Shock isolation using magnetorheologically responsive technology

The purpose of this thesis is to develop a shock isolation system using magnetorheologically (MR) responsive technology to isolate shock input to various components in the light weight military vehicles susceptible to ballistic shock effects; Two methods are chosen for isolation of the shock. One is the friction damper based on MR fluid and the other is an elastomer based on magnetically responsive elastomer (MRE). Both approaches can be utilized for semi-active control schemes that have been widely used because of its unique feature of using variable damping and stiffness characteristics of the isolator; In this thesis, both computer simulation and experimental verification are presented to show the effectiveness of the technologies in isolating the shock and the performance is evaluated by the comparison with the passive isolator as a baseline

Assessment of Peripheral Arterial Disease in Diabetic Foot Ulcer in South Indian Population: A Prospective study

INTRODUCTION: Diabetic foot ulcer (DFU) is very common yet challenging complication of diabetes worldwide. These ulcers are biologically compromised majorly by ischemia and neuropathy. Ischemia has gained recognition as a significant cause of DFU. The association of peripheral arterial disease(PAD) largely impacts the treatment outcomes of DFU in terms of ulcer healing, lower limb amputations and mortality. The burden of PAD in DFU in South Indian population has not been assessed adequately in the recent years. A multidisciplinary approach to DFU and prompt diagnosis of ischemia will decrease the loss of limb and life. OBJECTIVE: The objective of the study was to assess the peripheral arterial disease and associated risk factors in patients with diabetic foot ulcer. METHODS: A total of 100 patients were evaluated in this study. The patients were subjected to detailed history and clinical examination which included distal pulse assessment, ankle-brachial index(ABI) and duplex scan to evaluate PAD. The data was subjected to statistical analysis to find out association between parameters of interest. RESULTS: The prevalence of PAD in DFU was found to be 36%. There is significant association of PAD with high WIFI index and longer diabetic duration (p=0.007) with mean disease duration of 10 years. Osteomyelitis is strongly associated with PAD (59%, p=0.003). PAD was associated with higher amputation rates (53.8%, p=0.003). Also higher amputation rates correlated with a high WIFI score (p=0.0001) and higher Fontaine grades. Wound culture most commonly revealed a polymicrobial isolate followed by gram negative aerobes sensitive to aminoglycosides. CONCLUSION: Previous studies aimed to study prevalence of PAD in diabetes irrespective of foot ulcer. The present study analyzed various factors coexisting with DFU and PAD. The results conclude that peripheral arterial disease is a potential risk factor for major limb amputations

Profiling Supply Chain Integration: Differences in Practices, Relationships and Performance between Integration Stages

Integration is recognized as a critical determinant of supply chain performance. In this study, we empirically examine how organizations that are at different stages of integration differ in their practices, relationships and performance. Analyses of data collected from 375 companies indicate that the use of information technologies and process innovations (practices), the presence of positive relationships, and supply chain performance differ by integration stages

An Experimental Investigation of Complexity in Database Query Formulation Tasks

Information Technology professionals and other knowledge workers rely on their ability to extract data from organizational databases to respond to business questions and support decision making. Structured query language (SQL) is the standard programming language for querying data in relational databases, and SQL skills are in high demand and are taught in most introductory database courses. We examined students’ performance on query formulation tasks, in an experimental setting which varied the complexity of the query and the ambiguity of the information request. Our results confirm the main effects of query complexity and request ambiguity found in prior studies (Borthick et al. 2001). In addition, we found an interaction effect between complexity and ambiguity, namely that low ambiguity is more important as tasks increase in complexity. We also found that students’ confidence with entity-relationship diagrams corresponds to reduced time spent on query formulation, and their ability to evaluate the accuracy of their queries reduces as query complexity increases. We discuss the implications of these findings with some suggestions for future research

Query Structure and Data Model Mapping Errors in Information Retrieval Tasks

SQL query writing is a challenging task for novices, even after considerable training. Query writing is a programming task and a translation task where the writer must translate a user’s request for information into code that conforms to the structure, constraints, and syntax of an SQL SELECT statement and that references specific tables and columns from a database. This paper investigates the impact of two instructional interventions on query errors under conditions of low and high query complexity. Data was collected from an experimental study of 63 undergraduate students nearing completion of a 15-week database course. Our analysis reveals specific areas of query writing where each of the interventions helped, and hindered, task performance. We discuss the implications of these findings for improving SQL training and for future research on SQL training effectiveness