Proceeding of 13th IEEE Annual International Phoenix Conference on Computers and Communications最新文献

{"title":"Structures for fault-tolerant distributed protocols","authors":"M. Neilsen","doi":"10.1109/PCCC.1994.504097","DOIUrl":"https://doi.org/10.1109/PCCC.1994.504097","url":null,"abstract":"In distributed systems, many protocols have been formalized in terms of the data structures used by the protocols. These data structures, called quorum structures, include quorum sets, coteries, and bicoteries. However, quorum structures only have two states either a quorum is available or at is not. In order to obtain more information about the state of the system, d a t a structures that have multiple states must be used. In this paper, we formally define such structures, called multistate structures. Then, these structures are used to define new, fault-tolerant protocols. Such protocols represent a significant improvement over existing protocols because they are able to capture more information about the current state of the system. Consequently, they allow for graceful degradation. The cost of using these protocols is a small increase in message complexity. However, this small increase in message complexity can result in a significant increase in fault tole ran ce .","PeriodicalId":203232,"journal":{"name":"Proceeding of 13th IEEE Annual International Phoenix Conference on Computers and Communications","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132109502","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}

{"title":"Design of the Interface Between the Intensive Care Unit and Hospital/Radiology Information Systems a","authors":"Y. Alsafadi, K. Maloney, K. McNeill, M. V. Parra, R. Martinez, J. Guice","doi":"10.1109/PCCC.1994.504145","DOIUrl":"https://doi.org/10.1109/PCCC.1994.504145","url":null,"abstract":"This paper discusses the design and the implementation of the interface between the Medical Image Access System for the Intensive Care Unit (MIAS/ICU) and the hospital/radiology information systems (HIS/RIS) operated by Information Systems Services (ISS) of the University Medical Center, Tucson, Arizona. The report addresses the problem of obtaining current status information on patients to be used in the MIAS/ICU system. Hospital information systems operated by ISS exchange patient information using Health Level 7 (HL7) messages over the hospital Ethernet network. The MIAS/ICU consists of 5 components: an image reader to read image plates from portable x-ray units; Image Server to store images; Data Server which is a database for patient information; Viewing Workstation a commercial workstation with two monitors used by physicians at ICU for early, uno cial viewing of images; these components are integrated by an FDDI network. These images need to be supplemented by patient's current status information. A gateway was designed and implemented to extract useful data from HL7 messages and pass them to the data server. Most medical information exchange interface designs tend to be proprietary, hard-wired, and application speci c. This design and implementation is open; can be easily customizable to suit di erent medical institutions; allowed us to exibly experiment with di erent con gurations; and is operating reliably in a clinical setting. It is a generic design for interfaces between medical information applications. This paper brie y reviews the HL7 standard. It then provides an overview of the MIAS/ICU project, the gateway software architecture, the gateway software implementation, and design limitations. This gateway is currently operational within the MIAS/ICU system at University Medical Center, Tucson, Arizona. 1 2 1 This work is supported by: a gift from Fuji Medical Systems U.S.A., funding and support from University Medical Center, and an equipment grant from Digital Equipment Corporation. 2 International Phoenix Conference on Computers and Communications (IPCCC), Phoenix, Arizona, April 12-15, 1994","PeriodicalId":203232,"journal":{"name":"Proceeding of 13th IEEE Annual International Phoenix Conference on Computers and Communications","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131098102","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}

{"title":"On the Performance of Trellis Coded Modulation in a Concatenated Reed-Bolomon Systern","authors":"M. Ross, N. Ashley, W. Osborne","doi":"10.1109/PCCC.1994.504152","DOIUrl":"https://doi.org/10.1109/PCCC.1994.504152","url":null,"abstract":"Concatenated systems combining the error correcting power of trellis codes and Reed-Solomon (RS) codes have been used to achieve error rates between and on satelite communications links [l]. The need for spectral efficiency has motivated consideration of of non-binary signalling with Ungerboeck [2,3] codes or the Pragmatic standard recently proposed by Viterbi [4], in place of quaternary signalling with rate 1/2 coding. In this paper we investigates the use of 8-PSK trellis-coded modulation (TCM) in a concatenated system using a (255,233) RS code. The use of the 8-PSK codes doubles the spectral efficiency with a performance cost of approximately 2 dB.","PeriodicalId":203232,"journal":{"name":"Proceeding of 13th IEEE Annual International Phoenix Conference on Computers and Communications","volume":"11 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133092003","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}

