Sampling rainfall events: a novel approach to generate large correlated samples

2012 ◽  
Vol 44 (2) ◽  
pp. 351-361 ◽  
Author(s):  
Siao Sun ◽  
Soon-Thiam Khu ◽  
Slobodan Djordjević

It is essential that the correlation between variables is considered properly when using sampling-based methods. Modeling rainfall events is of great interest because the rainfall is usually the major driving force of hydrosystems. A novel method for generating correlated samples is introduced providing that the marginal distributions of variables as well as their correlations between them are known. The basic idea of the method is to adjust the correlations between samples by rearranging the positions inside marginal samples after each marginal sample is generated according to its distribution. The group method is developed in order to facilitate an efficient generation of correlated samples of large sizes. The theoretical precision associated with the group method is derived. There is a trade off between the computational efficiency of the algorithm and the precision that can be achieved when using different numbers of groups. The method is successfully applied to two cases of rainfall sample generation problems. The effectiveness of the group method is studied. Large group numbers are recommended in practical use as the samples distribute more broadly regardless of computational efficiency.

Author(s):  
J Ph Guillet ◽  
E Pilon ◽  
Y Shimizu ◽  
M S Zidi

Abstract This article is the first of a series of three presenting an alternative method of computing the one-loop scalar integrals. This novel method enjoys a couple of interesting features as compared with the method closely following ’t Hooft and Veltman adopted previously. It directly proceeds in terms of the quantities driving algebraic reduction methods. It applies to the three-point functions and, in a similar way, to the four-point functions. It also extends to complex masses without much complication. Lastly, it extends to kinematics more general than that of the physical, e.g., collider processes relevant at one loop. This last feature may be useful when considering the application of this method beyond one loop using generalized one-loop integrals as building blocks.


2018 ◽  
Vol 123 (1259) ◽  
pp. 79-92
Author(s):  
A. Kumar ◽  
A. K. Ghosh

ABSTRACTIn this paper, a Gaussian process regression (GPR)-based novel method is proposed for non-linear aerodynamic modelling of the aircraft using flight data. This data-driven regression approach uses the kernel-based probabilistic model to predict the non-linearity. The efficacy of this method is examined and validated by estimating force and moment coefficients using research aircraft flight data. Estimated coefficients of aerodynamic force and moment using GPR method are compared with the estimated coefficients using maximum-likelihood estimation (MLE) method. Estimated coefficients from the GPR method are statistically analysed and found to be at par with estimated coefficients from MLE, which is popularly used as a conventional method. GPR approach does not require to solve the complex equations of motion. GPR further can be directed for the generalised applications in the area of aeroelasticity, load estimation, and optimisation.


2016 ◽  
Vol 81 (10) ◽  
pp. 1111-1119 ◽  
Author(s):  
Fatemeh Bagheri ◽  
Abolfazl Olyaei

A novel method was developed for synthesizing a series of new three dentate Schiff base ligands starting from hydroxynaphthalidene pyrimidinyl amines with o-phenylenediamines or o-aminophenol or 2-amino-3-hydroxy-pyri-dine in the presence of formic acid catalyst under solvent-free conditions. In these reactions [1+1] condensation product as half-unit ligand was obtained. Moreover, the reaction of hydroxynaphthalidene pyrimidinyl amines with 3,4-diamino-pyridine and 1,8-naphthalenediamine lead to the formation of C2-naphthylated imidazopyridine and dihydropyrimidine, respectively. The attractive features of this protocol are: use of inexpensive catalyst, operationally simple, short reaction times, easy handling, and good yields.


2020 ◽  
Vol 8 (6) ◽  
pp. 5820-5825

Human computer interaction is a fast growing area of research where in the physiological signals are used to identify human emotion states. Identifying emotion states can be done using various approaches. One such approach which gained interest of research is through physiological signals using EEG. In the present work, a novel approach is proposed to elicit emotion states using 3-D Video-audio stimuli. Around 66 subjects were involved during data acquisition using 32 channel Enobio device. FIR filter is used to preprocess the acquired raw EEG signals. The desired frequency bands like alpha, delta, beta and theta are extracted using 8-level DWT. The statistical features, Hurst exponential, entropy, power, energy, differential entropy of each bands are computed. Artificial Neural network is implemented using Sequential Keras model and applied on the extracted features to classify in to four classes (HVLA, HVHA, LVHA and LVLA) and eight discrete emotion states like clam, relax, happy, joy, sad, fear, tensed and bored. The performance of ANN classifier found to perform better for 4- classes than 8-classes with a classification rate of 90.835% and 74.0446% respectively. The proposed model achieved better performance rate in detecting discrete emotion states. This model can be used to build applications on health like stress / depression detection and on entertainment to build emotional DJ.


