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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Towards modeling of retrofit processes

Szymkiewicz, Paul M. 21 September 2015 (has links)
Energy retrofits can be executed by a building owner with or without the supervision of a third-party agent. We define process models to capture third-party energy retrofit inspection activities, and refine, augment, and generalize those models to then examine the impact of third-party retrofit inspections. Buildings included in the study vary considerably in type, and so do retrofit programs applied to those buildings.
2

Making Sense of Business Process Descriptions: An Experimental Comparison of Graphical and Textual Notations

Ottensooser, Avner, Fekete, Alan, Reijers, Hajo A., Mendling, Jan, Menictas, Con 03 1900 (has links) (PDF)
How effective is a notation in conveying the writer's intent correctly? This paper identifies understandability of design notations as an important aspect which calls for an experimental comparison. We compare the success of university students in interpreting business process descriptions, for an established graphical notation (BPMN) and for an alternative textual notation (based on written use-cases). Because a design must be read by diverse communities, including technically-trained professionals such as developers and business analysts, as well as end-users and stakeholders from a wider business setting, we used different types of participants in our experiment. Specifically, we included those who had formal training in process description, and others who had not. Our experiments showed significant increases by both groups in their understanding of the process from reading the textual model. This was not so for the graphical model, where only the trained readers showed significant increases. This finding points at the value of educating readers of graphical descriptions in that particular notation when they become exposed to such models in their daily work.
3

Large-Scale Dynamic Optimization Under Uncertainty using Parallel Computing

Washington, Ian D. January 2016 (has links)
This research focuses on the development of a solution strategy for the optimization of large-scale dynamic systems under uncertainty. Uncertainty resides naturally within the external forces posed to the system or from within the system itself. For example, in chemical process systems, external inputs include flow rates, temperatures or compositions; while internal sources include kinetic or mass transport parameters; and empirical parameters used within thermodynamic correlations and expressions. The goal in devising a dynamic optimization approach which explicitly accounts for uncertainty is to do so in a manner which is computationally tractable and is general enough to handle various types and sources of uncertainty. The approach developed in this thesis follows a so-called multiperiod technique whereby the infinite dimensional uncertainty space is discretized at numerous points (known as periods or scenarios) which creates different possible realizations of the uncertain parameters. The resulting optimization formulation encompasses an approximated expected value of a chosen objective functional subject to a dynamic model for all the generated realizations of the uncertain parameters. The dynamic model can be solved, using an appropriate numerical method, in an embedded manner for which the solution is used to construct the optimization formulation constraints; or alternatively the model could be completely discretized over the temporal domain and posed directly as part of the optimization formulation. Our approach in this thesis has mainly focused on the embedded model technique for dynamic optimization which can either follow a single- or multiple-shooting solution method. The first contribution of the thesis investigates a combined multiperiod multiple-shooting dynamic optimization approach for the design of dynamic systems using ordinary differential equation (ODE) or differential-algebraic equation (DAE) process models. A major aspect of this approach is the analysis of the parallel solution of the embedded model within the optimization formulation. As part of this analysis, we further consider the application of the dynamic optimization approach to several design and operation applications. Another vmajor contribution of the thesis is the development of a nonlinear programming (NLP) solver based on an approach that combines sequential quadratic programming (SQP) with an interior-point method (IPM) for the quadratic programming subproblem. A unique aspect of the approach is that the inherent structure (and parallelism) of the multiperiod formulation is exploited at the linear algebra level within the SQP-IPM nonlinear programming algorithm using an explicit Schur-complement decomposition. Our NLP solution approach is further assessed using several static and dynamic optimization benchmark examples. / Thesis / Doctor of Philosophy (PhD)
4

Modelagem de processos de negócio : rótulos e ontologias / Business process modeling: labels and ontologies

