Ion Lungu

Ion Lungu
Bucharest Academy of Economic Studies | ASE

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69
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273
Citations

Publications

Publications (69)
Conference Paper
Full-text available
Using automated capital investment software systems is a common task today. At the beginning of the third millennium, modern investors are using artificial intelligence resources and methods to find the best investment opportunities on capital markets and to process the trading orders. One of the most important aspects of this activity, besides the...
Article
Full-text available
Trading the financial markets is a common idea nowadays. Millions of market participants, individuals, companies or public funds are buying and selling different equities in order to obtain profit from the buy and sell price difference. Once the equity was established, the main question marks are when to buy, when to sell and how long to keep the o...
Chapter
This paper presents an extended version of the article “Forecasting solutions for photovoltaic power plants in Romania” that has been accepted and successfully defended at The 15th International Conference on Informatics in Economy (IE 2016). The installing of photovoltaic power plants (PVPPs) is increasing rapidly in Romania. The national power gr...
Article
Full-text available
In this paper, we have developed a series of neural networks in order to design a decision support system for predicting, analysing and monitoring the performance indicators in the field of renewable energies in Romania. We have first analysed a series of comparative aspects regarding the algorithms used for developing the neural networks: the Leve...
Article
Full-text available
Taking into account the well-known benefits of using renewable energy as an important energy source, some practical aspects regarding operation must be underlined. In the specific case of wind power plants (WPP) forecasting the generated wind power is the most important issue for assuring stability of Romania's National Power System (NPS) and econo...
Article
Full-text available
In this paper different aspects regarding smart metering systems integration have been depicted. Smart metering systems, renewable energy sources integration and advanced tariff systems implementation require informatics solution that could automatically collect and process data, forecast the behavior of electricity consumers, analyze trends regard...
Conference Paper
Integration of renewable energy sources mainly implies several advanced technologies such as smart metering devices, implementation of advanced tariff systems, informatics systems for load profile analyses and decision making on electricity consumption, etc. At electricity consumers' level, smart metering devices along with load profile calculation...
Article
Full-text available
While the exploitation of the renewable resources takes more ground, especially internationally, also in Romania we can identify some major projects in the field of renewable energy, considered of great interest nowadays. As we talk of an environment with low predictability, stimulating investors can be achieved by using decision support systems wi...
Article
Increasing energy demand, the current problems of global climate change and the interaction of political and economic interests in the energy markets determine governments, researchers and professionals to be more aware of energy use. The European Union established the ambitious objective for the year 2020 to lower energy consumption by 20%, improv...
Article
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eographical Information Systems are used in solving many regional development related problems, around the world. Starting from some national programs to famous international ones, such as INSPIRE program, each such initiative uses geospatial data as well in the process of building regional development strategies. This paper presents the main techn...
Article
Traffic simulators based on microscopic models are a detailed approach to infrastructure and policy evaluation. They allow a closer to reality representation of the factors that influence traffic flow: individual driver and vehicle attributes, dynamic route decisions, lane changing and restrictions, driver cooperation. Such aspects add to the compl...
Article
In this paper, we have researched the possibility of using graphics processing units (GPUs) for generating a variety of random numbers. We have compared the performance obtained on the latest GPUs architectures with the one recorded on a high-end central processing unit, we have analyzed the main features of each architecture that influence the per...
Article
Finance-related problems require more and more computations; therefore, the problem of finding efficient implementations for option pricing models on modern architectures has become an important challenge. Although there are numerous implementations of the Monte Carlo method on central processing units, many of them face limitations arising from th...
Conference Paper
Full-text available
Query optimization is one of the most important problems in databases. Query optimization can be talked about in different scenarios with different tools and different results. In this paper we'll talk about query processing and optimization and test strategies in different context, starting from simple queries continuing with correlated queries, j...
Article
In this paper, we first briefly describe some mathematical aspects regarding the computation of eigenvalues, followed by an original approach: a bisection algorithm useful in computing eigenvalues for a tridiagonal symmetric matrix of arbitrary size, using the computing capabilities of the latest graphics processing units that incorporate the Compu...
