28 research outputs found

    Error Cost Escalation Through the Project Life Cycle

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    It is well known that the costs to fix errors increase as the project matures, but how fast do those costs build? A study was performed to determine the relative cost of fixing errors discovered during various phases of a project life cycle. This study used three approaches to determine the relative costs: the bottom-up cost method, the total cost breakdown method, and the top-down hypothetical project method. The approaches and results described in this paper presume development of a hardware/software system having project characteristics similar to those used in the development of a large, complex spacecraft, a military aircraft, or a small communications satellite. The results show the degree to which costs escalate, as errors are discovered and fixed at later and later phases in the project life cycle. If the cost of fixing a requirements error discovered during the requirements phase is defined to be 1 unit, the cost to fix that error if found during the design phase increases to 3 - 8 units; at the manufacturing/build phase, the cost to fix the error is 7 - 16 units; at the integration and test phase, the cost to fix the error becomes 21 - 78 units; and at the operations phase, the cost to fix the requirements error ranged from 29 units to more than 1500 unit

    ‘It's all the way you look at it, you know’: reading Bill ‘Bojangles’ Robinson's film career

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    This paper engages with a major paradox in African American tap dancer Bill ‘Bojangles’ Robinson's film image – namely, its concurrent adherences to and contestations of dehumanising racial iconography – to reveal the complex and often ambivalent ways in which identity is staged and enacted. Although Robinson is often understood as an embodiment of popular cultural imagery historically designed to dehumanise African Americans, this paper shows that Robinson's artistry displaces these readings by providing viewing pleasure for black, as much as white, audiences. Robinson's racially segregated scenes in Dixiana (1930) and Hooray for Love (1935) illuminate classical Hollywood's racial codes, whilst also showing how his inclusion within these otherwise all-white films provides grounding for creative and self-reflexive artistry. The films' references to Robinson's stage image and artistry overlap with minstrelsy-derived constructions of ‘blackness’, with the effect that they heighten possible interpretations of his cinematic persona by evading representational conclusion. Ultimately, Robinson's films should be read as sites of representational struggle that help to uncover the slipperiness of performances of African American identities in 1930s Hollywood

    The Science Performance of JWST as Characterized in Commissioning

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    This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

    From design to operations: a process management life-cycle performance measurement system for Public-Private Partnerships

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    YesPublic–Private Partnerships (PPPs) have become a critical vehicle for delivering infrastructure worldwide. Yet, the use of such a procurement strategy has received considerable criticism, as they have been prone to experiencing time/cost overruns and during their operation poorly managed. A key issue contributing to the poor performance of PPPs is the paucity of an effective and comprehensive performance measurement system. There has been a tendency for the performance of PPPs to be measured based on their ex-post criteria of time, cost and quality. Such criteria do not accommodate the complexities and lifecycle of an asset. In addressing this problem, the methodology of sequential triangulation is used to develop and examine the effectiveness of a ‘Process Management Life Cycle Performance Measurement System’. The research provides public authorities and private-sector entities embarking on PPPs with a robust mechanism to effectively measure, control and manage their projects’ life cycle performances, ensuring the assets are ‘future proofed’

    Fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin with gemtuzumab ozogamicin improves event-free survival in younger patients with newly diagnosed aml and overall survival in patients with npm1 and flt3 mutations

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    Purpose To determine the optimal induction chemotherapy regimen for younger adults with newly diagnosed AML without known adverse risk cytogenetics. Patients and Methods One thousand thirty-three patients were randomly assigned to intensified (fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin [FLAG-Ida]) or standard (daunorubicin and Ara-C [DA]) induction chemotherapy, with one or two doses of gemtuzumab ozogamicin (GO). The primary end point was overall survival (OS). Results There was no difference in remission rate after two courses between FLAG-Ida + GO and DA + GO (complete remission [CR] + CR with incomplete hematologic recovery 93% v 91%) or in day 60 mortality (4.3% v 4.6%). There was no difference in OS (66% v 63%; P = .41); however, the risk of relapse was lower with FLAG-Ida + GO (24% v 41%; P < .001) and 3-year event-free survival was higher (57% v 45%; P < .001). In patients with an NPM1 mutation (30%), 3-year OS was significantly higher with FLAG-Ida + GO (82% v 64%; P = .005). NPM1 measurable residual disease (MRD) clearance was also greater, with 88% versus 77% becoming MRD-negative in peripheral blood after cycle 2 (P = .02). Three-year OS was also higher in patients with a FLT3 mutation (64% v 54%; P = .047). Fewer transplants were performed in patients receiving FLAG-Ida + GO (238 v 278; P = .02). There was no difference in outcome according to the number of GO doses, although NPM1 MRD clearance was higher with two doses in the DA arm. Patients with core binding factor AML treated with DA and one dose of GO had a 3-year OS of 96% with no survival benefit from FLAG-Ida + GO. Conclusion Overall, FLAG-Ida + GO significantly reduced relapse without improving OS. However, exploratory analyses show that patients with NPM1 and FLT3 mutations had substantial improvements in OS. By contrast, in patients with core binding factor AML, outcomes were excellent with DA + GO with no FLAG-Ida benefit

    From Afar to Zulu : a dictionary of African cultures /

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    Plasmodial incompatibility in the myxomycetes: a review

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    Clark J, Haskins EF 2012 -Plasmodial incompatibility in the myxomycetes: a review. Mycosphere 3(2), 131-141, Doi 10.5943/mycosphere/3/2/3 Two myxomycete phaneroplasmodia of the same species undergo somatic fusion only if they are phenotypically identical for a complex genetic incompatibility system. This system consists of a three tiered polygenic complex with dominant and recessive alleles. Thus, plasmodia must be phenotypically identical for approximately 16 loci in order to fuse (CC and Cc are phenotypically identical, but different from cc). The first level of the system (having a minimum of seven Fus loci) controls membrane fusion, and it apparently prevents fusion unless the two plasmodia have identical membrane or slime sheath components. The second level (having a minimum of six Cz loci) produces a rapid lysis of a small mixed region, of the two plasmodia, if membrane fusion has occurred. This lysis is directional in that it targets the recessive phenotype, and it is apparently triggered by some pre-formed substances when they come into contact with a different plasmodium. The third level (having a minimum of three Let loci) comes into play if membrane fusion occurs and there is no rapid lysis of the mixed plasmodium. It produces a slow lethal reaction, which targets and degrades the nuclei of the recessive phenotype. This reaction occurs over a period of five to twenty hours and requires the synthesis of new RNA and proteins. Since, this complex system produces a minimum of 65,536 different incompatibility phenotypes, it is highly unlikely that any two phaneroplasmodia will undergo a successful fusion unless they are very closely related. Species with aphaneroplasmoida apparently have a similar system, but species with small protoplasmodia do not appear to undergo any type of plasmodial fusion
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