\u201cIt can be assumed that, if our conceptual model is valid, then\u2026\u201d: The Construction of Multiple Identities in Economics vs. Marketing

The paper compares the disciplines of marketing and economics, by using keywords as indicators of identity at three main levels: professional, academic and disciplinary. The corpus-based analysis of keywords how scholars from the two disciplines craft their niche of expertise and identity, showing, for instance, the empirical drive of marketing as opposed to the hypothetical nature of economic

Dynamical Properties of Interaction Data

Network dynamics are typically presented as a time series of network properties captured at each period. The current approach examines the dynamical properties of transmission via novel measures on an integrated, temporally extended network representation of interaction data across time. Because it encodes time and interactions as network connections, static network measures can be applied to this "temporal web" to reveal features of the dynamics themselves. Here we provide the technical details and apply it to agent-based implementations of the well-known SEIR and SEIS epidemiological models.Comment: 29 pages, 15 figure

Advanced Visual Interfaces for Informed Decision-Making

This thesis presents new interactive visualization techniques and systems intended to support users with real-world decisions such as selecting a product from a large variety of similar offerings, finding appropriate wording as a non-native speaker, and assessing an alleged case of plagiarism. The Product Explorer is a significantly improved interactive Parallel Coordinates display for facilitating the product selection process in cases where many attributes and numerous alternatives have to be considered. A novel visual representation for categorical and ordered data with only few occurring values, the so-called extended areas, in combination with cubic curves for connecting the parallel axes, are crucial for providing an effective overview of the entire dataset and to facilitate the tracing of individual products. The visual query interface supports users in quickly narrowing down the product search to a small subset or even a single product. The scalability of the approach towards a large number of attributes and products is enhanced by the possibility of setting some constraints on final attributes and, therefore, reducing the number of considered attributes and data items. Furthermore, an attribute repository allows users to focus on the most important attributes at first and to bring in additional criteria for product selection later in the decision process. A user study confirmed that the Product Explorer is indeed an excellent tool for its intended purpose for casual users. The Wordgraph is a layered graph visualization for the interactive exploration of search results for complex keywords-in-context queries. The system relies on the Netspeak web service and is designed to support non-native speakers in finding customary phrases. Uncertainties about the commonness of phrases are expressed with the help of wildcard-based queries. The visualization presents the alternatives for the wildcards in a multi-column layout: one column per wildcard with the other query fragments in between. The Wordgraph visualization displays the sorted results for all wildcards at once by appropriately arranging the words of each column. A user study confirmed that this is a significant advantage over simple textual result lists. Furthermore, visual interfaces to filter, navigate, and expand the graph allow interactive refinement and expansion of wildcard-containing queries. Furthermore, this thesis presents an advanced visual analysis tool for assessing and presenting alleged cases of plagiarism and provides a three-level approach for exploring the so-called finding spots in their context. The overview shows the relationship of the entire suspicious document to the set of source documents. An intermediate glyph-based view reveals the structural and textual differences and similarities of a set of finding spots and their corresponding source text fragments. Eventually, the actual fragments of the finding spot can be shown in a side-by-side view with a novel structured wrapping of both the source, as well as the suspicious text. The three different levels of detail are tied together by versatile navigation and selection operations. Reviews with plagiarism experts confirm that this tool can effectively support their workflow and provides a significant improvement over existing static visualizations for assessing and presenting plagiarism cases. The three main contributions of this research have a lot in common aside from being carefully designed and scientifically grounded solutions to real-world decision problems. The first two visualizations facilitate the decision for a single possibility out of many alternatives, whereas the latter ones deal with text at varying levels of detail. All visual representations are clearly structured based on horizontal and vertical layers contained in a single view and they all employ edges for depicting the most important relationships between attributes, words, or different levels of detail. A detailed analysis considering the context of the established decision-making literature reveals that important steps of common decision models are well-supported by the three visualization systems presented in this thesis

Induction: a formal perspective

The aim of this contribution is to provide a rather general answer to Hume's problem. To this end, induction is treated within a straightforward formal paradigm, i.e., several connected levels of abstraction. Within this setting, many concrete models are discussed. On the one hand, models from mathematics, statistics and information science demonstrate how induction might succeed. On the other hand, standard examples from philosophy highlight fundamental difficulties. Thus it transpires that the difference between unbounded and bounded inductive steps is crucial: While unbounded leaps of faith are never justi�ed, there may well be reasonable bounded inductive steps. In this endeavour, the twin concepts of information and probability prove to be indispensable, pinning down the crucial arguments, and, at times, reducing them to calculations. Essentially, a precise study of boundedness settles Goodman's challenge. Hume's more profound claim of seemingly inevitable circularity is answered by obviously non-circular hierarchical structures

On construction, performance, and diversification for structured queries on the semantic desktop

