scholarly journals Accuracy Evaluation of Least-Squares Method for a Class of Systems with Multi-Errors in Input and Output**This work is supported by the National Key Basic Research Program of China (973 Program) under Grant No. 2014CB845301 and the National Center for Mathematics and Interdisciplinary Sciences, Chinese Academy of Sciences

2015 ◽  
Vol 48 (28) ◽  
pp. 320-325
Author(s):  
Bai Wenyan ◽  
Su Qiya ◽  
Xue wenchao ◽  
Huang Yi ◽  
Fang Haitao
Keyword(s):  
Least Squares ◽  
Research Program ◽  
Least Squares Method ◽  
Basic Research ◽  
Accuracy Evaluation ◽  
Input And Output ◽  
Chinese Academy Of Sciences ◽  
Academy Of Sciences

scholarly journals Lu Yu: the past and future of condensed matter physics

2015 ◽  
Vol 2 (3) ◽  
pp. 371-376
Author(s):  
Mu-ming Poo ◽  
Ling Wang
Keyword(s):  
Condensed Matter ◽  
Rooted Tree ◽  
Basic Research ◽  
Condensed Matter Physics ◽  
Fed State ◽  
The Past ◽  
Chinese Academy Of Sciences ◽  
History Of ◽  
Theoretical Physicist ◽  
Academy Of Sciences

Abstract Lu Yu, a distinguished theoretical physicist at the Institute of Physics (IOP) of Chinese Academy of Sciences (CAS), has witnessed the development of Chinese physics over the past five decades, from the difficult period of 1960s when physicists worked in a ‘half-fed’ state to the present flowering springtime of Chinese physics in which many breakthroughs at the frontier of physics are attracting international recognition. He considers these achievements to be not merely ‘intermittent bubbles’, but the cumulative result of sustained governmental support of basic research over the past decades. In his area of condensed-matter physics, Yu sees ‘a big deep-rooted tree with many branches—some old branches have withered away, but new shoots continue to appear’. In a recent interview with NSR, Yu reflected upon the recent history of condensed-matter physics in China—what has been accomplished and what lies ahead—and his view on the development of physics in general.

scholarly journals Directional scale elasticity considering the management preference of decision-makers

2021 ◽  
Author(s):  
Tiantian REN ◽  
Zhongbao Zhou ◽  
Ruiyang Li ◽  
Wenbin Liu
Keyword(s):  
Data Envelopment Analysis ◽  
Returns To Scale ◽  
Basic Research ◽  
Decision Makers ◽  
Data Envelopment ◽  
Scale Elasticity ◽  
Chinese Academy Of Sciences ◽  
Simplifying Assumptions ◽  
Academy Of Sciences ◽  
Simultaneous Change

Most data envelopment analysis (DEA) studies on scale elasticity (SE) and returns to scale (RTS) of efficient units arise from the traditional definitions of them in economics, which is based on measuring radial changes in outputs caused by the simultaneous change in all inputs. In actual multiple inputs/outputs activities, the goals of expanding inputs are not only to obtain increases in outputs, but also to expect the proportions of such increases consistent with the management preference of decision-makers. However, the management preference is usually not radial changes in outputs. With the latter goal into consideration, this paper proposes the directional SE and RTS in a general formula for multi-output activities, and offers a DEA-based model for the formula of directional SE at any point on the DEA frontier, which is straightforward and requires no simplifying assumptions. Finally, the empirical part employs the data of 16 basic research institutions in Chinese Academy of Sciences (CAS) to illustrate the superiority of the proposed theories and methods.

scholarly journals The development of geophysics in the early period of the People's Republic of China based on the Institute of Geophysics, Chinese Academy of Sciences (1950–1966)

2021 ◽  
Vol 12 (1) ◽  
pp. 21-41
Author(s):  
Zhihui Zhang ◽  
Rui Wang
Keyword(s):  
Social History ◽  
Early Period ◽  
Basic Research ◽  
Space Physics ◽  
Policy Support ◽  
Scientific Development ◽  
Republic Of China ◽  
Chinese Academy Of Sciences ◽  
The 1950S ◽  
Academy Of Sciences

Abstract. From the perspective of the social history of science and transnational history, this paper reviewed the development of the Institute of Geophysics, Chinese Academy of Sciences (IGCAS), rather than focusing on its scientific achievements. Before the 1950s, the discipline of geophysics in China, except for the branch of meteorology, had a very weak foundation, and few researchers were engaged in it. The systematic development of geophysics began with the establishment of IGCAS. In this paper, the early development of IGCAS was researched thoroughly. At first, we briefly reviewed the establishment process for IGCAS. After being promoted by the desire of scientists to develop big geophysics, the Chinese Academy of Sciences (CAS) integrated scattered academic forces, which included geomagnetism and geophysical exploration, to establish the IGCAS. The IGCAS was based on the Institute of Meteorology of Academia Sinica in the Republic of China era. After that, we summarized work done by IGCAS in the development of geophysics from the 1950s to 1966, the year in which the Cultural Revolution began. We focused on policy support, adjustment of organizational structure, and scientific capacity building, when China was facing an isolated international diplomatic environment, continuous domestic political movements, and an austere social economy. Then, to bolster the development of geophysics in China, the slogan of “Missions Drive Disciplines”, which was instilled and implemented by the Chinese scientific community, was introduced briefly. The scientific development of the IGCAS and typical examples in several branches of geophysics, which included atmospheric science, seismology, space physics, and other fields, were systematically summarized and benchmarked to the international academic level. We then summarized the basic research on geophysics carried out by the institute in economic construction and national defense. Finally, the experience and lessons in the development of this institute and its effect on geophysics in China were explored.

INTRODUCTION OF EIO MODEL IN TLS METHOD TO CALCULATE THE COORDINATES TRANSFORMATION BY HELMERT’S FORMULA

InterConf ◽  
2021 ◽  
pp. 256-266
Author(s):  
Huynh Nguyen Dinh Quoc ◽  
Dang Xuan Truong ◽  
Tran Thi Bao Tram
Keyword(s):  
Least Squares ◽  
Iterative Algorithm ◽  
Coordinate Transformation ◽  
Least Squares Method ◽  
Total Least Squares ◽  
Geodetic Data ◽  
Large Dimension ◽  
Accuracy Evaluation ◽  
Matrix Inverse ◽  
Coordinates Transformation

The EIO (Errors In Observations) model is used in the total least squares method to calculate, process geodetic data. Next to the classical least squares method, it is applied to solve more solutions. When we use the EIO model in calculus and process, performing a matrix inverse has a large dimension will be avoided. Moreover, the calculation and accuracy evaluation steps are based on the iterative algorithm to get the results. In this paper, the authors use the procedure of calculating and evaluating the accuracy of the EIO model in the experimental calculation of the coordinate transformation according to the Helmert formula

‘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.

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