Article
Full-text available
This paper identifies the characteristics of a wind farm and the influence factors for these, grouped by the objective function, the input parameters, the nature of parameters and the criteria they apply for, i.e. the objective function, the input parameters, the optimal value, the nature of parameters and the criteria. It proposes an algorithm for...
Article
The emerging world-wide e-society creates new ways of interaction between people with different cultures and backgrounds. Communication systems as forums, blogs, and comments are easily accessible to end users. In this context, user generated content management revealed to be a difficult but necessary task. Studying and interpreting user generated...
Conference Paper
Developing intelligent systems in public institutions such as the Power Grid Companies require efficient methods in order to support better decisions. The Power Grid Companies must fundament their investment decisions by estimating all the benefits and costs during the life cycle of a wind power plant. In order to estimate the financial feasibility...
Article
Full-text available
The purpose of an informational system is to reflect the business it is supposed to assist. This is the reason why the informational system needs a representation of the business objects that are involved in the processes and also the business rules that are applied to the business objects. Every object is simpler than we can think and also more co...
Article
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Starting from the need to develop efficient IT systems, we intend to review the optimization methods and tools that can be used by SQL Server database administrators and developers of applications based on Microsoft technology, focusing on the latest version of the proprietary DBMS, SQL Server 2008. We’ll reflect on the objectives to be considered...
Article
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In this paper, we depict some of the most widely used data mining algorithms that have an overwhelming utility and influence in the research community. A data mining algorithm can be regarded as a tool that creates a data mining model. After analyzing a set of data, an algorithm searches for specific trends and patterns, then defines the parameters...
Article
Executive Information Systems are designed to improve the quality of strategic level of management in organization through a new type of technology and several techniques for extracting, transforming, processing, integrating and presenting data. In order to build analytic reports for Executive Information Systems (EIS) in an organization we need to...
Article
Full-text available
A Geographic Information System can be used in order to store, analyze and predict data regarding wind parks. Such data can refer to the natural factors that can affect the wind turbines, the placement of the turbines or their power capacity. In this paper we discuss the possibility to manage wind parks in Romania, based on the wind speed and altit...
Article
In this paper we are analyzing the performance of XML processing in different scenarios involving receiving large quantity of such documents. We are analyzing the loading and processing speed in four different scenarios involving an adapter written in an universal programming language and a relational database.
Article
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Phishing has grown significantly in volume over the time, becoming the most usual web threat today. The present economic crisis is an added argument for the great increase in number of attempts to cheat internet users, both businesses and private ones. The present research is aimed at helping the IT environment get a more precise view over the phis...
Article
Full-text available
The authors of this article are going to bring into light the significance, the place and the role of information systems in the university education process. At the same time they define the objectives and the target group of the subject named Economic Information Systems and state the competence gained by students by studying this subject. Specia...
Article
Full-text available
Developing Decision Support Systems in public institutions such as the National Power Grid Companies require applying very efficient methods in order to support the decisions. The decision support system in the National Power Grid Companies can integrate the energy prediction achieved by some data mining algorithms that help managers to fundament t...
Conference Paper
Full-text available
The investment of public institutions in wind power plants or in any type of power plants implies the necessity to justify their financial feasibility. This is done by estimating all the benefits and costs during the life cycle. In order to estimate the revenues, we need to know with certain accuracy the output of these power plants. In the case of...
Article
The shape memory alloys possess attractive characteristics as actuation elements. They are capable of transforming thermal energy into mechanical work. This paper presents our results in developing a modular linear and rotary family of shape memory alloy actuators, designed in several dimensions, in order to actuate high performance precision engin...
Article
Full-text available
Often, Business Intelligence Systems (BIS) require historical data or data collected from var-ious sources. The solution is found in data warehouses, which are the main technology used to extract, transform, load and store data in the organizational Business Intelligence projects. The development cycle of a data warehouse involves lots of resources...
Article
Full-text available
In this article we will present a practical solution for building an integration tier between an online trading platform and two stock exchange markets, in a SOA like architecture. We will present, in the space constraint of an article, how a solution can be build using XML, Java and PL/SQL and not third-party costly solutions. This approach, even...
