Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158235
Gülsen Taskin Kaya, O. Ersoy, M. Kamasak
Classification of nonlinearly separable data by nonlinear support vector machines is often a difficult task, especially due to the necessity of a choosing a convenient kernel type. Moreover, in order to get high classification accuracy with the nonlinear SVM, kernel parameters should be determined by using a cross validation algorithm before classification. However, this process is time consuming. In this study, we propose a new classification method that we name Support Vector Selection and Adaptation (SVSA). SVSA does not require any kernel selection and it is applicable to both linearly and nonlinearly separable data. The results show that the SVSA has promising performance that is competitive with the traditional linear and nonlinear SVM methods.
{"title":"Support Vector Selection and Adaptation and its application in remote sensing","authors":"Gülsen Taskin Kaya, O. Ersoy, M. Kamasak","doi":"10.1109/RAST.2009.5158235","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158235","url":null,"abstract":"Classification of nonlinearly separable data by nonlinear support vector machines is often a difficult task, especially due to the necessity of a choosing a convenient kernel type. Moreover, in order to get high classification accuracy with the nonlinear SVM, kernel parameters should be determined by using a cross validation algorithm before classification. However, this process is time consuming. In this study, we propose a new classification method that we name Support Vector Selection and Adaptation (SVSA). SVSA does not require any kernel selection and it is applicable to both linearly and nonlinearly separable data. The results show that the SVSA has promising performance that is competitive with the traditional linear and nonlinear SVM methods.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115273726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158203
U. Hasirci, A. Balikci
In this study, an alternative launcher design for earth-to-orbit (ETO) microsatellite systems is addressed. The main goal of the design is to reduce the cost of launching operation. For this aim, a new topology is introduced and a sample design is presented. The paper proposes a vertical take-off Electromagnetic Launcher (EML) for ETO microsatellite systems. Design specifications are 6 km/s muzzle velocity and 20000 Gee's acceleration for a 100 kg payloade 6 km/s muzzle velocity and 20000 Gee's acceleration for a 100 kg payload. It is expected that proposed design presents a powerful alternative to conventional launchers and existing electromagnetic launchers for ETO systems.
{"title":"Design of an Electromagnetic Launcher for Earth-to-Orbit (ETO) microsatellite systems","authors":"U. Hasirci, A. Balikci","doi":"10.1109/RAST.2009.5158203","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158203","url":null,"abstract":"In this study, an alternative launcher design for earth-to-orbit (ETO) microsatellite systems is addressed. The main goal of the design is to reduce the cost of launching operation. For this aim, a new topology is introduced and a sample design is presented. The paper proposes a vertical take-off Electromagnetic Launcher (EML) for ETO microsatellite systems. Design specifications are 6 km/s muzzle velocity and 20000 Gee's acceleration for a 100 kg payloade 6 km/s muzzle velocity and 20000 Gee's acceleration for a 100 kg payload. It is expected that proposed design presents a powerful alternative to conventional launchers and existing electromagnetic launchers for ETO systems.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128482516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158187
Seyyed Jamal Addin Mostafavi yazdi, S. Irani
This paper presents transverse vibration of double cracked beam using assumed mode method. First we described the assumed mode method for transverse vibration of continuous systems. Assumed mode method has been used for continuous models, Also Assumed mode method may be used to derive the equations of motion of other linearly elastic systems. For the Bernoulli-Euler beam the strain energy and kinetic energy have been derived. General coordinates of model are assumed as function of time and coordinate. The admissible function that considered must be satisfied the boundary conditions. Then the mass and stiffness matrix have been obtained from strain and kinetic energy. Only steps those are actually required in using the Assumed-Modes Method to arrive at the equations of motion of an N-DOF model of a continuous system.
