Using Subsystems beyond Oil

Chapter 6 moves beyond oil. It starts by showing how the subsystems framework lends itself to a particular method or approach to research. That method encourages analysts to really get to know the empirics of their subject before jumping to causal analysis. The chapter then addresses some additional theoretical questions not covered in chapter 2. For example, it identifies the standards of quality by which we can assess competing subsystems analyses from different analysts, and considers how changes at the subsystem level aggregate up to affect an ordering theme at the systemic level (e.g., the liberal order). The goal is to show how scholars can apply the subsystems framework in an analytically fertile way.

Robust decentralized controller design in time domain: Equivalent subsystem approach

In this paper, the original method to design of PID robust decentralized controller is obtained for linear time-invariant large-scale uncertain system. The controller design procedure performs on the subsystem level such that the closed-loop stability and performance of complex system in the frame of the designer chosen controller design procedure ( H 2 , L 2 -gain, pole placement,...) is guaranteed. The proposed method is implemented in two steps. In the first step, the required dynamic properties of the subsystems are determined so as to ensure the stability of complex system. In the second step, on the subsystem level a decentralized controller design is provided using any suitable design procedure for each subsystem.

Input Parameters for Airborne Brake Wear Emission Simulations: A Comprehensive Review

Non-exhaust emissions, generated by the wear of brake systems, tires, roads, clutches, and road resuspension, are responsible for a large part of airborne pollutants in urban areas. Brake wear accounts for 55% of non-exhaust emissions and significantly contributes to urban health diseases related to air pollution. A major part of the studies reported in the scientific literature are focused on experimental methods to sample and characterize brake wear particles in a reliable, representative, and repeatable way. In this framework, simulation is an important tool, which makes it possible to give interpretations of the experimental results, formulate new testing approaches, and predict the emission produced by brakes. The present comprehensive literature review aims to introduce the state of the art of the research on the different aspects of airborne wear debris resulting from brake systems which can be used as inputs in future simulation models. In this review, previous studies focusing on airborne emissions produced by brake systems are investigated in three main categories: the subsystem level, system level, and environmental level. As well as all the information provided in the literature, the simulation methodologies are also investigated at all levels. It can be concluded from the present review study that various factors, such as the uncertainty and repeatability of the brake wear experiments, distinguish the results of the subsystem and system levels. This gap should be taken into account in the development of future experimental and simulation methods for the investigation of airborne brake wear emissions.

Statistical Reliability Assessment for Small Sample of Failure Data of Dumper Diesel Engines Based on Power Law Process and Maximum Likelihood Estimation

Dumpers or dump trucks are used all over the world to move overburden from many opencast mines. Diesel engines are the main driving force behind the trucks. The frequency of damage due to the failure of diesel engines is enormous. Therefore, efforts are necessary to analyze failure to reduce the downtime periods. A detailed analysis of engine failure at the subsystem level needs to be done. Reliability analysis and maintenance planning remain the norm in this regard. The obstacle faced while analysing the reliability of dumpers was the availability of a large number of data failures. In this paper, this issue is addressed by using Common Beta Hypothesis test and Meta-analysis test. The engine is divided into five subsystems. The result shows that all five subsystems pass the CBH test and Meta-analysis test. Accordingly, the failure data is grouped. The trend test of grouped failure data shows that the Failure data of two subsystems follows the independent and identically distributed characteristics while the remaining three do not follow it. The reliability is estimated for all five subsystems. Finally, fuel supply subsystems show the highest reliability while the lowest value is seen for self-starting subsystems.

APPLICATION OF GREEN RETROFIT TECHNOLOGY: A SYSTEMATIC REVIEW

Green retrofitting is a valuable approach for upgrading existing buildings towards sustainable performances. However, the lack of knowledge about the true cost effects and potential savings of green retrofits distracts building proprietors from paying those retrofits. Therefore, the current study reviewed fourteen studies available in the extant literature and identified twenty-eight different green retrofits incorporated into various buildings with their cost effects and saving potentials through a subsequent desktop study. The results indicated that the majority of green retrofits offer savings related to energy consumption, CO2 emissions, cooling load, and operating costs. Moreover, energy-saving lighting modifications are widely done in most buildings, while solar collectors, photovoltaics, and low-emission double glazing are used less often due to the long payback period and increased cost of implementation. Alternatively, the use of retrofits with lower costs and high savings, like BMS, lighting controllers, and boiler efficiency improvements, offsets the above setbacks. Furthermore, the highlighted retrofits include green roofing, bicycle parks, CO2 sensors, and air tightening retrofits, which also save energy. Rainwater harvesting absorbs carbon dioxide and runoff water, where implementing subsystem-level water meters, appliances with low flow rates, and greywater recycling save and recycle the portable water. Accordingly, the study promotes the effective implementation of green retrofits in future buildings.

Redundant ADS and INS High Sensitivity Fault Detection Method

The fault detection function of GLT method is approximately proportional to the square of fault value, the value of the fault detection function is lower than the detection threshold when the soft fault is small, which leads to the low sensitivity of soft fault detection and the high rate of missing detection. The IM-SPRT method rapidly increases the value of fault detection function above the threshold of fault detection by accumulating small soft fault values, so it has high sensitivity for soft fault detection, however, the end time of the fault cannot be judged timely, resulting in a high false alarm for fault detection. In view of the above problems, this paper proposes a high-sensitivity fault detection method for redundant systems based on GLT/IM-SPRT. This method uses the IM-SPRT method to detect weak and soft faults and sets the IM-SPRT method fault detection function value to zero by the GLT fault detection result, and isolates the fault with GLT. On this basis, a framework of high-sensitivity fault detection and isolation methods for redundant ADS and INS systems is designed. The simulation results of soft and hard fault detection and isolation of three-redundancy ADS subsystem level and INS sensor level show that the method in this paper can improve the sensitivity of fault detection and reduce the rate of missed detection.