This paper studies the problem of interference-free broadcast in wireless ad hoc networks. In particular, we are interested in asymmetric power assignments so that the induced broadcast communication graph is both, en...
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Adaptive management of a software service system can take advantage of a performance model which can predict the effect of proposed changes, before they are deployed. As the system varies over time the model parameter...
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ISBN:
(纸本)9781450305198
Adaptive management of a software service system can take advantage of a performance model which can predict the effect of proposed changes, before they are deployed. As the system varies over time the model parameters can be tracked by an estimator such as a Kalman Filter, so that decisions can be updated. The filter is valuable when parameters are "hidden" and cannot be directly measured without excessive cost (as is usually the case for the CPU time of a service). Because there may be significant delays in some management control actions (especially in deploying a new replica of a service), it is also important to be able to predict the changes ahead somewhat in time, that is, to predict the trends. The trend predictor itself needs to be estimated from observed trends in the model parameters. This work uses an autoregressive model for trend prediction and integrates it with the parameter estimator, in a single Kalman Filter, using auxiliary states for the parameter evolution process. This paper describes how the trend model is constructed, and evaluates its effectiveness. It compares the overall performance predictions to a simpler trend predictor using linear extrapolation of the fitted parameter time-series, which turns out to be almost as good. The approach is validated on a real system running a benchmark web application.
In this paper we address the question of "Why is it that a mobile robot, programmed in a certain way and placed in some environment to execute a program, behaves in the way it does?". We present three real w...
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Nowadays, "cards" are becoming part of our lives. The cards enable us to obtain different kinds of services conveniently, but may also bring us economic loss if they are used illegally by some malicious thir...
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Finding lines of code similar to a code fragment across large knowledge bases in fractions of a second is a new branch of code clone research also known as real-time code clone search. Among the requirements real-time...
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We report a generalized approach to deal with patient motion in robotic image-guided surgery, along with in silico and dry laboratory tests on a neurosurgical robot setup. External patient motion events (excluding phy...
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ISBN:
(纸本)9781457711992
We report a generalized approach to deal with patient motion in robotic image-guided surgery, along with in silico and dry laboratory tests on a neurosurgical robot setup. External patient motion events (excluding physiological motion) can occur during surgery despite body fixation, and can endanger the outcome of the surgery, as they invalidate the registration between the robot and the patient. The core of the compensation algorithm is to rely on the combination of the robot joint encoders, tracking data and the internal coordinate frame of the intra-operative navigation system to ensure accurate execution of the pre-operative plan. The method allows for the continuous correction of the registration through identifying the actual surgical event in the operating room. From the control point of view, the intra-operative events have been categorized as robot motion, camera motion, patient motion and the combinations of these. The registration update is based on the use of the most reliable reference frame and extending-window averaging to compensate for the occurred patient motion. Simulation results were performed on a generic image-guided robot model, and on a skull base surgery robot. Patient motion events were detected in 80% of the cases, which already leads to a gradual improvement of the procedure. The proposed structure allows for a more generic, probability-based handling of the operating room events that may lead to safer and more accurate surgical treatment in the future.
The purpose of this paper is to reduce the Denial of Service (DoS) attacks on peer-to-peer networks by hiding the position of the file and to prove the effectiveness through the fuzzy logic. In general to protect the ...
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We present a method for identification of gene regulatory network topology using a time series of gene expression data. The underlying assumption in our method is that the functions that describe regulatory relations ...
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In this paper, we propose an online algorithm for multimodal categorization based on the autonomously acquired multimodal information and partial words given by human users. For multimodal concept formation, multimoda...
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ISBN:
(纸本)9781467317375
In this paper, we propose an online algorithm for multimodal categorization based on the autonomously acquired multimodal information and partial words given by human users. For multimodal concept formation, multimodal latent Dirichlet allocation (MLDA) using Gibbs sampling is extended to an online version. We introduce a particle filter, which significantly improve the performance of the online MLDA, to keep tracking good models among various models with different parameters. We also introduce an unsupervised word segmentation method based on hierarchical Pitman-Yor Language Model (HPYLM). Since the HPYLM requires no predefined lexicon, we can make the robot system that learns concepts and words in completely unsupervised manner. The proposed algorithms are implemented on a real robot and tested using real everyday objects to show the validity of the proposed system.
Return-Oriented Programming (ROP) is a technique which leverages the instruction gadgets in existing libraries/executables to construct Turing complete programs. However, ROP attack is usually composed with gadgets wh...
ISBN:
(纸本)9781450305648
Return-Oriented Programming (ROP) is a technique which leverages the instruction gadgets in existing libraries/executables to construct Turing complete programs. However, ROP attack is usually composed with gadgets which are ending in ret instruction without the corresponding call instruction. Based on this fact, several defense mechanisms have been proposed to detect the ROP malicious code. To circumvent these defenses, Return-Oriented Programming without returns has been proposed recently, which uses the gadgets ending in jmp instruction but with much diversity. In this paper, we propose an improved ROP techniques to construct the ROP shellcode without returns. Meanwhile we implement a tool to automatically construct the real-world Return-Oriented Programming without returns shell-code, which as demonstrated in our experiment can bypass most of the existing ROP defenses. Copyright 2011 ACM.
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