Pub Date : 2001-07-04DOI: 10.1109/EURCON.2001.938160
K. El-Shennawy, M. Nasr, M. Abdelwahab
This paper presents an efficient two-digit algorithm for coding speech at low bit rates. This algorithm was suggested based on the constant factor algorithm (CFA) used in adaptive quantization. This has lend to an improvement in SNR and larger dynamic range at the expense of a small increase in the required channel bandwidth. A further improvement to the two-digit system is demonstrated by using an optimized second-order prediction which achieves a gain of 3 to 4 dB in SNR over the original first-order system. Moreover a two-digit speech coder with an incremental step size adaptation algorithm is proposed to benefit from the advantages of simple and efficient speech encoders using incremental step size adaptation such as the Song Voice Incremental Algorithm (SVIA).
{"title":"On improving the performance of a two-digit encoding scheme using a modified predictor","authors":"K. El-Shennawy, M. Nasr, M. Abdelwahab","doi":"10.1109/EURCON.2001.938160","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938160","url":null,"abstract":"This paper presents an efficient two-digit algorithm for coding speech at low bit rates. This algorithm was suggested based on the constant factor algorithm (CFA) used in adaptive quantization. This has lend to an improvement in SNR and larger dynamic range at the expense of a small increase in the required channel bandwidth. A further improvement to the two-digit system is demonstrated by using an optimized second-order prediction which achieves a gain of 3 to 4 dB in SNR over the original first-order system. Moreover a two-digit speech coder with an incremental step size adaptation algorithm is proposed to benefit from the advantages of simple and efficient speech encoders using incremental step size adaptation such as the Song Voice Incremental Algorithm (SVIA).","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"54 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120892684","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938112
A. Veglis, E. Avraam
In the last ten years, there has been considerable interest in the educational applications of electronic networking. The use of the WWW has been adopted into every aspect of educational life. The academic community supports the use of the Web as a tool to enhance teaching and learning. The problem is that the implementation of Web courses is not an easy task. This paper presents the available tools for developing Web courses and proposes an alternative approach. The implementation of Web courses for teaching trainee teachers in a supplementary teacher education course is also presented and discussed.
{"title":"Using the Web in supplementary teacher education","authors":"A. Veglis, E. Avraam","doi":"10.1109/EURCON.2001.938112","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938112","url":null,"abstract":"In the last ten years, there has been considerable interest in the educational applications of electronic networking. The use of the WWW has been adopted into every aspect of educational life. The academic community supports the use of the Web as a tool to enhance teaching and learning. The problem is that the implementation of Web courses is not an easy task. This paper presents the available tools for developing Web courses and proposes an alternative approach. The implementation of Web courses for teaching trainee teachers in a supplementary teacher education course is also presented and discussed.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116920205","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938132
W. Pogribny, I. Rozhankivsky, V. Lozynsky
Methods of matching digital filtering of noise-like signals for synchronisation of communications systems are studied. To increase the efficiency of the differential processing of such signals in the time domain, the use of a noise-like signal representation in sign delta modulation format (SignDM) has been proposed. The SignDM codes are determined by the values of differences between signal samples in PCM formats with a differential zone, which is defined a priori. These codes belong to the set {-1,0,1}. SignDM's sampling rate is equal to the Nyquist frequency. The resolution of matching filtering depending on the changing of the differential zone is studied by computer simulations. The peculiarities of creating analog signals on the basis of the noise-like codes have been presented, too. The structure of the matching filter (MF) with SignDM is discussed, too.
{"title":"Differential filtration of noise-like signals for synchronization tasks","authors":"W. Pogribny, I. Rozhankivsky, V. Lozynsky","doi":"10.1109/EURCON.2001.938132","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938132","url":null,"abstract":"Methods of matching digital filtering of noise-like signals for synchronisation of communications systems are studied. To increase the efficiency of the differential processing of such signals in the time domain, the use of a noise-like signal representation in sign delta modulation format (SignDM) has been proposed. The SignDM codes are determined by the values of differences between signal samples in PCM formats with a differential zone, which is defined a priori. These codes belong to the set {-1,0,1}. SignDM's sampling rate is equal to the Nyquist frequency. The resolution of matching filtering depending on the changing of the differential zone is studied by computer simulations. The peculiarities of creating analog signals on the basis of the noise-like codes have been presented, too. The structure of the matching filter (MF) with SignDM is discussed, too.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117166826","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938167
I. Cheng, A. Basu, Yibo Zhang, S. Tripathi
Traditionally, multimedia delivery on the Internet has concentrated on providing a single service quality, "best effort", where all types of media are given the same level of importance in a network. Only recently has there been an emphasis on monitoring bandwidth in a network, and adjusting service quality depending on the current bandwidth. One important aspect on which little research has been done is: "how can users specify the requirements and priorities by which multimedia quality should be adjusted given bandwidth limitations"? We design a quality of service (QoS) specification strategy and delivery criteria using adaptive bandwidth monitoring that best fits the specifications to the available resources. In order to provide QoS-based delivery a prioritization method has been designed to order information according to the preferences of a user. Java applets and CGI programming tools are used to provide an interactive Web retrieval environment. At present, JPEG quality, resolution and delay are used as parameters to determine the QoS. We are extending the work to include video delivery and distributed implementation with QoS in the future.
