Fine-Grained Frequencies Meet Synchronous Transmission

<div>Fine-grained frequencies have been used in several recent works to enhance network throughput as well as combat Cross Technology Interference (CTI) issues in licence free ISM bands. We observe that synchronous communication based strategies, due to the scope of inter-frequency capture-effect, are inherently more capable of supporting in-parallel communication over multiple channels even when the Center Frequency Distance (CFD) of the channels are very low (<5 MHz). In this work, we pursue an in-depth study of how fine-grained frequencies can be used in conjunction with synchronous communication to extract the maximum benefit from a very narrow band of available frequencies (e.g., 2- 5 MHz) for in-parallel intra-group communication. In this direction, we propose a simple and efficient group formation strategy to automatically define groups in a given WSN/IoT network to boost up in-parallel intra-group communication efficiency. Through extensive experimental evaluations in existing WSN/IoT testbeds, we show that in-parallel one-to-all dissemination in the groups formed through the proposed strategy can execute with upto 73% higher reliability while consuming upto 41% lower energy as compared to the same running among the groups formed through naive strategy with only 4 consecutive frequencies separated by 1 MHz and upto 20 groups.</div>

Fine-Grained Frequencies Meet Synchronous Transmission

<div>Fine-grained frequencies have been used in several recent works to enhance network throughput as well as combat Cross Technology Interference (CTI) issues in licence free ISM bands. We observe that synchronous communication based strategies, due to the scope of inter-frequency capture-effect, are inherently more capable of supporting in-parallel communication over multiple channels even when the Center Frequency Distance (CFD) of the channels are very low (<5 MHz). In this work, we pursue an in-depth study of how fine-grained frequencies can be used in conjunction with synchronous communication to extract the maximum benefit from a very narrow band of available frequencies (e.g., 2- 5 MHz) for in-parallel intra-group communication. In this direction, we propose a simple and efficient group formation strategy to automatically define groups in a given WSN/IoT network to boost up in-parallel intra-group communication efficiency. Through extensive experimental evaluations in existing WSN/IoT testbeds, we show that in-parallel one-to-all dissemination in the groups formed through the proposed strategy can execute with upto 73% higher reliability while consuming upto 41% lower energy as compared to the same running among the groups formed through naive strategy with only 4 consecutive frequencies separated by 1 MHz and upto 20 groups.</div>

Fine-Grained Frequencies Meet Synchronous Transmission

<div>Fine-grained frequencies have been used in several recent works to enhance network throughput as well as combat Cross Technology Interference (CTI) issues in licence free ISM bands. We observe that synchronous communication based strategies, due to the scope of inter-frequency capture-effect, are inherently more capable of supporting in-parallel communication over multiple channels even when the Center Frequency Distance (CFD) of the channels are very low (<5 MHz). In this work, we pursue an in-depth study of how fine-grained frequencies can be used in conjunction with synchronous communication to extract the maximum benefit from a very narrow band of available frequencies (e.g., 2- 5 MHz) for in-parallel intra-group communication. In this direction, we propose a simple and efficient group formation strategy to automatically define groups in a given WSN/IoT network to boost up in-parallel intra-group communication efficiency. Through extensive experimental evaluations in existing WSN/IoT testbeds, we show that in-parallel one-to-all dissemination in the groups formed through the proposed strategy can execute with upto 73% higher reliability while consuming upto 41% lower energy as compared to the same running among the groups formed through naive strategy with only 4 consecutive frequencies separated by 1 MHz and upto 20 groups.</div>

Performance evaluation of a WISP for the 2.4GHz and 5.8GHz bands supported in a factorial model

The wireless networks supported in the 802.11 standard play an important role in the field of connectivity, due to the benefits related to mobility, availability, speed and low cost of implementation. This study aims to experimentally find the factors that affect the performance of a WISP (Wireless Internet Service Provider) based on the 802.11 standard. In the proposed scenario, the behavior of the Throughput and delays in the transmission processes were analyzed based on factors such as frequency, distance and the number of stations connected to the Access point under study. In the results obtained, it was possible to demonstrate the levels of influence that the factors mentioned above reflected in relation to the performance of the link and the available bandwidth. The proposed model can be considered as an excellent tool for the analysis of future works related to the design of WISP.

Automatic Stomatal Segmentation Based on Delaunay-Rayleigh Frequency Distance

The CO2 and water vapor exchange between leaf and atmosphere are relevant for plant physiology. This process is done through the stomata. These structures are fundamental in the study of plants since their properties are linked to the evolutionary process of the plant, as well as its environmental and phytohormonal conditions. Stomatal detection is a complex task due to the noise and morphology of the microscopic images. Although in recent years segmentation algorithms have been developed that automate this process, they all use techniques that explore chromatic characteristics. This research explores a unique feature in plants, which corresponds to the stomatal spatial distribution within the leaf structure. Unlike segmentation techniques based on deep learning tools, we emphasize the search for an optimal threshold level, so that a high percentage of stomata can be detected, independent of the size and shape of the stomata. This last feature has not been reported in the literature, except for those results of geometric structure formation in the salt formation and other biological formations.

Feasibility and Reliability of a Questionnaire to Assess the Mode, Frequency, Distance and Time of Commuting to and from School: The PACO Study

Active commuting to and from school has several health implications. Self-reporting is the most common assessment tool, but there is a high heterogeneity of questionnaires in the scientific literature. The purpose of this study was to analyse the feasibility and reliability of the Spanish “New Version of Mode and Frequency of Commuting To and From School” questionnaire in children and adolescents. A total of 635 children (5–12 years old) and 362 adolescents (12–18 years old) filled out the questionnaire twice (14 days apart). Feasibility was evaluated using an observational checklist. The test-retest reliability of the “New Version of Mode and Frequency of Commuting To and From School” questionnaire and the distance and time to school were examined using the kappa and weight kappa coefficient (κ). No misunderstanding of questions was reported. The time to complete the questionnaire was 15 ± 3.62 and 9 ± 2.26 min for children and adolescents, respectively. The questionnaire showed substantial and almost perfect kappa coefficients for the overall six items (k = 0.61–0.94) in children and adolescents. The “New Version of Mode and Frequency of Commuting To and From School” questionnaire is a feasible and reliable questionnaire in Spanish children and adolescents.

Study on Unknown Term Translation Mining from Google Snippets

Bilingual web pages are widely used to mine translations of unknown terms. This study focused on an effective solution for obtaining relevant web pages, extracting translations with correct lexical boundaries, and ranking the translation candidates. This research adopted co-occurrence information to obtain the subject terms and then expanded the source query with the translation of the subject terms to collect effective bilingual search engine snippets. Afterwards, valid candidates were extracted from small-sized, noisy bilingual corpora using an improved frequency change measurement that combines adjacent information. This research developed a method that considers surface patterns, frequency–distance, and phonetic features to elect an appropriate translation. The experimental results revealed that the proposed method performed remarkably well for mining translations of unknown terms.