2008 42nd Annual Conference on Information Sciences and Systems, 2008
Abstract A cross-layer optimization combining retransmission diversity with multi-user diversity ... more Abstract A cross-layer optimization combining retransmission diversity with multi-user diversity is investigated for wireless communications. To this end, a joint design of adaptive modulation and coding with retransmission-based automatic repeat request protocol is ...
ABSTRACT Aeronautical communication networks (ACN) is an emerging concept in which aeronautical s... more ABSTRACT Aeronautical communication networks (ACN) is an emerging concept in which aeronautical stations (AS) are considered as a part of multi-tier network for the future wireless communication system. An AS could be a commercial plane, helicopter, or any other low orbit station, i.e., Unmanned air vehicle, high altitude platform. The goal of ACN is to provide high throughput and cost effective communication network for aeronautical applications (i.e., Air traffic control (ATC), air traffic management (ATM) communications, and commercial in-flight Internet activities), and terrestrial networks by using aeronautical platforms as a backbone. In this paper, we investigate the issues about connectivity, throughput, and delay in ACN. First, topology of ACN is presented as a simple mobile ad hoc network and connectivity analysis is provided. Then, by using information obtained from connectivity analysis, we investigate two communication models, i.e., single-hop and two-hop, in which each source AS is communicating with its destination AS with or without the help of intermediate relay AS, respectively. In our throughput analysis, we use the method of finding the maximum number of concurrent successful transmissions to derive ACN throughput upper bounds for the two communication models. We conclude that the two-hop model achieves greater throughput scaling than the single-hop model for ACN and multi-hop models cannot achieve better throughput scaling than two-hop model. Furthermore, since delay issue is more salient in two-hop communication, we characterize the delay performance and derive the closed-form average end-to-end delay for the two-hop model. Finally, computer simulations are performed and it is shown that ACN is robust in terms of throughput and delay performances.
The International journal of artificial organs, 2008
The use of citrate as an anticoagulant in continuous renal replacement therapy is an effective me... more The use of citrate as an anticoagulant in continuous renal replacement therapy is an effective method to achieve regional anticoagulation of the extracorporeal blood circuit and to avoid systemic anticoagulation. This allows bleeding complications to be reduced and filter life time to be prolonged. However, citrate enters the systemic circulation and is metabolized in the liver to bicarbonate, causing metabolic alkalosis in some patients. In this case report, we discuss therapeutic interventions to control the acid-base status and to restore normal pH during continuous citrate hemodialysis.
The International journal of artificial organs, 2007
beta2-microglobulin (beta2MG) is pivotal to the pathogenesis of dialysis-related amyloidosis. We ... more beta2-microglobulin (beta2MG) is pivotal to the pathogenesis of dialysis-related amyloidosis. We compared the effects of high cut-off hemodialysis (HCO-HD) with those of standard high-flux hemodialysis (HF-HD) regarding the concentration and clearance of beta2MG and albumin. We enrolled ten patients with acute renal failure in a double-blind, cross-over, randomized controlled trial. Each patient received four hours of HCO-HD (estimated in vivo cutoff 50-60 kDa) and four hours of HF-HD (estimated in vivo cutoff 15-20 kDa) in random order. Statistical methods and outcome measures: As data lacked normal distribution, we used nonparametric statistical analysis. Plasma and dialysate concentrations of beta2MG and albumin were measured at baseline and after four hours of each study treatment. We found significantly greater diffusive beta2MG clearances for HCO-HD compared to HF-HD (at the start: 71.8 ml/min vs. 5.1 ml/min; P=0.008 and at the end: 68.8 ml/min vs. 5.7 ml/min; P=0.008). We fou...
The Genius dialysis system is increasingly used as an intermittent hemodialysis device in the set... more The Genius dialysis system is increasingly used as an intermittent hemodialysis device in the setting of acute renal failure. Slow extended hemodialysis is preferred in the case of critical ill patients. In this study we established a safe and feasible citrate anticoagulation protocol for slow extended hemodialysis (SLED) with the Genius system. We compared six anticoagulation protocols using SLED in 34 critically ill patients with acute renal failure. One group (A) received only citrate anticoagulation. Four groups (B - D) were treated with citrate and different additional systemic anticoagulation. Patients in the last group (F) were anticoagulated with heparin and were free of citrate anticoagulation. The total number of treatments was 103. A 4% sodium citrate solution was infused into the arterial line of the dialysis device for citrate anticoagulation. The dialysis solution contained one mmol/L of calcium. No additional calcium supplementation was done. We monitored electrolyte,...