{"title":"QoS specification and adaptive bandwidth monitoring for multimedia delivery","authors":"I. Cheng, A. Basu, Yibo Zhang, S. Tripathi","doi":"10.1109/EURCON.2001.938167","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938167","url":null,"abstract":"Traditionally, multimedia delivery on the Internet has concentrated on providing a single service quality, \"best effort\", where all types of media are given the same level of importance in a network. Only recently has there been an emphasis on monitoring bandwidth in a network, and adjusting service quality depending on the current bandwidth. One important aspect on which little research has been done is: \"how can users specify the requirements and priorities by which multimedia quality should be adjusted given bandwidth limitations\"? We design a quality of service (QoS) specification strategy and delivery criteria using adaptive bandwidth monitoring that best fits the specifications to the available resources. In order to provide QoS-based delivery a prioritization method has been designed to order information according to the preferences of a user. Java applets and CGI programming tools are used to provide an interactive Web retrieval environment. At present, JPEG quality, resolution and delay are used as parameters to determine the QoS. We are extending the work to include video delivery and distributed implementation with QoS in the future.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127084959","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938159
R. Róka
This paper introduces a proposal for the utilization of VMSK modulation at the signal transport by means of xDSL technologies. First, the basic characteristics of the MSK and VMSK modulations are presented. Then we present a part dedicated to the mathematical analysis of the VMSK modulation. In the final part, we compare the QAM and VMSK modulation techniques and discuss the advantages of the VMSK and the possibilities for its utilization for high-speed transmission on metallic lines.
{"title":"The utilization of the VMSK modulation at the signal transport by means of xDSL technologies","authors":"R. Róka","doi":"10.1109/EURCON.2001.938159","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938159","url":null,"abstract":"This paper introduces a proposal for the utilization of VMSK modulation at the signal transport by means of xDSL technologies. First, the basic characteristics of the MSK and VMSK modulations are presented. Then we present a part dedicated to the mathematical analysis of the VMSK modulation. In the final part, we compare the QAM and VMSK modulation techniques and discuss the advantages of the VMSK and the possibilities for its utilization for high-speed transmission on metallic lines.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133856690","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938126
A. Zejak, I. Simic, B. Zrnic
The ambiguity function of chirp radar is shaped by compression filter design. The proposed optimization procedure for compression filter synthesis takes into account minimum loss in resolution and maximum reduction of sidelobes in the preferred Doppler range. This algorithm can be applied in high-resolution radar and sonar design.
{"title":"Chirp radar ambiguity function shaping","authors":"A. Zejak, I. Simic, B. Zrnic","doi":"10.1109/EURCON.2001.938126","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938126","url":null,"abstract":"The ambiguity function of chirp radar is shaped by compression filter design. The proposed optimization procedure for compression filter synthesis takes into account minimum loss in resolution and maximum reduction of sidelobes in the preferred Doppler range. This algorithm can be applied in high-resolution radar and sonar design.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132334702","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 : 2001-07-04DOI: 10.1109/EURCON.2001.937782
Stanislav Milanovic, Z. Petrovic
A storage area network deployment within a global communications company is presented. The new storage-centric infrastructure includes an open, modular and scalable storage network, not tied to any one server or application. A leading provider of telecommunication solutions was looking to move ahead quickly with SAN technology to achieve early and sustainable competitive advantage by leveraging its information resources.
