Apollo experience report: Certification test program

A review of the Apollo spacecraft certification (qualification) test program is presented. The approach to devising the spectrum of dynamic and climatic environments, the formulation of test durations, and the relative significance of the formal certification test program compared with development testing and acceptance testing are reviewed. Management controls for the formulation of test requirements, test techniques, data review, and acceptance of test results are considered. Significant experience gained from the Apollo spacecraft certification test program which may be applicable to future manned spacecraft is presented

Imperfect Certification

This paper proposes a model for a certification market with an imperfect testing technology. Such a technology only assures that whenever two products are tested the higher quality product is more likely to pass than the lower quality one.When only one certifier with such testing technology is present in the market, it is found that this monopoly certifier can be completely ignored in equilibrium, in contrast to the prediction of a model with perfect testing technology. A separating equilibrium is also supported in which only relatively high quality types (products) choose to pay for the certification service. It is true that in such an equilibrium having a certificate is better than not. The exact value of a certificate, however, depends both on the prior distribution of product quality and the nature of the testing technology.Welfare accounting shows that the monopolistic certifier’s profit maximizing conduct can lead to under or over supply of certification service depending on model specification. Optimal certification fee is always positive and such that it makes all positive types choose to test. In the case of two competing certifiers with identical testing technologies, the intuition of Bertrand competition does not necessarily hold. Segmentation equilibrium in which higher seller types choose the more expensive certification service and not so high types choose the less expensive service can be supported. As an application, we argue that the fee differentiation between major and non-major auditing firms need not be a result of any differences in their auditing technologies.Asymmetric information, imperfect certification

Certifying Services in Cloud: The Case for a Hybrid, Incremental and Multi-layer Approach

The use of clouds raises significant security concerns for the services they provide. Addressing these concerns requires novel models of cloud service certification based on multiple forms of evidence including testing and monitoring data, and trusted computing proofs. CUMULUS is a novel infrastructure for realising such certification models

Qualifications and certification of nondestructive testing personnel

Personnel handbook states criteria for test methods including radiation, ultrasonics, eddy current, liquid penetrant, and magnetic particle. Subject categories are thoroughly defined and substructured

If You Can't Trust the Farmer, Who Can You Trust? The Effect of Certification Types on Purchases of Organic Produce

An information asymmetry exists in the market for organic produce since consumers cannot determine whether produce is organically or conventionally grown. Various methods may solve this problem including signaling, reputation, and certification. Signaling and reputation may not work well, because signals are noisy, and reputation may be difficult for a producer to establish. Certification of the farm and its growing methods shows the most promise. A survey instrument testing the efficacy of certification is presented along with empirical analysis suggesting that no notable difference existed between independent certification methods, although independent certification had significantly different effects than self-certification.Asymmetric information, Certification, Ordered probit, Organic produce, Agribusiness,

RSDIMU acceptance testing system: Overview of acceptance software and procedures

An overview of the acceptance software and certification testing procedures is presented

Manufacture and evaluation of Li/BCX DD cells

This project is divided into four main tasks: cell manufacture, acceptance, and lot certification of cells, performance testing of cells, and abuse testing of cells. Lithium/bromine chloride in thionyl chloride (Li/BCX) 149 DD cells (PN 3B2085-XA) were built according to the provisions of Electrochem Industries Quality Plan 17096. Acceptance and lot certification testing was performed according to NASA JSC Document EP5-83-025, Revision B. Acceptance testing included open circuit and load voltage check, visual examination, size and weight measurements, and high temperature exposure. Lot certification tests were performed for capacity performance and for performance under conditions of thermal and electrical abuse. These tests included 149 C exposure, capacity discharge, fuse check, high temperature exposure, high rate discharge, short circuit, vibration, and overdischarge testing. A quantity of 200 cells was delivered to Johnson Space Center for life test evaluation. A parametric evaluation of the capacity discharge of Li/BCX DD cells was performed over a variety of temperatures and discharge rates. This testing served to map the performance capability of the cell. Tests were also performed over a variety of electrical and thermal abuse conditions. Abuse tests included short circuit, charging, overdischarge, high temperature exposure, shock, and vibration

Noise-resistant device-independent certification of Bell state measurements

Device-independent certification refers to the characterization of an apparatus without reference to the internal description of other devices. It is a trustworthy certification method, free of assumption on the underlying Hilbert space dimension and on calibration methods. We show how it can be used to quantify the quality of a Bell state measurement, whether deterministic, partial or probabilistic. Our certification is noise resistant and opens the way towards the device-independent self-testing of Bell state measurements in existing experiments.Comment: 5+5 pages, 3+3 figures. See also related work by Marc Olivier Renou et a

System reliability and risk assessment task goals and status

The major focus for continued development of the Numerical Evaluation of Stochastic Structures Under Stress (NESSUS) codes is in support of system testing and certification of advanced propulsion systems. Propulsion system testing has evolved over the years from tests designed to show success, to tests designed to reveal reliability issues before service use. Such test conditions as performance envelope corners, high rotor imbalance, power dwells, and overspeed tests are designed to shake out problems that can be associated with low and high cycle fatigue, creep, and stress rupture, bearing durability, and the like. Subsystem testing supports system certification by standing as an early evaluation of the same durability and reliability concerns as for the entire system. The NESSUS software system is being further developed to support the definition of rigorous subsystem and system test definition and reliability certification. The principal technical issues are outlined which are related to system reliability, including key technology issues such as failure mode synergism, sequential failure mechanisms, and fault tree definition