ABSTRACT Biometric fusion is an essential procedure in any multi-modal biometric person recogniti... more ABSTRACT Biometric fusion is an essential procedure in any multi-modal biometric person recognition system, and it can be performed at sensor, feature, score and decision levels. This paper proposes to use a simulated annealing SA algorithm for the integration of multi-modal biometric data. The proposed method is applied to a Audio-Visual AV person recognition database that includes both acoustic and visual information. Superior performance of the proposed method is demonstrated through experimentation on 40 subjects in an AV database.
International Journal of Intelligent Systems Technologies and Applications, 2009
ABSTRACT This paper proposes and analyses the pyramidal Gabor eigenface (PGE) algorithm for face ... more ABSTRACT This paper proposes and analyses the pyramidal Gabor eigenface (PGE) algorithm for face recognition. It can be realised directly in the spatial domain by using one-dimensional (1D) filter masks to extract the Gabor facial features. This is in contrast to the two-dimensional (2D) Fourier implementation that must be applied in both frequency and spatial domains in the general 2D Gabor-based facial feature extraction methods. Eigenface decomposition is then used to further reduce the redundancy of these face features. Because, Gabor features are characterised by strong spatial locality with scale and orientation selectivity, they can cope with variation problems due to illumination, facial expression change and orientation. Eigenface cannot handle such variations. The analysis of the algorithm and the experimental results using AT&T (formally Olivetti) face database show that the cost of the algorithm and the number of Gabor features in the PGE algorithm are significantly lower than the ones in the classic 2D Gabor wavelet-based methods and have better recognition results.
... (1998) combined frontal face, face profile and voice, and the results showed that the sum rul... more ... (1998) combined frontal face, face profile and voice, and the results showed that the sum rule was the most reliable, as compared with the others. Wark and Sridharan (1999) used the opinions from text-independent speech and lip movement modalities at score level. ...
IEEE Communications Surveys & Tutorials, Jan 1, 2014
Wireless Sensor Networking is one of the most promising technologies that have applications rangi... more Wireless Sensor Networking is one of the most promising technologies that have applications ranging from health care to tactical military. Although Wireless Sensor Networks (WSNs) have appealing features (e.g., low installation cost, unattended network operation), due to the lack of a physical line of defense (i.e., there are no gateways or switches to monitor the information flow), the security of such networks is a big concern, especially for the applications where confidentiality has prime importance. Therefore, in order to operate WSNs in a secure way, any kind of intrusions should be detected before attackers can harm the network (i.e., sensor nodes) and/or information destination (i.e., data sink or base station). In this article, a survey of the state-of-the-art in Intrusion Detection Systems (IDSs) that are proposed for WSNs is presented. Firstly, detailed information about IDSs is provided. Secondly, a brief survey of IDSs proposed for Mobile Ad-Hoc Networks (MANETs) is presented and applicability of those systems to WSNs are discussed. Thirdly, IDSs proposed for WSNs are presented. This is followed by the analysis and comparison of each scheme along with their advantages and disadvantages. Finally, guidelines on IDSs that are potentially applicable to WSNs are provided. Our survey is concluded by highlighting open research issues in the field.
Citrate anticoagulation is an excellent alternative to heparin anticoagulation for critically ill... more Citrate anticoagulation is an excellent alternative to heparin anticoagulation for critically ill patients requiring continuous renal replacement therapy. In this article, we provide a safe and an easy-to-handle citrate anticoagulation protocol with variable treatment doses and excellent control of the acid-base status. Prospective observational study. University hospital. One hundred sixty-two patients with acute renal failure requiring renal replacement therapy were enrolled in the study. A continuous venovenous hemodialysis-based citrate anticoagulation protocol using a 4% trisodium solution, a specially designed dialysate fluid, and a continuous calcium infusion were used. The study period was 6 days. Hemofilters were changed routinely after 72 hours of treatment. The patients were grouped according to body weight, with patients below 60 kg body weight in group 1, patients with at least 60 kg and up to 90 kg body weight in group 2, and patients with a body weight of above 90 kg in group 3. Dialysate flow was adapted according to body size and matched approximately 2 L/hr for a patient with average body size. Blood flow, citrate flow, and calcium flow were adjusted according to the dialysate flow used. Median filter run time was 61.5 hours (interquartile range: 34.5-81.1 hours). Only 5% of all hemofilters had to be changed because of clotting. The prescribed treatment dose was achieved in all patients. Acid-base and electrolyte control were excellent in all groups. In the rare cases of metabolic disarrangement during citrate anticoagulation, acid-base values were rapidly corrected by modifying either the dialysate flow or alternatively the blood flow rate. Eight patients (5%) developed signs of citrate accumulation indicated by an increase of the total calcium >3 mmol/L or a need for high calcium substitution. We provide a safe and an easy-to-handle citrate anticoagulation protocol that allows an excellent acid-base and electrolyte control in critically ill patients with acute renal failure. The protocol can be adapted to patients' need, allowing a wide spectrum of treatment doses.
