Predicting Remaining Useful Life with Similarity-Based Priors

Prognostics is the area of research that is concerned with predicting the remaining useful life of machines and machine parts. The remaining useful life is the time during which a machine or part can be used, before it must be replaced or repaired. To create accurate predictions, predictive techniques must take external data into account on the operating conditions of the part and events that occurred during its lifetime. However, such data is often not available. Similarity-based techniques can help in such cases. They are based on the hypothesis that if a curve developed similarly to other curves up to a point, it will probably continue to do so. This paper presents a novel technique for similarity-based remaining useful life prediction. In particular, it combines Bayesian updating with priors that are based on similarity estimation. The paper shows that this technique outperforms other techniques on long-term predictions by a large margin, although other techniques still perform better on short-term predictions.</p

Strengthening of energy security & low-carbon growth in Asia: Role of regional energy cooperation through trade

Prudent demand-supply management of energy is pivotal for the energy security of the countries and transitions towards the sustainable low-carbon energy system. This study empirically investigates the existing demand-supply gaps of energy in the South-though-East Asian (StEA) countries and analyzes how the gaps can be minimized most efficiently through intraregional energy trade. Stochastic Frontier Gravity model extended with the determinants of efficiency models used for both primary energy and Renewable Energy Goods (REG) trade. The result implies that for most of the countries, intraregional export of primary energy, as well as REG, are positively influenced by Gross Domestic Products (GDP) of the exporting and importing countries. Tariff and distance adversely affect the exports while the implication of cross exchange ratio seems minimal in both cases. Regional Trade Agreements (RTA) are also found to have notable positive impact on intraregional trade. Results show that China and Thailand are the most-efficient in this intraregional primary energy export, while Bangladesh and Myanmar remain the least-efficient. China and Japan are the most-efficient in REG exports, while Bangladesh remains the least-efficient. On average, the whole region has the weighted export efficiency of 56.5% in intraregional primary energy trade and 63.1% in REG trade. The determinants of efficiency model reveals that institutional quality, better infrastructure, goods market efficiency, and technological readiness have reasonable impacts to enhance the countries’ intraregional energy trade efficiencies

Failure Analysis of a Mobile Crane: A Case Study

This paper presents metallurgical failure analysis method to find the root cause of a mobile crane turret bolts failure. Focus of the metallurgical analysis was to identify the root causes of the failure of turret bolts which led to the collapse of the mobile crane. The turret bolts were made of high strength steel. Comprehensive engineering analysis suggested that the turret bolts failure was initiated with fatigue. The fatigue was most likely initiated by the corrosion at the bolt surface and accelerated by the loosening of bolts due to long servicing life and/or fluctuating tensile load. Based on the investigations, recommendations are provided to guide the operation of the mobile crane to prevent the premature failure.</p