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121.
Toward a theory of managing creativity-intensive processes: a creative industries study 总被引:1,自引:0,他引:1
Stefan Seidel 《Information Systems and E-Business Management》2011,9(4):407-446
This paper reports the results of an exploratory, theory-building study on the impact of creativity on business processes,
their management, and the use of information technology (IT) in particular. The empirical evidence was derived from organizations
within the creative industries, specifically film and visual effects (VFX) production. An adapted grounded theory approach
was employed in order to analyze the data. The study identifies the dynamics of business processes that can be described as
highly dependent on creativity, intensively involving the client, complex, and interdependent. It explains the processes’
organizational context as well as strategies and IT systems that organizations use in order to manage these processes. The
study suggests that creativity-intensive processes are characterized by high levels of uncertainty with regard to outcome,
process structure, and required resources. Creative organizations pursue both creative and operational process performance
while simultaneously mitigating creative and operational risk. 相似文献
122.
This paper deals with an approach allowing to associate visual textures with given human perceptions. Hereby, based on a forward model associating human perceptions for given visual textures, the deduction of an reverse process is presented which is able to associate and characterize visual textures for given human perceptions. For doing so, we propose a constraint-based genetic algorithm approach, which is able to minimize a specific optimization problem containing constraints in form of band-widths for valid individuals (low level features extracted from textures) in a population. The constraints are determined by relationships between (low level) features characterizing textures in form of high-dimensional approximation models. Additionally, in each iteration step checking for valid individuals is carried out with a texture/non-texture classifier or by using a convex hull over a set of valid textures. The whole approach is evaluated based on a real-world texture set used as a start population in the genetic algorithm and by defining various kinds of human perceptions (for which textures are sought) represented by adjective vectors in the aesthetic space. The generated individuals (low level feature vectors) have a high level of fitness (they are quite close to the pre-defined adjective vectors) and a small distance to the initial population. The textures synthesized based on the generated individuals are visualized and compared with textures synthesized by a time-intensive direct texture mixing and re-combination method based on a real-world texture data base. 相似文献
123.
Dirk Abbeloos Moritz Diehl Michael Hinze Stefan Vandewalle 《Computing and Visualization in Science》2011,14(1):27-38
We present a nested multigrid method to optimize time-periodic, parabolic, partial differential equations (PDE). We consider
a quadratic tracking objective with a linear parabolic PDE constraint. The first order optimality conditions, given by a coupled
system of boundary value problems can be rewritten as an Fredholm integral equation of the second kind, which is solved by
a multigrid of the second kind. The evaluation of the integral operator consists of solving sequentially a boundary value
problem for respectively the state and the adjoints. Both problems are solved efficiently by a time-periodic space-time multigrid
method. 相似文献
124.
Zhengxiong Yang Stefan Kollmannsberger Alexander Düster Martin Ruess Eduardo Grande Garcia Rainer Burgkart Ernst Rank 《Computing and Visualization in Science》2011,14(5):207-216
Numerous numerical methods have been developed in an effort to accurately predict stresses in bones. The largest group are variants of the h-version of the finite element method (h-FEM), where low order Ansatz functions are used. By contrast, we3 investigate a combination of high order FEM and a fictitious domain approach, the finite cell method (FCM). While the FCM has been verified and validated in previous publications, this article proposes methods on how the FCM can be made computationally efficient to the extent that it can be used for patient specific, interactive bone simulations. This approach is called computational steering and allows to change input parameters like the position of an implant, material or loads and leads to an almost instantaneous change in the output (stress lines, deformations). This direct feedback gives the user an immediate impression of the impact of his actions to an extent which, otherwise, is hard to obtain by the use of classical non interactive computations. Specifically, we investigate an application to pre-surgical planning of a total hip replacement where it is desirable to select an optimal implant for a specific patient. Herein, optimal is meant in the sense that the expected post-operative stress distribution in the bone closely resembles that before the operation. 相似文献
125.
Mike Espig Wolfgang Hackbusch Stefan Handschuh Reinhold Schneider 《Computing and Visualization in Science》2011,14(6):271-285
We discuss the calculus of variations in tensor representations with a special focus on tensor networks and apply it to functionals of practical interest. The survey provides all necessary ingredients for applying minimization methods in a general setting. The important cases of target functionals which are linear and quadratic with respect to the tensor product are discussed, and combinations of these functionals are presented in detail. As an example, we consider the representation rank compression in tensor networks. For the numerical treatment, we use the nonlinear block Gauss?CSeidel method. We demonstrate the rate of convergence in numerical tests. 相似文献
126.
