Search results for "HEURISTICS"
showing 10 items of 191 documents
A computational proposal for a robust estimation of the Pareto tail index: An application to emerging markets
2022
Abstract In this work, we backtest and compare, under the VaR risk measure, the fitting performances of three classes of density distributions (Gaussian, Stable and Pareto) with respect to three different types of emerging markets: Egypt, Qatar and Mexico. We also propose a new technique for the estimation of the Pareto tail index by means of the Threshold Accepting (TAVaR) and the Hybrid Particle Swarm Optimization algorithm (H-PSOVaR). Furthermore, we test the accuracy and robustness of our estimates demonstrating the effectiveness of the proposed approach.
A Review of Bias Research in Auditing: Opportunities for Integrating Experimental Psychology and Experimental Economics
2009
The objective of this paper is to show opportunities for integrating psychological and economics research in auditing. For this purpose, auditing research that employs both the methodologies of experimental psychology and experimental economics is collectively reviewed. The review is structured along three fundamental research questions: (1) Are auditors prone to biases; (2) what are the consequences of biased judgment in auditing; and (3) do features of the audit environment interact with the biased judgment? While both the research approach of experimental psychology and experimental economics are employed for addressing these resesarch questions, both approaches differ in their focus and…
Learning User's Confidence for Active Learning
2013
In this paper, we study the applicability of active learning in operative scenarios: more particularly, we consider the well-known contradiction between the active learning heuristics, which rank the pixels according to their uncertainty, and the user's confidence in labeling, which is related to both the homogeneity of the pixel context and user's knowledge of the scene. We propose a filtering scheme based on a classifier that learns the confidence of the user in labeling, thus minimizing the queries where the user would not be able to provide a class for the pixel. The capacity of a model to learn the user's confidence is studied in detail, also showing the effect of resolution is such a …
Active emulation of computer codes with Gaussian processes – Application to remote sensing
2020
Many fields of science and engineering rely on running simulations with complex and computationally expensive models to understand the involved processes in the system of interest. Nevertheless, the high cost involved hamper reliable and exhaustive simulations. Very often such codes incorporate heuristics that ironically make them less tractable and transparent. This paper introduces an active learning methodology for adaptively constructing surrogate models, i.e. emulators, of such costly computer codes in a multi-output setting. The proposed technique is sequential and adaptive, and is based on the optimization of a suitable acquisition function. It aims to achieve accurate approximations…
A survey of active learning algorithms for supervised remote sensing image classification
2011
Defining an efficient training set is one of the most delicate phases for the success of remote sensing image classification routines. The complexity of the problem, the limited temporal and financial resources, as well as the high intraclass variance can make an algorithm fail if it is trained with a suboptimal dataset. Active learning aims at building efficient training sets by iteratively improving the model performance through sampling. A user-defined heuristic ranks the unlabeled pixels according to a function of the uncertainty of their class membership and then the user is asked to provide labels for the most uncertain pixels. This paper reviews and tests the main families of active …
Capture Aware Sequential Waterfilling for LoraWAN Adaptive Data Rate
2020
LoRaWAN (Long Range Wide Area Network) is emerging as an attractive network infrastructure for ultra low power Internet of Things devices. Even if the technology itself is quite mature and specified, the currently deployed wireless resource allocation strategies are still coarse and based on rough heuristics. This paper proposes an innovative "sequential waterfilling" strategy for assigning Spreading Factors (SF) to End-Devices (ED). Our design relies on three complementary approaches: i) equalize the Time-on-Air of the packets transmitted by the system's EDs in each spreading factor's group; ii) balance the spreading factors across multiple access gateways, and iii) keep into account the c…
The Psychological Foundations of Management in Family Firms: Values, Biases, and Heuristics
2021
Considering the heterogeneity of family firm behaviors as reflecting the values, biases, and heuristics of individuals, we discuss the implications of the psychological foundations of management in family firms. We develop a conceptual framework for investigating how the values, biases, and heuristics of family and nonfamily members affect strategic decision-making and the outcomes of family firms. To advance the field, we put forward some relevant questions and offer a future research agenda at the intersection of the psychological foundations of management and family business.
Arc crossing minimization in graphs with GRASP
2001
Graphs are commonly used to represent information in many fields of science and engineering. Automatic drawing tools generate comprehensible graphs from data, taking into account a variety of properties, enabling users to see important relationships in the data. The goal of limiting the number of arc crossings is a well-admitted criterion for a good drawing. In this paper, we present a Greedy Randomized Adaptive Search Procedure (GRASP) for the problem of minimizing arc crossings in graphs. Computational experiments with 200 graphs with up to 350 vertices are presented to assess the merit of the method. We show that simple heuristics are very fast but result in inferior solutions, while hig…
Communities of Communication: Making Sense of the “Social” in Social Media
2012
As social media usage permeates people's lives, an increasing portion of their daily behavior leaves digital traces to be used by researchers. Social scientists can hope to gain new insight into the previously hidden but digitally recorded aspects of our digital social lives. Beyond aggregate and individual-level studies of user behavior, the digital traces also enable scientific examination of the structure of social interaction through networks. At the same time, the large scale and networked nature of social media data pose a new set of challenges to be overcome through the development of sound methodologies. We take stock of current methodological promises and challenges in social media…
A heuristic model-based approach for compensating wind effects in ski jumping.
2021
Wind influences the jump length in ski jumping, which raises questions about the fairness. To counteract the wind problem, the International Ski Federation has introduced a wind compensation system in 2009: time-averaged wind velocity components tangential to the landing slope are obtained from several sites along the landing slope, and these data are used in a linear statistical model for estimating the jump length effect of wind. This is considered in the total score of the ski jump. However, it has been shown that the jump length effect estimates can be inaccurate and misleading. The present manuscript introduces an alternative mathematical wind compensation approach that is based on an …