Article
Full-text available
This article is an extended version of a paper presented in the WSEAS MCBE09 conference in which we will present in more detail practical solution for building an integration tier between an online trading platform and two stock exchange markets, in a SOA like architecture. Our solution is constructed using XML, Java and PL/SQL and not third-party...
Article
Full-text available
The development cycle of a decision support system involves many resources, time and high cost and above all, the database schema used in the system is built only for some specific tasks. So, a relational database schema or a data warehouse prototype cannot be easily mapped and reused in multiple DSS projects. In this paper we propose an object-ori...
Article
Full-text available
The development cycle of a decision support system involves many resources, time and high cost and above all, the database schema used in the system is built only for some specific tasks. So, a relational database schema or a data warehouse prototype cannot be easily mapped and reused in multiple DSS projects. In this paper we propose an object-ori...
Article
The first part of the paper treats the general problems concerning the shape memory alloy actuators and their operation principle. Then, our work referring to the developing a modular family of linear and rotational actuators, realized in many typo dimensions, in a compact design, with facile connection with the actuated mechanisms and supplying mo...
Article
Full-text available
The database systems have nowadays an increasingly important role in the knowledge-based society, in which computers have penetrated all fields of activity and the Internet tends to develop worldwide. In the current informatics context, the development of the applications with databases is the work of the specialists. Using databases, reach a datab...
Article
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In this paper we describe our study on organic topic recognition and knowledge extraction from online documents. Firstly we will introduce the current state of information extraction with ontology support then we will present our approach, corpus, theoretical background, algorithm, experiments and research goals. At the end we will draw some conclu...
Article
Full-text available
In time, the integration needs of companies increased. Even though not taken very seriously, integration solutions in general, and portals in particular, slowly become leaders in turning new principles into practical experiences. In the beginning, portals focused on aggregating, organizing, and indexing unstructured data, but modern portals now do...
Article
Full-text available
Often, Business Intelligence Systems (BIS) require historical data or data collected from var-ious sources. The solution is found in data warehouses, which are the main technology used to extract, transform, load and store data in the organizational Business Intelligence projects. The development cycle of a data warehouse involves lots of resources...
Article
Full-text available
As a high level development environment, the Java technologies offer support to the development of distributed applications, independent of the platform, providing a robust set of methods to access the databases, used to create software components on the server side, as well as on the client side. Analyzing the evolution of Java tools to access dat...
Article
Full-text available
In order to improve the quality of Business Intelligence Systems in an organization we can choose to build the system using BI techniques such as OLAP and data warehousing or by using traditional reports based on SQL queries. The cost and developing time for BI tools is greater than those for SQL Reports and these factors are important in taking de...
Article
Full-text available
Integration within public institutions is useful in better aligning the IT with the core processes, but also helps the various parts of the business work with each other better, enabling important business strategies like straight-through processing, improved public service through singe-view-of-customer portals, business activity monitoring and hi...
Conference Paper
Full-text available
The Business Intelligence project's team is always confronted with a major problem: low performance in data extraction from data warehouses. This problem can be critical because of the major impact in the using the data from data warehouse: if a BI report is taking a lot of time to run then it is useless or the data displayed are no longer availabl...
Article
Full-text available
Since its introduction, Extensible Markup Language (XML) has evolved and helped us evolve in the way which we think about structuring, describing, and exchanging information. The ways in which XML is used in the software industry are many and growing. For example, for Web services the importance of XML is crucial; all key Web service technologies a...
Article
In this paper we performed a basic and common DBA tasks on the two products and measured the time taken and the steps required to complete each task, to assess their relative manageability. The time taken to complete the tasks was then weighted according to their frequency of use in a typical DBA workday to arrive at an overall time savings percent...
Article
Oracle Human Resources (Oracle HRMS) represents a strong set of applications for the optimization of the human capital an organization disposes of. In the new economy, based on the Internet, the optimum usage of work force is one of the imperatives in e-business. In order to successfully meet this target, an organization needs a simple and efficien...
Article
Full-text available
The problem of low performance in data extraction from data warehouse can be critical in the Business Intelligence projects because of the major impact in the using the data from data warehouse: if a BI report is taking a lot of time to run or the data displayed are no longer available for taking critical decisions, the project can be compromised....
