Pub Date : 1997-09-09DOI: 10.1109/ICICS.1997.647168
B. Paliwal, H. Diwakar, J. Jhala
Few commercially available RDBMSs provide multimedia support. Of the few which do, there is no standard way by means of which multimedia objects are supported. We have tried to use ODBC support for creating an application which supports multimedia objects loosely coupled to any RDBMS which may or may not support multi-media objects. The multi-media objects are stored on a file system distributed over the network and the application developed handles issues like concurrency, integrity and recovery. This loosely coupled approach allows the independent existence of the RDBMS, solves the problem of storage of large amounts of multimedia data by providing a file system that is distributed across nodes of a network.
{"title":"Loosely coupled multimedia database management system","authors":"B. Paliwal, H. Diwakar, J. Jhala","doi":"10.1109/ICICS.1997.647168","DOIUrl":"https://doi.org/10.1109/ICICS.1997.647168","url":null,"abstract":"Few commercially available RDBMSs provide multimedia support. Of the few which do, there is no standard way by means of which multimedia objects are supported. We have tried to use ODBC support for creating an application which supports multimedia objects loosely coupled to any RDBMS which may or may not support multi-media objects. The multi-media objects are stored on a file system distributed over the network and the application developed handles issues like concurrency, integrity and recovery. This loosely coupled approach allows the independent existence of the RDBMS, solves the problem of storage of large amounts of multimedia data by providing a file system that is distributed across nodes of a network.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"59 1","pages":"593-595 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87420694","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 : 1997-09-09DOI: 10.1109/ICICS.1997.652140
F. Lo, T. Ng, T. I. Yuk
Channel sense multiple access with collision detection (CSMA/CD) is a very simple and efficient way of allowing many stations to transmit messages to a central server down a shared channel. In wireless networks, however, collision detection is difficult to implement, and in such cases CSMA alone may have to be used. It is shown that a multichannel CSMA network can be almost as efficient in utilizing the bandwidth available to the network as an equivalent single channel CSMA/CD network. Furthermore, multichannel CSMA networks provide better throughput and delay performance than equivalent single channel CSMA systems, even when the message generation probability and the number of stations in the network are varied.
{"title":"Performance of multichannel CSMA networks","authors":"F. Lo, T. Ng, T. I. Yuk","doi":"10.1109/ICICS.1997.652140","DOIUrl":"https://doi.org/10.1109/ICICS.1997.652140","url":null,"abstract":"Channel sense multiple access with collision detection (CSMA/CD) is a very simple and efficient way of allowing many stations to transmit messages to a central server down a shared channel. In wireless networks, however, collision detection is difficult to implement, and in such cases CSMA alone may have to be used. It is shown that a multichannel CSMA network can be almost as efficient in utilizing the bandwidth available to the network as an equivalent single channel CSMA/CD network. Furthermore, multichannel CSMA networks provide better throughput and delay performance than equivalent single channel CSMA systems, even when the message generation probability and the number of stations in the network are varied.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"2 1","pages":"1045-1049 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82170084","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 : 1997-09-09DOI: 10.1109/ICICS.1997.647118
Z. Fan, P. Mars
We demonstrate how fast and accurate estimates of quality of service (QOS) parameters can be obtained for an ATM multiplexer queueing model fed by heterogeneous Markovian traffic sources. We achieve this by constructing a simple approximation of the buffer overflow probability: Pr(Q>B)/spl ap/De/sup -/spl theta/*B/, where /spl theta/* is the asymptotic decay rate of the tail of the distribution, and D is a prefactor obtained from the Bahadur-Rao theorem. Upper bounds on other QOS parameters, such as cell loss ratio, mean cell delay and cell delay variance, can all be derived from this estimate. It has been shown that this approximation is much more accurate than the pure effective bandwidth one Pr(Q>B)/spl ap/e/sup -/spl theta/*B/, which ignores the statistical multiplexing gain due to a large number of sources. One attraction of the proposed method is that the speed of computation of D and /spl theta/* is independent of the size of the system. Thus our analytical techniques can be implemented fast enough for real-time administration of admission control in ATM networks.
