An aspect-oriented approach to designing role-based access control services

Access control (AC) limits access to the resources of a system only to authorized entities. Given that information systems today are increasingly interconnected, AC is extremely important. The implementation of an AC service is a complicated task. Yet the requirements to an AC service vary a lot. Accordingly, the design of an AC service should be flexible and extensible in order to save development effort and time. Unfortunately, with conventional object-oriented techniques, when an extension has not been anticipated at the design time, the modification incurred by the extension is often invasive. Invasive changes destroy design modularity, further deteriorate design extensibility, and even worse, they reduce product reliability. ^ A concern is crosscutting if it spans multiple object-oriented classes. It was identified that invasive changes were due to the crosscutting nature of most unplanned extensions. To overcome this problem, an aspect-oriented design approach for AC services was proposed, as aspect-oriented techniques could effectively encapsulate crosscutting concerns. The proposed approach was applied to develop an AC framework that supported role-based access control model. In the framework, the core role-based access control mechanism is given in an object-oriented design, while each extension is captured as an aspect. The resulting framework is well-modularized, flexible, and most importantly, supports noninvasive adaptation. ^ In addition, a process to formalize the aspect-oriented design was described. The purpose is to provide high assurance for AC services. Object-Z was used to specify the static structure and Predicate/Transition net was used to model the dynamic behavior. Object-Z was extended to facilitate specification in an aspect-oriented style. The process of formal modeling helps designers to enhance their understanding of the design, hence to detect problems. Furthermore, the specification can be mathematically verified. This provides confidence that the design is correct. It was illustrated through an example that the model was ready for formal analysis. ^

Managing conflict in user-oriented development environments: Effects on information systems success

Today, many organizations are turning to new approaches to building and maintaining information systems (I/S) to cope with a highly competitive business environment. Current anecdotal evidence indicates that the approaches being used improve the effectiveness of software development by encouraging active user participation throughout the development process. Unfortunately, very little is known about how the use of such approaches enhances the ability of team members to develop I/S that are responsive to changing business conditions.^ Drawing from predominant theories of organizational conflict, this study develops and tests a model of conflict among members of a development team. The model proposes that development approaches provide the relevant context conditioning the management and resolution of conflict in software development which, in turn, are crucial for the success of the development process.^ Empirical testing of the model was conducted using data collected through a combination of interviews with I/S executives and surveys of team members and business users at nine organizations. Results of path analysis provide support for the model's main prediction that integrative conflict management and distributive conflict management can contribute to I/S success by influencing differently the manifestation and resolution of conflict in software development. Further, analyses of variance indicate that object-oriented development, when compared to rapid and structured development, appears to produce the lowest levels of conflict management, conflict resolution, and I/S success.^ The proposed model and findings suggest academic implications for understanding the effects of different conflict management behaviors on software development outcomes, and practical implications for better managing the software development process, especially in user-oriented development environments. ^

A nested Petri net framework for modeling and analyzing multi-agent systems

In the past two decades, multi-agent systems (MAS) have emerged as a new paradigm for conceptualizing large and complex distributed software systems. A multi-agent system view provides a natural abstraction for both the structure and the behavior of modern-day software systems. Although there were many conceptual frameworks for using multi-agent systems, there was no well established and widely accepted method for modeling multi-agent systems. This dissertation research addressed the representation and analysis of multi-agent systems based on model-oriented formal methods. The objective was to provide a systematic approach for studying MAS at an early stage of system development to ensure the quality of design. ^ Given that there was no well-defined formal model directly supporting agent-oriented modeling, this study was centered on three main topics: (1) adapting a well-known formal model, predicate transition nets (PrT nets), to support MAS modeling; (2) formulating a modeling methodology to ease the construction of formal MAS models; and (3) developing a technique to support machine analysis of formal MAS models using model checking technology. PrT nets were extended to include the notions of dynamic structure, agent communication and coordination to support agent-oriented modeling. An aspect-oriented technique was developed to address the modularity of agent models and compositionality of incremental analysis. A set of translation rules were defined to systematically translate formal MAS models to concrete models that can be verified through the model checker SPIN (Simple Promela Interpreter). ^ This dissertation presents the framework developed for modeling and analyzing MAS, including a well-defined process model based on nested PrT nets, and a comprehensive methodology to guide the construction and analysis of formal MAS models.^

