scholarly journals Classification and Evolution Analysis of Key Transportation Technologies Based on Bibliometrics

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Hua Chen ◽  
Ming Cai ◽  
Ke Huang ◽  
Shuxin Jin
Keyword(s):  
Least Squares ◽  
Least Squares Method ◽  
Gaussian Mixture ◽  
Annual Number ◽  
Bibliometric Method ◽  
Simulation Techniques ◽  
Key Technologies ◽  
Number Of Publications ◽  
And Control ◽  
Transportation Technologies

To study the classification and evolution of key technologies in the transportation field, the data of 36 authoritative SCI journals in the transportation field were collected from the Web of Science core collection database from 2001 to 2020. Based on the bibliometric method, this study used Python to process and visualize data, combined with bibliometric software VOSviewer to assist data visualization. Firstly, a preprocessing data algorithm was designed to deduplicate the collected data, merge synonyms, and extract key technologies. Then the paper records that contained the key technology lexicon were filtered out. Next, the annual number of publications and the distribution of key technologies over time were counted. The least squares method was used to fit the distribution of the annual proportion of the publications, and the slope k1 of the fitted linear regression equation was used to determine the research interest trend of key technologies. The key technologies were divided into “hot technology,” “cold technology,” and “other technologies,” according to the research heat trend. In order to further explore the research hotspots, the least squares method was also used to fit the citations of all technologies to obtain the slope k2. We use the Gaussian mixture model (GMM) algorithm to cluster k1 and k2 of each technology. As a result, the 144 technologies were divided into 13 super-key technologies, 60 key technologies, 59 relative key technologies, and 12 lower-key technologies. Then, the evolution of key technologies was analyzed from two perspectives of weighted evolution and cumulative evolution. And the technology evolution trend in the transportation field in the past 20 years was explored. Finally, the cooccurrence clustering method was adopted to divide key transportation technologies into five categories: vehicle technology and control, optimization algorithms and simulation techniques, artificial intelligence and big data, Internet of Things and computing, and communication technology. The research results can provide references for different people in the transportation field, including but not limited to researchers, journal editors, and funding agencies.

Forecast and Control for the Amount of Rural Economic Crops

2014 ◽  
Vol 687-691 ◽  
pp. 4857-4860
Author(s):  
Wen Xi Duan
Keyword(s):  
Least Squares ◽  
Linear Function ◽  
Statistical Methods ◽  
Historical Data ◽  
Least Squares Method ◽  
The Real ◽  
Straight Line ◽  
Line Equation ◽  
And Control

The planting amount is determined by farmers according to the profit of planting economic crops. Moreover, the planting profit is estimated by using the statistical methods. The relation between the planting amount and the profit is similar to a linear function. However, the straight line equation has been set by using the historical data, calculating the slope of the straight line or adopting the least squares method. Therefore, the planting amount in next year will be calculated based on the equation. In a word, the planting amount in next year will be adjusted and controlled on the basis of the calculated planting amount and the real demand in the market.

Plant Allelopathy Research and Development: 60 Years (1960-2019)

2021 ◽  
Vol 52 (2) ◽  
pp. 163-180
Author(s):  
J.L. Wang ◽  
Z.H. Zhang ◽  
C. Hu ◽  
R.Y. Fu ◽  
G. Hu
Keyword(s):  
The United States ◽  
Research Field ◽  
Annual Number ◽  
Production Plant ◽  
Bibliometric Method ◽  
Research Directions ◽  
Main Research ◽  
Initial Stage ◽  
Number Of Publications ◽  
Academy Of Sciences

environment. It is one of the hotspots in Ecology and Agronomy. In this paper, we have retrieved from the Web of Science (WoS) SCI-E database the allelopathy-related studies (1960-2019). The Annual Number of Publications, Authors, Countries, Institutions, Journals and Keywords were analyzed by the bibliometric method to determine the research trends and hotspot changes in this field over the past 6 decades. From 1960-2019, the WoS database included 4,114 studies in the field of plant allelopathy. During this period of 60 years, the number of publications has gone through three stages: (i). Initial Stage (1960-1990), (ii). Growing Stage (1991-2009) and (iii). Stable Stage (2010-2019). The studies were conducted by 9,956 authors at 2,166 institutions across 100 countries. The United States, China, and Japan have the highest number of publications. The top three institutions with the highest number of publications are the Chinese Academy of Sciences, Kagawa University and USDA, USA. The top three authors are H. Kato-Noguchi, F.A. Macias, and C.H. Kong. The major Journals in this field are: (i). Allelopathy Journal, (ii). Journal of Chemical Ecology and (iii). Plant and Soil. The results of keyword clustering showed that the main research directions in this field are: (i). Metabonomics undergoing allelopathy, (ii). Functions of allelopathy substances, (iii). Molecular biology, (iv). Allelopathy of aquatic plants, (v). Alien plants invasion and (vi). Application of plant allelopathy in agroforestry production. Plant allelopathy is a research field that aims to maintain stable development. Future studies should focus on strengthening the cooperation among international scholars in plant allelopathy research and improving the output in frontier and hotspot areas.