Gassen, Jonas Bulegon January 2014 (has links)
Modelos de processo são compostos de elementos gráficos e texto. Entretanto, as palavras utilizadas para nomear os elementos durante a modelagem de processos possuem potencial ambiguidade, o que pode resultar em problemas de qualidade do modelo de processo. Ontologias são bastante citadas na literatura como possível solução para tais problemas. Um dos principais aspectos discutidos nesta tese refere-se às palavras utilizadas para representar conceitos em rótulos de elementos de processo e porque ontologias podem contribuir para melhorar essa representação. Além disso, é apresentada uma análise sobre como especificações de requisitos podem influenciar, em alguns aspectos, os rótulos utilizados durante a modelagem de processos. A discussão acerca de ontologias neste contexto é conceitual. Ademais, um experimento foi realizado para analisar empiricamente o problema do vocabulário no contexto de modelos de processo. No experimento, a seleção de termos representados com diferentes níveis de explicitação, nas especificações de requisitos, é avaliada. Os resultados sugerem que o problema do vocabulário ocorre significativamente em modelos de processo. Além disso, diferentes níveis de explicitação afetam os rótulos criados, porém não são o suficiente para resolver o problema do vocabulário. Em relação à ontologias, há uma carência de pesquisas demonstrando se esses artefatos aprimoram de fato a modelagem de processos ou os modelos de processo resultantes. Uma análise sobre estes aspectos é apresentada, a fim de verificar se as ontologias não acabam por trazer desvantagens, ex. aumentar a carga cognitiva ou causar interferência retroativa. Para tal, um protótipo de ferramenta de modelagem de processos com suporte de ontologias foi construído, o qual registra as ações dos usuários durante o projeto. O suporte utiliza uma abordagem proposta nesta tese. Um segundo experimento foi realizado utilizando tal protótipo. Os resultados sugerem que a abordagem proposta provê suporte de ontologias sem degradar a qualidade da modelagem de processos para os quesitos carga cognitiva, tempo consumido e interferência retroativa. Neste sentido, conclui-se que é possível utilizar ontologias para melhorar a modelagem de processos sem deteriorar a qualidade da modelagem, pelo menos para os aspectos verificados no experimento. / Process models are composed of graphical elements and words. However, words used to name elements during process design have potentially ambiguous meanings, which might result in quality problems. An artifact widely referred to address these problems is ontologies. One of the main aspects discussed in the current thesis are related to words used to represent concepts in labels and why ontologies can improve this representation. Also, we analyze how the requirements specifications can influence the terms used during modeling. In this point, the discussion regarding ontologies is conceptual. We performed an experiment to analyze empirically the vocabulary problem in the context of process models. In the experiment the selection of terms represented with different levels of explicitness in requirements specifications is evaluated. Our findings suggest that the vocabulary problem occurs in process models. Also, different levels of explicitness affect the labels but are not sufficient to solve the vocabulary problem. It is well known the use of ontologies, dictionaries, thesaurus and so on as a means to improve activity labels of process models, among other aspects. However, there is a lack of researches showing whether these artifacts indeed improve modeling or the resultant process models. In this paper we analyze ontology support regarding process modeling. Another main aspect of this thesis is to verify whether ontologies, while supporting modeling, do not generate drawbacks such as increasing modeler’s cognitive load or creating retroactive interference. To this end, a prototype created in this thesis, which provides ontology support for modeling and registers user actions was adapted. The ontology support follows a modeling approach proposed by us. The experiment findings suggest that the approach was able to provide ontology support without increase cognitive load and time consumption for the task. In this light, it is possible to improve process modeling with support of other artifacts without compromising the modeling task, at least for the aspects covered in the experiment.
5

Modelagem de processos de negócio : rótulos e ontologias / Business process modeling: labels and ontologies