Development of ``HealthServe'': A measure of customer service orientation in healthcare

An assessment tool designed to measure a customer service orientation among RN's and LPN's was developed using a content-oriented approach. Critical incidents were first developed by asking two samples of healthcare managers (n = 52 and 25) to identify various customer-contact situations. The critical incidents were then used to formulate a 121-item instrument. Patient-contact workers from 3 hospitals (n = 102) completed the instrument along with the NEO-FFI, a measure of the Big Five personality factors. Concurrently, managers completed a performance evaluation scale on the employees participating in the study in order to determine the predictive validity of the instrument.^ Through a criterion-keying approach, the instrument was scaled down to 38 items. The correlation between HealthServe and the supervisory ratings of performance evaluation data supported the instrument's criterion-related validity (r =.66, p $<$.0001). Incremental validity of HealthServe over the Big Five was found with HealthServe accounting for 46% of the variance.^ The NEO-FFI was used to assess the correlation between personality traits and HealthServe. A factor analysis of HealthServe suggested 4 factors which were correlated with the NEO-FFI scores. Results indicated that HealthServe was related to Extraversion, Openness to Experience, Agreeableness, Conscientiousness and negatively related to Neuroticism.^ The benefits of the test construction procedure used here over the use of broad-based measures of personality were discussed as well as the limitations of using a concurrent validation strategy. Recommendations for future studies were provided. ^

A review of Taiwan's technological five-year junior college mechanical engineering curriculum development: 1948 to 1994

Taiwan's technological five-year junior college (TFYJC) was founded in 1948 to train technicians to meet the demand coming from national construction. Site level professionals never were trained in curriculum development as this was under strict national control. The purpose of this study is to present an accurate narrative of Taiwan's TFYJC mechanical engineering curriculum development history in order to display the focus, rationale, and influencing forces of the evolving curriculum. This study employed historical research methodology and used document analysis as the primary approach.^ This analysis revealed that the target FYJC curriculum was manufacturing-oriented. The range of government control shifted from little, to full, then to partial control of the curriculum, from autonomy to uniformity then to partial autonomy. The intention of the target curriculum development was always to advance domestic economic development. Voices from the academia and government also influenced curriculum development decisions. Currently, the government has instituted a shift in focus and content causing individual institutions to develop curriculum responses addressing the challenge of advancing Taiwan's position in a global economy.^ Considering the shift in policy and practice, individual institutions intending to design curriculum are advised to implement empirical needs assessments of students, graduates, and employers and to engage in critical studies of emerging resources in order to provide effective in service training. To accomplish this end, TFYJC faculty and administration need training in curriculum theory and practice and evaluation. ^

A case study of the development of the Argentinean community college system

In the 1980's and 1990's, Argentina was undergoing significant political, social and economic changes as a result of the change over from a military driven government to elected governments. A major aspect of the change was an increased emphasis on privatization, and promotion of foreign and domestic investment in Argentina. Higher education leaders were increasingly drawn into developing a national strategy for changing the educational structure to help facilitate changes in other aspects of the society. Preliminary reviews by the Argentinean higher education leaders indicated that adaptation of the American community college promised to help achieve the national goals. ^ The purpose of this study was to determine: if and how the community college concept, an American invention, could be adapted to function in Argentina, a nation with a significantly different history of political, social, cultural and economic development. Achieving this purpose involved: identifying the key leaders in the movement that developed to apply the community college concept in Argentina; the study of their perspectives regarding the movement as it developed; and tracking the assistance given by selected American community college leaders. ^ The case study method was employed in this research, using interview and historical data collection. Key leaders from higher education in the United States and Argentina were interviewed in-depth, to determine their views. An interview protocol with appropriate sub-questions was followed to ensure complete coverage. The interviewees identified several major areas of education in need of change including, the system, access to the system, new areas of study, integration into the hemisphere and, in general, decentralization. Historical review revealed a steady development of the community college concept in Argentina reflected in documentation of events, conceptual writings and legal structures. ^ It was concluded that there is a community college structure beginning to emerge that, so far, in broad outline, follows the structure developed in the United States. It is anticipated however, that future developments will include conceptual aspects to the model reflective of Argentina. ^