[no abstract

Optimizing Cryptographic Obfuscation

Cryptographic obfuscation is a powerful tool that makes programs “unintelligible” yet still runnable. It essentially gives programs the ability to keep secrets. The practical applications of obfuscation range from keeping secrets in banking applications to preventing software theft to providing secure messaging applications. The cryptographic applications of obfuscation are also vast – a tool that hides secrets in programs essentially enables all other cryptographic constructions. Despite (or perhaps due to) its power, obfuscation is currently wildly inefficient and on shaky theoretical ground. Its shaky theoretical ground in particular has resulted in a lack of engineering effort at making it more efficient. In this work, we focus largely on efficiency. We explore the concrete efficiency of multilinear maps, which are the basis of many cryptographic obfuscation constructions. Multilinear maps are mathematical objects that allow oblivious addition and multiplication of encrypted values. Using multilinear maps, we give the first ever implementations of obfuscation and multi-input functional encryption (MIFE: a variant of obfuscation) for branching programs. Along the way, we create the 5Gen framework for implementations of multilinear map-based applications. We apply the 5Gen framework to experiment with obfuscating point functions and MIFE of order-revealing encryption. We also explore efficiency in the context of obfuscators and MIFE for circuits. Circuits are more efficient than branching programs for many functions. We give the first MIFE construction for circuits and prove its security in an ideal model. Our scheme is efficient. To compare, we implement all known circuit obfuscation schemes using the 5Gen framework, and experiment with obfuscating a PRF. This results in the most complex PRF obfuscated to date – with 12 bits of security. Finally, recently Bishop et al. showed an obfuscation scheme for the specific functionality of wildcard pattern-matching [BKM+18]. This is a simple type of string matching where strings must match a pattern exactly except where there are wildcards. This obfuscation scheme simply relies on the generic group model, with no multilinear maps. Inspired by their work, and the deep connection of functional encryption to obfuscation, we give a function-private, public-key functional encryption scheme for the same wildcard pattern-matching functionality. Our scheme is the first such scheme and we prove its security in a generic model

Business process model repositories : efficient process retrieval

As organizations increasingly work in process-oriented manner, the number of business process models that they develop and have to maintain increases. As a consequence, it has become common for organizations to have collections of hundreds or even thousands of business process models. When a collection contains such a large number of business process models, it is impossible to manage that collection manually. Therefore, Business Process (BP) Model Repositories are required that store large collections of process models and provide techniques for managing these collections automatically and efficiently. The goal of research described in this thesis is to improve on existing BP Model Repositories, by improving the management techniques that are supported by these repositories on an aspect that has received little attention so far. Looking ahead at the results of the research, the aspect that will be selected for improvement is the process retrieval aspect. The two main research activities that will be carried in the context of this research are the following. Firstly, a survey of Business Process Model Repositories is performed to identity an unsolved aspect to be enhanced. The functionality of existing BP Model Repositories is listed and summarized as a framework for BP Model Repositories. After comparing the functionality that is provided by existing BP Model Repositories, based on the framework, efficient process retrieval is selected as the aspect that will be improved. This aspect is selected, because, although existing BP Model Repositories provide techniques for process retrieval, none of them focus on the efficiency of process retrieval. Secondly, an indexing technique for process retrieval (both process similarity search and process querying) is proposed. The index is constructed using features of process models. Features are small and characteristic fragments of process models. As such, by matching features of a given query/search model and features of a process model in a collection, a small set of models in the collection that potentially match the query/search model can be retrieved efficiently through the index. Techniques are also proposed to further check whether a potential match is an actual match for the query/search model. All of the above techniques are implemented as a component of the AProMoRe (an Advanced Process Model Repository) process repository. To evaluate the proposed process retrieval techniques, experiments are run using both real-life and synthetic process model collections. Experimental results show that on average the process retrieval techniques proposed in this thesis performs at least one order of magnitude faster than existing techniques

System Architecture for Distributed Control Systems and Electricity Market Infrastructures.

M.S. Thesis. University of Hawaiʻi at Mānoa 2018

Structural abstraction: a mechanism for modular program construction

Abstraction mechanisms in programming languages aim to allow orthogonal pieces of functionality to be developed separately; complex software can then be constructed through the composition of these pieces. The effectiveness of such mechanisms lies in their support for modularity and reusability: The behavior of a piece of code should be reasoned about modularly---independently of the specific compositions it may participate in; the computation of a piece of code should allow specialization, so that it is reusable for different compositions. This dissertation introduces structural abstraction: a mechanism that advances the state of the art by allowing the writing of highly reusable code---code whose structure can be specialized per composition, while maintaining a high level of modularity. Structural abstraction provides a disciplined way for code to inspect the structure of its clients in composition, and declare its own structure accordingly. The hallmark feature of structural abstraction is that, despite its emphasis on greater reusability, it still allows modular type checking: A piece of structurally abstract code can be type-checked independently of its uses in compositions---an invaluable feature for highly reusable components that will be statically composed by other programmers. This dissertation introduces two structural abstraction techniques: static type conditions, and morphing. Static type conditions allow code to be conditionally declared based on subtyping constraints. A client of a piece of code can configure a desirable set of features by composing the code with types that satisfy the appropriate subtyping conditions. Morphing allows code to be iteratively declared, by statically reflecting over the structural members of code that it would be composed with. A morphing piece of code can mimic the structure of its clients in composition, or change its shape according to its clients in a pattern-based manner. Using either static type conditions or morphing, the structure of a piece of code is not statically determined, but can be automatically specialized by clients. Static type conditions and morphing both guarantee the modular type-safety of code: regardless of specific client configurations, code is guaranteed to be well-typed.Ph.D.Committee Chair: Yannis Smaragdakis; Committee Member: Oege de Moor; Committee Member: Richard LeBlanc; Committee Member: Santosh Pande; Committee Member: Spencer Rugabe