{"title":"The Flexible Hypercube Multiprocessor System","authors":"Guan Xin-Li, T. Hameenanttila, J. Carothers, Chen Jian-xin","doi":"10.1109/PCCC.1994.504126","DOIUrl":"https://doi.org/10.1109/PCCC.1994.504126","url":null,"abstract":"A new interconnection network known as the Flexible Hypercube is introduced. The Flexible Hypercube is a fault-tolerant architecture that can be constructed for an arbitrary number of nodes and is incrementally expandable. This network architecture maintains the strong features of the Hypercube while overcoming deficiencies in expandability and flexibility. It is shown to have strong node connectivity, a small diameter, and a high degree of fault tolerance. The Flexible Hypercube network is suitable for the design of both parallel computer systems and distributed computer networks. Efficient fault-free and fault-tolerant message-routing algorithms for this network are presented.","PeriodicalId":203232,"journal":{"name":"Proceeding of 13th IEEE Annual International Phoenix Conference on Computers and Communications","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124157748","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}

{"title":"Efficient Algorithms for Forward and Inverse Transformations between Haar Spectrum and Binary Decisi","authors":"B. Falkowski, Chip-Hong Chang","doi":"10.1109/PCCC.1994.504160","DOIUrl":"https://doi.org/10.1109/PCCC.1994.504160","url":null,"abstract":"An algorithm has been developed to calculate the Haar transform of Boolean functions from their Binary Decision Diagram (BDD) representation. The method of decomposition of Haar spectral coefficients in terms of the cofactors of Boolean functions that resembles known Shannon decomposition of such functions has been introduced. Based on the above decomposition, a second new algorithm is presented to synthesize ordered Binary Decision Diagram directly from Haar spectrum of Boolean functions.","PeriodicalId":203232,"journal":{"name":"Proceeding of 13th IEEE Annual International Phoenix Conference on Computers and Communications","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114954147","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}

{"title":"Implementation and performance evaluation of a self-timed multiprocessor scheduler on a shared-memor","authors":"F. A. Samadzadeh, A.A. Thobani, M. Samadzadeh","doi":"10.1109/PCCC.1994.504093","DOIUrl":"https://doi.org/10.1109/PCCC.1994.504093","url":null,"abstract":"A new multiprocessor scheduling heuristic, Ranked Weight heuristic, based on the Critical Path approach is presented. The proposed heuristic is embedded in a multiprocessor scheduling algorithm that divides the tasks in a task system into a number of independent layers and schedules the resulting task sets using an urgency xule based on the proposed heuristic. Performance of the proposed scheduling algorithm is measured through extensive performance modeling studies. The behavior of the algorithm is described in terms of the number of processors required for execution of a task system and the actual number of allocated processors. The multiprocessor scheduler described in this paper is implemented on a Sequent Symmetry machine using a self-timed scheduling approach. Due to the timeshared multiuser nature of processing on Sequent, a benchmarking program is used to collect the run-time overhead associated with self-timed scheduling of task systems. The run-time behavior of task systems is analyzed and described in terms of each task system's scheduled critical pafh.","PeriodicalId":203232,"journal":{"name":"Proceeding of 13th IEEE Annual International Phoenix Conference on Computers and Communications","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129493589","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}