The effect of basketball sport aerobics on basketball skill development for fifth-grade students

The purpose of this study was to investigate the effectiveness of an experimental teaching method, Sport Aerobics, on the basketball skill acquisition of fifth grade students. This study investigated the differences in the shooting, dribbling, and passing scores of students taught with Sport Aerobics instruction compared to those taught with a traditional method, Practice Style. Sport Aerobics is an instructional method based on a theoretical framework developed by the researcher to enhance skill acquisition. This framework leads to teaching strategies such as using immediate feedback and specific cueing; arranging for students to engage in object free movement; arranging lessons, according to the framework's concept of movement progression, into lessons staged according to skill and sub-skill complexity; and instructing based on whole group organization. Sport Aerobic instructional strategies were designed to facilitate process learning that is recognized as important in today's development learning approach for age related curriculums. In contrast, the traditional Practice Style uses product-oriented strategies. ^ Four classrooms, consisting of seventy-nine fifth grade students from two physical education programs, at different locations, were randomly assigned to two treatments; Sport Aerobics and Practice Style for instruction over a 15 period curriculum. Using the American Alliance Physical Education Recreation & Dance tests, both groups were pretested and posttested for skill achievement of shooting, dribbling, and passing. Pretest and posttest skill score samples were collected and evaluated. ANCOVAs were performed on the posttests adjusted for the pretests to determine whether or not there would be greater achievement of skills with the Sport Aerobics method. Results failed to establish significant scoring differences between the two methods. Based on the literature and study findings a recommendation is made that longer lesson units will assist in the investigation of the effectiveness of both the instructional model and the individual elements that facilitate skill acquisition. ^

Endothelin receptor B and neural crest derived melanocyte development

Neural Crest cells (NCC) constitute a unique embryonic cell population that arises between the prospective epidermis and the dorsal aspect of the neural tube of vertebrates. NCC migrate ventromedially and dorsolaterally throughout the developing embryo giving rise to the peripheral nervous system constituents and melanocytes that ultimately reside in the skin and hair follicles respectively. Mice and humans with mutations in the Endothelin receptor b (Ednrb) gene manifest strikingly similar phenotypes characterized by hypopigmentation, hearing loss and megacolon these are due to absence of melanocytes in the skin and inner ear and lack of enteric ganglia in the distal part of the gut, respectively. Piebald lethal mice and humans with Hirschsprung's disease or Waardenburg syndrome carry different mutations in the Ednrb gene. The major goals of this project were to determine whether the action of Ednrb in NCC is required prior to commitment of these cells to the melanocytic lineage and to investigate its potential participation in the actual process of commitment. In order to achieve these goals transgenic mice that express Ednrb under two different regulatory elements were created. The first, Dct-Ednrb, expresses Ednrb under the control of the DOPAchrome tautomerase (Dct) promoter to direct expression to already committed melanocyte precursors. The second, Nes-Ednrb, expresses Ednrb under the regulation of the human nestin gene second enhancer to direct expression to pre-migratory NCC. Crosses of the Dct-Ednrb mouse with piebald lethal showed that the transgene was capable of rescuing the hypopigmentation phenotype of the later. This result indicates that the action of Ednrb after NCC commit to the melanocytic lineage is sufficient for normal melanocyte development. The Dct-Ednrb was further crossed with two other hypopigmentation mutants that carry mutations in the transcription factors Sox10 and Pax3. The transgene rescued the phenotype of the Sox10 mutant only. This suggests that Ednrb interacts with Sox10 but not with Pax3 during melanocyte development. The Nes-Ednrb mice developed a hypopigmentation phenotype that was augmented when crossed with piebald lethal or lethal spotting (mutation in Edn3, the ligand for Ednrb) mice but was rescued by over expression of Edn3. These results suggest that alterations in Ednrb expression early in development affect melanocyte development. This study provides novel information necessary to better understand the early embryonic development of NCC, clarifies specific interactions between different melanogenic genes and, could eventually help in the implementation of therapies for human pigmentary genetic disorders. ^

