scholarly journals The Entropy Method

2021 ◽  
Author(s):  
Russell Johnson-Laird ◽  
Philip Nicholas Johnson-Laird

Everyone knows that athletes can get the ‘hot hand’ and have a streak in which theyperform better than normal, or an awful slump. But, a trio of psychologists – Gilovich,Vallone, and Tversky – published an analysis in 1985 showing that two NBA teamsshowed no such effects in either field goals or free throws. Later in 1989, Tversky andGilovich debunked the hot hand in a further article in this journal. Basketball playerswere not the only ones to be dumbfounded. Yet, belief in the hot hand has beenblamed for all sorts of anomalous bets on outcomes in sports, games in casinos, andtrades in the stock market.

2021 ◽  
Author(s):  
Russell Johnson-Laird ◽  
Philip Nicholas Johnson-Laird

Everyone knows that athletes can get the ‘hot hand’ and have a streak in which they perform better than normal, or an awful slump. But, a trio of psychologists – Gilovich, Vallone, and Tversky – published an analysis in 1985 showing that two NBA teams showed no such effects in either field goals or free throws. Later in 1989, Tversky and Gilovich debunked the hot hand in a further article in this journal. Basketball players were not the only ones to be dumbfounded. Yet, belief in the hot hand has been blamed for all sorts of anomalous bets on outcomes in sports, games in casinos, and trades in the stock market.


2013 ◽  
Vol 4 (3) ◽  
pp. 361
Author(s):  
Marwan Asri

Banz (1981) and Reiganum (1981) claim that, in terms of returncreation, small firms tend to perform better than large firms. They implicitly claim that the phenomena (which is known as size effect) is stable and exists over the period of examination. This study intends to investigate the existence of size effect in Indonesian market and more specifically, to test whether stages of economic cycle (expansion and contraction stages) determine the existence of the effect. The results of the study show that size effect does exist in the market for the whole period of observation (1991-2001). However, when the period is divided into two parts according to the stage of economic cycle, the  statistical analysis results are not supportive to the conclusion about the size effect.


Author(s):  
Jesper Rangvid

This chapter studies the characteristics of the most important and well-known factors. Factor portfolios are portfolios of stocks based on certain characteristics, such as the size of the company, the price of the stock in relation to, e.g., the earnings of the company, the sector within which the firm operates, etc.Factors that perform better than the overall stock market tend to suffer more during recessions. To compensate investors for their underperformance during recessions, returns on these factors during expansions are so high that average stock returns over the full business cycle end out being high. Conversely, those factors that provide lower average returns than the overall stock market do so because they perform relatively better during recessions. The business cycle again plays an important role for understanding stock-market patterns.


Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 258 ◽  
Author(s):  
Luyue Xia ◽  
Jiachen Wang ◽  
Shanshan Liu ◽  
Zhuo Li ◽  
Haitian Pan

Reducing the emissions of greenhouse gas is a worldwide problem that needs to be solved urgently for sustainable development in the future. The solubility of CO2 in ionic liquids is one of the important basic data for capturing CO2. Considering the disadvantages of experimental measurements, e.g., time-consuming and expensive, the complex parameters of mechanism modeling and the poor stability of single data-driven modeling, a multi-model fusion modeling method is proposed in order to predict the solubility of CO2 in ionic liquids. The multiple sub-models are built by the training set. The sub-models with better performance are selected through the validation set. Then, linear fusion models are established by minimizing the sum of squares of the error and information entropy method respectively. Finally, the performance of the fusion model is verified by the test set. The results showed that the prediction effect of the linear fusion models is better than that of the other three optimal sub-models. The prediction effect of the linear fusion model based on information entropy method is better than that of the least square error method. Through the research work, an effective and feasible modeling method is provided for accurately predicting the solubility of CO2 in ionic liquids. It can provide important basic conditions for evaluating and screening higher selective ionic liquids.