{"title":"Fast and accurate estimation of ATM quality of service parameters with applications to call admission control","authors":"Z. Fan, P. Mars","doi":"10.1109/ICICS.1997.647118","DOIUrl":"https://doi.org/10.1109/ICICS.1997.647118","url":null,"abstract":"We demonstrate how fast and accurate estimates of quality of service (QOS) parameters can be obtained for an ATM multiplexer queueing model fed by heterogeneous Markovian traffic sources. We achieve this by constructing a simple approximation of the buffer overflow probability: Pr(Q>B)/spl ap/De/sup -/spl theta/*B/, where /spl theta/* is the asymptotic decay rate of the tail of the distribution, and D is a prefactor obtained from the Bahadur-Rao theorem. Upper bounds on other QOS parameters, such as cell loss ratio, mean cell delay and cell delay variance, can all be derived from this estimate. It has been shown that this approximation is much more accurate than the pure effective bandwidth one Pr(Q>B)/spl ap/e/sup -/spl theta/*B/, which ignores the statistical multiplexing gain due to a large number of sources. One attraction of the proposed method is that the speed of computation of D and /spl theta/* is independent of the size of the system. Thus our analytical techniques can be implemented fast enough for real-time administration of admission control in ATM networks.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"19 1","pages":"351-356 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82406499","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 : 1997-09-09DOI: 10.1109/ICICS.1997.647119
Yoon-Young An, W. Rhee, Hong-shik Park
We show the movable boundary (MB) method is the effective bandwidth allocation strategy for the ABR service. The MB method can guarantee the QOS requirement according to the service priority and improve bandwidth utilization using the characteristics of the ABR service. The threshold values of the MB are obtained by simulation. The MB method with the fixed thresholds, however, may not have good performance to variation of input traffic parameters. We suggest the dynamic MB method which changes the threshold values adaptively according to the required bandwidth of input traffic.
{"title":"Bandwidth allocation method supporting ABR service in ATM networks","authors":"Yoon-Young An, W. Rhee, Hong-shik Park","doi":"10.1109/ICICS.1997.647119","DOIUrl":"https://doi.org/10.1109/ICICS.1997.647119","url":null,"abstract":"We show the movable boundary (MB) method is the effective bandwidth allocation strategy for the ABR service. The MB method can guarantee the QOS requirement according to the service priority and improve bandwidth utilization using the characteristics of the ABR service. The threshold values of the MB are obtained by simulation. The MB method with the fixed thresholds, however, may not have good performance to variation of input traffic parameters. We suggest the dynamic MB method which changes the threshold values adaptively according to the required bandwidth of input traffic.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"102 1","pages":"357-361 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79696523","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 : 1997-09-09DOI: 10.1109/ICICS.1997.652055
J. Friedrich, D. Schlegel
This paper compares three different methods for controlling data flow over high speed wide area networks. It presents a novel mechanism that measures the exact receiver capabilities in order to improve the rate based flow control algorithm. Unlike standard protocols like TCP/IP with their credit based flow control, the new protocol, dynamic speed transfer protocol (DSTP), uses this special rate based scheme. With additional optimization, the protocol is able to reach both, high transmission speed and a nearly optimal usage of bandwidth.
{"title":"End-to-end flow control algorithms for high speed data transmission over ATM","authors":"J. Friedrich, D. Schlegel","doi":"10.1109/ICICS.1997.652055","DOIUrl":"https://doi.org/10.1109/ICICS.1997.652055","url":null,"abstract":"This paper compares three different methods for controlling data flow over high speed wide area networks. It presents a novel mechanism that measures the exact receiver capabilities in order to improve the rate based flow control algorithm. Unlike standard protocols like TCP/IP with their credit based flow control, the new protocol, dynamic speed transfer protocol (DSTP), uses this special rate based scheme. With additional optimization, the protocol is able to reach both, high transmission speed and a nearly optimal usage of bandwidth.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"82 3 1","pages":"640-643 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79745969","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 : 1997-09-09DOI: 10.1109/ICICS.1997.652221
M. Jian, A. Kot, M.H. Er
An improved time delay estimator based on the symmetry measurement of the generalised cross-correlation (GCC) function is proposed. At a strong reverberation case, multiple peaks are chosen from the GCC function and the peak with the best symmetry measure is determined as the time delay estimate. Computer simulation results in a room environment for different source locations show the significant improvement on the percentage of anomalies of the time delay estimates against the maximum likelihood TDE (MLTDE) and PHAT methods, it also shows that the proposed time delay estimation is robust to the presence of multi-path propagation, even under a strong reverberation condition and with the source located close to the wall.