{"title":"Total Systems Management in Open Architecture Provisioning Systems","authors":"L. E. Heindel, K. J. Schlieber","doi":"10.1109/PCCC.1994.504143","DOIUrl":"https://doi.org/10.1109/PCCC.1994.504143","url":null,"abstract":"A growing challenge in the transition of Telecommunications Provisioning Systems from a closed architecture to a Distributed Open Architecture is the need for effective system management tools that encompass not only network management, but also application management functionality. Networking the various Provisioning System components resulted in a heterogeneous multi-vendor environment. At the time, the lack of industry standards in the communications as well as the systems management area gave rise to the development of proprietary communications protocols and network management solutions. This paper concentrates on the analysis of a proprietary Total Management System (TMS) designed to combine applications and network monitoring in a heterogeneous Provisioning System environment. Bellcore’s long-term strategic direction is towards implementing the Open System Interconnection (OSI) Management standards model to provide a consistent management environment within Provisioning Systems. In this paper we discuss the transition strategy and an approach to integrating OS1 defined CMIP/ CMISE management protocols, the TCP/IP defined SNMP protocol and proprietary legacy network management systems to produce an Open Architecture Total Management System to complement our Open Architecture Provisioning System strat-","PeriodicalId":203232,"journal":{"name":"Proceeding of 13th IEEE Annual International Phoenix Conference on Computers and Communications","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129498793","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}

{"title":"An available copy protocol tolerating network partitions","authors":"J. París","doi":"10.1109/PCCC.1994.504096","DOIUrl":"https://doi.org/10.1109/PCCC.1994.504096","url":null,"abstract":"Maintaining in a consistent state multiple copies of the same data is a complex task, especially when the copies reside on sites that can be separated from each other by network partitions. All existing replication controls that tolerate network partitions use quorums to provide mutual exclusion and prevent inconsistent updates. Unfortunately these protocols require a minimum of n + 2 voting sites to guarantee that the data will remain accessible in the presence of n site failures. As a result, they provide much lower data availabilities than protocols that exclude communication failures. We present here a replication protocol that extends the available copy approach to environments where communication failures may cause network partitions. Our protocol assumes that replicas monitor the communication paths linking them with their peers and can therefore detect network partitions. As a result, each individual replica can safely establish whether it has remained up to date or is likely to have missed some updates. We evaluate under standard Markovian assumptions the availability of a replicated file consisting of two replicas managed by our robust available copy protocol when the two replicas are separated by one gateway. We find our protocol to perform much better than (1) dynamic-linear voting with three replicas, (2) dynamic-linear voting with two replicas and one witness, (3) voting with ghosts with two replicas, and (4) voting with bystanders with two replicas.","PeriodicalId":203232,"journal":{"name":"Proceeding of 13th IEEE Annual International Phoenix Conference on Computers and Communications","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129243215","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}

{"title":"Network traffic measurement of the X window system","authors":"N. Basil, C. Williamson","doi":"10.1109/PCCC.1994.504106","DOIUrl":"https://doi.org/10.1109/PCCC.1994.504106","url":null,"abstract":"The X Window System is a popular windowing system that runs on a wide range of computing and graphics machines. X servers and clients communicate over a network so that applications running on remote hosts can be displayed locally through graphical interfaces. This paper presents measurements of network traffic and message transfer for the X Window System. A network traffic monitoring tool, tcpdump, is used to collect packet traces in order to study the traffic between a server and a client for various X applications. X protocol messages for the applications are also recorded by a monitor called xmon. The measurements are taken on a 10 Mb/s Ethernet LAN. Experimental results show that packets are produced equitably between clients and servers. The bulk of the bytes are, however, directed from dients to servers. The bandwidth requirements are particularly high for applications that display documents, images, or video. Examination of X protocol messages manifests the dominance of request messages in frequency as well as size.","PeriodicalId":203232,"journal":{"name":"Proceeding of 13th IEEE Annual International Phoenix Conference on Computers and Communications","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125408142","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}

{"title":"On-the-fly message filtering in a distributed simulation application","authors":"M. Bassiouni, M. Chiu, M. Garnsey","doi":"10.1109/PCCC.1994.504087","DOIUrl":"https://doi.org/10.1109/PCCC.1994.504087","url":null,"abstract":"Data filtering is one of the techniques that can help achieve real-time linkage in large-scale distributed interactive simulation (DIS). We present the results of our work to design and evaluate data filtering schemes for DIS networks. Detailed algorithms suitable for the implementation of data filtering in the gateways of DIS networks are given. Methods to solve the problem of inaccurate state information caused by message filtering are presented and evaluated. Performance results of the filtering schemes are discussed.","PeriodicalId":203232,"journal":{"name":"Proceeding of 13th IEEE Annual International Phoenix Conference on Computers and Communications","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121076631","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}