With the resources provided by communication technologies, E-learning has been employed in multip... more With the resources provided by communication technologies, E-learning has been employed in multiple universities, as well as in wide range of training centers and schools. This book presents a structured collection of chapters, dealing with the subject and stressing the importance of E-learning. It shows the evolution of E-learning, with discussion about tools, methodologies, improvements and new possibilities for long-distance learning. The book is divided into three sections and their respective chapters refer to three macro areas. The first section of the book covers methodologies and tools applied for E-learning, considering collaborative methodologies and specific environments. The second section is about E-learning assessment, highlighting studies about E-learning features and evaluations for different methodologies. The last section deals with the new developments in E-learning, emphasizing subjects like knowledge building in virtual environments, new proposals for architectures in tutoring systems, and case studies.
E-learning enables students to pace their studies according to their needs, making learning acces... more E-learning enables students to pace their studies according to their needs, making learning accessible to (1) people who do not have enough free time for studying - they can program their lessons according to their available schedule; (2) those far from a school (geographical issues), or the ones unable to attend classes due to some physical or medical restriction. Therefore, cultural, geographical and physical obstructions can be removed, making it possible for students to select their path and time for the learning course. Students are then allowed to choose the main objectives they are suitable to fulfill. This book regards E-learning challenges, opening a way to understand and discuss questions related to long-distance and lifelong learning, E-learning for people with special needs and, lastly, presenting case study about the relationship between the quality of interaction and the quality of learning achieved in experiences of E-learning formation.
2013 47th International Carnahan Conference on Security Technology, Oct 1, 2013
ABSTRACT Currently communications through mobile devices are necessary, but use of these is restr... more ABSTRACT Currently communications through mobile devices are necessary, but use of these is restricted due to the presence of attacks on communications. The encrypted authentication and data encryption are techniques to protect against such threats. Among the different types of encryption algorithms that exist, some are unsafe and additionally may require high computational costs, this also causes the communications not to be carried out at the appropriate times and sometimes the session establishing process fails. This paper shows a strategy that allows an analysis of the most common and safe encryption algorithms, specifically Rijndael (Advanced Encryption Standard-AES), SERPENT and TWOFISH, in order to establish which one of these is the most optimum to be implemented in smartphones and tablets; additionally other algorithms are relate, which are used commonly in many applications, tests are carried out over mobiles devices, which measure the performance and computational cost of the devices when they run each algorithm.
For many applications based on Mobile Ad Hoc Networks
(MANETs), the position of the nodes is gene... more For many applications based on Mobile Ad Hoc Networks (MANETs), the position of the nodes is generally hard to be determined. In sensor networks, for instance, such information may be critical for the MANETs. Additionally, one problem to be faced in this scenario is the fake parameters broadcasted by misbehaving/malicious nodes, which can either compromise results about positioning, or deplete power resources of mobile devices. Therefore, in this paper we propose a model for (1) identifying the fake parameters broadcasted in the network, and for (2) detecting the malicious/misbehaving nodes. The Linear Regression and Variance Analysis (LRVA) are both the basis for the multi-step-ahead predictions in this paper. Through NS-2 and Avrora, we simulated the movement and energy consumption of nodes in a MANET, analyzing the time series of beacon-packets exchanged in the network. As a result of the LRVA employment, the fake parameters broadcasted in the network were detected, with the malicious/misbehaving nodes identified. The simulations presented in this paper show low power consumption, which allows the jointly employment of LRVA with other security techniques in the MANETs.
Technology development, mainly for telecommunications and computer systems, was a key factor for ... more Technology development, mainly for telecommunications and computer systems, was a key factor for the interactivity and, thus, for the expansion of e-learning. This book is divided into two parts, presenting some proposals to deal with e-learning challenges, opening up a way of learning about and discussing new methodologies to increase the interaction level of classes and implementing technical tools for helping students to make better use of e-learning resources. In the first part, the reader may find chapters mentioning the required infrastructure for e-learning models and processes, organizational practices, suggestions, implementation of methods for assessing results, and case studies focused on pedagogical aspects that can be applied generically in different environments. The second part is related to tools that can be adopted by users such as graphical tools for engineering, mobile phone networks, and techniques to build robots, among others. Moreover, part two includes some chapters dedicated specifically to e-learning areas like engineering and architecture.
