UG-based research and development of 3D pipe layout system of the aircraft engine

AbstractStandardized design method is important for the airworthiness certification. Based on the principles and features of the aircraft engine external pipe system, in this paper, the research on the theory of automation of pipe layout has been done. We also put forward the process of automatic and mixed generation of pipe layout, the design of pipe layout system and the resolution of arbitrariness of pipe layout. In order to improve the efficiency of the system, a parameterized component library has been built, on the basis of the secondary development of UG. Therefore, the automation pipe layout and the real-time modification have been achieved. According to the predefined rules, constraint test and result output of the system can be conducted

An Improved Entity Similarity Measurement Method

To facilitate the integration of learning resources categorized under different ontology representations, the techniques of ontology mapping can be applied. Through many algorithms and systems have been proposed for ontology mapping, they do not have an automatic weighting strategy on class features to automate the ontology mapping process. A novel method of computing the feature weights is proposed by feature semantic analysis, defining characteristics of the different entities similarity calculation model and weight calculation model. The results show that it makes the ontology mapping process more automatic while retaining satisfying accuracy. Improve ontology mapping effectiveness

Utility of Landsat Image in the Study of Land Cover and Land Surface Temperature Change

AbstractScientists have aimed at exploring land use and land cover (LULC) and their environmental influence in order to improve our understanding of the causes and consequences of these phenomena. This study addresses and use and land cover change (LUCC) in the upper reaches of Pearl River Delta, China, from 1990 to 2008. Based on remotely sensed images of Landsat, LUCC and land surface temperature were assessed. Results showed that land surface temperature was highly influenced by the LUCC from 1990 to 2008. An examination of the relationship between the LULC and LST maps was finally conducted to comprehension their interactions. Results indicated that Landsat image was effective for quantifying the heat environment and providing reliable measurements of land use change. LST was found to be positively correlated with impervious surface but negatively correlated with vegetated land. Each temperature zone was associated with a dominant LULC category

Overbuilding and development cascades under irrational expectations

The recent sluggish recovery in the U.S. house market has further motivated our research interests in overbuilding in real estate markets. Our model is an extension to Grenadier's (1996), who emphasizes rational investment decisions possibly leading to oversupply in real estate markets, by further allowing for the important implication of irrational expectation for the strategic interaction amongst competing investors. In this model, two market participants are asymmetric because one of them is allowed to have heterogeneous expectations about the growth and volatility of demand shocks. Unlike most of previous studies that only simply think of this phenomenon as a result of irrationality, our model further finds that irrational investors’ value-maximizing investment choices matter in understanding the strategic interaction of investment decisions in real estate markets, therefore providing additional insights into overbuilding and other puzzling phenomena in real estate markets