Article
Full-text available
The volume of data and numerous applications developed within a company can often generate a redundancy difficult to control. In the same time, the homogeneous or heterogeneous management systems of the companies become overcharged for obtaining useful information from databases. For this reason, the organizations develop specialized systems for th...
Conference Paper
Full-text available
In time, portals have evolved to meet the integration needs of companies. Even though not taken very seriously, they have slowly become leaders in turning new principles into practical experiences. In the beginning, portals focused on aggregating, organizing, and indexing unstructured data, but modern portals now do much more. Portal software conti...
Article
Full-text available
The article approaches the subject of business intelligence in the context of ERP projects, and presents the experience of a real industry project, its development and the problems it faced. It offers an insight into the main three phases of the project and it analyses the impact of technical problems and of company changes on the BI project, revea...
Article
The present paper is meant to describe the finite differences methods necessary to determine the value of financial options. In addition is presented the mathematic model of rating European type options. Value determination of an option is made through solving an equation with derivatives. Finding the analytical solutions is not at hand, reason for...
Article
Full-text available
In order to improve the quality of Management nformation Systems in an organization we can choose to build the system using Business Intelligence techniques such as OLAP and datawarehousing or by using traditional reports based on SQL queries. The cost and developing time for BI tools is greater than those for SQL Reports and these factors are impo...
Article
Full-text available
In today's economy access to quality information is a top requirement in any competitive organization. Managers want real-time information, in a desired format and at a convenient price. Lately, as a result of the new informational technologies (hardware and software) that are enabling the building of cheaper and faster informational systems, more...
Article
Full-text available
The Executive Information Systems (EIS) are designed to improve the quality of strategic level of management in organization through a new type of technology and several techniques for extracting, transforming, processing and presenting data in order to provide strategic information. These technologies are known as Business Intelligence Tools. This...
Article
Full-text available
In order to build analytic reports for Decision Support Systems (DSS) in an organization we can choose to do it by using Business Intelligence techniques such as OLAP and data warehousing or by using traditional reports based on SQL queries. The cost and developing time for BI tools is greater than those for SQL Reports and these factors are import...
Article
Today, the environment based on informatics influences continuously auditors’ work, because it creates new opportunities and new risks, additional rules in what concerns security, fairness and acceptable margin of error. The growth of the systems’ complexity, especially the informatics accounting Systems of ERP type (Enterprise Resource Planning),...
Article
The information system for administrating and distributing color images through the Internet ensures the consistent replication of color images, their storage - in an on-line data base - and predictable distribution, by means of a digitally distributed flow, based on Windows platform and POD (Print On Demand) technology. The consistent replication...
Article
Full-text available
Executive Information Systems are design to improve the quality of strategic level of management in organization through a new type of technology and several techniques for extracting, transforming, processing, integrating and presenting data in such a way that the organizational knowledge filters can easily associate with this data and turn it int...
Article
On-line transaction processing systems (OLTP) is profoundly different from dimensional data/warehouse, the basis for open decision support systems. Both OLTP and datawarehouse systems are greatly concerned with data consistency However OLTP consistency is microscopic. The point of transaction processing is to proces a very large number of atomic tr...
Article
Full-text available
The Internet is the perfect tool that can assure the market’s transparency for any user who wants to trade on the stock market. The investor can have access to the market news, financial calendar or the press releases of the issuers. A good online trading platform also provides real-time intraday quotes, trading history and technical analysis giv...
Article
Full-text available
This research presents the main elements of query optimizations in distributed systems. First, data architecture according with system level architecture in a distributed environment is presented. Then the architecture of a distributed database management system (DDBMS) is described on conceptual level followed by the presentation of the distribute...
Article
Full-text available
Options are nowadays transacted within a lot of stock exchanges worldwide. The problem of options gets a special importance due to the fact that many of the managerial decisions can be assimilated to options. The paper deals with numerical methods of financial options evaluation. The mathematical model of determining the values of an option of Euro...
Article
The main objective of EIS (Executive Information Systems) is to provide in real time representative informations to the high-level management. EIS is a subset of a class of technology solutions that also are referred to in the industry as Business Intelligence (BI) software. EIS provide solutions to support strategic activities such as goal setting...