{"title":"Time delay estimation at multi-path based on symmetry measure of GCC function","authors":"M. Jian, A. Kot, M.H. Er","doi":"10.1109/ICICS.1997.652221","DOIUrl":"https://doi.org/10.1109/ICICS.1997.652221","url":null,"abstract":"An improved time delay estimator based on the symmetry measurement of the generalised cross-correlation (GCC) function is proposed. At a strong reverberation case, multiple peaks are chosen from the GCC function and the peak with the best symmetry measure is determined as the time delay estimate. Computer simulation results in a room environment for different source locations show the significant improvement on the percentage of anomalies of the time delay estimates against the maximum likelihood TDE (MLTDE) and PHAT methods, it also shows that the proposed time delay estimation is robust to the presence of multi-path propagation, even under a strong reverberation condition and with the source located close to the wall.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"230 1","pages":"1401-1404 vol.3"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80251075","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 : 1997-09-09DOI: 10.1109/ICICS.1997.652256
S. Kang, Y. Aoki
We describe a new morphing technique using the Fourier transform. Two-dimensional (2-D) or three-dimensional (3-D) models are Fourier-transformed and the intensities of the transformed patterns are superposed and clipped, resulting in a blending pattern of two models. Morphing by the simple interpolation yields an interesting result between the models, but difficulty can arise if the models are composed of dominant higher frequency components. We therefore propose a new method, where the morphing of two models is done after dividing a higher-frequency dominant model into two lower-frequency dominant models. The morphing experiment was conducted to show the validity of the proposed methods using simple 2-D and 3-D models.
{"title":"Volume morphing by Fourier transform","authors":"S. Kang, Y. Aoki","doi":"10.1109/ICICS.1997.652256","DOIUrl":"https://doi.org/10.1109/ICICS.1997.652256","url":null,"abstract":"We describe a new morphing technique using the Fourier transform. Two-dimensional (2-D) or three-dimensional (3-D) models are Fourier-transformed and the intensities of the transformed patterns are superposed and clipped, resulting in a blending pattern of two models. Morphing by the simple interpolation yields an interesting result between the models, but difficulty can arise if the models are composed of dominant higher frequency components. We therefore propose a new method, where the morphing of two models is done after dividing a higher-frequency dominant model into two lower-frequency dominant models. The morphing experiment was conducted to show the validity of the proposed methods using simple 2-D and 3-D models.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"111 1","pages":"1562-1565 vol.3"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80623142","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 : 1997-09-09DOI: 10.1109/ICICS.1997.647046
V. Chu, W. Sun, M. Sweeting
Satellites in low Earth orbit (LEO) are accessible to an unprecedented number of users around the globe with numerous applications, especially with the recent rapid development in LEO satellite constellations for communications. Until a few years ago, advanced designs for satellite communications systems had focused on conventional geostationary Earth orbit (GEO) communications technologies which are not necessarily tailored to the LEO environment. Such sub-optimal designs were accommodated by the typical application of LEO satellites-remote sensing satellites-normally being large satellites with ever-increasing power and bandwidth and equipped with large ground stations. These days, the current trend of the satellite industry is towards smaller satellites and smaller terminals, made possible through continuous technological improvement. Advances in sensor and payload technology have permitted rapidly increasing amounts of data to be transferred. This, coupled with user demands for reliable, efficient data delivery from small satellites to even smaller terminals, calls for an urgent need to optimise the LEO communications link, particularly for payload data retrieval.