Adaptive E-learning was proposed to be suitable for students with unique profiles, particular int... more Adaptive E-learning was proposed to be suitable for students with unique profiles, particular interests, and from different domains of knowledge, so profiles may consider specific goals of the students, as well as different preferences, knowledge level, learning style, rendering psychological profile, and more. Another approach to be taken into account today is the self-directed learning. Unlike the adaptive E-learning, the Self-directed learning is related to independence or autonomy in learning; it is a logical link for readiness for E-learning, where students pace their classes according to their own needs.This book provides information on the On-Job Training and Interactive Teaching for E-learning and is divided into four sections. The first section covers motivations to be considered for E-learning while the second section presents challenges concerning E-learning in areas like Engineering, Medical education and Biological Studies. New approaches to E-learning are introduced in the third section, and the last section describes the implementation of E-learning Environments.
2013 47th International Carnahan Conference on Security Technology, Oct 1, 2013
ABSTRACT Illegal flights in South America is one of the major problems that aviation authorities ... more ABSTRACT Illegal flights in South America is one of the major problems that aviation authorities must face every day. Illicit aircrafts fly every day over countries and they keep their transponder inactivate to avoid secondary radar location over radar systems. This problem has become a major issue for the commercial aviation and the authorities. In an effort to determine the position of these aircrafts and predict their future movements, the authorities only have a spread and variable primary radar detection point over the radar system. A statistical approach of those data are presented in this paper trying to build a methodology to estimate and associate spread points detected by primary radar with at least two different targets. The parameters used to make that estimation are speed, direction and position. To develop the association of the spread points in a single track and further prediction a Kalman filter and a Best Linear Unbiased Estimator filter are used. Simulations results are presented to demonstrate the effectiveness of the proposed approach. Real time primary radar information is used to test the model.
Here it is proposed a conceptual model for geographic location of points in two dimensions, by th... more Here it is proposed a conceptual model for geographic location of points in two dimensions, by the use of triangulation. The triangulation method here described operates on an Ultra-wideband (UWB) Timed-array module with center frequency of 4GHz. The technique consists in two arrays of planar antennas located at predetermined points, which serve as receptor for new portable UWB transmitter equipped with an omnidirectional planar antenna. The relative coordinates are then computed using proposed mathematical models. The transmitter circuit was designed using 180nm Complementary Metal Oxide Semiconductor (CMOS) – IBM (7WL_5LM_MA) process and the planar antennas were designed on FR-4 substrate. Post-Layout Spice circuit simulations show the generation of pulses with 94.5mVpp amplitudes and 514ps width. The consumption is around 677µW per pulse using a 1.8V power supply at 100MHz pulse repetition rate (PRR). 3D electromagnetic simulations were performed using CST Microwave Studio 2011, ...
We present a Programmable Delay Control (PDC) for UWB Timed Array Radar Application, working with... more We present a Programmable Delay Control (PDC) for UWB Timed Array Radar Application, working with pulses in the GHz region, which requires a precise control of delays in the order of picoseconds. The major component of the PDC consists of a channel formed by two static inverters connected in series. Between the internal transition line (Vlinha) and the ground line (Vss), a digital variable capacitor is used to control the time of transitions (low-to-high and high-to-low) through their different times of charging and discharging. The circuits are designed using the integrated Spice environment with MicroWind 3 and LTSpice 4 VLSI Full custom project tools with the IBM SiGe 0.18 um process foundry. The Spice simulations showed a controllable delay time between 0 and 97ps, which, in the EM tests with CST Microwave Studio 2011, resulted in a controlled beam with center frequency of 4GHz, angular width of 27 ° and variable deflection between 12 º and -13 º, with a 8.3dB directivity and si...
