Computer aided process planning for multi-axis CNC machining using feature free polygonal CAD models

This dissertation provides new methods for the general area of Computer Aided Process Planning, often referred to as CAPP. It specifically focuses on 3 challenging problems in the area of multi-axis CNC machining process using feature free polygonal CAD models. The first research problem involves a new method for the rapid machining of Multi-Surface Parts. These types of parts typically have different requirements for each surface, for example, surface finish, accuracy, or functionality. The CAPP algorithms developed for this problem ensure the complete rapid machining of multi surface parts by providing better setup orientations to machine each surface. The second research problem is related to a new method for discrete multi-axis CNC machining of part models using feature free polygonal CAD models. This problem specifically considers a generic 3-axis CNC machining process for which CAPP algorithms are developed. These algorithms allow the rapid machining of a wide variety of parts with higher geometric accuracy by enabling access to visible surfaces through the choice of appropriate machine tool configurations (i.e. number of axes). The third research problem addresses challenges with geometric singularities that can occur when 2D slice models are used in process planning. The conversion from CAD to slice model results in the loss of model surface information, the consequence of which could be suboptimal or incorrect process planning. The algorithms developed here facilitate transfer of complete surface geometry information from CAD to slice models. The work of this dissertation will aid in developing the next generation of CAPP tools and result in lower cost and more accurately machined components

Economic and humanistic impact of medication nonadherence in patients with asthma and chronic obstructive pulmonary disease

Asthma and chronic obstructive pulmonary disease (COPD) significantly impact morbidity and mortality. In spite of the well-known benefits of prophylactic medication use, especially in asthma, the rate of medication nonadherence is more than 50%. In Phase I, this study examined the relationship between refill-based medication nonadherence and healthcare utilization/costs in patients with asthma, COPD, and those with both asthma and COPD from the West Virginia (WV) Public Employees Insurance Agency (PEIA) program. In Phase II, the study measured the relationship between refill-based and self-reported medication nonadherence, health-related quality of life (HRQL), and losses in workplace productivity, all of which were determined via a mailed questionnaire to patients identified from Phase I. Phase I Results: The prevalence of asthma in the study population was similar to national estimates (203/10,000), whereas the prevalence of COPD was higher (598/10,000). Among asthma-only and those with both asthma and COPD, more than half the patients received medications according to NHLBI guidelines. Refill-based medication adherence was highest in patients having both asthma and COPD, as compared to asthma-only or COPD-only enrollees. The number of adverse outcomes such as hospitalizations and ED visits increased with increasing refill-based adherence for the COPD-only patients. Total healthcare costs increased with increasing medication adherence for all three groups. Thus, increasing medication adherence was possibly a reflection of increasing disease severity. Phase II Results: The overall response rate was almost 23% (N = 918), and was highest for the asthma-only group (25%), followed by the \u27both\u27 group (24%), and the COPD-only group (15%). The perception of HRQL among WV PEIA enrollees was similar to those found in other studies. Only 40% of all Phase II respondents reported themselves as high adherent; the prevalence of self-reported adherence being similar in all three sub-groups. The correlations between self-reported and refill-based adherence in the three groups were not clinically significant. Medication adherence was a significant predictor of HRQL for the COPD-only group, with HRQL worsening with increasing adherence. Self-reported health status was a significant predictor of HRQL for each of the three disease groups; and HRQL worsened with deteriorating health status. In all three groups, medication adherence was not significantly associated with losses in workplace productivity dollars

