A Novel Life Cycle-based Principal Component Analysis Framework for Eco-efficiency Analysis: Case of the United States Manufacturing and Transportation Nexus

2015 ◽  
Vol 92 ◽  
pp. 327-342 ◽  
Author(s):  
Yong Shin Park ◽  
Gokhan Egilmez ◽  
Murat Kucukvar
Author(s):  
Kavir Patel ◽  
Ashfaaq Mohamed ◽  
Gary W. Van Vuuren

Volatile markets and economic environments can significantly distort the shape and smoothness of yield curve movements. This study explores the influence of movements in United States interest rates on South African interest rates. This study aims to identify the main underlying movements present in the United States and South African yield curves and to further determine the dominant factors that are responsible for driving South African interest rate movements. The principal settings for the study were the United States and South African markets representing, respectively, a developed and developing market. Principal component analysis was used to discern the major drivers of developing and developed market interest rates. The findings show that the principal component analysis technique is able to effectively classify and quantify the movements of yield curves across both markets in terms of three main factors, namely level, slope and curvature shifts. During certain periods, South African yield curve changes were largely driven by variations in United States interest rates and the rand/dollar exchange rate. Results also demonstrated that a volatile market and economic environment can significantly distort the shape and smoothness of yield curve movements.


2020 ◽  
Vol 12 (12) ◽  
pp. 5088
Author(s):  
Ali Karji ◽  
Mostafa Namian ◽  
Mohammadsoroush Tafazzoli

The need to build more facilities has intensified the inherited adverse impacts of the construction industry on the triple bottom lines of sustainability (i.e., people, planet, and profit). The current practice of sustainability in the construction industry is far from reaching the targeted green goals. In order to foster these endeavors, this study aims to explore sustainable construction barriers in the United States. To achieve the objective, first, 12 sustainability barriers were identified based on an excessive and comprehensive literature review and solicitation of experts’ opinions to validate the barriers. Next, a questionnaire survey was developed and distributed among 135 industry professionals to evaluate the relative importance of factors. To offer a practical solution, principal component analysis (PCA) was used to analyze the data and find the most effective barriers. The results show that four major barriers, including (1) pre-construction constraints, (2) managerial constraints, (3) legislative constraints, and (4) financial and planning constraints are the most influential challenges that the industry faces to foster sustainable construction. Practical solutions are suggested to tackle sustainable construction barriers. The findings of this study are beneficial to the architecture, engineering, and construction (AEC) industry members along with owners and policymakers.


2020 ◽  
Vol 214 ◽  
pp. 03003
Author(s):  
Jiayi Yan ◽  
Qian Pu ◽  
Junfei Liu

Based on the knowledge of economics, this paper selects 22 macroeconomic indicators that best reflect the overall economic situation of the United States. After differential, logarithmic and exponential preprocessing of the original data, this paper, based on the power spectral analysis model, adaptively identifies the periodicity of the selected economic indicators, and visualize the results. As a result, it screens out 11 indicators with obvious periodicity. In the process of solving the weighted distance based on principal component analysis, correlation test is first conducted on the selected 11 single indicators of periodicity to obtain Pearson correlation heatmap. Then, the principal components are extracted by selecting the first five principal components as the virtual indicators to represent the monthly economic situation, and calculating the weighted distance value between months for visualization. Finally, we select the results of 36 months’ smoothing for analysis, figure out the time intervals with similar economic situation, and verify the conjecture of economic periodicity. Finally, based on K-MEAN clustering analysis, the economic conditions of 352 months are classified into 3 clusters by using the weighted distance after 36 months’ smoothing. From the visualized results, it is found that there are two complete cycles, i.e. red-yellow-blue and red-yellow-blue, which is consistent with the conclusion of principal component analysis model, and proves the existence of economic cycle again. In conclusion, based on the above PCA weighted distance and clustering analysis, it can be concluded that the economic period is around 176 months, in favor of medium long periodicity theory.


2018 ◽  
Author(s):  
Juan F. Macias-Velasco ◽  
Ryan T. Brunson ◽  
Wayne B. Hunter ◽  
Blake R. Bextine

AbstractThe Asian Citrus Psyllid (ACP) (Diaphorina citri) is a Hemipteran which feeds on Citrus and is the principal vector of the pathogen Candidatus Liberibacter asiaticus (Las); the primary causal agent of Huanglongbing (HLB) or citrus greening disease. Currently HLB is the single greatest threat to the American citrus industry. Previous work has shown that that Cytochrome P450 (CYP4) genes are associated with insecticidal resistance to neonicotinoid insecticides. Infection by Las has also been shown to affect the expression of CYP4 genes. In this study the genetic relationships of ACP populations was evaluated using melting curve analysis of CYP4 genes. Principal component analysis shows the presence of two potential haplotypes. The groups identified by principal component analysis are significantly different from each other (P < 0.05) for all CYP4 genes tested. All populations are most likely within 2-3 mutations of each other. The existence of these mutations sheds light on the potential evolution of ACP in North America. Indicating either coevolution with Las or difference in imidacloprid basal selective pressure in the United States and Mexico.


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