Northeastern State University

About: Northeastern State University is a education organization based out in Tahlequah, Oklahoma, United States. It is known for research contribution in the topics: Wireless sensor network & Computer science. The organization has 477 authors who have published 831 publications receiving 21482 citations. The organization is also known as: NSU.

Evaluation of a clinical aberrometer for lower-order accuracy and repeatability, higher-order repeatability, and instrument myopia

Abstract: Background Refractive surgery has stimulated the development of aberrometers, which are instruments that measure higher-order aberrations The purpose of this study was to test one clinical aberrometer, the Complete Ophthalmic Analysis System (COAS), for its accuracy, repeatability, and instrument myopia for measuring sphere and astigmatism and its repeatability for measuring higher-order aberrations Methods Aberrations of 56 normal eyes (28 subjects) were measured with and without cycloplegia using a COAS, a conventional autorefractor and by subjective refraction We evaluated lower-order accuracy (sphere and astigmatism) of the COAS and autorefractor by comparing that data with that of subjective refraction We also tested COAS lower- and higher-order repeatability for 5 measurements taken in less than 1 minute We evaluated instrument myopia by comparing cycloplegic and noncycloplegic measurements of the same eye Data were analyzed for a 50-mm-diameter pupil Results Mean COAS spherical error was between –01 and +04 diopters (D), depending on cycloplegia and the kind of sphere power computation selected Cylinder power errors were less than 01 D COAS repeatability coefficients were better than 025 D, and instrument myopia was less than 04 D These were comparable with those of autorefraction Higher-order repeatability was sufficient to allow reliable measurement of normal third-order aberrations and spherical aberration Conclusions Accuracy, repeatability, and instrument myopia of the COAS are similar to those of a conventional autorefractor Accuracy and repeatability are also similar to those of subjective refraction Like an autorefractor, the COAS provides instantaneous, objective measurements of sphere and astigmatism, but it also measures higher-order aberrations We found that it is capable of reliably measuring problematic higher-order aberrations and is therefore a valuable asset for modern clinical eye care

An Adaptive Collection Scheme-Based Matrix Completion for Data Gathering in Energy-Harvesting Wireless Sensor Networks

Abstract: Advanced communications and networks greatly enhance the user experience and have a major impact on all aspects of people’s lifestyles. Widely deployed sensor nodes provide support for these services. However, although energy harvesting and transfer technology provides a solution to allow the long-term survival of wireless sensor nodes for wireless sensor networks, the single collection scheme causes a lot of energy waste. Thus, efficient energy utilization and fast data collection are still serious challenges for energy harvesting wireless sensor networks. To overcome these challenges, an adaptive collection scheme based on matrix completion (ACMC) is proposed to reduce delay and to improve the energy utilization of the network. In the ACMC scheme, compared with traditional data collection schemes, the data collection schemes vary with the available energy, collecting large amounts of data when the available energy is sufficient to obtain high-quality data-based applications. Otherwise, adaptive selecting the collected data based on previously collected data, the amount of data collected can be effectively reduced based on the application requirements, thereby improving the energy utilization of the network. The ACMC scheme also proposes a method for reducing the delay by increasing the duty cycle of the nodes that are far from the CC. At the same time, the transmission reliability of these nodes increases due to the increase in the transmission frequency. Thus, the ACMC scheme can also further reduce the delay of the network. The experimental results of the ACMC scheme in planar networks show better performance than the traditional data collection schemes and can improve the energy utilization of the network by 4.26%–6.68% while reducing the maximum delay by 9.4%.

Computerized general management games as strategic management learning environments

Abstract: The strategic management course continues to experience the greatest use of general, top management business games, and a number of games are available to the strategic management instructor Many are classical in their design, whereas others are of more recent vintage. Because the field of strategic management has changed dramatically from its beginnings in the late 1950s, a representative sample of games was examined based on their ability to service both the field's current knowledge domain and its unique analytical tools and devices. Depending on the instructor's desired learning outcomes, some games are more capable than others in accomplishing those results. No game provided perfect coverage of the strategic management field, thereby requiring the use of compensatory activities on the instructor's part.

A Trust-Based Secure Routing Scheme Using the Traceback Approach for Energy-Harvesting Wireless Sensor Networks

Abstract: The Internet of things (IoT) is composed of billions of sensing devices that are subject to threats stemming from increasing reliance on communications technologies. A Trust-Based Secure Routing (TBSR) scheme using the traceback approach is proposed to improve the security of data routing and maximize the use of available energy in Energy-Harvesting Wireless Sensor Networks (EHWSNs). The main contributions of a TBSR are (a) the source nodes send data and notification to sinks through disjoint paths, separately; in such a mechanism, the data and notification can be verified independently to ensure their security. (b) Furthermore, the data and notification adopt a dynamic probability of marking and logging approach during the routing. Therefore, when attacked, the network will adopt the traceback approach to locate and clear malicious nodes to ensure security. The probability of marking is determined based on the level of battery remaining; when nodes harvest more energy, the probability of marking is higher, which can improve network security. Because if the probability of marking is higher, the number of marked nodes on the data packet routing path will be more, and the sink will be more likely to trace back the data packet routing path and find malicious nodes according to this notification. When data packets are routed again, they tend to bypass these malicious nodes, which make the success rate of routing higher and lead to improved network security. When the battery level is low, the probability of marking will be decreased, which is able to save energy. For logging, when the battery level is high, the network adopts a larger probability of marking and smaller probability of logging to transmit notification to the sink, which can reserve enough storage space to meet the storage demand for the period of the battery on low level; when the battery level is low, increasing the probability of logging can reduce energy consumption. After the level of battery remaining is high enough, nodes then send the notification which was logged before to the sink. Compared with past solutions, our results indicate that the performance of the TBSR scheme has been improved comprehensively; it can effectively increase the quantity of notification received by the sink by 20%, increase energy efficiency by 11%, reduce the maximum storage capacity needed by nodes by 33.3% and improve the success rate of routing by approximately 16.30%.