Process planning for the rapid machining of custom bone implants

This thesis proposes a new process planning methodology for rapid machining of bone implants with customized surface characteristics. Bone implants are used in patients to replace voids in the fractured bones created during accident or trauma. Use of bone implants allow better fracture healing in the patients and restore the original bone strength. The manufacturing process used for creating bone implants in this thesis is highly automated CNC-RP invented at Rapid Manufacturing and Prototyping Lab (RMPL) at Iowa State University. CNC-RP is a 4th axis rapid machining process where the part is machined using cylindrical stock fixed between two opposing chucks. In addition to conventional 3 axes, the chucks provide 4th rotary axis that allows automated fixturing setups for machining the part. The process planning steps for CNC-RP therefore includes calculating minimum number of setup orientations required to create the part about the rotary axis. The algorithms developed in this thesis work towards calculating a minimum number of orientations required to create bone implant with their respective surface characteristics. Usually bone implants may have up to 3 types of surfaces (articular/periosteal/fractured) with (high/medium/low) finish. Currently CNC-RP is capable of creating accurate bone implants from different clinically relevant materials with same surface finish on all of the implant surfaces. However in order to enhance the functionality of the bone implants in the biological environment, it is usually advisable to create implant surfaces with their respective characteristics. This can be achieved by using setup orientations that would generally isolate implant surfaces and machine them with individual finishes. This thesis therefore focuses on developing process planning algorithms for calculating minimum number of orientations required to create customized implant surfaces and control related issues. The bone implants created using new customization algorithms would have enhanced functionality. This would reduce the fracture healing time for the patient and restore the original bone strength. The software package created using new algorithms will be termed as CNC-RPbio throughout in this thesis The three main tasks in this thesis are a) calculating setup orientations in a specific sequence for implant surfaces b) Algorithms for calculating a minimum number of setup orientations to create implant surfaces c) Machining operation sequence. These three research tasks are explained in details in chapter 4 of this thesis. The layout of this thesis is as follows. Chapter 1 provides introduction, background and motivation to the research in this thesis. Chapter 2 provides a literature review explaining different researches conducted to study the effects of different surface finish on the bone implants on their functionality. It also presents different non-traditional and RP techniques used to create bone implant geometries with customized surfaces, their advantages and limitations. Chapter 3 gives the overview of process planning algorithms used for CNC-RP and those needed for CNC-RPbio. Chapter 4 is the main chapter of the thesis including process planning algorithms for rapid machining of bone implants with customized surfaces using CNC-RP in details, while Chapter 5 provides Conclusions and Future work

A Study on Coporate Governance and the Financial Performance of Selected Indian Companies

Good governance is the expectations of every stakeholder, specially, shareholder. Governance is related with the controlling of the activity and controlling of the corporate sector can be termed as corporate governance. But the implementation of ‘Corporate Governance’ is not that much simple as its meaning. Corporate Governance is recently emerged concept and has taken the attention of each and every country, investors and corporate professionals. Corporate governance is the practice, which requires transparency, accountability and good performance from the corporate executives. It has, its strong base from the internal management of company, to the shareholders’ value as well as corporate social responsibility. Reasons for selecting corporate level units which are functioning in India is to find out whether corporate governance is actually being practiced by the corporate level executives or not

Improving Preparedness in Epidemic Healthcare using Data Science

Dengue fever or dengue is a virus spread through mosquito bites. This virus present itself in the form of fever, headaches, vomiting, nausea and in some cases it can lead to death. Since this illness is carried by mosquitoes. By forecasting the spread of this disease the health agencies can better organize their preventive measures such as vaccination and provide information to the public about this illness. Interactive information visualization and visual analytics methods will bring profound changes to personal health programs, clinical healthcare delivery, and public health policymaking. This paper offers several challenges for data visualization and analytics researchers. The problems and challenges are aligned a roadmap for Predictive, Preemptive, Personalized, and Participative Healthcare Systems to improve the preparedness in epidemic healthcare for future

Intertwined Functions of Separase and Caspase in Cell Division and Programmed Cell Death.