Gassen, Jonas Bulegon January 2014 (has links)
Modelos de processo são compostos de elementos gráficos e texto. Entretanto, as palavras utilizadas para nomear os elementos durante a modelagem de processos possuem potencial ambiguidade, o que pode resultar em problemas de qualidade do modelo de processo. Ontologias são bastante citadas na literatura como possível solução para tais problemas. Um dos principais aspectos discutidos nesta tese refere-se às palavras utilizadas para representar conceitos em rótulos de elementos de processo e porque ontologias podem contribuir para melhorar essa representação. Além disso, é apresentada uma análise sobre como especificações de requisitos podem influenciar, em alguns aspectos, os rótulos utilizados durante a modelagem de processos. A discussão acerca de ontologias neste contexto é conceitual. Ademais, um experimento foi realizado para analisar empiricamente o problema do vocabulário no contexto de modelos de processo. No experimento, a seleção de termos representados com diferentes níveis de explicitação, nas especificações de requisitos, é avaliada. Os resultados sugerem que o problema do vocabulário ocorre significativamente em modelos de processo. Além disso, diferentes níveis de explicitação afetam os rótulos criados, porém não são o suficiente para resolver o problema do vocabulário. Em relação à ontologias, há uma carência de pesquisas demonstrando se esses artefatos aprimoram de fato a modelagem de processos ou os modelos de processo resultantes. Uma análise sobre estes aspectos é apresentada, a fim de verificar se as ontologias não acabam por trazer desvantagens, ex. aumentar a carga cognitiva ou causar interferência retroativa. Para tal, um protótipo de ferramenta de modelagem de processos com suporte de ontologias foi construído, o qual registra as ações dos usuários durante o projeto. O suporte utiliza uma abordagem proposta nesta tese. Um segundo experimento foi realizado utilizando tal protótipo. Os resultados sugerem que a abordagem proposta provê suporte de ontologias sem degradar a qualidade da modelagem de processos para os quesitos carga cognitiva, tempo consumido e interferência retroativa. Neste sentido, conclui-se que é possível utilizar ontologias para melhorar a modelagem de processos sem deteriorar a qualidade da modelagem, pelo menos para os aspectos verificados no experimento. / Process models are composed of graphical elements and words. However, words used to name elements during process design have potentially ambiguous meanings, which might result in quality problems. An artifact widely referred to address these problems is ontologies. One of the main aspects discussed in the current thesis are related to words used to represent concepts in labels and why ontologies can improve this representation. Also, we analyze how the requirements specifications can influence the terms used during modeling. In this point, the discussion regarding ontologies is conceptual. We performed an experiment to analyze empirically the vocabulary problem in the context of process models. In the experiment the selection of terms represented with different levels of explicitness in requirements specifications is evaluated. Our findings suggest that the vocabulary problem occurs in process models. Also, different levels of explicitness affect the labels but are not sufficient to solve the vocabulary problem. It is well known the use of ontologies, dictionaries, thesaurus and so on as a means to improve activity labels of process models, among other aspects. However, there is a lack of researches showing whether these artifacts indeed improve modeling or the resultant process models. In this paper we analyze ontology support regarding process modeling. Another main aspect of this thesis is to verify whether ontologies, while supporting modeling, do not generate drawbacks such as increasing modeler’s cognitive load or creating retroactive interference. To this end, a prototype created in this thesis, which provides ontology support for modeling and registers user actions was adapted. The ontology support follows a modeling approach proposed by us. The experiment findings suggest that the approach was able to provide ontology support without increase cognitive load and time consumption for the task. In this light, it is possible to improve process modeling with support of other artifacts without compromising the modeling task, at least for the aspects covered in the experiment.
6

Modelagem de processos de negócio : rótulos e ontologias / Business process modeling: labels and ontologies

