves the network lifetime by 7.47 times in a WSN with 4 data collection points and 300 sensor nodes

The influence of induced mutagenesis on reproductive behavior of Drosophila subobscura and the role of sexual selection in relationto the level of mutational load

Prema teorijskim očekivanjima seksualna selekcija može smanjivati mutaciona opterećenja u populacijama. Mužjaci koji su boljeg genetičkog kvaliteta bi trebalo da budu uspešniji u parenju u poređenju sa mužjacima lošijeg genetičkog kvaliteta. Na taj način ženke, prilikom izbora partnera za parenje, mogu da eliminišu one mužjake koji nose štetne alele, i da smanje mogućnost prenošenja štetnih alela u sledeću generaciju. Seksualna selekcija će redukovati mutaciona opterećenja i povećavati adaptivnu vrednost populacije, ako je većina mutacija štetna i za adaptivnu vrednost i za osobine koje utiču na uspešnost mužjaka u parenju. Istraživanja poslednjih godina su dala rezultate koji idu u prilog ovoj teoriji, ali i oprečne rezultate. Ovakva kontradiktornost proizilazi iz kompleksnosti problematike usled različitih reproduktivnih strategija vrsta, kao i različitih reproduktivnih strategija mužjaka i ženki. Takođe, osobine koje utiču na komponente adaptivne vrednosti, kao i na uspešnost u parenju, su veoma složene, pod determinacijom velikog broja gena, i u čijoj osnovi leže kompleksne genske interakcije. Iako se kao osobine koje su cilj seksualne selekcije najčešće analiziraju sekundarne polne karakteristike, i mnoge druge osobine određuju atraktivnost mužjaka. To su i morfološke, fiziološke, ponašajne i druge osobine koje utiču na uspešnost u parenju, a mogu se nazvati osobinama koje su zavisne od opšteg stanja mužjaka (eng. condition-dependent traits)...According to theoretical predictions sexual selection can reduce mutational load in populations. Males of good genetic quality should be more successful in matings, compared to the males of low genetic quality. In this way females, through the choice of mating partners, can eliminate males carriers of deleterious alleles, and reduce transmission of deleterious alleles to the next generation. Sexual selection will purge mutational load and increase fitness if most mutations were deleterious to both nonsexual fitness and condition-dependent traits affecting mating success. Studies in recent years have yielded results that support this theory, but opposite results are obtained, as well. This contradiction arises from different reproductive strategies of species, and different reproductive strategies of males and females. Traits that affect fitness components, as well as mating success, are under polygenic determination, with very complex gene interactions. Although secondary sexual traits were usually analyzed as target of sexual selection, many other traits can determine male attractiveness. Traits such as morphological, physiological, behavior and other, affecting mating success, can be termed as condition-dependent traits. In order to test this hypothesis, that sexual selection can reduce mutational load, two experimental groups were formed from the same population genetic pool of Drosophila subobscura, which differed in the level of mutational load. Mutations were induced in one group, using 30Gy ionizing radiation. The effect of sexual selection in reduction of mutational load was measured through different components of male mating behavior (courtship occurrence, courtship latency, courtship intensity, mating occurrence,latency to mating and duration of mating)...

Radio Context Awareness and Applications

The context refers to “any information that can be used to characterize the situation of an entity, where an entity can be a person, place, or physical object.” Radio context awareness is defined as the ability of detecting and estimating a system state or parameter, either globally or concerning one of its components, in a radio system for enhancing performance at the physical, network, or application layers. In this paper, we review the fundamentals of context awareness and the recent advances in the main radio techniques that increase the context awareness and smartness, posing challenges and renewed opportunities to added-value applications in the context of the next generation of wireless networks

Radio context awareness and applications

The context refers to “any information that can be used to characterize the situation of an entity, where an entity can be a person, place, or physical object.” Radio context awareness is defined as the ability of detecting and estimating a system state or parameter, either globally or concerning one of its components, in a radio system for enhancing performance at the physical, network, or application layers. In this paper, we review the fundamentals of context awareness and the recent advances in the main radio techniques that increase the context awareness and smartness, posing challenges and renewed opportunities to added-value applications in the context of the next generation of wireless networks.Peer Reviewe