Michael Koukias - Academia.edu (original) (raw)

Papers by Michael Koukias

THE THESIS CONSISTS OF A DESIGN/CONSTRUCTION PART A THEORY/COMPUTATION PART AND AN APPLICATION PA... more THE THESIS CONSISTS OF A DESIGN/CONSTRUCTION PART A THEORY/COMPUTATION PART AND AN APPLICATION PART. IN THE FIRST PART A NEW MP-CONTROLLED TEST-CALL EQUIPMENT IS PRESENTED, WHICH ALLOWS THE ANALYTICAL RECORDING OF SUCCESSFUL/UNSUCCUSSFUL CALLS AT EVERY INTERMEDIATE PART OF A TELEPHONE ROUTE. THE IMPORTANT ADVANTAGES OF THE EQUIPMENT IS THAT IT ALLOWS A FAST, COST-EFFECTIVE AND WIDE INVESTIGATION OF THE TELEPHONE NETWORK AND THE LOCATION OF TRAFFIC BOTTLENECKS AT INTERMEDIATE TRUNKS OF THE ROUTES. IN THE SECOND PART A NEW METHOD OF ESTIMATING THE OFFERED TRAFFIC, THE LOAD AND THE LOSS FROM THE TEST-CALLING RESULTS AT EACH PART OF A TELEPHONE ROUTE IS PRESENTED. THE METHOD LEADS TO THE CONSTRUCTION OF TABLES AND DIAGRAMS WHICH MAKE PRACTICAL APPLICATIONS EASIER AND HAS THE IMPORTANT ADVANTAGE OF ALLOWING THE ESTIMATION OF TRAFFIC ETC. IN EVERY PART OF A NETWORK AS EASILY, FAST AND COST-EFFECTIVELY AS THE MEASUREMENT WITH THE TEST-CALL EQUIPMENT. IN THE THIRD PART THE APPLICATION OF TH...

Copyright © 2010 George J. Mandellos et al. This is an open access article distributed under the ... more Copyright © 2010 George J. Mandellos et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Standard Communication Protocol for Computer-assisted Electrocardiography (SCP-ECG) provides standardized communication among different ECG devices and medical information systems. This paper extends the use of this protocol in order to be included in health monitoring systems. It introduces new sections into SCP-ECG structure for transferring data for positioning, allergies, and five additional biosignals: noninvasive blood pressure (NiBP), body temperature (Temp), Carbon dioxide (CO2), blood oxygen saturation (SPO2), and pulse rate. It also introduces new tags in existing sections for transferring comprehensive demographic data. The proposed enhanced version is referred to as e-SCP-ECG + protocol. This paper also considers the...

Telemedicine applications are being widely evolved and computerization overtakes health care indu... more Telemedicine applications are being widely evolved and computerization overtakes health care industry. However, patient medical data is not concentrated yet and even within hospital centers, access to electronic media is restricted to computer equipped offices. Exploiting web technologies we have implemented remote access to health records, making use of wireless networks and web modules, so that users are not restricted

[1991 Proceedings] 6th Mediterranean Electrotechnical Conference

An architecture for line concentrators that simplifies the design, construction, and testing proc... more An architecture for line concentrators that simplifies the design, construction, and testing processes and improves the quality of service is presented. This architecture provides a series of novel features concerning hardware and software, facilities, performance and reliability, while the line concentrator manufacturing and maintenance costs are lower than that of similar existing equipment. An industrial prototype based on the architecture

Biomedical Engineering, 2009

IEICE Transactions on Communications, 2007

Abstract Bursty traffic is dominant,in modern,communication,networks,and keeps the call-level QoS... more Abstract Bursty traffic is dominant,in modern,communication,networks,and keeps the call-level QoS assessment an open issue. ON-OFF traffic models are commonly,used to describe bursty traffic. We propose an ON-OFF traffic model,of a single link which,accommodates,service-classes of finite population (f-ON-OFF). Calls compete,for the available link bandwidth,under the complete sharing policy. Accepted calls enter the system via state ON and then may alternate between

Electronics Letters, 1986

This paper presents the design and development of an application on Electrocardiogram (ECG) manag... more This paper presents the design and development of an application on Electrocardiogram (ECG) management area. This application makes possible the receiving, processing, storing, and retrieving ECG data. The ECG data are recorded with digital ECG devices (carts) constructed by various manufacturers and are transmitted to the telemedicine services workstations (hosts). In order to overcome the incompatibilities between the cart manufacturers (e.g. data format) the application adopts the utilization of Standard Communication Protocol for Computer assisted Electrocardiography (SCP-ECG protocol). The application development is also based on a platform that complies with ITU-T standards, in order to guarantee the interaction and interoperability of an H320 (ISDN) or H323 (IP) user (cardiologist or cardiology fellow). At the time of writing this paper, the application (reception and manipulation of SCP-ECG complied data) has been tested with carts, and with SCP-ECG compatible data files. The proposed module is going to be used as stand alone application or as a plug-in to be incorporated in telemedicine platforms such as the OTE-TS telemedicine service, a telematics service for telemedicine applications, developed for the Hellenic Telecommunication Organization (OTE).