Burst attacks (e.g. Brute Force, DoS, DDoS, etc) have become a great concern for the today’s comp... more Burst attacks (e.g. Brute Force, DoS, DDoS, etc) have become a great concern for the today’s computer networks, causing millions of losses to the society. Even though the detection of burst attacks is widely investigated, there is a gap in the academic literature regarding the predicting models for antici- pating such security issue. As the frequency of bursts depends on the behavior of the attackers, it is hard to determine the exact moment when a burst starts. In this paper we propose a new model for aggregating peaks of a burst - specifically for the brute force attack - at a single point called One Point Analysis (OPA). We applied the OPA technique in a prototype, so the beginning of each burst was predicted by the use of (a) Pseudo-Random Binary Sequences (PRBS), and (b) Exponential Weighted Moving Averages (EWMA). For evaluating the results, the OPA was compared to other techniques by two indicators, and it was possible coming to a conclusion regarding the OPA effectiveness.
With the resources provided by communication technologies, E-learning has been employed in multip... more With the resources provided by communication technologies, E-learning has been employed in multiple universities, as well as in wide range of training centers and schools. This book presents a structured collection of chapters, dealing with the subject and stressing the importance of E-learning. It shows the evolution of E-learning, with discussion about tools, methodologies, improvements and new possibilities for long-distance learning. The book is divided into three sections and their respective chapters refer to three macro areas. The first section of the book covers methodologies and tools applied for E-learning, considering collaborative methodologies and specific environments. The second section is about E-learning assessment, highlighting studies about E-learning features and evaluations for different methodologies. The last section deals with the new developments in E-learning, emphasizing subjects like knowledge building in virtual environments, new proposals for architectures in tutoring systems, and case studies.
E-learning enables students to pace their studies according to their needs, making learning acces... more E-learning enables students to pace their studies according to their needs, making learning accessible to (1) people who do not have enough free time for studying - they can program their lessons according to their available schedule; (2) those far from a school (geographical issues), or the ones unable to attend classes due to some physical or medical restriction. Therefore, cultural, geographical and physical obstructions can be removed, making it possible for students to select their path and time for the learning course. Students are then allowed to choose the main objectives they are suitable to fulfill. This book regards E-learning challenges, opening a way to understand and discuss questions related to long-distance and lifelong learning, E-learning for people with special needs and, lastly, presenting case study about the relationship between the quality of interaction and the quality of learning achieved in experiences of E-learning formation.
2013 47th International Carnahan Conference on Security Technology, Oct 1, 2013
ABSTRACT Currently communications through mobile devices are necessary, but use of these is restr... more ABSTRACT Currently communications through mobile devices are necessary, but use of these is restricted due to the presence of attacks on communications. The encrypted authentication and data encryption are techniques to protect against such threats. Among the different types of encryption algorithms that exist, some are unsafe and additionally may require high computational costs, this also causes the communications not to be carried out at the appropriate times and sometimes the session establishing process fails. This paper shows a strategy that allows an analysis of the most common and safe encryption algorithms, specifically Rijndael (Advanced Encryption Standard-AES), SERPENT and TWOFISH, in order to establish which one of these is the most optimum to be implemented in smartphones and tablets; additionally other algorithms are relate, which are used commonly in many applications, tests are carried out over mobiles devices, which measure the performance and computational cost of the devices when they run each algorithm.
For many applications based on Mobile Ad Hoc Networks
(MANETs), the position of the nodes is gene... more For many applications based on Mobile Ad Hoc Networks (MANETs), the position of the nodes is generally hard to be determined. In sensor networks, for instance, such information may be critical for the MANETs. Additionally, one problem to be faced in this scenario is the fake parameters broadcasted by misbehaving/malicious nodes, which can either compromise results about positioning, or deplete power resources of mobile devices. Therefore, in this paper we propose a model for (1) identifying the fake parameters broadcasted in the network, and for (2) detecting the malicious/misbehaving nodes. The Linear Regression and Variance Analysis (LRVA) are both the basis for the multi-step-ahead predictions in this paper. Through NS-2 and Avrora, we simulated the movement and energy consumption of nodes in a MANET, analyzing the time series of beacon-packets exchanged in the network. As a result of the LRVA employment, the fake parameters broadcasted in the network were detected, with the malicious/misbehaving nodes identified. The simulations presented in this paper show low power consumption, which allows the jointly employment of LRVA with other security techniques in the MANETs.