{"title":"Transverse vibration of double cracked beam using assumed mode method","authors":"Seyyed Jamal Addin Mostafavi yazdi, S. Irani","doi":"10.1109/RAST.2009.5158187","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158187","url":null,"abstract":"This paper presents transverse vibration of double cracked beam using assumed mode method. First we described the assumed mode method for transverse vibration of continuous systems. Assumed mode method has been used for continuous models, Also Assumed mode method may be used to derive the equations of motion of other linearly elastic systems. For the Bernoulli-Euler beam the strain energy and kinetic energy have been derived. General coordinates of model are assumed as function of time and coordinate. The admissible function that considered must be satisfied the boundary conditions. Then the mass and stiffness matrix have been obtained from strain and kinetic energy. Only steps those are actually required in using the Assumed-Modes Method to arrive at the equations of motion of an N-DOF model of a continuous system.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122695825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158245
Shirzad Shahriari, Yoon Choi, Amir Eshraghi, H. Hwang, Z. Aliyazicioglu
To guarantee service quality, it is desirable to shape the antenna pattern so that it provides uniform gain over the intended service region. The beam shaping design example used in this paper demonstrates how the minimax algorithm shapes the antenna mainlobe to circular and elliptical beams and does so in such manner that the shape of the antenna mainlobe matches the geographical contour of the continental United States. The array antennas used in this simulation study are 148 and 244 non-uniformly spaced element antennas.
{"title":"Antenna beam shaping using a non-uniform array antenna","authors":"Shirzad Shahriari, Yoon Choi, Amir Eshraghi, H. Hwang, Z. Aliyazicioglu","doi":"10.1109/RAST.2009.5158245","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158245","url":null,"abstract":"To guarantee service quality, it is desirable to shape the antenna pattern so that it provides uniform gain over the intended service region. The beam shaping design example used in this paper demonstrates how the minimax algorithm shapes the antenna mainlobe to circular and elliptical beams and does so in such manner that the shape of the antenna mainlobe matches the geographical contour of the continental United States. The array antennas used in this simulation study are 148 and 244 non-uniformly spaced element antennas.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122259599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158289
S. V. Mathisen, R. Schlanbusch, P. J. Nicklasson, Frank R. Vedal
In this paper we present dynamics of an inertial measurement unit (IMU) in for educational use. Students will learn how to use mathematical expressions on kinematics and dynamics, with use of a simulator and a small scale test site. Combining the simulator and the test site will bring the theoretical expression out with a practical side. The main part of this paper is focused on how to use the sensors data from the IMU to simulate the translational and rotational dynamics in real-time. This will provide a more hands on experience for students, learning the theory of spacecraft dynamics.
{"title":"Real-time inertial navigation system for educational use","authors":"S. V. Mathisen, R. Schlanbusch, P. J. Nicklasson, Frank R. Vedal","doi":"10.1109/RAST.2009.5158289","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158289","url":null,"abstract":"In this paper we present dynamics of an inertial measurement unit (IMU) in for educational use. Students will learn how to use mathematical expressions on kinematics and dynamics, with use of a simulator and a small scale test site. Combining the simulator and the test site will bring the theoretical expression out with a practical side. The main part of this paper is focused on how to use the sensors data from the IMU to simulate the translational and rotational dynamics in real-time. This will provide a more hands on experience for students, learning the theory of spacecraft dynamics.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124035545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158190
H. Uyanık
In this numerical study vibrations of a fully clamped composite plate subjected to impulsive pressure loadings are controlled by using piezoelectric patches. Finite element methods are preferred for numerical solutions. For obtaining finite element model of the smart plate structure, semiloof shell finite element including piezoelectric effects is used. Mode summation method is used for reducing the degrees of freedom of the finite element model and state-space equations are obtained from the reduced finite element model for determining appropriate control strategies. Optimal linear quadratic regulator (LQR) approach has been used to determine the feedback gain matrix and vibrations of the plate suppressed successfully.
