The current state of software engineering practices in medical software development is discussed. The authors focus on patient safety (freedom from harm by a medical device) and patient vulnerability (possible indirec...
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The current state of software engineering practices in medical software development is discussed. The authors focus on patient safety (freedom from harm by a medical device) and patient vulnerability (possible indirect harm due to erroneous output). A definition of medical software which can be viewed as a three-dimensional model for medical software classification is proposed. To reduce patient vulnerability and enhance patient safety, specific points of control are derived from the model, and the implications of classification and control for medical software are discussed.< >
In this paper, we analyze the performance of GI/GI/s/s+r systems. In particular we examine steady-state call blocking and time blocking. We vary several parameters such as the number of servers, the number of waiting ...
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In this paper, we analyze the performance of GI/GI/s/s+r systems. In particular we examine steady-state call blocking and time blocking. We vary several parameters such as the number of servers, the number of waiting spaces, the squared coefficients of variation of the arrival and the service processes, and the third moment of the arrival process. We show that these parameters significantly affect system performance. Thus, for most systems with bursty and skewed traffic patterns, simpler models are insufficient. However, in certain circumstances, when the arrivals are either highly bursty or highly skewed, the Markovian assumption gives acceptable approximations to the GI/GI/s/s+r model. Finally, we observe a behavior that is similar to Erlang's insensitivity property in the M/G/s/s model.< >
An estimate of the information a database contains and the quantification of the vulnerability of that database to compromise by inferential methods is discussed. Such a measure could be used to evaluate the deterrent...
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This paper describes methods for increasing the security of data being stored in a distributed hash table (DHT) which leverages the inherent properties of the DHT to provide a secure storage substrate. The methods pre...
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ISBN:
(纸本)9781424423897
This paper describes methods for increasing the security of data being stored in a distributed hash table (DHT) which leverages the inherent properties of the DHT to provide a secure storage substrate. The methods presented are based upon a framework referred to as "scatter, conceal, and recover" (SCAR). The standard method of securing data in a DHT is to encrypt the data using symmetrical encryption before storing it in the network. SCAR provides this level of security, but also prevents any known cryptoanalisys from being performed. It does this by dividing data into multiple blocks and scattering these blocks within the DHT. The security of SCAR is provided by the property that an attacker is unable to obtain and reassemble the data blocks correctly. However, if the attacker has access to the network communication, the likelihood of a successful attack is significantly increased. This paper defines how such attacks can be executed and provides methods for ensuring data security in spite of such attacks.
Selective encryption is a technique to save computational complexity or enable new system functionality by encrypting only a portion of a compressed bitstream while achieving adequate security. Although suggested in a...
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Selective encryption is a technique to save computational complexity or enable new system functionality by encrypting only a portion of a compressed bitstream while achieving adequate security. Although suggested in a number of specific cases, selective encryption could be much more widely used in consumer electronic applications, ranging from mobile multimedia terminals to digital cameras, were it subjected to a more thorough security analysis. We describe selective encryption and develop a simple scalar quantizer example to demonstrate the power of the concept, list a number of potential consumer electronics applications, then describe an appropriate method for developing and analyzing selective encryption for particular compression algorithms. We summarize results from the application of this method to the MPEG-2 video compression algorithm.
The virtual path (VP) concept has been gaining attention in terms of effective deployment of ATM (asynchronous transfer mode) networks in recent years. In this paper, we discuss a multi-hour, multi-traffic class netwo...
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The virtual path (VP) concept has been gaining attention in terms of effective deployment of ATM (asynchronous transfer mode) networks in recent years. In this paper, we discuss a multi-hour, multi-traffic class network (capacity) design model for providing specified quality-of-service in dynamically reconfigurable ATM networks. Our approach is based on statistical multiplexing of traffic within a traffic class by using a virtual path for the class and deterministic multiplexing of different virtual paths, and on providing dynamic bandwidth and reconfigurability through the virtual path concept depending on traffic load during the course of the day. We show that, for test problems based on realistic network data, our approach does between 6% to 20% better than a local shortest path heuristic in terms of network cost. We also show that considering network dynamism through variation of traffic during the course of a day by doing dynamic bandwidth and virtual path reconfiguration can save between 10% to 14% in network design costs compared to a static network based on maximum busy hour traffic.
With the emerging ATM broadband networks, there will be a need for connectivity between LANs and broadband networks. The possibility of seamless internetworking between these networks has generated a significant resea...
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With the emerging ATM broadband networks, there will be a need for connectivity between LANs and broadband networks. The possibility of seamless internetworking between these networks has generated a significant research interest in providing connection-oriented service over LANs. Also, the multimedia nature of traffic is likely to necessitate a connection-oriented service for communication among the LAN terminals as well as between a LAN terminal and non-LAN terminals on ATM networks. We present a technique to provide connection-oriented service on LANs employing a bandwidth reservation scheme. Then we show how this technique is incorporated into a multimedia LAN (MLAN) protocol to provide connection-oriented service. The performance of the protocol under connection-oriented service is evaluated and the results are presented.
In a comment, fatal mistakes in the proof in Campbell and Higgins' (1991) main theorem concerning minimal visibility graphs are discussed. These mistakes stem from the incorrectness of Lemma 4 and Lemma 5, which ...
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In a comment, fatal mistakes in the proof in Campbell and Higgins' (1991) main theorem concerning minimal visibility graphs are discussed. These mistakes stem from the incorrectness of Lemma 4 and Lemma 5, which are the backbone of the main theorem. Counterexamples to the lemmas are provided.
To verify whether a spanning tree T(V,E) of graph G(V,E') is a minimum spanning tree, two parallel algorithms are presented. The first algorithm requires O(log n) time and O(max{m/log n, n/sup 3/2//log n}) process...
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ISBN:
(纸本)0818665556
To verify whether a spanning tree T(V,E) of graph G(V,E') is a minimum spanning tree, two parallel algorithms are presented. The first algorithm requires O(log n) time and O(max{m/log n, n/sup 3/2//log n}) processors, where |E'|=m and |V|=n. The second algorithm requires O(log n) time and O(m) processors or O(log nloglog n) time and O(max{m/log n, n}) processors. The first algorithm is optimal when G is dense, compared with its O(m) time sequential version. The second algorithm has better performance when G is sparse. By using above results, we also present an efficient algorithm for sensitivity analysis of minimum spanning trees which requires O(log n) time and O(max{m, n/sup 2//log n}) processors. All proposed algorithms in this paper are based on the parallel computational model called CREW PRAM.
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