Magnetohydrodynamics (MHD) Engineering Test Facility (ETF) 200 MWe power plant. Design Requirements Document (DRD)

A description and the design requirements for the 200 MWe (nominal) net output MHD Engineering Test Facility (ETF) Conceptual Design, are presented. Performance requirements for the plant are identified and process conditions are indicated at interface stations between the major systems comprising the plant. Also included are the description, functions, interfaces and requirements for each of these major systems. The lastest information (1980-1981) from the MHD technology program are integrated with elements of a conventional steam electric power generating plant

Reliability and mass analysis of dynamic power conversion systems with parallel of standby redundancy

A combinatorial reliability approach is used to identify potential dynamic power conversion systems for space mission applications. A reliability and mass analysis is also performed, specifically for a 100 kWe nuclear Brayton power conversion system with parallel redundancy. Although this study is done for a reactor outlet temperature of 1100K, preliminary system mass estimates are also included for reactor outlet temperatures ranging up to 1500 K

Profit Analysis of a Warm Standby Non-Identical Units System with Single Server Subject to Priority

The present paper deals with the profit analysis of a warm standby non-identical (one is main unit another is duplicate unit) units system with single server. The model consists of two non-identical units –one is operative and the other kept as warm standby and one unit is sufficient to make the system in operative mode. The main unit may fail directly from normal mode and the warm standby unit can fail owing to remain unused for a longer period of time. There is a single server, who gives priority to repair of the main unit over the repair of the duplicate unit. The time is taken to repair activity by the server follows negative exponential distribution whereas the distributions of unit are taken as arbitrary with different probability density functions. The expressions of various efficiency measures are analyzed in steady state using semi-Markov process and regenerative point technique. Also, taking the arbitrary values for the parameters (i.e. ?, µ, ? and ?) to delineate the behavior of some important performance measures to check the efficacy of the system model under such situations shown in the graphs

Availability modeling and evaluation on high performance cluster computing systems

Cluster computing has been attracting more and more attention from both the industrial and the academic world for its enormous computing power, cost effective, and scalability. Beowulf type cluster, for example, is a typical High Performance Computing (HPC) cluster system. Availability, as a key attribute of the system, needs to be considered at the system design stage and monitored at mission time. Moreover, system monitoring is a must to help identify the defects and ensure the system\u27s availability requirement. In this study, novel solutions which provide availability modeling, model evaluation, and data analysis as a single framework have been investigated. Three key components in the investigation are availability modeling, model evaluation, and data analysis. The general availability concepts and modeling techniques are briefly reviewed. The system\u27s availability model is divided into submodels based upon their functionalities. Furthermore, an object oriented Markov model specification to facilitate availability modeling and runtime configuration has been developed. Numerical solutions for Markov models are examined, especially on the uniformization method. Alternative implementations of the method are discussed; particularly on analyzing the cost of an alternative solution for small state space model, and different ways for solving large sparse Markov models. The dissertation also presents a monitoring and data analysis framework, which is responsible for failure analysis and availability reconfiguration. In addition, the event logs provided from the Lawrence Livermore National Laboratory have been studied and applied to validate the proposed techniques

Evaluation of Some Reliability Characteristics of a Single Unit System Requiring Two Types of supporting Device for Operations

This study presents the reliability assessment of a single unit connected to two types of external supporting devices for its operation. Each type of external supporting device has two copies I and II on standby. First order differential difference equations method is used to obtain the explicit expression for the steady state availability, busy period due to failure of type I and II supporting devices of repairmen, steady-state availability and profit function. Based on assumed numerical values given to system parameters, graphical illustrations are given to highlight important results. Comparisons are performed to highlight the impact of unit failure and repair rates on availability and profit

Enhancement in Reliability for Multi-core system consisting of One Instruction Cores

Rapid CMOS device size reduction resulted in billions of transistors on a chip have led to integration of many cores leading to many challenges such as increased power dissipation, thermal dissipation, occurrence of transient faults and permanent faults. The mitigation of transient faults and permanent faults at the core level has become an important design parameter in a multi-core scenario. Core level techniques is a redundancy-based fault mitigation technique that improves the lifetime reliability of multi-core systems. In an asymmetric multi-core system, the smaller cores provide fault tolerance to larger cores is a core level fault mitigation technique that has gained momentum and focus from many researchers. The paper presents an economical, asymmetric multi-core system with one instruction cores (MCSOIC). The term Hardware Cost Estimation signifies power and area estimation for MCS-OIC. In MCSOIC, OIC is a warm standby redundant core. OICs provide functional support to conventional cores for shorter periods of time. To evaluate the idea, different configurations of MCSOIC is synthesized using FPGA and ASIC. The maximum power overhead and maximum area overhead are 0.46% and 11.4% respectively. The behavior of OICs in MCS-OIC is modelled using a One-Shot System (OSS) model for reliability analysis. The model parameters namely, readiness, wakeup probability and start-up-strategy for OSS are mapped to the multi-core systems with OICs. Expressions for system reliability is derived. System reliability is estimated for special cases.Comment: 46 page

How reliable is smartness? And how smart is reliability?

This paper highlights major reliability concerns in the trend of building smartness in everything from devices to systems. It alerts engineers to determine the trade-off equilibrium of new smartness in a more practical and realistic manner. The discussion is based on several common roles of smart practices that include software; driver; and redundancy. The major concerns are expressed in five areas: series reliability shrinkage; cold standby's intrinsic imperfection; crossroad & roundabout jeopardy; software unreliability and cyber vulnerability.postprin