Timely sister chromatid separation, promoted by separase, is essential for faithful chromosome segregation. Separase is a member of the CD clan of cysteine proteases, which also includes the pro-apoptotic enzymes known as caspases. We report a role for the C. elegans separase SEP-1, primarily known for its essential activity in cell division and cortical granule exocytosis, in developmentally programmed cell death when the predominant pro-apoptotic caspase CED-3 is compromised. Loss of SEP-1 results in extra surviving cells in a weak ced-3(-) mutant, and suppresses the embryonic lethality of a mutant defective for the apoptotic suppressor ced-9/Bcl-2 implicating SEP-1 in execution of apoptosis. We also report apparent non-apoptotic roles for CED-3 in promoting germ cell proliferation, meiotic chromosome disjunction, egg shell formation, and the normal rate of embryonic development. Moreover, loss of the soma-specific (CSP-3) and germline-specific (CSP-2) caspase inhibitors result in CED-3-dependent suppression of embryonic lethality and meiotic chromosome non-disjunction respectively, when separase function is compromised. Thus, while caspases and separases have evolved different substrate specificities associated with their specialized functions in apoptosis and cell division respectively, they appear to have retained the residual ability to participate in both processes, supporting the view that co-option of components in cell division may have led to the innovation of programmed cell suicide early in metazoan evolution

Blogs as Channels for Disseminating Health Technology Innovations

Objectives: The objective of this study was to describe the features of health informatics blogs on the Internet. Methods: A search was conducted in August, 2016 using the search engine, Google, and key words: ‘mobile health blog,’ ‘telehealth/telemedicine blog,’ ‘Electronic Health Record blog,’ ‘personalized health record blog,’ ‘population health decision support system blog,’ and ‘public/population health dashboard blog.’ The first 24 blogs resulting from each key word search were recorded, generating 144 blogs. A total of 109 unique blogs resulted after removing duplicates and non-functional sites. Results: Blogs with ‘.com’ extensions were most prevalent (72%, n = 79). More than half of the blogs (79%, n = 86) were created by industries. Mobile health (88%, n = 96), telehealth (82%, n = 89), and health IT (78%, n = 85) were the predominant topics covered. Health providers (44%, n = 48), industries (33%, n = 36), patients/consumers (25%, n = 27) and payers/insurance providers (19%, n = 21) constituted the most common target audience. Blogs catering to payers commonly used ‘.org’ extension (n = 10 out of 21), compared to ‘.com’ (n = 7) or ‘.gov’ (n = 2) (p \u3c 0.0001). Significant differences were also observed by topics covered health IT (p = 0.007), subscription (p = 0.048) and LinkedIn social media (p = 0.019) across the website extensions. Conclusions: Further research is needed to examine the use of blogs as channels of communication of best evidence in health informatics research among diverse stakeholders. The role of blogs as policy informatics tools need to be evaluated in order for stakeholders to collaborate, coordinate and share opportunities and challenges of various public health programs and policies

Ground State Properties of Quantum Skyrmions described by Neural Network Quantum States

We investigate the ground state properties of quantum skyrmions in a ferromagnet using variational Monte Carlo with the neural network quantum state as variational ansatz. We study the ground states of a two-dimensional quantum Heisenberg model in the presence of the Dzyaloshinskii-Moriya interaction (DMI). We show that the ground state accommodates a quantum skyrmion for a large range of parameters, especially at large DMI. The spins in these quantum skyrmions are weakly entangled, and the entanglement increases with decreasing DMI. We also find that the central spin is completely disentangled from the rest of the lattice, establishing a non-destructive way of detecting this type of skyrmion by local magnetization measurements. While neural networks are well suited to detect weakly entangled skyrmions with large DMI, they struggle to describe skyrmions in the small DMI regime due to nearly degenerate ground states and strong entanglement. In this paper, we propose a method to identify this regime and a technique to alleviate the problem. Finally, we analyze the workings of the neural network and explore its limits by pruning. Our work shows that neural network quantum states can be efficiently used to describe the quantum magnetism of large systems exceeding the size manageable in exact diagonalization by far.Comment: 12 pages, 6 figure