Performance Modelling and Evaluation of ATM Networks, 1995

The purpose of this paper is to propose a new priority scheduling method that dynamically manages... more The purpose of this paper is to propose a new priority scheduling method that dynamically manages four classes of ATM traffic and assigns different priority levels according to the QoS requirements of each class. Its performance has been studied by simulation under the application on an ATM statistical multiplexer. The results have shown that this scheme satisfies the loss and delay requirements of the ATM classes for a large range of traffic load.

Nowadays, the telecom network traffic environment is composed mostly of emerging multirate servic... more Nowadays, the telecom network traffic environment is composed mostly of emerging multirate services whose calls can tolerate bandwidth compression either by extending their service-time (elastic services) or not (adaptive services). The coexistence of elastic and adaptive services makes the call-level performance analysis and evaluation of modern networks much more complicated. To contribute, in this paper, we present a new multirate loss model for elastic and adaptive services with finite traffic-source population. Thus, the call arrival process is a quasi-random process which is, in many cases, a more realistic consideration than a random (Poisson) process. The proposed model does not have a product form solution, and therefore, we propose approximate but recursive formulas for the efficient calculation of the call-level performance metrics, such as time and call congestion probabilities and link utilization. The consistency and the accuracy of the new model are verified through s...

We focus on the computation of Call Blocking Probabilities (CBP) in a single link loss model wher... more We focus on the computation of Call Blocking Probabilities (CBP) in a single link loss model where calls come from service-classes of finite sources, as it happens in the environment of wireless networks. We review the Engset Multirate Loss Model and the Single Retry Loss Model for finite sources in which blocked calls may immediately retry once to be connected

Ieice Transactions on Communications, Jul 1, 2007

This paper presents an integrated decision support platform for medical specialists, which use th... more This paper presents an integrated decision support platform for medical specialists, which use the signals from different points of the human body as a part of the patient examination. This platform is a software application for the acquisition, archiving, presenting and processing of medical signals. Moreover, this application preserves data that concern patient's history and past medical treatment. The coexistence of medical signals and patient history data in a functional interface supports doctors to result in the potentially more accurate diagnosis and treatment for each incident. Application's architecture provides the user with an integrated electronic working domain handling diverse types of information and medical records. The design and the implementation of the platform was a result of a close collaboration between engineers and doctors in order the development of a real efficient tool for the medical specialists to be achieved.

We consider a single transmission link that accommodates both constant bit rate (CBR) service-cla... more We consider a single transmission link that accommodates both constant bit rate (CBR) service-classes and bursty service-classes of ON-OFF type, under the complete sharing policy. We assume that the call arrival process of each service-class is quasi-random, while the service time of calls of each service-class is exponentially distributed. When a call is accepted in the system it may alternate

In this paper, we consider a single-link modeled as a loss system, which accommodates multirate t... more In this paper, we consider a single-link modeled as a loss system, which accommodates multirate traffic of elastic and adaptive calls. Calls arrive in the link according to a Poisson process, have a peak-bandwidth requirement while their service time is exponentially distributed. If the available link bandwidth is lower than the peak-bandwidth requirement of a new call, then the call can retry to be connected in the link with reduced bandwidth, one or more times (single/multi-retry loss model). If the available link bandwidth is still lower than the last bandwidth requirement of the call, then the call can be accepted in the link by compressing the bandwidth of all inservice calls (of all service-classes) together with its last bandwidth requirement. In this multirate loss system, we study the effect of the bandwidth reservation (BR) policy on Call Blocking Probabilities (CBP) and link utilization. The BR policy achieves CBP equalization among calls of different service-classes, or guarantees a certain quality of service for each service-class. The proposed single/multi-retry loss models under the BR policy do not have a product form solution, and therefore we propose approximate recursive formulas for the efficient calculation of CBP and link utilization. Simulation results validate the results obtained by the analytical models.

Ieee International Conference on Communications 2005 Icc 2005 2005, May 16, 2005

We consider an ON-OFF traffic model of a single link which accommodates service-classes of finite... more We consider an ON-OFF traffic model of a single link which accommodates service-classes of finite population. Calls arrive according to a quasi-random process and, if accepted, enter the system via state ON; then calls may alternate between ON-OFF states. When a call is transferred to state OFF, it releases the bandwidth held in state ON, while when it tries to

Conference Proceedings Annual International Conference of the Ieee Engineering in Medicine and Biology Society Ieee Engineering in Medicine and Biology Society Conference, 2009

An evaluation of a wide area Telemedicine System (TS) designed for a country with singular geomor... more An evaluation of a wide area Telemedicine System (TS) designed for a country with singular geomorphology like Greece is presented. It targets to improve the outcome in emergency cases, by means of an early and specialized pre-hospital treatment. The TS makes use of modern technologies leading to the cooperation of 30 mobile medical units, 3 Telemedicine Coordination Centers and 7 Regional Teleconference Rooms. An adaptive protocol is used to reduce the data transmission time and the resources required for archiving. An automated network switching keeps the communication live in most cases while a telemedicine service co-ordinates all the co-operating endpoints, providing call and connection management, remote healthcare assistance, teleconference capabilities and real-time vital signs&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; transmission.

2014 9th International Symposium on Communication Systems, Networks & Digital Sign (CSNDSP), 2014