Structural Health Monitoring using Index Based Reasoning for Unmanned Aerial Vehicles

Unmanned Aerial Vehicles (UAVs) may develop cracks, erosion, delamination or other damages due to aging, fatigue or extreme loads. Identifying these damages is critical for the safe and reliable operation of the systems. ^ Structural Health Monitoring (SHM) is capable of determining the conditions of systems automatically and continually through processing and interpreting the data collected from a network of sensors embedded into the systems. With the desired awareness of the systems’ health conditions, SHM can greatly reduce operational cost and speed up maintenance processes. ^ The purpose of this study is to develop an effective, low-cost, flexible and fault tolerant structural health monitoring system. The proposed Index Based Reasoning (IBR) system started as a simple look-up-table based diagnostic system. Later, Fast Fourier Transformation analysis and neural network diagnosis with self-learning capabilities were added. The current version is capable of classifying different health conditions with the learned characteristic patterns, after training with the sensory data acquired from the operating system under different status. ^ The proposed IBR systems are hierarchy and distributed networks deployed into systems to monitor their health conditions. Each IBR node processes the sensory data to extract the features of the signal. Classifying tools are then used to evaluate the local conditions with health index (HI) values. The HI values will be carried to other IBR nodes in the next level of the structured network. The overall health condition of the system can be obtained by evaluating all the local health conditions. ^ The performance of IBR systems has been evaluated by both simulation and experimental studies. The IBR system has been proven successful on simulated cases of a turbojet engine, a high displacement actuator, and a quad rotor helicopter. For its application on experimental data of a four rotor helicopter, IBR also performed acceptably accurate. The proposed IBR system is a perfect fit for the low-cost UAVs to be the onboard structural health management system. It can also be a backup system for aircraft and advanced Space Utility Vehicles. ^

What makes online grocers work? A case study analysis of factors contributing to online grocery store profitability

This research examined the factors contributing to the performance of online grocers prior to, and following, the 2000 dot.com collapse. The primary goals were to assess the relationship between a company’s business model(s) and its performance in the online grocery channel and to determine if there were other company and/or market related factors that could account for company performance. ^ To assess the primary goals, a case based theory building process was utilized. A three-way cross-case analysis comprising Peapod, GroceryWorks, and Tesco examined the common profit components, the structural category (e.g., pure-play, partnership, and hybrid) profit components, and the idiosyncratic profit components related to each specific company. ^ Based on the analysis, it was determined that online grocery store business models could be represented at three distinct, but hierarchically, related levels. The first level was termed the core model and represented the basic profit structure that all online grocers needed in order to conduct operations. The next model level was termed the structural model and represented the profit structure associated with the specific business model configuration (i.e., pure-play, partnership, hybrid). The last model level was termed the augmented model and represented the company’s business model when idiosyncratic profit components were included. In relation to the five company related factors, scalability, rate of expansion, and the automation level were potential candidates for helping to explain online grocer performance. In addition, all the market structure related factors were deemed possible candidates for helping to explain online grocer performance. ^ The study concluded by positing an alternative hypothesis concerning the performance of online grocers. Prior to this study, the prevailing wisdom was that the business models were the primary cause of online grocer performance. However, based on the core model analysis, it was hypothesized that the customer relationship activities (i.e., advertising, promotions, and loyalty program tie-ins) were the real drivers of online grocer performance. ^

What Makes Online Grocers Work? A Case Study Analysis of Factors Contributing to Online Grocery Store Profitability

