A dataset is imbalanced if the classification categories are not approximately equally represente... more A dataset is imbalanced if the classification categories are not approximately equally represented. Recent years brought increased interest in applying machine learning techniques to difficult "real-world" problems, many of which are characterized by imbalanced data. Additionally the distribution of the testing data may differ from that of the training data, and the true misclassification costs may be unknown at learning time. Predictive accuracy, a popular choice for evaluating performance of a classifier, might not be appropriate when the data is imbalanced andlor the costs of different errors vary markedly. In this Chapter, we discuss some of the sampling techniques used for balancing the datasets, and the performance measures more appropriate for mining imbalanced datasets.
25-Jul-1990 Offeq-2, Israel's second research and development satellite, was inserted into an orb... more 25-Jul-1990 Offeq-2, Israel's second research and development satellite, was inserted into an orbit of 214 km perigee altitude by 1570 km apogee altitude on April 3, 1990. Its primary mission was to further demonstrate IAI's satellite technology development and its ground station's ability to track the satellite, send it commands and receive its telemetry. The Offeq-2 satellite was expected to be on-orbit for about two to two and a half months (60 to 75 days) , and actually was on orbit over three months (97 days). It was expected, due to the dynamic behavior of a spin stabilized satellite under the influence of drag and orbital regression, to enter a period of electrical power loss. This was also expected on Offeq-l but did not occur due to the rapid development of the coning angle. However, this did occur on Offeq-2, on May the 2nd, as predicted, due to the lack of this rapid coning development. Power did return on May the 8th, and we were able to reconstruct this event successfully. During the lifetime of Offeq-2, all its objectives were accomplished. The TLM data received provided very valuable information for future use in the planning, designing and operating Israel's future satellites. This paper reports on the integration of subsystem telemetry data evaluation into a multiple reconstruction of the satellite's performance over several events. This was accomplished using a systems engineering approach, which combined the efforts in several areas: attitude determination via sensor TLM data, dynamic simulations of the attitude and orientation motion, orbital semi-major axis decay, coning angle estimation and electrical power TLM analysis and reconstruction, including analysis of the thermal TLM. We were able to successfully reconstruct the events of the flight including the power outage and resumption. 1.
The most significant events and phenomena that occurred during the Ofeq-2 flight are evaluated in... more The most significant events and phenomena that occurred during the Ofeq-2 flight are evaluated in this work. Particular attention is paid to the physical and technological factors which affected its orbital lifetime. Comparison of Ofeq-2 telemetry results with prelaunch estimations and with Ofeq-1 flight data are presented. The satellite's orbit and mission characteristics are defined and the principal systems of Ofeq-2 are described. Topics addressed include the interaction between the spinner's attitude with respect to the sun and consequent electric power generation. The coning angle development history, the role of the solar data evaluation, and the factors influencing drag are also analyzed. All of these affected the Ofeq-2 power outage-recovery event. The orbit determination and the coning angle evolution estimation methods are discussed in some detail. A brief report on radiation effects on computer RAM (random access memory) is also given. An integrative systems engineering approach summary of the telemetry data reconstruction and analysis concludes the paper.
This chapter describes data mining in finance by discussing financial tasks, specifics of methodo... more This chapter describes data mining in finance by discussing financial tasks, specifics of methodologies and techniques in this data mining area. It includes time dependence, data selection, forecast horizon, measures of success, quality of patterns, hypothesis evaluation, problem ID, method profile, attribute-based and relational methodologies. The second part of the chapter discusses data mining models and practice in finance. It covers use of neural networks in portfolio management, design of interpretable trading rules and discovering money laundering schemes using decision rules and relational data mining methodology.
Data Mining and Knowledge Discovery Handbook, 2000
ABSTRACT In this chapter we describe some basic concepts from fuzzy logic and how their applicabi... more ABSTRACT In this chapter we describe some basic concepts from fuzzy logic and how their applicability to Data Mining. First we discuss some basic terms from fuzzy set theory and fuzzy logic. Then, we provide examples that show how fuzzy sets and fuzzy logic can be applied best to discover knowledge from a given database.
