Search results for "PLE"
showing 10 items of 22773 documents
How and Why to Start and Run a SIGCHI Local Chapter
2015
There is a vast and increasing interest towards local HCI communities around the globe and in particular on geographical areas in which HCI has only recently started to gain increasing interest by local industries as well as academic institutions. A SIGCHI Local Chapter is one of the ways a local HCI community can organize and get visibility and support for their activities. However, many active volunteers in this field might not be aware of this possibility. The main goal of the Chapters' SIG in CHI'15 is to inform interested parties of SIGCHI Local Chapters and to find ways in which SIGCHI could better support local HCI communities with their various needs all over the world.
Value Creation and Evolution of a Value Network: A Longitudinal Case Study on a Platform-as-a-Service Provider
2014
Current research on cloud computing emphasizes the important role of Platform-as-a-Service (PaaS) providers. However, little is known about how PaaS providers can offer value to the content providers and firms operating the platform. The findings demonstrate how a small PaaS provider in the cloud gaming market was able to develop a strong position in the value network by offering direct and indirect value to its partners. The findings also reveal how the firm developed its value network over fourteen years, from a complex network with several actors to a very simple value network which included only partners of prime importance. peerReviewed
Linear fusion of interrupted reports in cooperative spectrum sensing for cognitive radio networks
2015
Interrupted reporting has recently been introduced as an effective method to increase the energy efficiency of cooperative spectrum sensing schemes in cognitive radio networks. In this paper, joint optimization of the reporting and fusion phases in a cooperative sensing with interrupted reporting is considered. This optimization aims at finding the best weights used at the fusion center to construct a linear fusion of the received interrupted reports, jointly with Bernoulli distributions governing the statistical behavior of the interruptions. The problem is formulated by using the deflection criterion and as a nonconvex quadratic program which is then solved for a suboptimal solution, in a…
Reduced Order Models for Pricing European and American Options under Stochastic Volatility and Jump-Diffusion Models
2017
Abstract European options can be priced by solving parabolic partial(-integro) differential equations under stochastic volatility and jump-diffusion models like the Heston, Merton, and Bates models. American option prices can be obtained by solving linear complementary problems (LCPs) with the same operators. A finite difference discretization leads to a so-called full order model (FOM). Reduced order models (ROMs) are derived employing proper orthogonal decomposition (POD). The early exercise constraint of American options is enforced by a penalty on subset of grid points. The presented numerical experiments demonstrate that pricing with ROMs can be orders of magnitude faster within a give…
Reduced Order Models for Pricing American Options under Stochastic Volatility and Jump-diffusion Models
2016
American options can be priced by solving linear complementary problems (LCPs) with parabolic partial(-integro) differential operators under stochastic volatility and jump-diffusion models like Heston, Merton, and Bates models. These operators are discretized using finite difference methods leading to a so-called full order model (FOM). Here reduced order models (ROMs) are derived employing proper orthogonal decomposition (POD) and non negative matrix factorization (NNMF) in order to make pricing much faster within a given model parameter variation range. The numerical experiments demonstrate orders of magnitude faster pricing with ROMs. peerReviewed
Iterative Methods for Pricing American Options under the Bates Model
2013
We consider the numerical pricing of American options under the Bates model which adds log-normally distributed jumps for the asset value to the Heston stochastic volatility model. A linear complementarity problem (LCP) is formulated where partial derivatives are discretized using finite differences and the integral resulting from the jumps is evaluated using simple quadrature. A rapidly converging fixed point iteration is described for the LCP, where each iterate requires the solution of an LCP. These are easily solved using a projected algebraic multigrid (PAMG) method. The numerical experiments demonstrate the efficiency of the proposed approach. Furthermore, they show that the PAMG meth…
Super-fit and population size reduction in compact Differential Evolution
2011
Although Differential Evolution is an efficient and versatile optimizer, it has a wide margin of improvement. During the latest years much effort of computer scientists studying Differential Evolution has been oriented towards the improvement of the algorithmic paradigm by adding and modifying components. In particular, two modifications lead to important improvements to the original algorithmic performance. The first is the super-fit mechanism, that is the injection at the beginning of the optimization process of a solution previously improved by another algorithm. The second is the progressive reduction of the population size during the evolution of the population. Recently, the algorithm…
Mobile Banking Services Continuous Usage -- Case Study of Finland
2016
Finland is at the forefront of using new information systems, such as mobile banking (m-banking). The present study develops and tests a model of continuous usage intentions toward m-banking services for a sample of 273 Finnish m-banking users. Results confirm the hypothesized direct relationships between self-congruence and perceived value, perceived risk and perceived value, perceived value and continuous usage, and continuous usage and word of mouth. The frequency of usage of m-banking services and experience moderate the relationship between perceived value and continuous usage. We discuss the theoretical and managerial implications of the study results and present recommendations for f…
BioImageXD: an open, general-purpose and high-throughput image-processing platform
2012
BioImageXD puts open-source computer science tools for three-dimensional visualization and analysis into the hands of all researchers, through a user-friendly graphical interface tuned to the needs of biologists. BioImageXD has no restrictive licenses or undisclosed algorithms and enables publication of precise, reproducible and modifiable workflows. It allows simple construction of processing pipelines and should enable biologists to perform challenging analyses of complex processes. We demonstrate its performance in a study of integrin clustering in response to selected inhibitors.
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…