Search results for "Time"
showing 10 items of 12336 documents
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
An efficient cluster-based outdoor user positioning using LTE and WLAN signal strengths
2015
In this paper we propose a novel cluster-based RF fingerprinting method for outdoor user-equipment (UE) positioning using both LTE and WLAN signals. It uses a simple cost effective agglomerative hierarchical clustering with Davies-Bouldin criterion to select the optimal cluster number. The positioning method does not require training signature formation prior to UE position estimation phase. It is capable of reducing the search space for clustering operation by using LTE cell-ID searching criteria. This enables the method to estimate UE positioning in short time with less computational expense. To validate the cluster-based positioning real-time field measurements were collected using readi…
Using Video Conferencing and Video Recordings for Upper Secondary Distance Teaching: Teachers' View Points
2016
In Finland the “Isoverstas” (formely ISOverkosto) network of schools coordinates the development of upper secondary distance learning services. The community actually is quite extensive with 65 member schools. In this paper we introduce the results related using synchronous and asynchronous online video resources for distance teaching. The topic is approached broadly at the level of schools and different support services as well as the pedagogical practices of individual teachers. The research data consists of wiki stories written by teachers, the interviews of selected teachers, and an online survey. Data-based content analysis was chosen as the main analysis method with the aim of highlig…
An Information System Design Product Theory for Integrated Order, Transportation and Warehouse Management Systems
2013
Globalization, lead time reduction and cost pressures, and other factors make it nontrivial for most companies to devise and manage effective logistics services to meet client requirements. They are better off using the services of specialized third party logistics service providers. These providers compete fiercely and need to develop and improve their services continuously to gain competitive advantage. Integrating the logistics process for improving communication and coordination is the most feasible way for third party logistics providers to deal with these pressures. Yet, the extant literature provides little theoretical guidance for integrating the logistics life-cycle, including orde…
LOCAL CONTROL OF SOUND IN STOCHASTIC DOMAINS BASED ON FINITE ELEMENT MODELS
2011
A numerical method for optimizing the local control of sound in a stochastic domain is developed. A three-dimensional enclosed acoustic space, for example, a cabin with acoustic actuators in given locations is modeled using the finite element method in the frequency domain. The optimal local noise control signals minimizing the least square of the pressure field in the silent region are given by the solution of a quadratic optimization problem. The developed method computes a robust local noise control in the presence of randomly varying parameters such as variations in the acoustic space. Numerical examples consider the noise experienced by a vehicle driver with a varying posture. In a mod…
An Approach for Network Outage Detection from Drive-Testing Databases
2012
A data-mining framework for analyzing a cellular network drive testing database is described in this paper. The presented method is designed to detect sleeping base stations, network outage, and change of the dominance areas in a cognitive and self-organizing manner. The essence of the method is to find similarities between periodical network measurements and previously known outage data. For this purpose, diffusion maps dimensionality reduction and nearest neighbor data classification methods are utilized. The method is cognitive because it requires training data for the outage detection. In addition, the method is autonomous because it uses minimization of drive testing (MDT) functionalit…
Efficient Time Integration of Maxwell's Equations with Generalized Finite Differences
2015
We consider the computationally efficient time integration of Maxwell’s equations using discrete exterior calculus (DEC) as the computational framework. With the theory of DEC, we associate the degrees of freedom of the electric and magnetic fields with primal and dual mesh structures, respectively. We concentrate on mesh constructions that imitate the geometry of the close packing in crystal lattices that is typical of elemental metals and intermetallic compounds. This class of computational grids has not been used previously in electromagnetics. For the simulation of wave propagation driven by time-harmonic source terms, we provide an optimized Hodge operator and a novel time discretizati…
Fall Detection Using Location Sensors and Accelerometers
2015
The rapid aging of the world's population is driving the development of pervasive solutions for elder care. These solutions, which often involve fall detection with accelerometers, are accurate in laboratory conditions but can fail in some real-life situations. To overcome this, the authors present the Confidence system, which detects falls mainly with location sensors. A user wears one to four tags. By detecting tag locations with sensors, the system can recognize the user's activity, such as falling and then lying down afterward, as well as the context in terms of the location in the home. The authors used a scenario consisting of events difficult to recognize as falls or nonfalls to comp…
Towards Computer-based Exams in CS1
2017
Even though IDEs are often a central tool when learning to program in CS1, many teachers still lean on paper-based exams. In this study, we examine the “test mode effect” in CS1 exams using the Rainfall problem. The test mode was two-phased. Half of the participants started working on the problem with pen and paper, while the other half had access to an IDE. After submitting their solution, all students could rework their solution on an IDE. The experiment was repeated twice during subsequent course instances. The results were mixed. From the marking perspective, there was no statistically significant difference resulting from the mode. However, the students starting with the paper-based pa…
Does the Learning Channel Really Matter? - Insights from Commercial Online ICT-training
2017
Evolving ICT has provided new options to participate to training. Online participation has been found to be cost effective, helping people to deal with the time and cost pressures they are facing on their jobs. Previous studies conducted in higher education sector indicates that student satisfaction or learning outcomes does not differ between online and classroom participants. However, little is known what is the situation in commercial ICT-training. This paper studied course feedbacks from courses having both online and classroom participants of a commercial ICT-training provider. Results revealed that the learning channel has no effect on satisfaction, perceived teacher’s substance and t…