Technology development, mainly for telecommunications and computer systems, was a key factor for ... more Technology development, mainly for telecommunications and computer systems, was a key factor for the interactivity and, thus, for the expansion of e-learning. This book is divided into two parts, presenting some proposals to deal with e-learning challenges, opening up a way of learning about and discussing new methodologies to increase the interaction level of classes and implementing technical tools for helping students to make better use of e-learning resources. In the first part, the reader may find chapters mentioning the required infrastructure for e-learning models and processes, organizational practices, suggestions, implementation of methods for assessing results, and case studies focused on pedagogical aspects that can be applied generically in different environments. The second part is related to tools that can be adopted by users such as graphical tools for engineering, mobile phone networks, and techniques to build robots, among others. Moreover, part two includes some chapters dedicated specifically to e-learning areas like engineering and architecture.
Adaptive E-learning was proposed to be suitable for students with unique profiles, particular int... more Adaptive E-learning was proposed to be suitable for students with unique profiles, particular interests, and from different domains of knowledge, so profiles may consider specific goals of the students, as well as different preferences, knowledge level, learning style, rendering psychological profile, and more. Another approach to be taken into account today is the self-directed learning. Unlike the adaptive E-learning, the Self-directed learning is related to independence or autonomy in learning; it is a logical link for readiness for E-learning, where students pace their classes according to their own needs.This book provides information on the On-Job Training and Interactive Teaching for E-learning and is divided into four sections. The first section covers motivations to be considered for E-learning while the second section presents challenges concerning E-learning in areas like Engineering, Medical education and Biological Studies. New approaches to E-learning are introduced in the third section, and the last section describes the implementation of E-learning Environments.
2013 47th International Carnahan Conference on Security Technology, Oct 1, 2013
ABSTRACT Illegal flights in South America is one of the major problems that aviation authorities ... more ABSTRACT Illegal flights in South America is one of the major problems that aviation authorities must face every day. Illicit aircrafts fly every day over countries and they keep their transponder inactivate to avoid secondary radar location over radar systems. This problem has become a major issue for the commercial aviation and the authorities. In an effort to determine the position of these aircrafts and predict their future movements, the authorities only have a spread and variable primary radar detection point over the radar system. A statistical approach of those data are presented in this paper trying to build a methodology to estimate and associate spread points detected by primary radar with at least two different targets. The parameters used to make that estimation are speed, direction and position. To develop the association of the spread points in a single track and further prediction a Kalman filter and a Best Linear Unbiased Estimator filter are used. Simulations results are presented to demonstrate the effectiveness of the proposed approach. Real time primary radar information is used to test the model.
Here it is proposed a conceptual model for geographic location of points in two dimensions, by th... more Here it is proposed a conceptual model for geographic location of points in two dimensions, by the use of triangulation. The triangulation method here described operates on an Ultra-wideband (UWB) Timed-array module with center frequency of 4GHz. The technique consists in two arrays of planar antennas located at predetermined points, which serve as receptor for new portable UWB transmitter equipped with an omnidirectional planar antenna. The relative coordinates are then computed using proposed mathematical models. The transmitter circuit was designed using 180nm Complementary Metal Oxide Semiconductor (CMOS) – IBM (7WL_5LM_MA) process and the planar antennas were designed on FR-4 substrate. Post-Layout Spice circuit simulations show the generation of pulses with 94.5mVpp amplitudes and 514ps width. The consumption is around 677µW per pulse using a 1.8V power supply at 100MHz pulse repetition rate (PRR). 3D electromagnetic simulations were performed using CST Microwave Studio 2011, ...