Gassen, Jonas Bulegon January 2014 (has links)
Modelos de processo são compostos de elementos gráficos e texto. Entretanto, as palavras utilizadas para nomear os elementos durante a modelagem de processos possuem potencial ambiguidade, o que pode resultar em problemas de qualidade do modelo de processo. Ontologias são bastante citadas na literatura como possível solução para tais problemas. Um dos principais aspectos discutidos nesta tese refere-se às palavras utilizadas para representar conceitos em rótulos de elementos de processo e porque ontologias podem contribuir para melhorar essa representação. Além disso, é apresentada uma análise sobre como especificações de requisitos podem influenciar, em alguns aspectos, os rótulos utilizados durante a modelagem de processos. A discussão acerca de ontologias neste contexto é conceitual. Ademais, um experimento foi realizado para analisar empiricamente o problema do vocabulário no contexto de modelos de processo. No experimento, a seleção de termos representados com diferentes níveis de explicitação, nas especificações de requisitos, é avaliada. Os resultados sugerem que o problema do vocabulário ocorre significativamente em modelos de processo. Além disso, diferentes níveis de explicitação afetam os rótulos criados, porém não são o suficiente para resolver o problema do vocabulário. Em relação à ontologias, há uma carência de pesquisas demonstrando se esses artefatos aprimoram de fato a modelagem de processos ou os modelos de processo resultantes. Uma análise sobre estes aspectos é apresentada, a fim de verificar se as ontologias não acabam por trazer desvantagens, ex. aumentar a carga cognitiva ou causar interferência retroativa. Para tal, um protótipo de ferramenta de modelagem de processos com suporte de ontologias foi construído, o qual registra as ações dos usuários durante o projeto. O suporte utiliza uma abordagem proposta nesta tese. Um segundo experimento foi realizado utilizando tal protótipo. Os resultados sugerem que a abordagem proposta provê suporte de ontologias sem degradar a qualidade da modelagem de processos para os quesitos carga cognitiva, tempo consumido e interferência retroativa. Neste sentido, conclui-se que é possível utilizar ontologias para melhorar a modelagem de processos sem deteriorar a qualidade da modelagem, pelo menos para os aspectos verificados no experimento. / Process models are composed of graphical elements and words. However, words used to name elements during process design have potentially ambiguous meanings, which might result in quality problems. An artifact widely referred to address these problems is ontologies. One of the main aspects discussed in the current thesis are related to words used to represent concepts in labels and why ontologies can improve this representation. Also, we analyze how the requirements specifications can influence the terms used during modeling. In this point, the discussion regarding ontologies is conceptual. We performed an experiment to analyze empirically the vocabulary problem in the context of process models. In the experiment the selection of terms represented with different levels of explicitness in requirements specifications is evaluated. Our findings suggest that the vocabulary problem occurs in process models. Also, different levels of explicitness affect the labels but are not sufficient to solve the vocabulary problem. It is well known the use of ontologies, dictionaries, thesaurus and so on as a means to improve activity labels of process models, among other aspects. However, there is a lack of researches showing whether these artifacts indeed improve modeling or the resultant process models. In this paper we analyze ontology support regarding process modeling. Another main aspect of this thesis is to verify whether ontologies, while supporting modeling, do not generate drawbacks such as increasing modeler’s cognitive load or creating retroactive interference. To this end, a prototype created in this thesis, which provides ontology support for modeling and registers user actions was adapted. The ontology support follows a modeling approach proposed by us. The experiment findings suggest that the approach was able to provide ontology support without increase cognitive load and time consumption for the task. In this light, it is possible to improve process modeling with support of other artifacts without compromising the modeling task, at least for the aspects covered in the experiment.
7

Process and Outcome Factors of Enterprise Transformation: A Study of the Retail Sector

Garcia, Dominie 30 May 2006 (has links)
A comprehensive model of enterprise transformation is developed, along with a more specific model that includes multiple process factors inherent in transformation. The process factors are drawn from literature as well as primary research conducted for the dissertation. Specific considerations of time, cognitive attention, control and leadership are proposed to affect various outcome measures of transformation. This dissertation is conducted within the context of the retail industry. Financial analyses are included in order to provide an empirical basis for choice of retail industry context. Interviews with multiple retail executives acted as a source of primary, qualitative data with which to develop the model and inform the creation of a survey. A broad based empirical survey provided a second source of data with which to test the hypotheses about the impacts of multiple transformation factors on success metrics. Results indicate a large percentage of the variance in the outcomes of transformation can be explained with specific, actionable measures. Clarity of goals and plans, and strong leadership support are all shown to be important in affecting successful change. Additional factors, including flexibility in plans and goals, and leadership communication levels provide additional support for the hypotheses. Implications for theory and practice are elaborated, and future considerations for the research are discussed.
8

