scholarly journals Ideal point error for model assessment in data-driven river flow forecasting

2012 ◽  
Vol 16 (8) ◽  
pp. 3049-3060 ◽  
Author(s):  
C. W. Dawson ◽  
N. J. Mount ◽  
R. J. Abrahart ◽  
A. Y. Shamseldin

Abstract. When analysing the performance of hydrological models in river forecasting, researchers use a number of diverse statistics. Although some statistics appear to be used more regularly in such analyses than others, there is a distinct lack of consistency in evaluation, making studies undertaken by different authors or performed at different locations difficult to compare in a meaningful manner. Moreover, even within individual reported case studies, substantial contradictions are found to occur between one measure of performance and another. In this paper we examine the ideal point error (IPE) metric – a recently introduced measure of model performance that integrates a number of recognised metrics in a logical way. Having a single, integrated measure of performance is appealing as it should permit more straightforward model inter-comparisons. However, this is reliant on a transferrable standardisation of the individual metrics that are combined to form the IPE. This paper examines one potential option for standardisation: the use of naive model benchmarking.

2012 ◽  
Vol 9 (2) ◽  
pp. 1671-1698
Author(s):  
C. W. Dawson ◽  
R. J. Abrahart ◽  
A. Y. Shamseldin ◽  
N. J. Mount

Abstract. When analysing the performance of hydrological models, researchers use a number of diverse statistics. Although some statistics appear to be used more regularly in such analyses than others, there is a distinct lack of consistency in evaluation, making studies undertaken by different authors or performed at different locations difficult to compare in a meaningful manner. Moreover, even within individual reported case studies, substantial contradictions are found to occur between one measure of performance and another. In this paper we examine the Ideal Point Error (IPE) metric ‐ a recently introduced measure of model performance that integrates a number of recognised metrics in a logical way. Having a single, integrated measure of performance is appealing as it should permit more straightforward model inter-comparisons. However, IPE relies on the adoption of a consistent and recognised benchmarking system. This paper examines one potential option for benchmarking IPE: the use of "persistence scenarios".


2014 ◽  
Vol 644-650 ◽  
pp. 1965-1968
Author(s):  
Yue Li Li ◽  
Chao Wang

The method provided in this paper can be according to the current population to readjust the weight, thus obtain toward the positive ideal point search pressure, finally converge to the optimal solution. This paper combines the feasible direction into genetic algorithm. This method can lead the individual to optimal solution region along feasible direction which approach the optimal solution sets. Through evaluating the degree of distance between chromosome and constrain, we introduce membership function into traditional GA and embed the information of infeasible solutions into fitness function. Propose a self-adapting evaluation function. This method can readjust the weights according to current group and then get the stress of searching to the ideal positive point. To a kind of fuzzy multi-objective optimization problem, propose a method of best satisfaction to transform the fuzzy models to clear ones and solve the models using GA based on interactive method. Then testify its validity though examples.


Author(s):  
Yang Xu ◽  
Yelin Fu ◽  
Kin Keung Lai

The primary purpose of this paper is to aggregate the overall rating based on guests’ online ratings by performing a social choice analysis of online hotel rating. Specifically, we first define the individual preference as the subjective judgement on the important order of the dimensions of online hotel rating, then quantify the individual preference through an analytical approach, the pessimistic and optimistic results of which are balanced by the Hurwicz criterion approach, lastly formulate the social choice result by means of the ideal-point concept. An empirical study using the real data collected from Trip.com is conducted to show the applicability and superiority of our methodology.


Author(s):  
Dominic Scott

This chapter presents a reading of Plato’s Republic. The Republic is among Plato’s most complex works. From its title, the first-time reader will expect a dialogue about political theory, yet the work starts from the perspective of the individual, coming to focus on the question of how, if at all, justice contributes to an agent’s happiness. Only after this question has been fully set out does the work evolve into an investigation of politics—of the ideal state and of the institutions that sustain it, especially those having to do with education. But the interest in individual justice and happiness is never left behind. Rather, the work weaves in and out of the two perspectives, individual and political, right through to its conclusion. All this may leave one wondering about the unity of the work. The chapter shows that, despite the enormous range of topics discussed, the Republic fits together as a coherent whole.


2021 ◽  
pp. 1354067X2110040
Author(s):  
Josefine Dilling ◽  
Anders Petersen

In this article, we argue that certain behaviour connected to the attempt to attain contemporary female body ideals in Denmark can be understood as an act of achievement and, thus, as an embodiment of the culture of achievement, as it is characterised in Præstationssamfundet, written by the Danish sociologist Anders Petersen (2016) Hans Reitzels Forlag . Arguing from cultural psychological and sociological standpoints, this article examines how the human body functions as a mediational tool in different ways from which the individual communicates both moral and aesthetic sociocultural ideals and values. Complex processes of embodiment, we argue, can be described with different levels of internalisation, externalisation and materialisation, where the body functions as a central mediator. Analysing the findings from a qualitative experimental study on contemporary body ideals carried out by the Danish psychologists Josefine Dilling and Maja Trillingsgaard, this article seeks to anchor such theoretical claims in central empirical findings. The main conclusions from the study are used to structure the article and build arguments on how expectations and ideals expressed in an achievement society become embodied.


Author(s):  
Wolfram Malter ◽  
Bo Jan Bachmann ◽  
Barbara Krug ◽  
Martin Hellmich ◽  
Max Zinser ◽  
...  

Abstract Background The current methods for calculating the ideal implant volume for breast reconstruction are based on pre- or intraoperative volume measurements of the existing breast volume and do not take into account the individual breast density of the woman. This study aims is to identify objective parameters that can help to improve the optimal implant selection. Materials and methods This retrospective analysis includes 198 breast cancer patients who underwent mastectomy. Breast densities (ACR) measured in mammography and MRI were compared with the removed breast tissue weight and volume of the implants used. In addition, the resected weight was compared directly with the implant volume to calculate a mathematical function. Results There was no significant correlation between the ACR values and the resected weights [correlation coefficient: mammography:− 0.117 (p = 0.176), MRI − 0.033 (p = 0.756)]. A negative correlation between the implant volumes and both imaging methods could be demonstrated [correlation coefficient: mammography − 0.268; p = 0.002; MRI was − 0.200 (p = 0.055)]. A highly significant correlation between the resected weights and the implant volumes (correlation coefficient 0.744; p < 0.001) was observed. This correlation corresponds to a power function (y = 34.71 x0.39), in which any resected weight can be used for the variable x to calculate the implant volume. Conclusion We were able to show that there is a significant correlation between the resected breast tissue and the implant volume. With our novel potency function, the appropriate implant volume can be calculated for any resected weight making it easier for the surgeon to choose a fitting implant in a simple and more objective manner.


1999 ◽  
Vol 10 (2) ◽  
pp. 402-409 ◽  
Author(s):  
A.F. Atiya ◽  
S.M. El-Shoura ◽  
S.I. Shaheen ◽  
M.S. El-Sherif

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