We present a Programmable Delay Control (PDC) for UWB Timed Array Radar Application, working with... more We present a Programmable Delay Control (PDC) for UWB Timed Array Radar Application, working with pulses in the GHz region, which requires a precise control of delays in the order of picoseconds. The major component of the PDC consists of a channel formed by two static inverters connected in series. Between the internal transition line (Vlinha) and the ground line (Vss), a digital variable capacitor is used to control the time of transitions (low-to-high and high-to-low) through their different times of charging and discharging. The circuits are designed using the integrated Spice environment with MicroWind 3 and LTSpice 4 VLSI Full custom project tools with the IBM SiGe 0.18 um process foundry. The Spice simulations showed a controllable delay time between 0 and 97ps, which, in the EM tests with CST Microwave Studio 2011, resulted in a controlled beam with center frequency of 4GHz, angular width of 27 ° and variable deflection between 12 º and -13 º, with a 8.3dB directivity and si...
Burst attacks (e.g. Brute Force, DoS, DDoS, etc) have become a great concern for the today’s comp... more Burst attacks (e.g. Brute Force, DoS, DDoS, etc) have become a great concern for the today’s computer networks, causing millions of losses to the society. Even though the detection of burst attacks is widely investigated, there is a gap in the academic literature regarding the predicting models for antici- pating such security issue. As the frequency of bursts depends on the behavior of the attackers, it is hard to determine the exact moment when a burst starts. In this paper we propose a new model for aggregating peaks of a burst - specifically for the brute force attack - at a single point called One Point Analysis (OPA). We applied the OPA technique in a prototype, so the beginning of each burst was predicted by the use of (a) Pseudo-Random Binary Sequences (PRBS), and (b) Exponential Weighted Moving Averages (EWMA). For evaluating the results, the OPA was compared to other techniques by two indicators, and it was possible coming to a conclusion regarding the OPA effectiveness.
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Papers by Sergio Kofuji
(MANETs), the position of the nodes is generally hard to
be determined. In sensor networks, for instance, such information
may be critical for the MANETs. Additionally, one problem to
be faced in this scenario is the fake parameters broadcasted
by misbehaving/malicious nodes, which can either compromise
results about positioning, or deplete power resources of mobile
devices. Therefore, in this paper we propose a model for (1)
identifying the fake parameters broadcasted in the network, and
for (2) detecting the malicious/misbehaving nodes. The Linear
Regression and Variance Analysis (LRVA) are both the basis for
the multi-step-ahead predictions in this paper. Through NS-2 and
Avrora, we simulated the movement and energy consumption of
nodes in a MANET, analyzing the time series of beacon-packets
exchanged in the network. As a result of the LRVA employment,
the fake parameters broadcasted in the network were detected,
with the malicious/misbehaving nodes identified. The simulations
presented in this paper show low power consumption, which
allows the jointly employment of LRVA with other security
techniques in the MANETs.
(MANETs), the position of the nodes is generally hard to
be determined. In sensor networks, for instance, such information
may be critical for the MANETs. Additionally, one problem to
be faced in this scenario is the fake parameters broadcasted
by misbehaving/malicious nodes, which can either compromise
results about positioning, or deplete power resources of mobile
devices. Therefore, in this paper we propose a model for (1)
identifying the fake parameters broadcasted in the network, and
for (2) detecting the malicious/misbehaving nodes. The Linear
Regression and Variance Analysis (LRVA) are both the basis for
the multi-step-ahead predictions in this paper. Through NS-2 and
Avrora, we simulated the movement and energy consumption of
nodes in a MANET, analyzing the time series of beacon-packets
exchanged in the network. As a result of the LRVA employment,
the fake parameters broadcasted in the network were detected,
with the malicious/misbehaving nodes identified. The simulations
presented in this paper show low power consumption, which
allows the jointly employment of LRVA with other security
techniques in the MANETs.