Strategies for Improved Earned Value Management Use by Defense Business Leaders

Project cost and schedule forecasting accuracy in the defense industry has not significantly changed since the 1960s, making it difficult for defense business leaders to implement successful earned value management (EVM) strategies. The purpose of this multiple case study was to explore EVM strategies that Washington, D.C. area defense contractor business leaders used to improve costs and schedule goal accomplishment. The conceptual framework for this study was the earned time theory. Data were collected from semistructured interviews from 5 defense contractor business leaders with demonstrated use of EVM strategy. The review of company documents focused on EVM use with reporting requirements, and archival EVM study analysis supplemented the data from the semistructured interviews. Data were triangulated and inductively analyzed for themes, and member checking was done to ensure credibility of the interpretations. Four themes emerged from the data: the use of EVM data to improve outcomes, the existence of essential strategies, the role of EVM as but a single tool, and the essential engagement of leadership. Findings may contribute to social change because defense business contractor leaders could help improve business performance and return resources for social improvement. Investment in social and environmental improvements can strengthen employee commitment and ultimately ties to the community at large, furthering social improvement

Program Transformations for Information Personalization

Personalization constitutes the mechanisms necessary to automatically customize information content, structure, and presentation to the end user to reduce information overload. Unlike traditional approaches to personalization, the central theme of our approach is to model a website as a program and conduct website transformation for personalization by program transformation (e.g., partial evaluation, program slicing). The goal of this paper is study personalization through a program transformation lens and develop a formal model, based on program transformations, for personalized interaction with hierarchical hypermedia. The specific research issues addressed involve identifying and developing program representations and transformations suitable for classes of hierarchical hypermedia and providing supplemental interactions for improving the personalized experience. The primary form of personalization discussed is out-of-turn interaction—a technique that empowers a user navigating a hierarchical website to postpone clicking on any of the hyperlinks presented on the current page and, instead, communicate the label of a hyperlink nested deeper in the hierarchy. When the user supplies out-of-turn input, we personalize the hierarchy to reflect the user\u27s informational need. While viewing a website as a program and site transformation as program transformation is non-traditional, it offers a new way of thinking about personalized interaction, especially with hierarchical hypermedia. Our use of program transformations casts personalization in a formal setting and provides a systematic and implementation-neutral approach to designing systems. Moreover, this approach helped connect our work to human-computer dialog management and, in particular, mixed-initiative interaction. Putting personalized web interaction on a fundamentally different landscape gave birth to this new line of research. Relating concepts in the web domain (e.g., sites, interactions) to notions in the program-theoretic domain (e.g., programs, transformations) constitutes the creativity in this work

Computing and Information Science (CIS)

Cornell University Courses of Study Vol. 97 2005/200

Complementary formalisms - synthesis, verification and visualization

Ph.DDOCTOR OF PHILOSOPH

Computing and Information Science

Cornell University Courses of Study Vol. 98 2006/200

Operational Strategies for Nigerian Refineries’ Business Sustainability

AbstractInefficient operations strategies can negatively impact refinery operations output. Refinery senior leaders who struggle to achieve operations efficiency are at high risk of failure. Grounded in Ulrich’s model of competency, the purpose of this qualitative multiple case study was to explore operations strategies leaders of oil and gas refineries in Nigeria used for business sustainability. The participants comprised five senior leaders in five refineries in Nigeria who demonstrated success in using operational strategies for business sustainability in oil and gas refineries. Data were collected from semistructured interviews and company documents consisting of the annual business plan, strategy document, and financial records. Thematic analysis was used to analyze the data. Nine themes emerged: (a) cost cutting and scaling up from smaller projects, (b) enforcing adequate operations and maintenance contracts, (c) guaranteeing consistent raw material supply, (d) exploring industry localization, (e) people-centric strategy, (f) establishment of effective management structure, (g) providing security architecture to local staff and foreigners, (h) creation of new revenue models, and (i) purpose-driven leadership. A key recommendation is for senior refinery leaders to collaborate with colleges and universities in Nigeria to develop a curriculum of successful operational strategies for refineries. The implications for positive social change include the potential for improved refinery industry sustainability, resulting in job creation and improved community development where refineries are located