Veronika Šoltészová Daniel Patel Stefan Bruckner Ivan Viola 《Computer Graphics Forum》2010,29(3):883-891
In this paper, we present a novel technique which simulates directional light scattering for more realistic interactive visualization of volume data. Our method extends the recent directional occlusion shading model by enabling light source positioning with practically no performance penalty. Light transport is approximated using a tilted cone‐shaped function which leaves elliptic footprints in the opacity buffer during slice‐based volume rendering. We perform an incremental blurring operation on the opacity buffer for each slice in front‐to‐back order. This buffer is then used to define the degree of occlusion for the subsequent slice. Our method is capable of generating high‐quality soft shadowing effects, allows interactive modification of all illumination and rendering parameters, and requires no pre‐computation. 相似文献
127.
Consider a rooted tree T of arbitrary maximum degree d representing a collection of n web pages connected via a set of links, all reachable from a source home page represented by the root of T. Each web page i carries a probability p
i
representative of the frequency with which it is visited. By adding hotlinks—shortcuts from a node to one of its descendents—we
wish to minimize the expected number of steps l needed to visit pages from the home page, expressed as a function of the entropy H(p) of the access probabilities p. This paper introduces several new strategies for effectively assigning hotlinks in a tree. For assigning exactly one hotlink
per node, our method guarantees an upper bound on l of 1.141H(p)+1 if d>2 and 1.08H(p)+2/3 if d=2. We also present the first efficient general methods for assigning at most k hotlinks per node in trees of arbitrary maximum degree, achieving bounds on l of at most
\frac2H(p)log(k+1)+1\frac{2H(p)}{\log(k+1)}+1
and
\fracH(p)log(k+d)-logd+1\frac{H(p)}{\log(k+d)-\log d}+1
, respectively. All our methods are strong, i.e., they provide the same guarantees on all subtrees after the assignment. We also present an algorithm implementing these
methods in O(nlog n) time, an improvement over the previous O(n
2) time algorithms. Finally we prove a Ω(nlog n) lower bound on the running time of any strong method that guarantee an average access time strictly better than 2H(p). 相似文献
128.
Jianhan Zhu Xiangji Huang Dawei Song Stefan Rüger 《Knowledge and Information Systems》2010,23(1):29-54
We argue that expert finding is sensitive to multiple document features in an organizational intranet. These document features
include multiple levels of associations between experts and a query topic from sentence, paragraph, up to document levels,
document authority information such as the PageRank, indegree, and URL length of documents, and internal document structures
that indicate the experts’ relationship with the content of documents. Our assumption is that expert finding can largely benefit
from the incorporation of these document features. However, existing language modeling approaches for expert finding have
not sufficiently taken into account these document features. We propose a novel language modeling approach, which integrates
multiple document features, for expert finding. Our experiments on two large scale TREC Enterprise Track datasets, i.e., the
W3C and CSIRO datasets, demonstrate that the natures of the two organizational intranets and two types of expert finding tasks,
i.e., key contact finding for CSIRO and knowledgeable person finding for W3C, influence the effectiveness of different document
features. Our work provides insights into which document features work for certain types of expert finding tasks, and helps
design expert finding strategies that are effective for different scenarios. Our main contribution is to develop an effective
formal method for modeling multiple document features in expert finding, and conduct a systematic investigation of their effects.
It is worth noting that our novel approach achieves better results in terms of MAP than previous language model based approaches
and the best automatic runs in both the TREC2006 and TREC2007 expert search tasks, respectively. 相似文献
129.
130.
Stefan Wagner 《Information and Software Technology》2010,52(11):1230-1241
ContextSoftware quality is a complex concept. Therefore, assessing and predicting it is still challenging in practice as well as in research. Activity-based quality models break down this complex concept into concrete definitions, more precisely facts about the system, process, and environment as well as their impact on activities performed on and with the system. However, these models lack an operationalisation that would allow them to be used in assessment and prediction of quality. Bayesian networks have been shown to be a viable means for this task incorporating variables with uncertainty.ObjectiveThe qualitative knowledge contained in activity-based quality models are an abundant basis for building Bayesian networks for quality assessment. This paper describes a four-step approach for deriving systematically a Bayesian network from an assessment goal and a quality model.MethodThe four steps of the approach are explained in detail and with running examples. Furthermore, an initial evaluation is performed, in which data from NASA projects and an open source system is obtained. The approach is applied to this data and its applicability is analysed.ResultsThe approach is applicable to the data from the NASA projects and the open source system. However, the predictive results vary depending on the availability and quality of the data, especially the underlying general distributions.ConclusionThe approach is viable in a realistic context but needs further investigation in case studies in order to analyse its predictive validity. 相似文献