{"title":"Building the enterprise-wide storage area network","authors":"Stanislav Milanovic, Z. Petrovic","doi":"10.1109/EURCON.2001.937782","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937782","url":null,"abstract":"A storage area network deployment within a global communications company is presented. The new storage-centric infrastructure includes an open, modular and scalable storage network, not tied to any one server or application. A leading provider of telecommunication solutions was looking to move ahead quickly with SAN technology to achieve early and sustainable competitive advantage by leveraging its information resources.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128437233","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 : 2001-07-04DOI: 10.1109/EURCON.2001.938119
I. Benc, M. Štefanec, S. Srbljic
To improve the performance of the multiprocessor, distributed and Internet-based systems, data replication is being introduced. Existence of multiple copies of the same object in the system causes the cache coherence problem. There are two basic mechanisms for maintaining cache coherence: write-invalidate and write-update mechanisms. Various protocols for multiprocessor and distributed systems have been developed that use both coherence mechanisms in order to maintain cache coherence with minimal overhead costs. These protocols are based on a decision function that dynamically switches between write-update and write-invalidate mechanisms. As a part of the hSATTL cache coherence protocol we designed a new decision function adapted for Internet-based systems that dynamically switches between basic coherence mechanisms. In order to prove the efficiency of the designed decision function we compared the performance of the hSATTL protocol with the performance of the ATTL and SATTL protocols, which do not implement decision functions. As the performance measure, we use the server load and the amount of data that is transferred between the server and the proxy in order to maintain cache coherence.
{"title":"Decision function in hybrid self-adaptive WWW cache coherence protocol (hSATTL)","authors":"I. Benc, M. Štefanec, S. Srbljic","doi":"10.1109/EURCON.2001.938119","DOIUrl":"https://doi.org/10.1109/EURCON.2001.938119","url":null,"abstract":"To improve the performance of the multiprocessor, distributed and Internet-based systems, data replication is being introduced. Existence of multiple copies of the same object in the system causes the cache coherence problem. There are two basic mechanisms for maintaining cache coherence: write-invalidate and write-update mechanisms. Various protocols for multiprocessor and distributed systems have been developed that use both coherence mechanisms in order to maintain cache coherence with minimal overhead costs. These protocols are based on a decision function that dynamically switches between write-update and write-invalidate mechanisms. As a part of the hSATTL cache coherence protocol we designed a new decision function adapted for Internet-based systems that dynamically switches between basic coherence mechanisms. In order to prove the efficiency of the designed decision function we compared the performance of the hSATTL protocol with the performance of the ATTL and SATTL protocols, which do not implement decision functions. As the performance measure, we use the server load and the amount of data that is transferred between the server and the proxy in order to maintain cache coherence.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122873115","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 : 2001-07-04DOI: 10.1109/EURCON.2001.937754
M. Koonert, H. Zepernick, S. Nordholm
Adaptive equalisation techniques are required in digital mobile radio systems to combat intersymbol interference, which is caused by the time-variant multipath propagation of signals. In this paper, we focus on the trans-European trunked radio (TETRA) system and examine decision feedback equaliser structures that may be used as an optional function in Class E equipment of the standard.
{"title":"Performance of an equaliser for trans-European trunked radio","authors":"M. Koonert, H. Zepernick, S. Nordholm","doi":"10.1109/EURCON.2001.937754","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937754","url":null,"abstract":"Adaptive equalisation techniques are required in digital mobile radio systems to combat intersymbol interference, which is caused by the time-variant multipath propagation of signals. In this paper, we focus on the trans-European trunked radio (TETRA) system and examine decision feedback equaliser structures that may be used as an optional function in Class E equipment of the standard.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"278 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123085683","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 : 2001-07-04DOI: 10.1109/EURCON.2001.937806
R. Stewart, R. Malayan, R. Roberts
This paper examines the development of communication theories and models from the process model of C.E. Shannon and W. Weaver (see "The Mathematical Theory of Communication", University of Illinois Press, Urbana, 1949) to a generalised communication model (see Stewart, R.W., IRNOP II Proceedings, 1998) and uses an example to show how this model is used to analyse organisation communications.
本文考察了沟通理论和模型的发展，从C.E.香农和W.韦弗的过程模型(见“沟通的数学理论”，伊利诺伊大学出版社，厄巴纳，1949年)到广义沟通模型(见斯图尔特，r.w.， IRNOP II Proceedings, 1998年)，并使用一个例子来展示如何使用该模型来分析组织沟通。
{"title":"The evolution and use of communication theories","authors":"R. Stewart, R. Malayan, R. Roberts","doi":"10.1109/EURCON.2001.937806","DOIUrl":"https://doi.org/10.1109/EURCON.2001.937806","url":null,"abstract":"This paper examines the development of communication theories and models from the process model of C.E. Shannon and W. Weaver (see \"The Mathematical Theory of Communication\", University of Illinois Press, Urbana, 1949) to a generalised communication model (see Stewart, R.W., IRNOP II Proceedings, 1998) and uses an example to show how this model is used to analyse organisation communications.","PeriodicalId":205662,"journal":{"name":"EUROCON'2001. International Conference on Trends in Communications. Technical Program, Proceedings (Cat. No.01EX439)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115334513","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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