Interactive inspection of complex multi-object industrial assemblies

The final publication is available at Springer via http://dx.doi.org/10.1016/j.cad.2016.06.005The use of virtual prototypes and digital models containing thousands of individual objects is commonplace in complex industrial applications like the cooperative design of huge ships. Designers are interested in selecting and editing specific sets of objects during the interactive inspection sessions. This is however not supported by standard visualization systems for huge models. In this paper we discuss in detail the concept of rendering front in multiresolution trees, their properties and the algorithms that construct the hierarchy and efficiently render it, applied to very complex CAD models, so that the model structure and the identities of objects are preserved. We also propose an algorithm for the interactive inspection of huge models which uses a rendering budget and supports selection of individual objects and sets of objects, displacement of the selected objects and real-time collision detection during these displacements. Our solution–based on the analysis of several existing view-dependent visualization schemes–uses a Hybrid Multiresolution Tree that mixes layers of exact geometry, simplified models and impostors, together with a time-critical, view-dependent algorithm and a Constrained Front. The algorithm has been successfully tested in real industrial environments; the models involved are presented and discussed in the paper.Peer ReviewedPostprint (author's final draft

Hubble Space Telescope: SRM/QA observations and lessons learned

The Hubble Space Telescope (HST) Optical Systems Board of Investigation was established on July 2, 1990 to review, analyze, and evaluate the facts and circumstances regarding the manufacture, development, and testing of the HST Optical Telescope Assembly (OTA). Specifically, the board was tasked to ascertain what caused the spherical aberration and how it escaped notice until on-orbit operation. The error that caused the on-orbit spherical aberration in the primary mirror was traced to the assembly process of the Reflective Null Corrector, one of the three Null Correctors developed as special test equipment (STE) to measure and test the primary mirror. Therefore, the safety, reliability, maintainability, and quality assurance (SRM&QA) investigation covers the events and the overall product assurance environment during the manufacturing phase of the primary mirror and Null Correctors (from 1978 through 1981). The SRM&QA issues that were identified during the HST investigation are summarized. The crucial product assurance requirements (including nonconformance processing) for the HST are examined. The history of Quality Assurance (QA) practices at Perkin-Elmer (P-E) for the period under investigation are reviewed. The importance of the information management function is discussed relative to data retention/control issues. Metrology and other critical technical issues also are discussed. The SRM&QA lessons learned from the investigation are presented along with specific recommendations. Appendix A provides the MSFC SRM&QA report. Appendix B provides supplemental reference materials. Appendix C presents the findings of the independent optical consultants, Optical Research Associates (ORA). Appendix D provides further details of the fault-tree analysis portion of the investigation process

Open process innovation: A multi-method study on the involvement of customers and consultants in public sector BPM

Following calls to enhance risk-sensitivity of second generation Operational Risk-Aware Information Systems (ORISs), this paper aims to address the lack of ontological/epistemological grounding for the concept of Operational Risk (OR). Herein, OR is regarded both as a property of a real system and as a representational phenomenon forming part of the core of ORIS in line with Weber’s (2003) view of the core of IS. The paper explores how the ontological/epistemological position of the Critical Realist philosophy of science assists in the Requirements Definition of ORISs by providing an ontology-driven representation of the heterogeneous nature of OR. The retroductive mode of logical inference enabled by Critical Realism supports the discovery of OR causal mechanisms when the historical data about operational loss events is limited. The ontological/epistemological position suggested in the paper contributes to better understanding and representation of OR, informs OR assessment in conditions of a constantly changing socio-economical environment, and so assists in the Requirements Definition of ORISs

Metric Development for Continuous Process Improvement

Air Force Smart Operations for the 21st Century (AFSO21) is not currently being used as effectively as it could be across the Air Force. Instead of trying to simply save money here or cut man-hours there, AFSO21 tools should be used to help the Air Force fly, fight and win better. the Air Force Institute of Technology (AFIT) has developed a methodology to identify specific target areas where continuous process improvement, i.e., AFSO21, can be applied to improve the bottom line of an organization. the first step of this process is to solicit the key performance indicators (KPIs) that best reflect the organization\u27s mission. the second step is to use and/or develop metrics based on those KPIs to measure the organization\u27s mission performance today. the third step is to capture the trends of those KPIs over time to see if the organization is getting better or worse. the final step is to identify the largest performance capability gaps in order to determine where AFSO21 resources should be applied to get the most bang for the buck . the result of this process should give the decision maker the ability to improve the bottom line of an organization by improving its weakest areas. Air Combat Command is used as a case study for the application of this methodology

A Total Cost Analysis of the Return Process Online and in Store

We become more and more connected to the Internet and companies need to use new channels to reach customers. Online shopping has become an important activity in customers’ shopping behaviour and there is a need for fashion retailers to examine their logistics process. Depending on which return policies a company have returns can generate a significant cost. It is therfore interesting for companies to calculate the total cost of returns and to examine the effects of different return policies

A High-Resolution Digital Terrain Model Mosaic of the Mars 2020 Perseverance Rover Landing Site at Jezero Crater

We demonstrate the capabilities of a published MADNet monocular height estimation network in producing a refined digital terrain model (DTM) mosaic at 50 cm/pixel resolution for the Mars 2020 Perseverance rover landing site in Jezero crater on Mars. Our approach utilizes the publicly available Mars 2020 Terrain Relative Navigation (TRN) High-Resolution Imaging Science Experiment (HiRISE) Digital Terrain Model (DTM) mosaic, which was originally created by the United States Geological Survey (USGS) Astrogeology Science Centre. Our resultant HiRISE MADNet DTM mosaic is strictly matched with the original HiRISE TRN DTM and orthoimage mosaics. These mosaics are themselves co-aligned with the USGS TRN Context Camera (CTX) based DTM and orthoimage mosaics, as well as the ESA/DLR/FUB (European Space Agency/German Aerospace Center/Free University Berlin) High Resolution Stereo Camera (HRSC) level 5 DTM and orthoimage mosaics. In this paper, we provide a brief description of the technical details, and present both visual and quantitative assessments of the refined MADNet HiRISE Jezero DTM mosaic product. This DTM product is now publicly available at http://dx.doi.org/10.17169/refubium-38359

Money, Credit Constraints, and Economic Activity

When government expenditures exceed current tax revenues, the resulting deficit must be financed either by issuing bonds, which imply obligations to levy future taxes, or by creating high-powered money. The choice between money and bonds is often thought to be of great moment for both real and nominal variables; that is, monetary policy matters.There is by now a wide empirical consensus that monetary policy has effects on real variables like output and employment. But there is far less agreement about why this is so. The purpose of this paper is to take issue with some currently fashionable views of why money has real effects,and to suggest a new theory, or rather resurrect an old one--the loanable funds theory--and give it new, improved microfoundations.