2008 42nd Annual Conference on Information Sciences and Systems, 2008
Abstract A cross-layer optimization combining retransmission diversity with multi-user diversity ... more Abstract A cross-layer optimization combining retransmission diversity with multi-user diversity is investigated for wireless communications. To this end, a joint design of adaptive modulation and coding with retransmission-based automatic repeat request protocol is ...
ABSTRACT Aeronautical communication networks (ACN) is an emerging concept in which aeronautical s... more ABSTRACT Aeronautical communication networks (ACN) is an emerging concept in which aeronautical stations (AS) are considered as a part of multi-tier network for the future wireless communication system. An AS could be a commercial plane, helicopter, or any other low orbit station, i.e., Unmanned air vehicle, high altitude platform. The goal of ACN is to provide high throughput and cost effective communication network for aeronautical applications (i.e., Air traffic control (ATC), air traffic management (ATM) communications, and commercial in-flight Internet activities), and terrestrial networks by using aeronautical platforms as a backbone. In this paper, we investigate the issues about connectivity, throughput, and delay in ACN. First, topology of ACN is presented as a simple mobile ad hoc network and connectivity analysis is provided. Then, by using information obtained from connectivity analysis, we investigate two communication models, i.e., single-hop and two-hop, in which each source AS is communicating with its destination AS with or without the help of intermediate relay AS, respectively. In our throughput analysis, we use the method of finding the maximum number of concurrent successful transmissions to derive ACN throughput upper bounds for the two communication models. We conclude that the two-hop model achieves greater throughput scaling than the single-hop model for ACN and multi-hop models cannot achieve better throughput scaling than two-hop model. Furthermore, since delay issue is more salient in two-hop communication, we characterize the delay performance and derive the closed-form average end-to-end delay for the two-hop model. Finally, computer simulations are performed and it is shown that ACN is robust in terms of throughput and delay performances.
The International journal of artificial organs, 2008
The use of citrate as an anticoagulant in continuous renal replacement therapy is an effective me... more The use of citrate as an anticoagulant in continuous renal replacement therapy is an effective method to achieve regional anticoagulation of the extracorporeal blood circuit and to avoid systemic anticoagulation. This allows bleeding complications to be reduced and filter life time to be prolonged. However, citrate enters the systemic circulation and is metabolized in the liver to bicarbonate, causing metabolic alkalosis in some patients. In this case report, we discuss therapeutic interventions to control the acid-base status and to restore normal pH during continuous citrate hemodialysis.
The International journal of artificial organs, 2007
beta2-microglobulin (beta2MG) is pivotal to the pathogenesis of dialysis-related amyloidosis. We ... more beta2-microglobulin (beta2MG) is pivotal to the pathogenesis of dialysis-related amyloidosis. We compared the effects of high cut-off hemodialysis (HCO-HD) with those of standard high-flux hemodialysis (HF-HD) regarding the concentration and clearance of beta2MG and albumin. We enrolled ten patients with acute renal failure in a double-blind, cross-over, randomized controlled trial. Each patient received four hours of HCO-HD (estimated in vivo cutoff 50-60 kDa) and four hours of HF-HD (estimated in vivo cutoff 15-20 kDa) in random order. Statistical methods and outcome measures: As data lacked normal distribution, we used nonparametric statistical analysis. Plasma and dialysate concentrations of beta2MG and albumin were measured at baseline and after four hours of each study treatment. We found significantly greater diffusive beta2MG clearances for HCO-HD compared to HF-HD (at the start: 71.8 ml/min vs. 5.1 ml/min; P=0.008 and at the end: 68.8 ml/min vs. 5.7 ml/min; P=0.008). We fou...
The Genius dialysis system is increasingly used as an intermittent hemodialysis device in the set... more The Genius dialysis system is increasingly used as an intermittent hemodialysis device in the setting of acute renal failure. Slow extended hemodialysis is preferred in the case of critical ill patients. In this study we established a safe and feasible citrate anticoagulation protocol for slow extended hemodialysis (SLED) with the Genius system. We compared six anticoagulation protocols using SLED in 34 critically ill patients with acute renal failure. One group (A) received only citrate anticoagulation. Four groups (B - D) were treated with citrate and different additional systemic anticoagulation. Patients in the last group (F) were anticoagulated with heparin and were free of citrate anticoagulation. The total number of treatments was 103. A 4% sodium citrate solution was infused into the arterial line of the dialysis device for citrate anticoagulation. The dialysis solution contained one mmol/L of calcium. No additional calcium supplementation was done. We monitored electrolyte,...
ABSTRACT Biometric fusion is an essential procedure in any multi-modal biometric person recogniti... more ABSTRACT Biometric fusion is an essential procedure in any multi-modal biometric person recognition system, and it can be performed at sensor, feature, score and decision levels. This paper proposes to use a simulated annealing SA algorithm for the integration of multi-modal biometric data. The proposed method is applied to a Audio-Visual AV person recognition database that includes both acoustic and visual information. Superior performance of the proposed method is demonstrated through experimentation on 40 subjects in an AV database.