This research examined the factors contributing to the performance of online grocers prior to, and following, the 2000 dot.com collapse. The primary goals were to assess the relationship between a company’s business model(s) and its performance in the online grocery channel and to determine if there were other company and/or market related factors that could account for company performance. To assess the primary goals, a case based theory building process was utilized. A three-way cross-case analysis comprising Peapod, GroceryWorks, and Tesco examined the common profit components, the structural category (e.g., pure-play, partnership, and hybrid) profit components, and the idiosyncratic profit components related to each specific company. Based on the analysis, it was determined that online grocery store business models could be represented at three distinct, but hierarchically, related levels. The first level was termed the core model and represented the basic profit structure that all online grocers needed in order to conduct operations. The next model level was termed the structural model and represented the profit structure associated with the specific business model configuration (i.e., pure-play, partnership, hybrid). The last model level was termed the augmented model and represented the company’s business model when idiosyncratic profit components were included. In relation to the five company related factors, scalability, rate of expansion, and the automation level were potential candidates for helping to explain online grocer performance. In addition, all the market structure related factors were deemed possible candidates for helping to explain online grocer performance. The study concluded by positing an alternative hypothesis concerning the performance of online grocers. Prior to this study, the prevailing wisdom was that the business models were the primary cause of online grocer performance. However, based on the core model analysis, it was hypothesized that the customer relationship activities (i.e., advertising, promotions, and loyalty program tie-ins) were the real drivers of online grocer performance.

Drivers of Innovation In Financing Transportation Infrastructure: A Systemic Investigation

Traditional methods of financing infrastructure, which include gas taxation, tax-exempt bonds, and reserve funds, have not been able to meet the growing demand for infrastructure. Innovative financing systems have emerged to close the gap that exists between the available and needed financing sources. The objective of the study presented in this paper is to assess determinants of innovative financing in the U.S. transportation infrastructure using a systemic approach. Innovation System of Systems approach is adopted for systemic assessment and a case-based research approach is utilized to explore the constituents of innovative financing for U.S. transportation infrastructure. The findings, which include constructs regarding the players, practices, and activities are used to create a model to enable understanding the dynamics of the drivers and inhibitors of innovation and, thus, to derive implications for practice. The model along with the constructs provides an analytical tool for practitioners in the U.S. transportation infrastructure.

A case study: Perceptions of the induction process of intern principals in Broward County Public Schools

The case study is a qualitative study of the perceptions of a purposeful sample of intern principal participants in Broward County Public School's 2001-2003 principal leadership induction program through survey, interview and document analysis of their experiences concerning their success or failure in achieving the position of principal. The study focused on constructs of professional and organizational socialization and instructional leadership that research suggests are vital and integrated components of the effective development of aspiring instructional leaders. ^ The findings revealed that purposeful mentoring, a variety of site placement, hands on practical experiences, in addition to the quality of experience measured by the number of years prior experience are positively reported to affect the degrees of success perceived by intern principals. The study validated the interrelatedness of the three constructs professional and organizational socialization and instructional leadership as components that are realized in the development process through formal and informal characteristics of socialization. The data gathered would be of benefit to principal leadership program designers to assist in their understanding of participants' successes and failures that influence individual needs based on their experience as perceived by this group. ^ Implications for further study are the need for better understanding of leadership development, continued reinforcement of best practices such as mentoring, site shadowing and coaching, clarification of the administrator's role, data analysis, curriculum implementation and student achievement. Organizations need to implement a common set of expectations, reasoning, attitudes, and understanding of purpose that guide behaviors. Recommendations are to design leadership induction programs to meet individual strengths and weaknesses not a one-size-fits-all program including a constructive and prescriptive two-way feedback system, select and assign mentors based on their expertise and candidate needs, varied site placements, develop skills to build collaborative relationships, and a standards based monitoring and assessment system to document program mastery and completion. ^

The emergence of a mass community-based ecotourism theme park : the case of Ejido Chacchoben, Quintana Roo, Mexico

In 1998, a dispute between a federal government agency and the local community of Chacchoben resulted in the emergence of a community-based ecotourism (CBE) enterprise to be fully owned and operated by the community in conjunction with a complex arrangement of agreements and partnerships with external actors. CBE is usually framed as a lower-impact, often small-scale alternative to mass tourism and as a conservation and development strategy that can hypothetically protect biologically diverse landscapes while improving the lives of marginalized peasant and indigenous communities through their participation. This case study analyzes the roles of common property land tenure and social capital and how the unique dilemma of a mass community-based ecotourism theme park emerged in Chacchoben. Findings indicate that local decisions and processes of development, conservation, and land use are affected by the complex interaction between local and external institutions and fluctuating levels of social capital.