We propose a new graphical password scheme. It is defined as a challenge-response identification. Hence, a password in our scheme is time-variant. User who knows the password is able to meet the challenge and to respo...
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ISBN:
(纸本)1932415165
We propose a new graphical password scheme. It is defined as a challenge-response identification. Hence, a password in our scheme is time-variant. User who knows the password is able to meet the challenge and to respond correctly. As a consequence, our graphical password scheme is shoulder-surfing resistant. An attacker still cannot tell what the password is, even if he/she has filmed a user's login process. Primary experiments on our graphical password scheme showed the scheme is promising.
In this paper, we present an analytical TCP model that takes into account of several issues that were ignored in the other existing models (such as those in), i.e., (i) the congestion window is not gradually decreased...
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ISBN:
(纸本)0780377524
In this paper, we present an analytical TCP model that takes into account of several issues that were ignored in the other existing models (such as those in), i.e., (i) the congestion window is not gradually decreased at the rate of w2p/2, but suddenly halved upon receipt of congestion indication and (ii) the congestion window is halved at most once during one round-trip time (RTT). We also include the delayed ACK option in the model. With the use of state feedback control theory, we then design, based on the enhanced TCP model, an AQM controller to stabilize the queue length at routers. The performance of the new controller is shown, via ns-2 simulation to outperform several other schemes under a variety of network scenarios and traffic loads, in terms of fluctuation in the queue length, link utilization, and packet loss ratio.
In this paper, we examine on-line learning problems in which the target concept is allowed to change over time. In each trial a master algorithm receives predictions from a large set of n experts. Its goal is to predi...
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In this paper, we examine on-line learning problems in which the target concept is allowed to change over time. In each trial a master algorithm receives predictions from a large set of n experts. Its goal is to predict almost as well as the best sequence of such experts chosen off-line by partitioning the training sequence into k + 1 sections and then choosing the best expert for each section. We build on methods developed by Herbster and Warmuth and consider an open problem posed by Freund where the experts in the best partition are from a small pool of size m. Since k m, the best expert shifts back and forth between the experts of the small pool. We propose algorithms that solve this open problem by mixing the past posteriors maintained by the master algorithm. We relate the number of bits needed for encoding the best partition to the loss bounds of the algorithms. Instead of paying log n for choosing the best expert in each section we first pay log (mn) bits in the bounds for identifying the pool of m experts and then log m bits per new section. In the bounds we also pay twice for encoding the boundaries of the sections.
In this paper, we present a matching method that can improve the classification performance of a fuzzy decision tree (FDT). This method takes into consideration prediction strength of leave nodes of a fuzzy decision t...
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ISBN:
(纸本)0780378652
In this paper, we present a matching method that can improve the classification performance of a fuzzy decision tree (FDT). This method takes into consideration prediction strength of leave nodes of a fuzzy decision tree by combining true degrees (CF) of fuzzy rules, generated from a fuzzy decision tree, with membership degrees of antecedent parts of rules when applied to cases for classification. We illustrate the importance of CF through an example. An experiment shows by using this method, we can obtain more accurate results of classification when compared to the original method and to those obtained using the C5.0 decision tree.
Symport and antiport are biological ways of transporting molecules through membranes in "collaborating" pairs;in the case of symport the two molecules pass in the same direction, in the case of antiport the ...
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We study the shape matching problem under the Hausdorff distance and its variants. Specifically, we consider two sets A, B of balls in d, d = 2, 3, and wish to find a translation t that minimizes the Hausdorff distanc...
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We study the shape matching problem under the Hausdorff distance and its variants. Specifically, we consider two sets A, B of balls in d, d = 2, 3, and wish to find a translation t that minimizes the Hausdorff distance between A + t, the set of all balls in A shifted by t, and B. We consider several variants of this problem. First, we extend the notion of Hausdorff distance from sets of points to sets of balls, so that each ball has to be matched with the nearest ball in the other set. We also consider the problem in the standard setting, by computing the Hausdorff distance between the unions of the two sets (as point sets). Second, we consider either all possible translates t (as is the standard approach), or consider only translations that keep the balls of A + t disjoint from those of B. We propose several exact and approximation algorithms for these problems. Since the Hausdorff distance is sensitive to outliers, we also propose efficient approximation algorithms for computing the minimum root-mean-square (rms) and the minimum summed Hausdorff distance, under translation, between two point sets in Rd. In order to obtain a fast algorithm for the summed Hausdorff distance, we propose a deterministic efficient dynamic data structure for maintaining an Ε-approximation of the 1-median of a set of points, under insertion and deletion.
Pair programming is a practice in which two programmers work collaboratively at one computer, on the same design, algorithm, or code. Prior research indicates that pair programmers produce higher quality code in essen...
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Pair programming is a practice in which two programmers work collaboratively at one computer, on the same design, algorithm, or code. Prior research indicates that pair programmers produce higher quality code in essentially half the time taken by solo programmers. An experiment was run to assess the efficacy of pair programming in an introductory computerscience course. Student pair programmers were more self-sufficient, generally perform better on projects and exams, and were more likely to complete the class with a grade of C or better than their solo counterparts. Results indicate that pair programming creates a laboratory environment conducive to more advanced, active learning than traditional labs;students and lab instructors report labs to be more productive and less frustrating.
A method is proposed to generate homoclinic solutions for an integrable nonlinear PDE with periodic boundaries. This approach resembles the dressing method known in the theory of solitons. The pole positions in the dr...
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The cutting triangular cycles of lines in space were investigated. It was shown that a collection of lines in 3-space can be cut into a subquadratic number of pieces, such that all depth cycles defined by triples of l...
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The cutting triangular cycles of lines in space were investigated. It was shown that a collection of lines in 3-space can be cut into a subquadratic number of pieces, such that all depth cycles defined by triples of lines are eliminated. A long-standing open problem in computational geometry, motivated by hidden-surface removal in computer graphics, was solved.
We present a method for shape reconstruction from several images of a moving object. The reconstruction is dense (up to image resolution). The method assumes that the motion is known, e.g., by tracking a small number ...
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We present a method for shape reconstruction from several images of a moving object. The reconstruction is dense (up to image resolution). The method assumes that the motion is known, e.g., by tracking a small number of feature points on the object. The object is assumed Lambertian (completely matte), light sources should not be very close to the object but otherwise arbitrary, and no knowledge of lighting conditions is required. An object changes its appearance significantly when it changes its orientation relative to light sources, causing violation of the common brightness constancy assumption. While a lot of effort is devoted to deal with this violation, we demonstrate how to exploit it to recover 3D structure from 2D images. We propose a new correspondence measure that enables point matching across views of a moving object. The method has been tested both on computer simulated examples and on a real object.
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