The role of community college faculty in teaching and learning for sustainable development

The purpose of this study was to explore the attitudes, beliefs, and practices of community college professors regarding education for sustainable development (ESD). In-depth interviews with 14 professors from different disciplines were conducted. The participants taught at Miami Dade College, Florida, a Talloires Declaration signatory since 2006, and all had attended Green Studies professional development workshops. Written documents such as assignments and samples of student work were used for triangulation. The annual report of the college’s Earth Ethics Institute and its Web site served as additional sources. The interviews were recorded, transcribed, and analyzed for common themes. The Talloires Declaration’s 10-point action plan and the key characteristics of ESD (UN DESD, 2006) served as the conceptual framework. The study found that the professors considered ESD an essential issue. The majority discussed the economic and social aspects of ESD; however, the environmental aspect was mentioned most frequently. The professors’ conceptualizations of ESD were influenced by their experiences and evidenced by the metaphors they used. Although their engagement with ESD differed, the professors expressed optimism toward ESD related teaching and learning. They regarded ESD as compatible with their subjects, and most had already been infusing sustainability into their courses or planned to do so. Additionally, the participants’ teaching practices reflected many of the characteristics of ESD. Even though the professors considered ESD challenging, they believed that they could make contributions to the college’s effort. The metaphor of “Planting a Seed” was frequently used to describe this holistic approach. The study also found that many professors regarded interpersonal relationships and communication significant factors for the advancement of ESD. The participants described several challenges to integrating ESD at their college. These related to time constraints, density of curriculum, institutional size and fragmentation, dearth of administrative support and incentives, students’ lack of academic preparation and sustainability awareness, students’ inability to focus on ESD because of personal, social, or economic circumstances, and professors’ frustration about a divisive atmosphere as a result of their engagement with sustainability. Despite these obstacles, the professors believed that ESD could be successfully woven into the community college experience.

The influence of study and travel abroad on the personal and professional development of students in architecture design programs

International travel has significant implications on the study of architecture. This study analyzed ways in which undergraduate and graduate students benefited from the experience of international travel and study abroad. Taken from the perspective of 15 individuals who were currently or had been architecture students at the University of Miami and Florida International University or who were alumni of the University of Florida and Syracuse University, the research explored how international travel and study abroad enhanced their awareness and understanding of architecture, and how it complemented their architecture curricula. This study also addressed a more personal aspect of international travel in order to learn how the experience and exposure to foreign cultures had positively influenced the personal and professional development of the participants.^ Participants’ individual and two-person semi-structured interviews about study abroad experiences were electronically recorded and transcribed for analysis. A second interview was conducted with five of the participants to obtain feedback concerning the accuracy of the transcripts and the interpretation of the data. Sketch journals and design projects were also analyzed from five participants and used as data for the purposes of better understanding what these individuals learned and experienced as part of their study abroad.^ Findings indicated that study abroad experiences helped to broaden student understanding about architecture and urban development. These experiences also opened the possibilities of creative and professional expression. For many, this was the most important aspect of their education as architects because it heightened their interest in architecture. These individuals talked about how they had the opportunity to experience contemporary and ancient buildings that they had learned about in their history and design classes on their home campuses. In terms of personal and professional development, many of the participants remarked that they became more independent and self-reliant because of their study abroad experiences. They also displayed a sense of global awareness and were interested in the cultures of their host nations. The study abroad experiences also had a lasting influence on their professional development.^

