Search results for " Stre"
showing 10 items of 6379 documents
On the Students' QoS-Awareness of Video Lectures
2016
Video lectures bring flexibility and enable distance learning in education. With the help of videos, educational organizations are able to serve a wider and more heterogeneous group of students. As streaming videos have become essential part of teaching in higher education, quality of service (QoS) issues should be taken more into consideration. However, systematic quality monitoring of video lecture delivery, to our knowledge, is rarely used in a way that would provide also the student with quality information. This paper describes our ongoing research on developing a streaming video quality evaluation tool integrated in a learning environment that our master’s students use. The tool serve…
H.264 QoS and Application Performance with Different Streaming Protocols
2015
Streaming techniques, including the selected streaming protocol, have an effect on the streaming quality. In this study, the performance of three different streaming protocols in a disturbed communication channel is evaluated with a modified version of the FFPlay player. A H.264 encoded video is used as a test sequence. The number of displayed image frames, the frame rate and playout duration are used as objective metrics for QoS. The metrics brings out differences of streaming protocols in our test environment. They are measured at the application level and have a connection to the user experience. peerReviewed
Software Renting in the Era of Cloud Computing
2012
In the new era of computing, software can be sold and delivered as a cloud service, and software renting has become as a strategic tool to compete in the market. Software renting has several advantages from the customer's point of view. However, for software providers it is challenging to ensure a profitable revenue stream when a license fee is replaced by a periodic rental fee. In this study, software renting was found to help the case firms to differentiate themselves from competitors; it also increased their competitive advantage by making the software available for a larger customer group. However, the negotiating power of larger customers impacted on software pricing, rental agreements…
Modelling Recurrent Events for Improving Online Change Detection
2016
The task of online change point detection in sensor data streams is often complicated due to presence of noise that can be mistaken for real changes and therefore affecting performance of change detectors. Most of the existing change detection methods assume that changes are independent from each other and occur at random in time. In this paper we study how performance of detectors can be improved in case of recurrent changes. We analytically demonstrate under which conditions and for how long recurrence information is useful for improving the detection accuracy. We propose a simple computationally efficient message passing procedure for calculating a predictive probability distribution of …
Scalable implementation of dependence clustering in Apache Spark
2017
This article proposes a scalable version of the Dependence Clustering algorithm which belongs to the class of spectral clustering methods. The method is implemented in Apache Spark using GraphX API primitives. Moreover, a fast approximate diffusion procedure that enables algorithms of spectral clustering type in Spark environment is introduced. In addition, the proposed algorithm is benchmarked against Spectral clustering. Results of applying the method to real-life data allow concluding that the implementation scales well, yet demonstrating good performance for densely connected graphs. peerReviewed
Effects of Temperature and Humidity on Radio Signal Strength in Outdoor Wireless Sensor Networks
2015
Many wireless sensor networks operating outdoors are exposed to changing weather conditions, which may cause severe degradation in system performance. Therefore, it is essential to explore the factors affecting radio link quality in order to mitigate their impact and to adapt to varying conditions. In this paper, we study the effects of temperature and humidity on radio signal strength in outdoor wireless sensor networks. Experimental measurements were performed using Atmel ZigBit 2.4GHz wireless modules, both in summer and wintertime. We employed all the radio channels specified by IEEE 802.15.4 for 2.4GHz ISM frequency band with two transmit power levels. The results show that changes in …
Video Streaming and Internalized Surveillance
2018
This paper aims to develop knowledge about the complicated ways in which the modern individual uses surveillance (techniques) and the ways surveillance uses the individual. My observational analysis of a videostreaming community reveals the central role that surveillance plays in participating and becoming visible in an online environment. The results show that through disciplinary and lateral surveillance, participants produced context-defined I-narrations and formed themselves following the normative judgment of the environment. The same mechanism may be observed in other videostreaming social media environments and the modern social media-saturated society in general. This is an inconspi…
Social support in the workplace for physicians in specialization training
2018
ABSTRACT When becoming a specialist, learning-through-service plays a significant role. The workplace affords good opportunities for learning, but the service-learning period may also impose stress on phycisians in specialization training. In medical work, social support has proved to be a very important factor in managing stress. Social support may afford advantages also for learning and professional identity building. However, little was known about how social support is perceived by doctors in specialization training. This study aimed to understand the perceptions of physicians in specialization training regarding social support communication in their workplace during their learning-thro…
Characterization of lignin enforced tannin/furanic foams
2020
Worldwide, tons of lignin is produced annually in pulping plants and it is mainly considered as a waste material. Usually lignin is burned to produce energy for the pulping reactors. The production of value-added materials from renewable materials like lignin, has proved to be challenging. In this study, the effects of addition of three different types of lignin in the production of tannin/furanic foams is investigated. The foams were matured, first at 373 K and finally carbonized at 1073 K and the properties of them including mechanical strength, specific surface area and pore development are investigated before and after thermal treatment. According to the results, higher mechanical stren…