International Journal of Intelligent Systems Technologies and Applications, 2009
ABSTRACT This paper proposes and analyses the pyramidal Gabor eigenface (PGE) algorithm for face ... more ABSTRACT This paper proposes and analyses the pyramidal Gabor eigenface (PGE) algorithm for face recognition. It can be realised directly in the spatial domain by using one-dimensional (1D) filter masks to extract the Gabor facial features. This is in contrast to the two-dimensional (2D) Fourier implementation that must be applied in both frequency and spatial domains in the general 2D Gabor-based facial feature extraction methods. Eigenface decomposition is then used to further reduce the redundancy of these face features. Because, Gabor features are characterised by strong spatial locality with scale and orientation selectivity, they can cope with variation problems due to illumination, facial expression change and orientation. Eigenface cannot handle such variations. The analysis of the algorithm and the experimental results using AT&T (formally Olivetti) face database show that the cost of the algorithm and the number of Gabor features in the PGE algorithm are significantly lower than the ones in the classic 2D Gabor wavelet-based methods and have better recognition results.
... (1998) combined frontal face, face profile and voice, and the results showed that the sum rul... more ... (1998) combined frontal face, face profile and voice, and the results showed that the sum rule was the most reliable, as compared with the others. Wark and Sridharan (1999) used the opinions from text-independent speech and lip movement modalities at score level. ...
IEEE Communications Surveys & Tutorials, Jan 1, 2014
Wireless Sensor Networking is one of the most promising technologies that have applications rangi... more Wireless Sensor Networking is one of the most promising technologies that have applications ranging from health care to tactical military. Although Wireless Sensor Networks (WSNs) have appealing features (e.g., low installation cost, unattended network operation), due to the lack of a physical line of defense (i.e., there are no gateways or switches to monitor the information flow), the security of such networks is a big concern, especially for the applications where confidentiality has prime importance. Therefore, in order to operate WSNs in a secure way, any kind of intrusions should be detected before attackers can harm the network (i.e., sensor nodes) and/or information destination (i.e., data sink or base station). In this article, a survey of the state-of-the-art in Intrusion Detection Systems (IDSs) that are proposed for WSNs is presented. Firstly, detailed information about IDSs is provided. Secondly, a brief survey of IDSs proposed for Mobile Ad-Hoc Networks (MANETs) is presented and applicability of those systems to WSNs are discussed. Thirdly, IDSs proposed for WSNs are presented. This is followed by the analysis and comparison of each scheme along with their advantages and disadvantages. Finally, guidelines on IDSs that are potentially applicable to WSNs are provided. Our survey is concluded by highlighting open research issues in the field.
Citrate anticoagulation is an excellent alternative to heparin anticoagulation for critically ill... more Citrate anticoagulation is an excellent alternative to heparin anticoagulation for critically ill patients requiring continuous renal replacement therapy. In this article, we provide a safe and an easy-to-handle citrate anticoagulation protocol with variable treatment doses and excellent control of the acid-base status. Prospective observational study. University hospital. One hundred sixty-two patients with acute renal failure requiring renal replacement therapy were enrolled in the study. A continuous venovenous hemodialysis-based citrate anticoagulation protocol using a 4% trisodium solution, a specially designed dialysate fluid, and a continuous calcium infusion were used. The study period was 6 days. Hemofilters were changed routinely after 72 hours of treatment. The patients were grouped according to body weight, with patients below 60 kg body weight in group 1, patients with at least 60 kg and up to 90 kg body weight in group 2, and patients with a body weight of above 90 kg in group 3. Dialysate flow was adapted according to body size and matched approximately 2 L/hr for a patient with average body size. Blood flow, citrate flow, and calcium flow were adjusted according to the dialysate flow used. Median filter run time was 61.5 hours (interquartile range: 34.5-81.1 hours). Only 5% of all hemofilters had to be changed because of clotting. The prescribed treatment dose was achieved in all patients. Acid-base and electrolyte control were excellent in all groups. In the rare cases of metabolic disarrangement during citrate anticoagulation, acid-base values were rapidly corrected by modifying either the dialysate flow or alternatively the blood flow rate. Eight patients (5%) developed signs of citrate accumulation indicated by an increase of the total calcium >3 mmol/L or a need for high calcium substitution. We provide a safe and an easy-to-handle citrate anticoagulation protocol that allows an excellent acid-base and electrolyte control in critically ill patients with acute renal failure. The protocol can be adapted to patients' need, allowing a wide spectrum of treatment doses.
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Papers by Salvatore Domenic Morgera