Adaptive software fault prediction approach using object-oriented metrics

As users continually request additional functionality, software systems will continue to grow in their complexity, as well as in their susceptibility to failures. Particularly for sensitive systems requiring higher levels of reliability, faulty system modules may increase development and maintenance cost. Hence, identifying them early would support the development of reliable systems through improved scheduling and quality control. Research effort to predict software modules likely to contain faults, as a consequence, has been substantial. Although a wide range of fault prediction models have been proposed, we remain far from having reliable tools that can be widely applied to real industrial systems. For projects with known fault histories, numerous research studies show that statistical models can provide reasonable estimates at predicting faulty modules using software metrics. However, as context-specific metrics differ from project to project, the task of predicting across projects is difficult to achieve. Prediction models obtained from one project experience are ineffective in their ability to predict fault-prone modules when applied to other projects. Hence, taking full benefit of the existing work in software development community has been substantially limited. As a step towards solving this problem, in this dissertation we propose a fault prediction approach that exploits existing prediction models, adapting them to improve their ability to predict faulty system modules across different software projects.

Toward a unified theory of task -oriented and relationship -oriented leader behavior: A multi -country generalizability study

The theoretical foundation of this study comes from the significant recurrence throughout the leadership literature of two distinct behaviors, task orientation and relationship orientation. Task orientation and relationship orientation are assumed to be generic behaviors, which are universally observed and applied in organizations, even though they may be uniquely enacted in organizations across cultures. The lack of empirical evidence supporting these assumptions provided the impetus to hypothetically develop and empirically confirm the universal application of task orientation and relationship orientation and the generalizability of their measurement in a cross-cultural setting. Task orientation and relationship orientation are operationalized through consideration and initiation of structure, two well-established theoretical leadership constructs. Multiple-group mean and covariance structures (MACS) analyses are used to simultaneously validate the generalizability of the two hypothesized constructs across the 12 cultural groups and to assess whether the similarities and differences discovered are measurement and scaling artifacts or reflect true cross-cultural differences. The data were collected by the author and others as part of a larger international research project. The data are comprised of 2341 managers from 12 countries/regions. The results provide compelling evidence that task orientation and relationship orientation, reliably and validly operationalized through consideration and initiation of structure, are generalizable across the countries/regions sampled. But the results also reveal significant differences in the perception of these behaviors, suggesting that some aspects of task orientation and relationship orientation are strongly affected by cultural influences. These (similarities and) differences reflect directly interpretable, error-free effects among the constructs at the behavioral level. Thus, task orientation and relationship orientation can demonstrate different relations among cultures, yet still be defined equivalently across the 11 cultures studied. The differences found in this study are true differences and may contain information about cultural influences characterizing each cultural context (i.e. group). The nature of such influences should be examined before the results can be meaningfully interpreted. To examine the effects of cultural characteristics on the constructs, additional hypotheses on the constructs' latent parameters can be tested across groups. Construct-level tests are illustrated in hypothetical examples in light of the study's results. The study contributes significantly to the theoretical understanding of the nature and generalizability of psychological constructs. The theoretical and practical implications of embedding context into a unified theory of task orientated and relationship oriented leader behavior are proposed. Limitations and contributions are also discussed. ^

