scholarly journals A Single-Hop Broadcasting Method Based on Busy Tone

2012 ◽  
Vol 6-7 ◽  
pp. 1140-1144
Author(s):  
Wen Jing Cao ◽  
Qing Tian Han ◽  
Sheng Hong Xu

Single-hop broadcasting is a basic information dissemination method. For broadcasting method, wireless channel reservation and channel state indication are two factors effecting information dissemination performance. In this paper, existing channel reservation and channel state indication mechanisms were studied, the limitations of them were analyzed, and a single–hop broadcasting method based on busy tone is proposed. With OPNET network simulation platform, the proposed broadcasting method is modeled and implemented. Experimental results show that the proposed method performs well.

2012 ◽  
Vol 6-7 ◽  
pp. 1135-1139
Author(s):  
Wen Jing Cao ◽  
Qing Tian Han ◽  
Sheng Hong Xu

When the receiving nodes are uncertain or the topology of the ad hoc network is high dynamic, broadcasting is an effective data dissemination method. In this research, a broadcasting method based on busy tone is modeled and implemented with the network simulation platform OPNET, and the performance of the broadcasting method is analyzed based on experimental results. Experimental results show that, in the network with various load, performance of the broadcasting method based on busy tone is good.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2143
Author(s):  
Chunzhi Hou ◽  
Zhensen Wu ◽  
Jiaji Wu ◽  
Yunhua Cao ◽  
Leke Lin ◽  
...  

Deterministic channel models, such as the three-dimensional (3D) ray launching method, can yield wireless channel parameters. In the non-line-of-sight (NLOS) propagation, the outdoor 3D ray launching method that considers diffraction effects is more accurate than the one that does not. While considering the diffraction effect, obtaining the diffraction point is challenging. This paper proposed a method for determining diffracted rays using the receiving sphere method in 3D ray launching. The diffraction point is determined using the shortest distance method between two straight lines, and the signal loss from the transmitting to receiving antennas is obtained. Furthermore, experiments on a millimeter wave in a microcell scenario were performed. The test results of the wireless channel parameters were compared with theoretical calculations. The results obtained via the 3D ray launching method that only considers the specular reflection and direct rays agree with the experimental results in the line-of-sight (LOS); furthermore, they generate larger errors compared with the experimental results in the NLOS. The results obtained via the 3D ray launching method that considers the direct ray, reflected rays, and diffracted rays agree with the experimental results both in the LOS and NLOS. Therefore, the 3D ray launching method that considers the diffraction effect can improve the prediction accuracy of the millimeter wave channel parameters in a microcell.


Phonology ◽  
2020 ◽  
Vol 37 (3) ◽  
pp. 383-418
Author(s):  
Shigeto Kawahara

An experiment showed that Japanese speakers’ judgement of Pokémons’ evolution status on the basis of nonce names is affected both by mora count and by the presence of a voiced obstruent. The effects of mora count are a case of counting cumulativity, and the interaction between the two factors a case of ganging-up cumulativity. Together, the patterns result in what Hayes (2020) calls ‘wug-shaped curves’, a quantitative signature predicted by MaxEnt. I show in this paper that the experimental results can indeed be successfully modelled with MaxEnt, and also that Stochastic Optimality Theory faces an interesting set of challenges. The study was inspired by a proposal made within formal phonology, and reveals important previously understudied aspects of sound symbolism. In addition, it demonstrates how cumulativity is manifested in linguistic patterns. The work here shows that formal phonology and research on sound symbolism can be mutually beneficial.


2017 ◽  
Vol 13 (4) ◽  
pp. 408-418 ◽  
Author(s):  
Mustafa S. Aljumaily ◽  
Ghaida A. Al-Suhail

Purpose Recently, many researches have been devoted to studying the possibility of using wireless signals of the Wi-Fi networks in human-gesture recognition. They focus on classifying gestures despite who is performing them, and only a few of the previous work make use of the wireless channel state information in identifying humans. This paper aims to recognize different humans and their multiple gestures in an indoor environment. Design/methodology/approach The authors designed a gesture recognition system that consists of channel state information data collection, preprocessing, features extraction and classification to guess the human and the gesture in the vicinity of a Wi-Fi-enabled device with modified Wi-Fi-device driver to collect the channel state information, and process it in real time. Findings The proposed system proved to work well for different humans and different gestures with an accuracy that ranges from 87 per cent for multiple humans and multiple gestures to 98 per cent for individual humans’ gesture recognition. Originality/value This paper used new preprocessing and filtering techniques, proposed new features to be extracted from the data and new classification method that have not been used in this field before.


2014 ◽  
Vol 596 ◽  
pp. 292-296
Author(s):  
Xin Li Li

PageRank algorithms only consider hyperlink information, without other page information such as page hits frequency, page update time and web page category. Therefore, the algorithms rank a lot of advertising pages and old pages pretty high and can’t meet the users' needs. This paper further studies the page meta-information such as category, page hits frequency and page update time. The Web page with high hits frequency and with smaller age should get a high rank, while the above two factors are more or less dependent on page category. Experimental results show that the algorithm has good results.


2005 ◽  
Vol 05 (01) ◽  
pp. 135-148 ◽  
Author(s):  
QIBIN SUN ◽  
SHUIMING YE ◽  
CHING-YUNG LIN ◽  
SHIH-FU CHANG

With the ambient use of digital images and the increasing concern on their integrity and originality, consumers are facing an emergent need of authenticating degraded images despite lossy compression and packet loss. In this paper, we propose a scheme to meet this need by incorporating watermarking solution into traditional cryptographic signature scheme to make the digital signatures robust to these image degradations. Due to the unpredictable degradations, the pre-processing and block shuffling techniques are applied onto the image at the signing end to stabilize the feature extracted at the verification end. The proposed approach is compatible with traditional cryptographic signature scheme except that the original image needs to be watermarked in order to guarantee the robustness of its derived digital signature. We demonstrate the effectiveness of this proposed scheme through practical experimental results.


1979 ◽  
Vol 25 (3) ◽  
pp. 429-431 ◽  
Author(s):  
R S Schifreen ◽  
R W Burnett

Abstract We re-examined the effects of wavelength error and spectral band width on the measurement of alkaline phosphatase activity. The methods we studied is relatively insensitive to these two factors, a conclusion we base on both experimental results and theoretical analysis. These findings are in conflict with a recently published report [Lott et al., Clin. Chem. 24, 938 (1978)], and we suggest a possible explanation for this.


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