Orbital Maneuvering system design evolution

Preliminary design considerations and changes made in the baseline space shuttle orbital maneuvering system (OMS) to reduce cost and weight are detailed. The definition of initial subsystem requirements, trade studies, and design approaches are considered. Design features of the engine, its injector, combustion chamber, nozzle extension and bipropellant valve are illustrated and discussed. The current OMS consists of two identical pods that use nitrogen tetroxide (NTO) and monomethylhydrazine (MMH) propellants to provide 1000 ft/sec of delta velocity for a payload of 65,000 pounds. Major systems are pressurant gas storage and control, propellant storage supply and quantity measurement, and the rocket engine, which includes a bipropellant valve, an injector/thrust chamber, and a nozzle. The subsystem provides orbit insertion, circularization, and on orbit and deorbit capability for the shuttle orbiter

Shaping Robust System through Evolution

Biological functions are generated as a result of developmental dynamics that form phenotypes governed by genotypes. The dynamical system for development is shaped through genetic evolution following natural selection based on the fitness of the phenotype. Here we study how this dynamical system is robust to noise during development and to genetic change by mutation. We adopt a simplified transcription regulation network model to govern gene expression, which gives a fitness function. Through simulations of the network that undergoes mutation and selection, we show that a certain level of noise in gene expression is required for the network to acquire both types of robustness. The results reveal how the noise that cells encounter during development shapes any network's robustness, not only to noise but also to mutations. We also establish a relationship between developmental and mutational robustness through phenotypic variances caused by genetic variation and epigenetic noise. A universal relationship between the two variances is derived, akin to the fluctuation-dissipation relationship known in physics

職務給制度の新しい展開 : 職務給制度・その4 (完)

Ⅰ.序　Ⅱ. 「同一労働・同一賃金の原則」の拡大と限界　(1) 「同一労働・同一賃金の原則」の拡大　(2) 「同一労働・同一賃金の原則」の限界　Ⅲ. 能力給の転化形態としての職務給　(1) 職務給としての能力給と個人給としての能力給　(2) 「同一労働・同一賃金の原則」による職務給と「同一労働力・同一賃金の原則」による個人給　Ⅳ. 我国の職務給制度における特徴　(1) 我国の職務給導入における独自性　(2) 我国の職務給制度における特徴　Ⅴ.

Evolution of the Burmese vowel system

Tibeto-Burman historical linguistics has relied heavily on the spelling of Burmese and Tibetan words as found in standard modern dictionaries, at the expense of the earliest attested records. This examination of the development of the Burmese vowel system, in the light of early Burmese philological data and comparisons to Old Chinese and Old Tibetan, facilitates a refined understanding of Burmese historical phonology and the reconstruction of Tibeto-Burman

System Evolution, Feedback and Compliant Architectures

Proceedings, International Workshop on Feedback and Evolution in Software and Business Processes (FEAST 2000), Imperial College, London. Supported by EPSRCPostprintNon peer reviewe

A New Generalized Harmonic Evolution System

A new representation of the Einstein evolution equations is presented that is first order, linearly degenerate, and symmetric hyperbolic. This new system uses the generalized harmonic method to specify the coordinates, and exponentially suppresses all small short-wavelength constraint violations. Physical and constraint-preserving boundary conditions are derived for this system, and numerical tests that demonstrate the effectiveness of the constraint suppression properties and the constraint-preserving boundary conditions are presented.Comment: Updated to agree with published versio

Moving system with speeded-up evolution

In the classical (non-quantum) relativity theory the course of the moving clock is dilated as compared to the course of the clock at rest (the Einstein dilation). Any unstable system may be regarded as a clock. The time evolution (e.g., the decay) of a uniformly moving physical system is considered using the relativistic quantum theory. The example of a moving system is given whose evolution turns out to be speeded-up instead of being dilated. A discussion of this paradoxical result is presented.Comment: 10 pages, LaTe