{"title":"Optimising the LEO satellite communications link through hybrid-ARQ techniques","authors":"V. Chu, W. Sun, M. Sweeting","doi":"10.1109/ICICS.1997.647046","DOIUrl":"https://doi.org/10.1109/ICICS.1997.647046","url":null,"abstract":"Satellites in low Earth orbit (LEO) are accessible to an unprecedented number of users around the globe with numerous applications, especially with the recent rapid development in LEO satellite constellations for communications. Until a few years ago, advanced designs for satellite communications systems had focused on conventional geostationary Earth orbit (GEO) communications technologies which are not necessarily tailored to the LEO environment. Such sub-optimal designs were accommodated by the typical application of LEO satellites-remote sensing satellites-normally being large satellites with ever-increasing power and bandwidth and equipped with large ground stations. These days, the current trend of the satellite industry is towards smaller satellites and smaller terminals, made possible through continuous technological improvement. Advances in sensor and payload technology have permitted rapidly increasing amounts of data to be transferred. This, coupled with user demands for reliable, efficient data delivery from small satellites to even smaller terminals, calls for an urgent need to optimise the LEO communications link, particularly for payload data retrieval.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"13 1","pages":"5-9 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83594285","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 : 1997-09-09DOI: 10.1109/ICICS.1997.652280
H. Beadle, K. Ramli, A. Samouelian
Traditional ways of interacting with hypermedia fail in a domestic setting because the user interaction devices typical of a desktop hypermedia system (mouse, keyboard, joystick, high resolution screen) are currently unavailable or are impractical in a domestic setting. We have investigated and prototyped an alternate interaction device based on a hand-held touchpad that we believe is practical in a domestic environment where people interact with hypermedia content for education and entertainment in a lounge room like setting. We have evaluated the usability level of the device in human trials and found that it performs better than keyboard-mouse combination, which is one of the most widely used interaction device today.
{"title":"A user interface device for domestic hypermedia","authors":"H. Beadle, K. Ramli, A. Samouelian","doi":"10.1109/ICICS.1997.652280","DOIUrl":"https://doi.org/10.1109/ICICS.1997.652280","url":null,"abstract":"Traditional ways of interacting with hypermedia fail in a domestic setting because the user interaction devices typical of a desktop hypermedia system (mouse, keyboard, joystick, high resolution screen) are currently unavailable or are impractical in a domestic setting. We have investigated and prototyped an alternate interaction device based on a hand-held touchpad that we believe is practical in a domestic environment where people interact with hypermedia content for education and entertainment in a lounge room like setting. We have evaluated the usability level of the device in human trials and found that it performs better than keyboard-mouse combination, which is one of the most widely used interaction device today.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"82 5 1","pages":"1677-1681 vol.3"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89587083","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 : 1997-09-09DOI: 10.1109/ICICS.1997.652268
Qian Wang, C.K. Liu, K. Li
The B-ISDN is designed to support various classes of traffic. Traffic with wide range of bandwidth, delay, loss requirements are expected to be carried by the network and match the expected grade of service (GoS). The inherent problems of large bandwidth, bursty and real-time requirements of variable bit rate (VBR) have attracted attentions of researchers in the past. We propose an equivalent bandwidth estimation algorithm for VBR video traffic. Our approach combines the statistical attributes, GoS requirements and network resources parameters to provide an integrated measure. This algorithm is computational simple, accurate and robust.
{"title":"Equivalent bandwidth of VBR video traffic","authors":"Qian Wang, C.K. Liu, K. Li","doi":"10.1109/ICICS.1997.652268","DOIUrl":"https://doi.org/10.1109/ICICS.1997.652268","url":null,"abstract":"The B-ISDN is designed to support various classes of traffic. Traffic with wide range of bandwidth, delay, loss requirements are expected to be carried by the network and match the expected grade of service (GoS). The inherent problems of large bandwidth, bursty and real-time requirements of variable bit rate (VBR) have attracted attentions of researchers in the past. We propose an equivalent bandwidth estimation algorithm for VBR video traffic. Our approach combines the statistical attributes, GoS requirements and network resources parameters to provide an integrated measure. This algorithm is computational simple, accurate and robust.","PeriodicalId":71361,"journal":{"name":"信息通信技术","volume":"42 1","pages":"1618-1622 vol.3"},"PeriodicalIF":0.0,"publicationDate":"1997-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89856005","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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