Pub Date : 2011-07-25DOI: 10.1109/INDS.2011.6024820
T. de Souza-Daw, T. Hoang, Tien Dzung Nguyen
Transcranial Ultrasound (TCD) is a neurosonological procedure to examine intracranial brain supplying arteries, by visualizing cerebral blood flow patterns. In patients suffering from severe blood flow disruption to the brain neurological pathology conditions such as stenosis, occlusions and vasospasm can be identified with TCD. Ischemic and hemorrhagic strokes require regular TCD monitoring. However, the TCD procedure is largely dependent on the operator's skills and experiences. Finding a suitable site on the temporal plane (an acoustic window) for transcranial insonoification can be challenging in patients with poor or no acoustic windows. In such cases, diagnosis and prognosis may be problematic. Approximately, 10–20% of patients have poor or no acoustic windows. Therefore, early detection of acoustic windows for transcranial sonograph is desirable. This paper examines ultrasound signals in-vitro bovine's biological transcranial media to early detect acoustic windows. The results suggest that transcranial acoustic windows can be detected with an ultrasound signal. Ultrasound attenuation-velocity and B-Mode Ultrasound detection contrast the temporal bone and the surrounding soft-tissue, suggesting that acoustic windows can be detected.
{"title":"Towards ultrasonic detection of acoustic windows for transcranial Doppler ultrasound and related procedures","authors":"T. de Souza-Daw, T. Hoang, Tien Dzung Nguyen","doi":"10.1109/INDS.2011.6024820","DOIUrl":"https://doi.org/10.1109/INDS.2011.6024820","url":null,"abstract":"Transcranial Ultrasound (TCD) is a neurosonological procedure to examine intracranial brain supplying arteries, by visualizing cerebral blood flow patterns. In patients suffering from severe blood flow disruption to the brain neurological pathology conditions such as stenosis, occlusions and vasospasm can be identified with TCD. Ischemic and hemorrhagic strokes require regular TCD monitoring. However, the TCD procedure is largely dependent on the operator's skills and experiences. Finding a suitable site on the temporal plane (an acoustic window) for transcranial insonoification can be challenging in patients with poor or no acoustic windows. In such cases, diagnosis and prognosis may be problematic. Approximately, 10–20% of patients have poor or no acoustic windows. Therefore, early detection of acoustic windows for transcranial sonograph is desirable. This paper examines ultrasound signals in-vitro bovine's biological transcranial media to early detect acoustic windows. The results suggest that transcranial acoustic windows can be detected with an ultrasound signal. Ultrasound attenuation-velocity and B-Mode Ultrasound detection contrast the temporal bone and the surrounding soft-tissue, suggesting that acoustic windows can be detected.","PeriodicalId":117809,"journal":{"name":"Proceedings of the Joint INDS'11 & ISTET'11","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128973111","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 : 2011-07-25DOI: 10.1109/INDS.2011.6024788
T. Thiessen, W. Mathis
There is a special class of nonlinear electronic circuits containing a fold in their state space which results in a jump behaviour in the system characteristic. This can lead to difficulties during the simulation of these systems with common circuit simulators. For this reason usually suitably located parasitic inductors L's and capacitors C's were added to regularize the electronic circuit. We for our purpose describe these circuits in a differential geometric setting to detect jump points ahead. Having the jump points and defining the jump direction with physical constraints, one can overcome the problems of jumps without adding regularization L's or C's. In this paper differential geometric methods were applied to two example circuits and numerical results were presented.
{"title":"Geometrical interpretation of jump phenomena in nonlinear dynamical circuits","authors":"T. Thiessen, W. Mathis","doi":"10.1109/INDS.2011.6024788","DOIUrl":"https://doi.org/10.1109/INDS.2011.6024788","url":null,"abstract":"There is a special class of nonlinear electronic circuits containing a fold in their state space which results in a jump behaviour in the system characteristic. This can lead to difficulties during the simulation of these systems with common circuit simulators. For this reason usually suitably located parasitic inductors L's and capacitors C's were added to regularize the electronic circuit. We for our purpose describe these circuits in a differential geometric setting to detect jump points ahead. Having the jump points and defining the jump direction with physical constraints, one can overcome the problems of jumps without adding regularization L's or C's. In this paper differential geometric methods were applied to two example circuits and numerical results were presented.","PeriodicalId":117809,"journal":{"name":"Proceedings of the Joint INDS'11 & ISTET'11","volume":"301 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114481268","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 : 2011-07-25DOI: 10.1109/INDS.2011.6024824
R. Trejo-Guerra, E. Tlelo-Cuautle, J. Muñoz-Pacheco, C. Sánchez-López
Since multi-scroll chaotic oscillators are known to have many challenges due to the parasitic effects in the circuit implementation, this paper analyzes their effect on the non-ideal slopes and presence of delays in the realization of the saw-tooth nonlinear function which is used to generate these oscillators. The proposed analysis and description is applicable for any comparator-based nonlinear functions, but followed by a particular dynamical multi-scroll system, which is observed to generate positive Lyapunov exponents for some regions of operation. This process helps us to get insights regarding the potential spectra limit related to a saw-tooth nonlinear function circuit.