Author(s):  
A. Brook ◽  
E. Ben Dor

A novel approach for radiometric calibration and atmospheric correction of airborne hyperspectral (HRS) data, termed supervised vicarious calibration (SVC) was proposed by Brook and Ben-Dor in 2010. The present study was aimed at validating this SVC approach by simultaneously using several different airborne HSR sensors that acquired HSR data over several selected sites at the same time. The general goal of this study was to apply a cross-calibration approach to examine the capability and stability of the SVC method and to examine its validity. This paper reports the result of the multi sensors campaign took place over Salon de Provenance, France on behalf of the ValCalHyp project took place in 2011. The SVC method enabled the rectification of the radiometric drift of each sensor and improves their performance significantly. The flight direction of the SVC targets was found to be a critical issue for such correction and recommendations have been set for future utilization of this novel method. The results of the SVC method were examined by comparing ground-truth spectra of several selected validation targets with the image spectra as well as by comparing the classified water quality images generated from all sensors over selected water bodies.


2020 ◽  
pp. 1085-1114
Author(s):  
Youngseok Choi ◽  
Jungsuk Oh ◽  
Jinsoo Park

This research proposes a novel method of measuring the dynamics of semantic relatedness. Research on semantic relatedness has a long history in the fields of computational linguistics, psychology, computer science, as well as information systems. Computing semantic relatedness has played a critical role in various situations, such as data integration and keyword recommendation. Many researchers have tried to propose more sophisticated techniques to measure semantic relatedness. However, little research has considered the change of semantic relatedness with the flow of time and occurrence of events. The authors' proposed method is validated by actual corpus data collected from a particular context over a specific period of time. They test the feasibility of our proposed method by constructing semantic networks by using the corpus collected during a different period of time. The experiment results show that our method can detect and manage the changes in semantic relatedness between concepts. Based on the results, the authors discuss the need for a dynamic semantic relatedness paradigm.


RSC Advances ◽  
2018 ◽  
Vol 8 (54) ◽  
pp. 30813-30824 ◽  
Author(s):  
Areej K. Al-Jwaid ◽  
Dmitriy Berillo ◽  
Irina N. Savina ◽  
Andrew B. Cundy ◽  
Jonathan L. Caplin

A novel method of crosslinking live bacteria into a stable 3D porous structure and its subsequent use in phenol degradation is reported.


Author(s):  
H. Ando ◽  
Y. Takami ◽  
N. Muramatsu

This paper discusses the enhancement of gripping efficiency of a gripping mechanism for miniature grippers. This gripping mechanism employs a displacement enlarging mechanism utilizing an elastic buckling of the flexible gripping fingers. Miniature grippers have been realized by the flexible gripping fingers acting as the displacement enlarging mechanism. However, there is a trade-off relation between the enlarged displacement and gripping force of the gripping mechanism. For this reason, the enhancement of gripping efficiency of the gripping mechanism has been experimentally attempted by constraining an elastic deformation of the flexible gripping fingers. The flexible gripping fingers are largely deformed due to elastic buckling after gripping an object. This elastic deformation is constrained by supports. Experiments have been conducted for some different cases of placement of the supports. The driving force, driving displacement and gripping force of the gripping mechanism have been measured. From experimental results, it has been confirmed that the enhancement of gripping efficiency of the gripping mechanism is feasible by controlling deformation of the flexible fingers passively.


Author(s):  
Esmaeil Keshavarz ◽  
Abbas Shoul

Trade-off problems concentrate on balancing the main parameters of a project as completion time, total cost and quality of activities. In this study, the problem of project time-cost-quality trade-off is formulated and solved from a new standpoint. For this purpose, completion time and crash cost of project are illustrated as fuzzy goals, also the dependency of implementing time of each activity and its execution-quality is described by a fuzzy number. The overall quality of the project execution is defined as the minimum execution-quality of the project activities that should be maximized. Based on some real assumptions, a three-objective programming problem associated with the time-cost-quality trade-off problem is formulated; then with the aim of identifying a fair and appropriate trade-off, the research problem is reformulated as a single objective linear programming by utilizing a fuzzy decision-making methodology. Generating a final preferred solution, rather than a set of Pareto optimal solutions, and having a reasonable interpretation are two most important advantages of the proposed approach. To explain the practical performance of the proposed models and approach, a time-cost-quality trade-off problem for a project with real data is solved and analyzed.


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