{"title":"Active vibration control of a fully clamped laminated composite plate subjected to impulsive pressure loadings","authors":"H. Uyanık","doi":"10.1109/RAST.2009.5158190","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158190","url":null,"abstract":"In this numerical study vibrations of a fully clamped composite plate subjected to impulsive pressure loadings are controlled by using piezoelectric patches. Finite element methods are preferred for numerical solutions. For obtaining finite element model of the smart plate structure, semiloof shell finite element including piezoelectric effects is used. Mode summation method is used for reducing the degrees of freedom of the finite element model and state-space equations are obtained from the reduced finite element model for determining appropriate control strategies. Optimal linear quadratic regulator (LQR) approach has been used to determine the feedback gain matrix and vibrations of the plate suppressed successfully.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121439363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158212
Ng Su Wai, Adhwa Amir Tan, Jessie Mee, M. Ismail, M. Subari
RazakSAT™ is Malaysia's second earth observation satellite. The Medium-sized Aperture Camera (MAC) is the instrument payload to be flown on the RazakSAT™. MAC operates on visible and near infrared wavelength (VNIR), including four multispectral bands from 450nm – 890nm and one panchromatic band from 510nm to 730nm. Its ground pixel resolution is 5m for multispectral bands and 2.5m for panchromatic band. At 685km nominal altitude, the image swath width for MAC is 20km. RazakSAT™ is scheduled to be launched into 9° inclination Near-Equatorial Orbit (NEqO) on April 2009. It provides a high number of passes (14 times per day over Malaysia) for communication with ground station, and imaging opportunity increases by 3 times more compared to a sun-synchronous orbit. In order to give user quality assurance of the operational imagery, ground calibration (pre-flight calibration) has been conducted. This report outlines the techniques adopted during pre-flight calibration of the radiometric response of the MAC system. Results from system level measurement of the instrument response, namely the dark response, signal-to-noise ratio (SNR), saturation radiance, dynamic range, characterization of individual detector, gain and linearity analysis for each spectral band are presented and discussed.
{"title":"Preflight radiometric calibration of RazakSAT™","authors":"Ng Su Wai, Adhwa Amir Tan, Jessie Mee, M. Ismail, M. Subari","doi":"10.1109/RAST.2009.5158212","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158212","url":null,"abstract":"RazakSAT™ is Malaysia's second earth observation satellite. The Medium-sized Aperture Camera (MAC) is the instrument payload to be flown on the RazakSAT™. MAC operates on visible and near infrared wavelength (VNIR), including four multispectral bands from 450nm – 890nm and one panchromatic band from 510nm to 730nm. Its ground pixel resolution is 5m for multispectral bands and 2.5m for panchromatic band. At 685km nominal altitude, the image swath width for MAC is 20km. RazakSAT™ is scheduled to be launched into 9° inclination Near-Equatorial Orbit (NEqO) on April 2009. It provides a high number of passes (14 times per day over Malaysia) for communication with ground station, and imaging opportunity increases by 3 times more compared to a sun-synchronous orbit. In order to give user quality assurance of the operational imagery, ground calibration (pre-flight calibration) has been conducted. This report outlines the techniques adopted during pre-flight calibration of the radiometric response of the MAC system. Results from system level measurement of the instrument response, namely the dark response, signal-to-noise ratio (SNR), saturation radiance, dynamic range, characterization of individual detector, gain and linearity analysis for each spectral band are presented and discussed.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127398917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158263
A. Panferov, A. Nebylov, S. Brodsky
Possible approaches to the mathematical description of different types of flexible vehicles are observed. Mass and aerodynamic characteristics are changing considerably during the flight of aerospace vehicles. From the point of view of control theory such vehicles are the typical non-linear and non-steady plants. The aim of designer is to create the light construction. For these reason such objects are deformed in flight, and their elastic properties appear. Elastic longitudinal and lateral oscillations of the complex form arise, which frequencies are changing during the flight. Elastic oscillations are usually described by differential partial equations or ordinary differential equations of the great dimension. Deformation of a body results in appearance of the local attack angles and slide angles. As a result of it, the local forces and moments of forces arise. These forces and moments are synchronized with the changes of local angles of attack and slide. The local forces and moments are the reasons of amplification or attenuation of elastic oscillations. This phenomena is known as aeroflexibility. At excessive development of elastic oscillations the structural failure may take place. Paying attention to these effects has a great importance at control of space stations and space probes, airplanes and other mobile objects liable to the considerable dynamic loads.