{"title":"Frequency limitations from the circuit realization of saw-tooth based multi-scroll oscillators","authors":"R. Trejo-Guerra, E. Tlelo-Cuautle, J. Muñoz-Pacheco, C. Sánchez-López","doi":"10.1109/INDS.2011.6024824","DOIUrl":"https://doi.org/10.1109/INDS.2011.6024824","url":null,"abstract":"Since multi-scroll chaotic oscillators are known to have many challenges due to the parasitic effects in the circuit implementation, this paper analyzes their effect on the non-ideal slopes and presence of delays in the realization of the saw-tooth nonlinear function which is used to generate these oscillators. The proposed analysis and description is applicable for any comparator-based nonlinear functions, but followed by a particular dynamical multi-scroll system, which is observed to generate positive Lyapunov exponents for some regions of operation. This process helps us to get insights regarding the potential spectra limit related to a saw-tooth nonlinear function circuit.","PeriodicalId":117809,"journal":{"name":"Proceedings of the Joint INDS'11 & ISTET'11","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114862643","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 : 2011-07-25DOI: 10.1109/INDS.2011.6024798
P. Lopato, T. Chady, R. Sikora, S. Gratkowski, M. Ziółkowski
In this paper we deal with full-wave modelling of pulsed terahertz systems utilized in non-destructive testing. At the outset, some basic information on the terahertz NDT and next general remarks on its numerical modelling are presented. Frequency domain FEM and time domain FDTD analysis is carried out. Finally comparison of computed and measured signals is shown in order to prove numerical analysis correctness.
{"title":"Numerical modelling of terahertz systems for nondestructive evaluation of dielectric materials","authors":"P. Lopato, T. Chady, R. Sikora, S. Gratkowski, M. Ziółkowski","doi":"10.1109/INDS.2011.6024798","DOIUrl":"https://doi.org/10.1109/INDS.2011.6024798","url":null,"abstract":"In this paper we deal with full-wave modelling of pulsed terahertz systems utilized in non-destructive testing. At the outset, some basic information on the terahertz NDT and next general remarks on its numerical modelling are presented. Frequency domain FEM and time domain FDTD analysis is carried out. Finally comparison of computed and measured signals is shown in order to prove numerical analysis correctness.","PeriodicalId":117809,"journal":{"name":"Proceedings of the Joint INDS'11 & ISTET'11","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127250900","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 : 2011-07-25DOI: 10.1007/978-3-642-34560-9_16
V. Kotlan, P. Karban, B. Ulrych, I. Doležel, P. Kus
{"title":"Hard-coupled modeling of induction shrink fit of gas-turbine active wheel","authors":"V. Kotlan, P. Karban, B. Ulrych, I. Doležel, P. Kus","doi":"10.1007/978-3-642-34560-9_16","DOIUrl":"https://doi.org/10.1007/978-3-642-34560-9_16","url":null,"abstract":"","PeriodicalId":117809,"journal":{"name":"Proceedings of the Joint INDS'11 & ISTET'11","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116487252","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 : 2011-07-25DOI: 10.1109/INDS.2011.6024818
R. Sikora, T. Chady, P. Baniukiewicz, P. Lopato, L. Napierała, T. Pietrusewicz, G. Psuj
In this paper an application, implemented functions and data base of welds defects destined to an Intelligent System for Radiogram Analysis ISAR for welds quality inspection is presented. System has to improve information contained in the radiogram, extract defects and decide on welds quality taking into account the relevant regulations.
{"title":"Intelligent System for Radiogram Analysis — Software application","authors":"R. Sikora, T. Chady, P. Baniukiewicz, P. Lopato, L. Napierała, T. Pietrusewicz, G. Psuj","doi":"10.1109/INDS.2011.6024818","DOIUrl":"https://doi.org/10.1109/INDS.2011.6024818","url":null,"abstract":"In this paper an application, implemented functions and data base of welds defects destined to an Intelligent System for Radiogram Analysis ISAR for welds quality inspection is presented. System has to improve information contained in the radiogram, extract defects and decide on welds quality taking into account the relevant regulations.","PeriodicalId":117809,"journal":{"name":"Proceedings of the Joint INDS'11 & ISTET'11","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132731254","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 : 2011-07-25DOI: 10.1109/INDS.2011.6024831
M. Agostinelli, R. Priewasser, S. Marsili, M. Huemer
Sliding mode is a very effective control strategy for switch mode DC-DC converters. However, its widespread adoption has been hampered by some of the drawbacks inherent to this control technique. Among these, the most important is apparently the varying operating frequency, which can cause electromagnetic-interference (EMI) problems. This problem is particularly critical in portable devices (e.g. smartphones, e-readers) where it is highly desirable that the DC-DC converters operate at a constant switching frequency to avoid interferences with other parts of the system. Several methods have been proposed in previous literature to stabilize the operating frequency of sliding mode controllers. In this paper, some of the most promising techniques are evaluated and applied to a specific test-case, i.e. a Buck converter for a wireless system. A detailed model of the DC-DC converter has been developed in order to obtain realistic results. The system parameters have been chosen to reflect an actual commercial application.