Data Mining and Knowledge Discovery Handbook, 2000
ABSTRACT In this chapter we describe some basic concepts from fuzzy logic and how their applicabi... more ABSTRACT In this chapter we describe some basic concepts from fuzzy logic and how their applicability to Data Mining. First we discuss some basic terms from fuzzy set theory and fuzzy logic. Then, we provide examples that show how fuzzy sets and fuzzy logic can be applied best to discover knowledge from a given database.
International Series in Intelligent Technologies, 2000
Data mining is a relatively new field in the area of database research and artificial intelligenc... more Data mining is a relatively new field in the area of database research and artificial intelligence. Although it has appeared in research literature for only a few years, it is now one of the main topics of interest for research institutes and commercial laboratories. ...
The most significant events and phenomena that occurred during the Ofeq-2 flight are evaluated in... more The most significant events and phenomena that occurred during the Ofeq-2 flight are evaluated in this work. Particular attention is paid to the physical and technological factors which affected its orbital lifetime. Comparison of Ofeq-2 telemetry results with prelaunch estimations and with Ofeq-1 flight data are presented. The satellite's orbit and mission characteristics are defined and the principal systems of Ofeq-2 are described. Topics addressed include the interaction between the spinner's attitude with respect to the sun and consequent electric power generation. The coning angle development history, the role of the solar data evaluation, and the factors influencing drag are also analyzed. All of these affected the Ofeq-2 power outage-recovery event. The orbit determination and the coning angle evolution estimation methods are discussed in some detail. A brief report on radiation effects on computer RAM (random access memory) is also given. An integrative systems en...
Data Mining and Knowledge Discovery Handbook, 2005
This chapter describes data mining in finance by discussing financial tasks, specifics of methodo... more This chapter describes data mining in finance by discussing financial tasks, specifics of methodologies and techniques in this data mining area. It includes time dependence, data selection, forecast horizon, measures of success, quality of patterns, hypothesis evaluation, problem ID, method profile, attribute-based and relational methodologies. The second part of the chapter discusses data mining models and practice in finance. It covers use of neural networks in portfolio management, design of interpretable trading rules and discovering money laundering schemes using decision rules and relational data mining methodology.
A dataset is imbalanced if the classification categories are not approximately equally represente... more A dataset is imbalanced if the classification categories are not approximately equally represented. Recent years brought increased interest in applying machine learning techniques to difficult "real-world" problems, many of which are characterized by imbalanced data. Additionally the distribution of the testing data may differ from that of the training data, and the true misclassification costs may be unknown at learning time. Predictive accuracy, a popular choice for evaluating performance of a classifier, might not be appropriate when the data is imbalanced andlor the costs of different errors vary markedly. In this Chapter, we discuss some of the sampling techniques used for balancing the datasets, and the performance measures more appropriate for mining imbalanced datasets.
25-Jul-1990 Offeq-2, Israel's second research and development satellite, was inserted into an orb... more 25-Jul-1990 Offeq-2, Israel's second research and development satellite, was inserted into an orbit of 214 km perigee altitude by 1570 km apogee altitude on April 3, 1990. Its primary mission was to further demonstrate IAI's satellite technology development and its ground station's ability to track the satellite, send it commands and receive its telemetry. The Offeq-2 satellite was expected to be on-orbit for about two to two and a half months (60 to 75 days) , and actually was on orbit over three months (97 days). It was expected, due to the dynamic behavior of a spin stabilized satellite under the influence of drag and orbital regression, to enter a period of electrical power loss. This was also expected on Offeq-l but did not occur due to the rapid development of the coning angle. However, this did occur on Offeq-2, on May the 2nd, as predicted, due to the lack of this rapid coning development. Power did return on May the 8th, and we were able to reconstruct this event successfully. During the lifetime of Offeq-2, all its objectives were accomplished. The TLM data received provided very valuable information for future use in the planning, designing and operating Israel's future satellites. This paper reports on the integration of subsystem telemetry data evaluation into a multiple reconstruction of the satellite's performance over several events. This was accomplished using a systems engineering approach, which combined the efforts in several areas: attitude determination via sensor TLM data, dynamic simulations of the attitude and orientation motion, orbital semi-major axis decay, coning angle estimation and electrical power TLM analysis and reconstruction, including analysis of the thermal TLM. We were able to successfully reconstruct the events of the flight including the power outage and resumption. 1.
