Can 6LoPLC Enable Indoor IoT ?

Energy conservation and network longevity are key requirements of Internet of things (IoT) applications. However, these can be challenging in indoor environments such as dwellings with reinforced concrete walls and high-bay areas using battery-powered wireless devices. This paper presents a low-power power line communication over IPv6 network (6LoPLC) for in-building IoT applications. 6LoPLC adopts a PLC physical layer (PHY) and exploits media access control (MAC) features of IEEE 802.15.4 devices as well as 6LoWPAN to deliver low-power, low rate PLC. One of the unique advantages of 6LoPLC is that the nodes are mains-connected which eliminates the network disruption caused by battery depletion in wireless nodes. Furthermore, 6LoPLC saves the time and effort on battery recharge or replacement, simplifies network management and reduces wiring cost. The results reveal that the proposed system can yield about 5.05 dB reduction in energy requirement relative to HomePlug Green PHY without violating the delay tolerance of the IoT applications. It is further shown that using the 6LoPLC technique, delays of about 48 ms and 129 ms are feasible in residential and commercial buildings respectively

Effects of traffic characteristics on energy consumption of IoT End Devices in Smart City

The rapid urbanisation in many parts of the world in the last few decades has intensified the challenges of urban living. Internet of Things (IoT) can be leveraged as a tool for transformation to provide technology-assisted city development and management. However, given that many of the nodes in smart cities are constrained devices, part of the medium-long term challenges is how to sustain the real-time monitoring capabilities of the city without disrupting services. This paper investigates the effects of data traffic characteristics on the active life of constrained devices in smart cities. The access network model employs two leading low-power wide area network (LP-WAN) technologies; long range wide area network (LoRaWAN) and Sigfox specifications in a star topology. The results show that in Europe, for lightweight applications such as smart street lighting that sends small payloads once a day, Sigfox and LoRaWAN can provide device lives of about 5.82 years and 13.25 years respectively. On the other hand, for intense applications such as smart bus stops, using payload of 12 bytes, if the number of messages sent per day is increased from 1 to 140, Sigfox device life reduces from 4.43 years to 0.8 years while that of that of LoRaWAN reduces from 13.1 years to 10.48 years

A New Approach for Designing Orthogonal Wavelets for Multicarrier Applications

yesThe Daubechies, coiflet and symlet wavelets, with properties of orthogonal wavelets are suitable for multicarrier transmission over band-limited channels. It has been shown that similar wavelets can be constructed by Lagrange approximation interpolation. In this work and using established wavelet design algorithms, it is shown that ideal filters can be approximated to construct new orthogonal wavelets. These new wavelets, in terms of BER behave slightly better than the wavelets mentioned above, and much better than biorthogonal wavelets, in multipath channels with additive white Gaussian noise (AWGN). It is shown that the construction, which uses a simple simultaneous solution to obtain the wavelet filters from the ideal filters based on established wavelet design algorithms, is simple and can easily be reproduced

Effet pesticide et screening des extraits de Azadirachta indica (A.) Juss. sur le termite Macrotermes bellicosus Rambur

Pour préconiser l'application en champ d'une plante naturelle à propriété insecticide comme alternative à la lutte chimique contre les termites ravageurs, d'importants prérequis s'imposent sur son efficacité. La toxicité, la dose létale, le mode d'action, la persistance d'efficacité et la composition chimique des extraits totaux aqueux, alcoolique et hexanique des feuilles et des graines du neem, Azadirachta indica, ont été examinés sur l'espèce de termite ravageur Macrotermes bellicosus. La toxicité par contact des extraits est élevée sur le termite et provoque la mortalité totale des populations testées. La persistance d'efficacité des extraits est de 2,4 à 4,2 jours. Les extraits aqueux et hexanique sont les plus toxiques (DL50 de 0,422 ± 0,018 à 4,466 ± 0,162 mg/l). Le contact et l'inhalation sont les deux voies essentielles à leur efficacité. L'extrait aqueux de graines, le plus actif, est de plus capable de se transmettre dans la colonie lors des tâches sociales. Mais il n'agit pas par ingestion et il semble anti-appétant vis-àvis du termite. Il contient des composés phénoliques (tanins et flavonoïdes) et des saponines. L'extrait hexanique de graines est de type oléique, renferme 11 acides gras et contient des terpénoïdes, des flavonoïdes et des saponines. (Résumé d'auteur

A Simplified Improvement on the Design of QO-STBC Based on Hadamard Matrices

yesIn this paper, a simplified approach for implementing QO-STBC is presented. It is based on the Hadamard matrix, in which the scheme exploits the Hadamard property to attain full diversity. Hadamard matrix has the characteristic that diagonalizes a quasi-cyclic matrix and decoding matrix that are diagonal matrix permit linear decoding. Using quasi-cyclic matrices in designing QO-STBC systems require that the codes should be rotated to reasonably separate one code from another such that error floor in the design can be minimized. It will be shown that, orthogonalizing the secondary codes and then imposing the Hadamard criteria that the scheme can be well diagonalized. The results of this simplified approach demonstrate full diversity and better performance than the interference-free QO-STBC. Results show about 4 dB gain with respect to the traditional QO-STBC scheme and performs alike with the earlier Hadamard based QO-STBC designed with rotation. These results achieve the consequent mathematical proposition of the Hadamard matrix and its property also shown in this study

OFDM systems design using harmonic wavelets

Orthogonal frequency-division multiplexing (OFDM) is a popular multi-carrier technique used in many digital communication systems such as wireless fidelity (Wi-Fi), long term evolution (LTE) and power line communication systems. It can be designed using fast Fourier transform (FFT) or wavelet transform (WT). The major drawback in using WT is that it is computationally inefficient. In this study, we introduce a simple and computationally efficient WT, harmonic wavelet transform, for OFDM signal processing. The new WT uses the orthogonal basis functions of conventional FFT-OFDM except that it involves translation and dilation of the input signal; the new wavelets is referred to as harmonic wavelets (HW). When compared with pilot-assisted OFDM system in terms of reduction in the peak-to-average power ratio, the results show that HW-OFDM outperforms FFT-OFDM by 3 dB at 10−4 CCDF (complementary cumulative distribution function). Over Rayleigh fading channel with additive white Gaussian noise (AWGN), the bit error ratio of both FFT-OFDM and HW-OFDM perfectly matched, showing that the proposed HW-OFDM is better in terms of peak-to-average power ratio reduction

Meningkatkan Hasil Belajar Siswa pada Materi Pewarisan Sifat melalui Pembelajaran Direct Instruction di SMP

: This study aims to determine the learning outcome model through direct instruction . This research is a classroom action research by providing research on the subject of action in two cycles of learning . Subjects in this study were students of class IX A SMP Negeri 1 Ledo academic year 2014/2015 . The data collection used observation sheet teaching practices and student achievement test cycle I and II . The results showed that the direct learning model of instruction in the material of heredity can increase the average value of learning outcomes in the first cycle of 63.7 and the second cycle of 72. The learning process of the two cycles have increased as much as 85