Pub. online:1 Jan 2019Type:Research ArticleOpen Access
Journal:Informatica
Volume 30, Issue 1 (2019), pp. 73–90
Abstract
Integration of algorithms of investment theory and artificial intelligence allows one to create a support system for investors in exchange markets based on the ensemble of long-short-term-memory (LSTM) based recurrent neural networks (RNN). The proposed support system contains five stages: preparation of historical data, prediction by an ensemble of LSTM RNNs, assessment of prediction distributions, investment portfolio formation and verification. The prediction process outputs a multi-modal distribution, which provides useful information for investors. The research compares four different strategies based on a combination of distribution forecasting models. The high-low strategy helps decision-makers in exchange markets to recognize signals of transactions and fix limits for expectations. A combination of high-low-daily-weekly predictions helps investors to make daily transactions with knowing distribution of exchange rates during the week. The shift in time of five hours between London and New York inspired us to create a UK-NY strategy, which allows investors to recognize the signals of the market in a very short time. The joined high-low-UK-NY strategy increases the possibility of recognizing the signals of transactions in a very short time and of fixing the limits for day trading. So, this support system for investors is verified as a profitable tool for speculators in the relatively risky currency market.
Journal:Informatica
Volume 17, Issue 1 (2006), pp. 39–54
Abstract
The asynchronous techniques that exist within the programming with distributed constraints are characterized by the occurrence of the nogood values during the search for the solution. The nogood type messages are sent among the agents with the purpose of realizing an intelligent backtrack and of ensuring the algorithm's completion.
In this article we analyzed the way in which a technique of obtaining efficient nogood values could combine with a technique of storing these values. In other words we try combining the resolvent-based learning technique introduced by Yokoo with the nogood processor technique in the case of asynchrounous weak-commitment search algorithm (AWCS). These techniques refer to the possibility of obtaining efficient nogoods, respectively to the way the nogood values are stored and the later use of information given by the nogoods in the process of selecting a new value for the variables associated to agents. Starting from this analysis we proposed certain modifications for the two known techniques.
We analyzed the situations in which the nogoods are distributed to more nogood processors handed by certain agents. We proposed a solution of distributing the nogood processors to the agents regarding the agents' order, with the purpose of reducing the storing and searching costs. We also analyzed the benefits the combining of nogood processor technique with the resolved-based learning technique could bring to the enhancement of the performance of AWCS technique. Finally, we analyzed the behavior of the techniques obtained in the case of messages filtering.
Journal:Informatica
Volume 13, Issue 4 (2002), pp. 465–484
Abstract
The presented article is about a research using artificial neural network (ANN) methods for compound (technical and fundamental) analysis and prognosis of Lithuania's National Stock Exchange (LNSE) indices LITIN, LITIN-A and LITIN-VVP. We employed initial pre-processing (analysis for entropy and correlation) for filtering out model input variables (LNSE indices, macroeconomic indicators, Stock Exchange indices of other countries such as the USA – Dow Jones and S&P, EU – Eurex, Russia – RTS). Investigations for the best approximation and forecasting capabilities were performed using different backpropagation ANN learning algorithms, configurations, iteration numbers, data form-factors, etc. A wide spectrum of different results has shown a high sensitivity to ANN parameters. ANN autoregressive, autoregressive causative and causative trend model performances were compared in the approximation and forecasting by a linear discriminant analysis.
Journal:Informatica
Volume 13, Issue 2 (2002), pp. 177–208
Abstract
The objective of expert systems is the use of Artificial Intelligence tools so as to solve problems within specific prefixed applications. Even when such systems are widely applied in diverse applications, as manufacturing or control systems, until now, there is an important gap in the development of a theory being applicable to a description of the involved problems in a unified way. This paper is an attempt in supplying a simple formal description of expert systems together with an application to a robot manipulator case.
Journal:Informatica
Volume 2, Issue 4 (1991), pp. 473–477
Abstract
The role of an interface between an algorithm and its environment for school students is discussed. The motivation of the use of Pascal functions and procedures instead of commonly used programs in the first lessons of programming is presented. The main features of an interpreter of algorithms (Pascal functions and procedures) implemented on school computer are presented.