{"title":"Mathematical models and control system designing for flexible missile","authors":"A. Panferov, A. Nebylov, S. Brodsky","doi":"10.1109/RAST.2009.5158263","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158263","url":null,"abstract":"Possible approaches to the mathematical description of different types of flexible vehicles are observed. Mass and aerodynamic characteristics are changing considerably during the flight of aerospace vehicles. From the point of view of control theory such vehicles are the typical non-linear and non-steady plants. The aim of designer is to create the light construction. For these reason such objects are deformed in flight, and their elastic properties appear. Elastic longitudinal and lateral oscillations of the complex form arise, which frequencies are changing during the flight. Elastic oscillations are usually described by differential partial equations or ordinary differential equations of the great dimension. Deformation of a body results in appearance of the local attack angles and slide angles. As a result of it, the local forces and moments of forces arise. These forces and moments are synchronized with the changes of local angles of attack and slide. The local forces and moments are the reasons of amplification or attenuation of elastic oscillations. This phenomena is known as aeroflexibility. At excessive development of elastic oscillations the structural failure may take place. Paying attention to these effects has a great importance at control of space stations and space probes, airplanes and other mobile objects liable to the considerable dynamic loads.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114893268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158255
H. Soken, C. Hajiyev
In this study, an Unscented Kalman Filter (UKF) algorithm, which integrates mathematical model of the attitude dynamics with the measurements of Inertial Measurement Unit (IMU) and the magnetometers, is designed. The identified vector is arranged from the Euler angles, angular rates, and the unknown constant components of the external torques (the gravity-gradient, magnetic field pressure and the sun radiation) acting on the pico satellite. Because of the inherent nonlinear dynamics and the nonlinear measurement model caused by the magnetometer measurements, UKF is selected as a filter algorithm. Performance of the proposed algorithm is demonstrated via simulations for a cube pico satellite.
{"title":"UKF for the identification of the pico satellite attitude dynamics parameters and the external torques on IMU and magnetometer measurements","authors":"H. Soken, C. Hajiyev","doi":"10.1109/RAST.2009.5158255","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158255","url":null,"abstract":"In this study, an Unscented Kalman Filter (UKF) algorithm, which integrates mathematical model of the attitude dynamics with the measurements of Inertial Measurement Unit (IMU) and the magnetometers, is designed. The identified vector is arranged from the Euler angles, angular rates, and the unknown constant components of the external torques (the gravity-gradient, magnetic field pressure and the sun radiation) acting on the pico satellite. Because of the inherent nonlinear dynamics and the nonlinear measurement model caused by the magnetometer measurements, UKF is selected as a filter algorithm. Performance of the proposed algorithm is demonstrated via simulations for a cube pico satellite.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133750744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158282
Thilanka Munasinghe
Pool boiling of a paramagnetic liquid in two identical tanks was created under microgravity conditions to study the characteristic behavior of bubbles under influence of a magnetic field. The main objective of this research project was to study the Kelvin force effect on bubbles in microgravity conditions. In addition, characteristics of bubble motion in pool boiling in microgravity condition with and without the influence of a magnetic field were studied. The reduced gravity conditions or microgravity conditions demonstrate the behavior in outer space environments.
{"title":"Studying the characteristics of bubble motion in pool boiling in microgravity conditions under the influence of a magnetic field","authors":"Thilanka Munasinghe","doi":"10.1109/RAST.2009.5158282","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158282","url":null,"abstract":"Pool boiling of a paramagnetic liquid in two identical tanks was created under microgravity conditions to study the characteristic behavior of bubbles under influence of a magnetic field. The main objective of this research project was to study the Kelvin force effect on bubbles in microgravity conditions. In addition, characteristics of bubble motion in pool boiling in microgravity condition with and without the influence of a magnetic field were studied. The reduced gravity conditions or microgravity conditions demonstrate the behavior in outer space environments.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130830786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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