The role of the transcription factor Ets1 in melanocyte development

Melanocytes, pigment-producing cells, derive from the neural crest (NC), a population of pluripotent cells that arise from the dorsal aspect of the neural tube during embryogenesis. Many genes required for melanocyte development were identified using mouse pigmentation mutants. The deletion of the transcription factor Ets1 in mice results in hypopigmentation; nevertheless, the function of Ets1 in melanocyte development is unknown. The goal of the present study was to establish the temporal requirement and role of Ets1 in murine melanocyte development. In the mouse, Ets1 is widely expressed in developing organs and tissues, including the NC. In the chick cranial NC, Ets1 is required for the expression of Sox10, a transcription factor critical for the development of melanocytes, enteric ganglia, and other NC derivatives. ^ Using a combination of immunofluorescence and cell survival assays Ets1 was found to be required between embryonic days 10 and 11, when it regulates NC cell and melanocyte precursor (melanoblast) survival. Given the requirement of Ets1 for Sox10 expression in the chick cranial NC, a potential interaction between these genes was investigated. Using genetic crosses, a synergistic genetic interaction between Ets1 and Sox10 in melanocyte development was found. Since Sox10 is essential for enteric ganglia formation, the importance of Ets1 on gut innervation was also examined. In mice, Ets1 deletion led to decreased gut innervation, which was exacerbated by Sox10 heterozygosity. ^ At the molecular level, Ets1 was found to activate a Sox10 enhancer critical for Sox10 expression in melanoblasts. Furthermore, mutating Ets1 at a site I characterized in the spontaneous variable spotting mouse pigmentation mutant, led to a 2-fold decrease in enhancer activation. Overexpression and knockdown of Ets1 did not affect Sox10 expression; nonetheless, Ets1 knockdown led to a 6-fold upregulation of the transcription factor Sox9, a gene required for melanocyte and chondrocyte development, but which impairs melanocyte development when its expression is prolonged. Together, these results suggest that Ets1 is required early during melanocyte development for NC cell and melanoblast survival, possibly acting upstream of Sox10. The transcription factor Ets1 may also act indirectly in melanocyte fate specification by repressing Sox9 expression, and consequently cartilage fate.^

Development of hardware in the loop real-time control techniques for hybrid power systems involving distributed demands and sustainable energy sources

The future power grid will effectively utilize renewable energy resources and distributed generation to respond to energy demand while incorporating information technology and communication infrastructure for their optimum operation. This dissertation contributes to the development of real-time techniques, for wide-area monitoring and secure real-time control and operation of hybrid power systems. ^ To handle the increased level of real-time data exchange, this dissertation develops a supervisory control and data acquisition (SCADA) system that is equipped with a state estimation scheme from the real-time data. This system is verified on a specially developed laboratory-based test bed facility, as a hardware and software platform, to emulate the actual scenarios of a real hybrid power system with the highest level of similarities and capabilities to practical utility systems. It includes phasor measurements at hundreds of measurement points on the system. These measurements were obtained from especially developed laboratory based Phasor Measurement Unit (PMU) that is utilized in addition to existing commercially based PMU’s. The developed PMU was used in conjunction with the interconnected system along with the commercial PMU’s. The tested studies included a new technique for detecting the partially islanded micro grids in addition to several real-time techniques for synchronization and parameter identifications of hybrid systems. ^ Moreover, due to numerous integration of renewable energy resources through DC microgrids, this dissertation performs several practical cases for improvement of interoperability of such systems. Moreover, increased number of small and dispersed generating stations and their need to connect fast and properly into the AC grids, urged this work to explore the challenges that arise in synchronization of generators to the grid and through introduction of a Dynamic Brake system to improve the process of connecting distributed generators to the power grid.^ Real time operation and control requires data communication security. A research effort in this dissertation was developed based on Trusted Sensing Base (TSB) process for data communication security. The innovative TSB approach improves the security aspect of the power grid as a cyber-physical system. It is based on available GPS synchronization technology and provides protection against confidentiality attacks in critical power system infrastructures. ^

Adaptive Software Fault Prediction Approach Using Object-Oriented Metrics

As users continually request additional functionality, software systems will continue to grow in their complexity, as well as in their susceptibility to failures. Particularly for sensitive systems requiring higher levels of reliability, faulty system modules may increase development and maintenance cost. Hence, identifying them early would support the development of reliable systems through improved scheduling and quality control. Research effort to predict software modules likely to contain faults, as a consequence, has been substantial. Although a wide range of fault prediction models have been proposed, we remain far from having reliable tools that can be widely applied to real industrial systems. For projects with known fault histories, numerous research studies show that statistical models can provide reasonable estimates at predicting faulty modules using software metrics. However, as context-specific metrics differ from project to project, the task of predicting across projects is difficult to achieve. Prediction models obtained from one project experience are ineffective in their ability to predict fault-prone modules when applied to other projects. Hence, taking full benefit of the existing work in software development community has been substantially limited. As a step towards solving this problem, in this dissertation we propose a fault prediction approach that exploits existing prediction models, adapting them to improve their ability to predict faulty system modules across different software projects.