Information ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 332
Author(s):  
Ernest Kwame Ampomah ◽  
Zhiguang Qin ◽  
Gabriel Nyame

Forecasting the direction and trend of stock price is an important task which helps investors to make prudent financial decisions in the stock market. Investment in the stock market has a big risk associated with it. Minimizing prediction error reduces the investment risk. Machine learning (ML) models typically perform better than statistical and econometric models. Also, ensemble ML models have been shown in the literature to be able to produce superior performance than single ML models. In this work, we compare the effectiveness of tree-based ensemble ML models (Random Forest (RF), XGBoost Classifier (XG), Bagging Classifier (BC), AdaBoost Classifier (Ada), Extra Trees Classifier (ET), and Voting Classifier (VC)) in forecasting the direction of stock price movement. Eight different stock data from three stock exchanges (NYSE, NASDAQ, and NSE) are randomly collected and used for the study. Each data set is split into training and test set. Ten-fold cross validation accuracy is used to evaluate the ML models on the training set. In addition, the ML models are evaluated on the test set using accuracy, precision, recall, F1-score, specificity, and area under receiver operating characteristics curve (AUC-ROC). Kendall W test of concordance is used to rank the performance of the tree-based ML algorithms. For the training set, the AdaBoost model performed better than the rest of the models. For the test set, accuracy, precision, F1-score, and AUC metrics generated results significant to rank the models, and the Extra Trees classifier outperformed the other models in all the rankings.


1985 ◽  
Vol 18 (6) ◽  
pp. 442-445 ◽  
Author(s):  
W. Wei

The principle of maximum entropy is adopted to derive a procedure for obtaining the electron density distribution in crystals from incomplete X-ray diffraction data. This method was applied to cementite and the result proved to be better than the conventional Fourier inversion in resolution as well as in the absence of ripples. The potential advantages of this method are: (1) the amount of subjective judgment imposed on unavailable data is significantly limited, and (2) the result of this method is consistent with the known information and maximally noncommittal with regard to the unknowns. It is shown that the method is especially well suited to the problem of the determination of a high-resolution electron density map from insufficient experimental data.


2007 ◽  
Vol 30 ◽  
pp. 659-684 ◽  
Author(s):  
I. Szita ◽  
A. Lorincz

In this article we propose a method that can deal with certain combinatorial reinforcement learning tasks. We demonstrate the approach in the popular Ms. Pac-Man game. We define a set of high-level observation and action modules, from which rule-based policies are constructed automatically. In these policies, actions are temporally extended, and may work concurrently. The policy of the agent is encoded by a compact decision list. The components of the list are selected from a large pool of rules, which can be either hand-crafted or generated automatically. A suitable selection of rules is learnt by the cross-entropy method, a recent global optimization algorithm that fits our framework smoothly. Cross-entropy-optimized policies perform better than our hand-crafted policy, and reach the score of average human players. We argue that learning is successful mainly because (i) policies may apply concurrent actions and thus the policy space is sufficiently rich, (ii) the search is biased towards low-complexity policies and therefore, solutions with a compact description can be found quickly if they exist.


2021 ◽  
Vol 7 (3) ◽  
pp. 236-242
Author(s):  
A. Ibodullaev

The development trends of the organized securities market in Uzbekistan, the main factors influencing the development of the organized market, as well as the trend of joint-stock companies, their issue, existing problems and ways of solving them are described. Based on the data, it can be said that the unorganized securities market in the country is developing better than the organized securities market. The size of the organized stock market does not match the expected share of the total stock market. This, in turn, requires a radical development of this market.


2020 ◽  
Vol 12 (17) ◽  
pp. 7124
Author(s):  
Se-Hak Chun ◽  
Young-Woong Ko

Case based reasoning is a knowledge discovery technique that uses similar past problems to solve current new problems. It has been applied to many tasks, including the prediction of temporal variables as well as learning techniques such as neural networks, genetic algorithms, decision trees, etc. This paper presents a geometric criterion for selecting similar cases that serve as an exemplar for the target. The proposed technique, called geometric Case Based Reasoning, uses a shape distance method that uses the number of sign changes of features for the target case, especially when extracting nearest neighbors. Thus, this method overcomes the limitation of conventional case-based reasoning in that it uses Euclidean distance and does not consider how nearest neighbors are similar to the target case in terms of changes between previous and current features in a time series. These concepts are investigated against the backdrop of a practical application involving the prediction of a stock market index. The results show that the proposed technique is significantly better than the random walk model at p < 0.01. However, it was not significantly better than the conventional CBR model in the hit rate measure and did not surpass the conventional CBR in the mean absolute percentage error.


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