‘Least squares’ method—theorem or law?

1980 ◽  
Vol 59 (9) ◽  
pp. 8
Author(s):  
D.E. Turnbull
Keyword(s):  
Least Squares ◽  
Least Squares Method

An Augmented Iteratively Re-weighted and Refined Least Squares Method for lp Minimization Problem in Inverse Modeling of Potential Field Magnetic Data

2020 ◽  
Vol 1 (3) ◽  
Author(s):  
Maysam Abedi
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
Least Squares ◽  
Minimization Problem ◽  
Potential Field ◽  
Field Data ◽  
Least Squares Method ◽  
Porphyry Copper ◽  
Magnetic Data ◽  
Magnetic Field Data

The presented work examines application of an Augmented Iteratively Re-weighted and Refined Least Squares method (AIRRLS) to construct a 3D magnetic susceptibility property from potential field magnetic anomalies. This algorithm replaces an lp minimization problem by a sequence of weighted linear systems in which the retrieved magnetic susceptibility model is successively converged to an optimum solution, while the regularization parameter is the stopping iteration numbers. To avoid the natural tendency of causative magnetic sources to concentrate at shallow depth, a prior depth weighting function is incorporated in the original formulation of the objective function. The speed of lp minimization problem is increased by inserting a pre-conditioner conjugate gradient method (PCCG) to solve the central system of equation in cases of large scale magnetic field data. It is assumed that there is no remanent magnetization since this study focuses on inversion of a geological structure with low magnetic susceptibility property. The method is applied on a multi-source noise-corrupted synthetic magnetic field data to demonstrate its suitability for 3D inversion, and then is applied to a real data pertaining to a geologically plausible porphyry copper unit.  The real case study located in  Semnan province of  Iran  consists  of  an arc-shaped  porphyry  andesite  covered  by  sedimentary  units  which  may  have  potential  of  mineral  occurrences, especially  porphyry copper. It is demonstrated that such structure extends down at depth, and consequently exploratory drilling is highly recommended for acquiring more pieces of information about its potential for ore-bearing mineralization.

Theoretical accuracy of the last squares method in the isotope dilution analysis

1984 ◽  
Vol 49 (4) ◽  
pp. 805-820
Author(s):  
Ján Klas
Keyword(s):  
Least Squares ◽  
Isotope Dilution ◽  
Least Squares Method ◽  
Isotope Dilution Analysis ◽  
Straight Line ◽  
The One ◽  
Two Parameter ◽  
Theoretical Accuracy

The accuracy of the least squares method in the isotope dilution analysis is studied using two models, viz a model of a two-parameter straight line and a model of a one-parameter straight line.The equations for the direct and the inverse isotope dilution methods are transformed into linear coordinates, and the intercept and slope of the two-parameter straight line and the slope of the one-parameter straight line are evaluated and treated.

Autonomous Vehicles in the Mobility System

2020 ◽  
pp. 500-514
Author(s):  
Thilo von Pape
Keyword(s):  
Artificial Intelligence ◽  
Mobile Phones ◽  
Mobile Communication ◽  
Autonomous Vehicles ◽  
Communication Research ◽  
Collective Control ◽  
System P ◽  
Mobility System ◽  
And Control ◽  
Transportation Technologies

This chapter discusses how autonomous vehicles (AVs) may interact with our evolving mobility system and what they mean for mobile communication research. It juxtaposes a conceptualization of AVs as manifestations of automation and artificial intelligence with an analysis of our mobility system as a historically grown hybrid of communication and transportation technologies. Since the emergence of railroad and telegraph, this system has evolved on two layers: an underlying infrastructure to power and coordinate the movements of objects, people, and ideas in industrially scaled speeds, volumes, and complexity and an interface to seamlessly access this infrastructure and control it. AVs are poised to further enhance the seamlessness which mobile phones and cars already lent to mobility. But in assuming increasingly sophisticated control tasks, AVs also disrupt an established shift toward individual control, demanding new interfaces to enable higher levels of individual and collective control over the mobility infrastructure.

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