1,720,986 research outputs found
Optimized Irrigation system for Water conservation using WSN Systems
No full textFarms, both public and private, make up the largest irrigated crop in Saudi Arabia by surface area. Although there have been improvements in sprinkler head technology and weather assimilation, state-of-the-art irrigation systems do nothing to adjust for heterogeneous terrain or varying crop environments. In this work, a computationally lightweight soil moisture movement model is developed, which allows the computation of optimal irrigation valve scheduling using standard optimization techniques. A prototype sensor system is produced with the ability to sense local soil moisture conditions, wirelessly communicate, and independently actuate based on the optimal schedule is centrally computed. This prototype could then be deployed to control a parallel irrigation systems covering a total of more than 10,000 ft2. It is shown that crop health can be maintained by using the topography of the space to take advantage of runoff to provide improved coverage while using an average of 23.4% less water. We also show that the initial capital and operating costs of our system could be amortized by our water savings in 13 months while maintaining and/or improving quality of irrigation and crop health
Crash Alert System
No full textThere is a growing number of fatalities due to car accidents in the United States. An influential indicator of survival rates is the time between the occurrence of the accident and the arrival of emergency responders to the scene. Reductions in this time may decrease the numbers of fatalities. Therefore, we want to build an Arduino-based warning system that gives visual and audio warning to drivers before collision. If the driver fails to avoid collision, the alert system is triggered and will alert authorities. Sensors and the accelerometer will determine if an accident occurred via text, email or phone call. With rising deaths associated with car accidents, responding swift can curve this alarming trend
A Study on the Performance of IEEE 802.16-2004 Includes STBC
Full text linkThis generation and coming generations depend entirely on wireless communication, where mobile communication is essential. The consumers want more efficiency, convenience, and user friendliness without losing performance. There has been an exponential growth for high speed broadband and more efficient and productive products are in production. The challenge is to produce more high speed, performance, mobile and nature friendly alternatives for the users. The solution for these requirements may just be WiMAX (Worldwide Interoperability for Microwave Access). WiMAX is a Broadband Wireless Access (BWA) technology that offers service to individuals and groups in sub-channels. In this experiment, our objective is to examine the performance of IEEE 802.16-2004 including the Multiple-Input Single-Output (MISO) and Space-Time Block Coding (STBC). We discovered the rate of data transmission is being increased in particular models. For example, 64 QAM ¾ is very efficient for particular ranges of bandwidths
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Structure-based modeling of head -related transfer functions towards interactive customization of binaural sound systems
No full textOne of the most popular techniques for creating spatialized virtual sounds is based on the use of Head-Related Transfer Functions (HRTFs). HRTFs are signal processing models that represent the modifications undergone by the acoustic signal as it travels from a sound source to each of the listener\u27s eardrums. These modifications are due to the interaction of the acoustic waves with the listener\u27s torso, shoulders, head and pinnae, or outer ears. As such, HRTFs are somewhat different for each listener. For a listener to perceive synthesized 3-D sound cues correctly, the synthesized cues must be similar to the listener\u27s own HRTFs. One can measure individual HRTFs using specialized recording systems, however, these systems are prohibitively expensive and restrict the portability of the 3-D sound system. HRTF-based systems also face several computational challenges. This dissertation presents an alternative method for the synthesis of binaural spatialized sounds. The sound entering the pinna undergoes several reflective, diffractive and resonant phenomena, which determine the HRTF. Using signal processing tools, such as Prony\u27s signal modeling method, an appropriate set of time delays and a resonant frequency were used to approximate the measured Head-Related Impulse Responses (HRIRs). Statistical analysis was used to find out empirical equations describing how the reflections and resonances are determined by the shape and size of the pinna features obtained from 3D images of 15 experimental subjects modeled in the project. These equations were used to yield “Model HRTFs” that can create elevation effects. Listening tests conducted on 10 subjects show that these model HRTFs are 5% more effective than generic HRTFs when it comes to localizing sounds in the frontal plane. The number of reversals (perception of sound source above the horizontal plane when actually it is below the plane and vice versa) was also reduced by 5.7%, showing the perceptual effectiveness of this approach. The model is simple, yet versatile because it relies on easy to measure parameters to create an individualized HRTF. This low-order parameterized model also reduces the computational and storage demands, while maintaining a sufficient number of perceptually relevant spectral cues
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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