6261034
An Economic Model of User Rating in an Online Recommender System
Economic modeling provides a formal mechanism to understand user incentives and behavior in online systems. In this paper we describe the process of building a parameterized economic model of user-contributed ratings in an online movie recommender system. We constructed a theoretical model to formalize our initial understanding of the system, and collected survey and behavioral data to calibrate an empirical model. This model explains 34% of the variation in user rating behavior. We found that while economic modeling in this domain requires an initial understanding of user behavior and access to an uncommonly broad set of user survey and behavioral data, it returns significant formal understanding of the activity being modeled.
17512619
Self-selection, slipping, salvaging, slacking, and stoning: the impacts of negative feedback at eBay
Analysis of usage history for a large panel of eBay sellers suggests that both seller and buyer behavior change in response to changes in a seller's feedback profile. Sellers are more likely to stop listing items right after receiving a negative feedback. Sellers who continue listing do not seem to improve their performance in order to salvage their reputations. Instead, sellers get more negative feedback after receiving a negative feedback. One reason is that observed negative feedback appears to be symptomatic of a temporary decline in the seller's quality, which is also reflected in other transactions around the same time. Receipt of negative feedback might also cause a decline in seller quality, but we find only weak evidence of that. Empirical evidence does support a second hypothesis, that buyers appear to be more willing to give negative feedback to sellers who have recently received other negative feedback.
39573562
Binary Trees and Uniform Distribution of Traffic Cutback
Abstract This article introduces the notion of the External Left Length (ELL) of binary trees, which is analogous to the notion of the External Path Length (EPL), and derives theorems about the ELL which correspond to well-known facts about the EPL. Results are applied to the analysis of the optimization of an algorithm for the smooth traffic cutback in data communication.
2501834
On the security of the Yen-Guo's domino signal encryption algorithm (DSEA)
Recently, a new domino signal encryption algorithm (DSEA) was proposed for digital signal transmission, especially for digital images and videos. This paper analyzes the security of DSEA, and points out the following weaknesses: (1) its security against the brute-force attack was overestimated; (2) it is not sufficiently secure against ciphertext-only attacks, and only one ciphertext is enough to get some information about the plaintext and to break the value of a sub-key; (3) it is insecure against known/chosen-plaintext attacks, in the sense that the secret key can be recovered from a number of continuous bytes of only one known/chosen plaintext and the corresponding ciphertext. Experimental results are given to show the performance of the proposed attacks, and some countermeasures are discussed to improve DSEA.
20338082
Guaranteed Cost Control of Networked Control Systems: An LMI Approach
In this paper, networked control systems (NCS) is modeled as a discrete-time linear state-delayed system with norm-bounded uncertainty. Inspired by the so-called descriptor model transformation, a delay-dependent sufficient condition for the existence of a guaranteed cost controller for NCS is presented by a set of linear matrix inequalities (LMIs). The resulting controller can not only asymptotically stabilize the system but also guarantee an adequate level of performance. Theoretical analysis and illustrative results show that the control strategy presented in this paper is effective and feasible.
14536606
On the security of an image encryption method
The security of digital images has attracted much attention, and many different image encryption methods have been proposed. Yen and Guo (see Proc. IEEE Workshop Signal Processing Systems, p.430-37, 1999) proposed a novel image encryption algorithm called BRIE (bit recirculation image encryption). This paper points out that BRIE is not secure enough from strict cryptographic viewpoint. It has been found that some defects exist in BRIE, and a known/chosen-plaintext attack can break BRIE with only one known/chosen plain-image. Experiments are made to verify the defects of BRIE and the feasibility of the attack.
16791890
JComp: A Reuse-Driven Componentization Framework for Java Applications
Program componentization has been proved to be an effective way to increase the speed and cost-effectiveness of reusing, maintaining, and understanding existing software systems. JComp is a componentization framework that supports semi-automatically extracting reusable components from an existing Java system and automatically transforming the existing system into a component-based system. Based on the automated class dominance analysis and domain knowledge, JComp introduces a novel technique to incrementally identify reusable components in a low cost but high precision way. Also, JComp provides a methodology to automate the transformation of existing object-oriented systems into component-based systems