{"title":"Constant switching frequency techniques for sliding mode control in DC-DC converters","authors":"M. Agostinelli, R. Priewasser, S. Marsili, M. Huemer","doi":"10.1109/INDS.2011.6024831","DOIUrl":"https://doi.org/10.1109/INDS.2011.6024831","url":null,"abstract":"Sliding mode is a very effective control strategy for switch mode DC-DC converters. However, its widespread adoption has been hampered by some of the drawbacks inherent to this control technique. Among these, the most important is apparently the varying operating frequency, which can cause electromagnetic-interference (EMI) problems. This problem is particularly critical in portable devices (e.g. smartphones, e-readers) where it is highly desirable that the DC-DC converters operate at a constant switching frequency to avoid interferences with other parts of the system. Several methods have been proposed in previous literature to stabilize the operating frequency of sliding mode controllers. In this paper, some of the most promising techniques are evaluated and applied to a specific test-case, i.e. a Buck converter for a wireless system. A detailed model of the DC-DC converter has been developed in order to obtain realistic results. The system parameters have been chosen to reflect an actual commercial application.","PeriodicalId":117809,"journal":{"name":"Proceedings of the Joint INDS'11 & ISTET'11","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114307081","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 : 2011-07-25DOI: 10.1109/INDS.2011.6024794
M. Pantelyat, O. Bíró, A. Stermecki
The 3D finite element technique has been used to calculate transient electromagnetic fields and forces due to negative sequence currents in large synchronous turbogenerator rotors. The paper is devoted to the finite element analysis of electromagnetic forces in the joints of nonmagnetic slot wedges along the rotor length. Force distributions in the time and frequency domains are obtained. The results will be used for the computer simulation of the mechanical vibrations of the rotor.
{"title":"Electromagnetic forces in synchronous turbogenerator rotor slot wedges","authors":"M. Pantelyat, O. Bíró, A. Stermecki","doi":"10.1109/INDS.2011.6024794","DOIUrl":"https://doi.org/10.1109/INDS.2011.6024794","url":null,"abstract":"The 3D finite element technique has been used to calculate transient electromagnetic fields and forces due to negative sequence currents in large synchronous turbogenerator rotors. The paper is devoted to the finite element analysis of electromagnetic forces in the joints of nonmagnetic slot wedges along the rotor length. Force distributions in the time and frequency domains are obtained. The results will be used for the computer simulation of the mechanical vibrations of the rotor.","PeriodicalId":117809,"journal":{"name":"Proceedings of the Joint INDS'11 & ISTET'11","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134500996","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 : 2011-07-25DOI: 10.1109/INDS.2011.6024803
N. Dat, T. Hoang
In this paper an FPGA-based implementation of Chaotic Pulse Position Modulation (CPPM) is described. The model of transmission in noisy channel is demonstrated. The result shows the operation, performance and feasibility of CPPM.
{"title":"Implementation of Chaotic Pulse-Position Modulation on FPGA","authors":"N. Dat, T. Hoang","doi":"10.1109/INDS.2011.6024803","DOIUrl":"https://doi.org/10.1109/INDS.2011.6024803","url":null,"abstract":"In this paper an FPGA-based implementation of Chaotic Pulse Position Modulation (CPPM) is described. The model of transmission in noisy channel is demonstrated. The result shows the operation, performance and feasibility of CPPM.","PeriodicalId":117809,"journal":{"name":"Proceedings of the Joint INDS'11 & ISTET'11","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128928063","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 : 2011-07-25DOI: 10.1109/INDS.2011.6024819
G. Tsenov, V. Mladenov
In this paper we present the conversion of arbitrary high order sigma-delta modulator Z-domain loopfilter transfer function into parallel form low order subsections in both S and Z domains. The benefit of this type filter form representation is the existence of theory that can validate sigma-delta modulator's stability. The S domain filter representation is suitable for analog schematic element value calculation stage done according to the utilized transfer function when direct analogue parallel loopfilter implementation is performed.
{"title":"Higher order sigma-delta modulator loopfilter paralel form representation in Z and S domain","authors":"G. Tsenov, V. Mladenov","doi":"10.1109/INDS.2011.6024819","DOIUrl":"https://doi.org/10.1109/INDS.2011.6024819","url":null,"abstract":"In this paper we present the conversion of arbitrary high order sigma-delta modulator Z-domain loopfilter transfer function into parallel form low order subsections in both S and Z domains. The benefit of this type filter form representation is the existence of theory that can validate sigma-delta modulator's stability. The S domain filter representation is suitable for analog schematic element value calculation stage done according to the utilized transfer function when direct analogue parallel loopfilter implementation is performed.","PeriodicalId":117809,"journal":{"name":"Proceedings of the Joint INDS'11 & ISTET'11","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120945668","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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