Article
Full-text available
The paper suggests the presentation of aspects concerning the informatization strategy for the control activity at the Romanian Court of Counts. The introduction of the audit assisted by computer through the accomplishment of an IT system and the required training of the personnel represents a priority in the short time and CCR medium strategy.
Article
Full-text available
In this paper, we analyze solutions for optimizing the data parallel prefix sum function using the Compute Unified Device Architecture (CUDA) that provides a viable solution for accelerating a broad class of applications. The parallel prefix sum function is an essential building block for many data mining algorithms, and therefore its optimization...
Article
In the last thirty years the idea of Decision Support System(DSS) generated in the same time a lot of expectations and a lot of speculations and frustrations too. Although there was a fast development of the electronic equipment, managers often felt disappointed about their trails to use information technologies for the decision process (the electr...
Article
Business Intelligence (BI) is a last hour informatics technology which focuses on the organization, functioning and managing an industry with the help of calculating techniques. The development of the industry on the market environment, but also on the digital context, has served as solid experience for accumulating necessary knowledge in the BI fi...
Article
Full-text available
This research presents the main methods of database fragmentation in distributed systems. First, the steps of the distributed database design are presented. Then the fragmentation rules and the fragmentation types is described followed by the presentation of a mixed fragmentation methodology for initial distributed database design based on a graphi...

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Projects (2)
Project
Through the SIPAMER project, the consortium aims to develop a prototype that integrates technical and economic indicators of the production of renewable energy in an intelligent online system and allow real-time analysis and consulting of performance and profitability of renewable energy plants. Through this project we want to support the work and development of renewable electricity producers, giving them the ability to make sound decisions, based on real data, reducing risk and speeding up responses to a dynamic and in continuous development market. Thus, we aim to develop an intelligent system available through an online platform that consists of two main modules: a configurable module destined for production units for monitoring, prediction and analysis of business processes and a module for analysis and simulation destined for regulatory authorities, allowing immediate access to the information and statements concerning the operations of renewable energy groups. The prototype will contain workable models for integrating and analyzing data from local plants, for the prediction of energy from renewable sources in order to improve the notifications from renewable power plants. The research project is geared towards finding effective solutions and the realization of a software prototype with application in the field of energy, where information technology can play an important role in increasing energetic but also economic efficiency. This is a new economic environment, but with great development opportunities (also due to European objectives of producing green energy); the production is influenced both by natural factors as well as economic ones in which decisions must be taken in real time; it is an area particularly important socially, economically and environmentally; there are no national systems that can be widely applied and that can integrate and analyze data derived from power plants. The decision-making process in this area is confronted with a multitude of heterogeneous information sources and an array of unpredictable or less predictable factors and it needs a more correct grounding of the strategies and decisions. Thus, we aim to realize an intelligent prototype for the prediction, analysis and monitoring of performance indicators of technological and business processes in the field of renewable energies built on an online cloud computing platform. This online environment will provide the infrastructure for organization and processing data, reducing the investments in hardware and software systems. For each renewable power plant there will be a module/service instantiated and configured in the cloud computing environment based on the following components: • A model of integration and data processing with which data derived from the management of current activities (production and energy trading) will be integrated into a centralized database in a cloud computing environment. Based on the integrated data a monitoring and prediction model for the production of renewable energy will be built. For advanced data analysis we will build a data warehouse in a cloud environment so that users from the production units would be able to view the summary of performance indicators, relating to technological and business processes. • A prediction model of energy produced from renewable sources by which we aim to improve the notifications made by power plants so as to decrease the costs associated with the differences between notification and actual production. The resulted experimental model will consist of methods and algorithms for data mining that we develop and validate based on data derived from test pilot units in which the prototype will be developed. • A model of advanced analysis, simulation and planning of activities at the strategic level composed of sets of performance indicators which the managers of the power plants will be able to parse through configurable reports that allow interactive analysis. • A model of data presentation through a cloud computing platform. We will develop an integrated portal for monitoring, prediction and advanced analysis aimed primarily at power plants units, but also to regulators so that returns and reports required by these authorities are made available on the platform and the flow of documents becomes more efficient. The prototype of the product will be incrementally tested and validated in order to reduce the risks and to include the changes along the way.