XML documents schema design

The eXtensible Markup Language (XML) is fast emerging as the dominant standard for storing, describing and interchanging data among various systems and databases on the intemet. It offers schema such as Document Type Definition (DTD) or XML Schema Definition (XSD) for defining the syntax and structure of XML documents. To enable efficient usage of XML documents in any application in large scale electronic environment, it is necessary to avoid data redundancies and update anomalies. Redundancy and anomalies in XML documents can lead not only to higher data storage cost but also to increased costs for data transfer and data manipulation.To overcome this problem, this thesis proposes to establish a formal framework of XML document schema design. To achieve this aim, we propose a method to improve and simplify XML schema design by incorporating a conceptual model of the DTD with a theory of database normalization. A conceptual diagram, Graph-Document Type Definition (G-DTD) is proposed to describe the structure of XML documents at the schema level. For G- DTD itself, we define a structure which incorporates attributes, simple elements, complex elements, and relationship types among them. Furthermore, semantic constraints are also precisely defined in order to capture semantic meanings among the defined XML objects.In addition, to provide a guideline to a well-designed schema for XML documents, we propose a set of normal forms for G-DTD on the basis of rules proposed by Arenas and Libkin and Lv. et al. The corresponding normalization rules to transform from a G- DTD into a normal form schema are also discussed. A case study is given to illustrate the applicability of the concept. As a result, we found that the new normal forms are more concise and practical, in particular as they allow the user to find an 'optimal' structure of XML elements/attributes at the schema level. To prove that our approach is applicable for the database designer, we develop a prototype of XML document schema design using a Z formal specification language. Finally, using the same case study, this formal specification is tested to check for correctness and consistency of the specification. Thus, this gives a confidence that our prototype can be implemented successfully to generate an automatic XML schema design

Modeling and Analysis of Software Product Line Variability in Clafer

Both feature and class modeling are used in Software Product Line (SPL) engineering to model variability. Feature models are used primarily to represent user-visible characteristics (i.e., features) of products; whereas class models are often used to model types of components and connectors in a product-line architecture. Previous works have explored the approach of using a single language to express both configurations of features and components. Their goal was to simplify the definition and analysis of feature-to-component mappings and to allow modeling component options as features. A prominent example of this approach is cardinality-based feature modeling, which extends feature models with multiple instantiation and references to express component-like, replicated features. Another example is to support feature modeling in a class modeling language, such as UML or MOF, using their profiling mechanisms and a stylized use of composition. Both examples have notable drawbacks: cardinality-based feature modeling lacks a constraint language and a well-defined semantics; encoding feature models as class models and their evolution bring extra complexity. This dissertation presents Clafer (class, feature, reference), a class modeling language with first-class support for feature modeling. Clafer can express rich structural models augmented with complex constraints, i.e., domain, variability, component models, and meta-models. Clafer supports: (i) class-based meta-models, (ii) object models (with uncertainty, if needed), (iii) feature models with attributes and multiple instantiation, (iv) configurations of feature models, (v) mixtures of meta- and feature models and model templates, and (vi) first-order logic constraints. Clafer also makes it possible to arrange models into multiple specialization and extension layers via constraints and inheritance. On the other hand, in designing Clafer we wanted to create a language that builds upon as few concepts as possible, and is easy to learn. The language is supported by tools for SPL verification and optimization. We propose to unify basic modeling constructs into a single concept, called clafer. In other words, Clafer is not a hybrid language. We identify several key mechanisms allowing a class modeling language to express feature models concisely. We provide Clafer with a formal semantics built in a novel, structurally explicit way. As Clafer subsumes cardinality-based feature modeling with attributes, references, and constraints, we are the first to precisely define semantics of such models. We also explore the notion of partial instantiation that allows for modeling with uncertainty and variability. We show that Object-Oriented Modeling (OOM) languages with no direct support for partial instances can support them via class modeling, using subclassing and strengthening multiplicity constraints. We make the encoding of partial instances via subclassing precise and general. Clafer uses this encoding and pushes the idea even further: it provides a syntactic unification of types and (partial) instances via subclassing and redefinition. We evaluate Clafer analytically and experimentally. The analytical evaluation shows that Clafer can concisely express feature and meta-models via a uniform syntax and unified semantics. The experimental evaluation shows that: 1) Clafer can express a variety of realistic rich structural models with complex constraints, such as variability models, meta-models, model templates, and domain models; and 2) that useful analyses can be performed within seconds

Photovoltaics and Electrification in Agriculture

Integration of photovoltaics and electrification in agriculture. Works on the integration of photovoltaics in agriculture, as well as electrification and microgrids in agriculture. In addition, some works on sustainability in agriculture are added