The most significant events and phenomena that occurred during the Ofeq-2 flight are evaluated in... more The most significant events and phenomena that occurred during the Ofeq-2 flight are evaluated in this work. Particular attention is paid to the physical and technological factors which affected its orbital lifetime. Comparison of Ofeq-2 telemetry results with prelaunch estimations and with Ofeq-1 flight data are presented. The satellite's orbit and mission characteristics are defined and the principal systems of Ofeq-2 are described. Topics addressed include the interaction between the spinner's attitude with respect to the sun and consequent electric power generation. The coning angle development history, the role of the solar data evaluation, and the factors influencing drag are also analyzed. All of these affected the Ofeq-2 power outage-recovery event. The orbit determination and the coning angle evolution estimation methods are discussed in some detail. A brief report on radiation effects on computer RAM (random access memory) is also given. An integrative systems engineering approach summary of the telemetry data reconstruction and analysis concludes the paper.
This chapter describes data mining in finance by discussing financial tasks, specifics of methodo... more This chapter describes data mining in finance by discussing financial tasks, specifics of methodologies and techniques in this data mining area. It includes time dependence, data selection, forecast horizon, measures of success, quality of patterns, hypothesis evaluation, problem ID, method profile, attribute-based and relational methodologies. The second part of the chapter discusses data mining models and practice in finance. It covers use of neural networks in portfolio management, design of interpretable trading rules and discovering money laundering schemes using decision rules and relational data mining methodology.
Data Mining and Knowledge Discovery Handbook, 2000
ABSTRACT In this chapter we describe some basic concepts from fuzzy logic and how their applicabi... more ABSTRACT In this chapter we describe some basic concepts from fuzzy logic and how their applicability to Data Mining. First we discuss some basic terms from fuzzy set theory and fuzzy logic. Then, we provide examples that show how fuzzy sets and fuzzy logic can be applied best to discover knowledge from a given database.
Data Mining and Knowledge Discovery Handbook, 2000
ABSTRACT In this chapter we describe some basic concepts from fuzzy logic and how their applicabi... more ABSTRACT In this chapter we describe some basic concepts from fuzzy logic and how their applicability to Data Mining. First we discuss some basic terms from fuzzy set theory and fuzzy logic. Then, we provide examples that show how fuzzy sets and fuzzy logic can be applied best to discover knowledge from a given database.
International Series in Intelligent Technologies, 2000
Data mining is a relatively new field in the area of database research and artificial intelligenc... more Data mining is a relatively new field in the area of database research and artificial intelligence. Although it has appeared in research literature for only a few years, it is now one of the main topics of interest for research institutes and commercial laboratories. ...
The most significant events and phenomena that occurred during the Ofeq-2 flight are evaluated in... more The most significant events and phenomena that occurred during the Ofeq-2 flight are evaluated in this work. Particular attention is paid to the physical and technological factors which affected its orbital lifetime. Comparison of Ofeq-2 telemetry results with prelaunch estimations and with Ofeq-1 flight data are presented. The satellite's orbit and mission characteristics are defined and the principal systems of Ofeq-2 are described. Topics addressed include the interaction between the spinner's attitude with respect to the sun and consequent electric power generation. The coning angle development history, the role of the solar data evaluation, and the factors influencing drag are also analyzed. All of these affected the Ofeq-2 power outage-recovery event. The orbit determination and the coning angle evolution estimation methods are discussed in some detail. A brief report on radiation effects on computer RAM (random access memory) is also given. An integrative systems en...
Data Mining and Knowledge Discovery Handbook, 2005
This chapter describes data mining in finance by discussing financial tasks, specifics of methodo... more This chapter describes data mining in finance by discussing financial tasks, specifics of methodologies and techniques in this data mining area. It includes time dependence, data selection, forecast horizon, measures of success, quality of patterns, hypothesis evaluation, problem ID, method profile, attribute-based and relational methodologies. The second part of the chapter discusses data mining models and practice in finance. It covers use of neural networks in portfolio management, design of interpretable trading rules and discovering money laundering schemes using decision rules and relational data mining methodology.
Uploads
Papers by Joseph Komem