Linguistic Refactoring of Business Process Models

Pittke, Fabian 11 1900 (has links) (PDF)
In the past decades, organizations had to face numerous challenges due to intensifying globalization and internationalization, shorter innovation cycles and growing IT support for business. Business process management is seen as a comprehensive approach to align business strategy, organization, controlling, and business activities to react flexibly to market changes. For this purpose, business process models are increasingly utilized to document and redesign relevant parts of the organization's business operations. Since companies tend to have a growing number of business process models stored in a process model repository, analysis techniques are required that assess the quality of these process models in an automatic fashion. While available techniques can easily check the formal content of a process model, there are only a few techniques available that analyze the natural language content of a process model. Therefore, techniques are required that address linguistic issues caused by the actual use of natural language. In order to close this gap, this doctoral thesis explicitly targets inconsistencies caused by natural language and investigates the potential of automatically detecting and resolving them under a linguistic perspective. In particular, this doctoral thesis provides the following contributions. First, it defines a classification framework that structures existing work on process model analysis and refactoring. Second, it introduces the notion of atomicity, which implements a strict consistency condition between the formal content and the textual content of a process model. Based on an explorative investigation, we reveal several reoccurring violation patterns are not compliant with the notion of atomicity. Third, this thesis proposes an automatic refactoring technique that formalizes the identified patterns to transform a non-atomic process models into an atomic one. Fourth, this thesis defines an automatic technique for detecting and refactoring synonyms and homonyms in process models, which is eventually useful to unify the terminology used in an organization. Fifth and finally, this thesis proposes a recommendation-based refactoring approach that addresses process models suffering from incompleteness and leading to several possible interpretations. The efficiency and usefulness of the proposed techniques is further evaluated by real-world process model repositories from various industries. (author's abstract)
9

Findings from an Experiment on Flow Direction of Business Process Models

Figl, Kathrin, Strembeck, Mark 09 1900 (has links) (PDF)
A core aspect of diagrammatic process modeling is the visualization of the logical and temporal order in which tasks are to be performed in a process. While conventions and guidelines exist that promote modeling processes from left-to-right or from top-to-bottom, no empirically validated design rationale can be provided for this choice so far. Therefore, this paper seeks to determine whether some flow directions are better than others from a cognitive point of view. We present the results of a controlled pilot experiment comparing the effects of four flow directions (left-to-right, right-to-left, top-to-bottom, bottom-to-top) on process model comprehension with a small sample size of 44 participants. Although there is a variety of theoretical arguments which support the use of a left-to-right flow direction as convention for process models, the preliminary empirical results of the pilot experiment were less clear-cut and showed that model readers also adapted well to uncommon reading directions.
10

Influence factors for local comprehensibility of process models

Figl, Kathrin, Laue, Ralf January 2015 (has links) (PDF)
The main aim of this study is to investigate human understanding of process models and to develop an improved understanding of its relevant influence factors. Aided by assumptions from cognitive psychology, this article attempts to address specific deductive reasoning difficulties based on process models. The authors developed a research model to capture the influence of two effects on the cognitive difficulty of reasoning tasks: (i) the presence of different control-flow patterns (such as conditional or parallel execution) in a process model and (ii) the interactivity of model elements. Based on solutions to 61 different reasoning tasks by 155 modelers, the results from this study indicate that the presence of certain control-flow patterns influences the cognitive difficulty of reasoning tasks. In particular, sequence is relatively easy, while loops in a model proved difficult. Modelers with higher process modeling knowledge performed better and rated subjective difficulty of loops lower than modelers with lower process modeling knowledge. The findings additionally support the prediction that interactivity between model elements is positively related to the cognitive difficulty of reasoning. Our research contributes to both academic literature on the comprehension of process models and practitioner literature focusing on cognitive difficulties when using process models.

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