Steganography is a study to hide secret message in multimedia cover which will be transmitted through the Internet. The cover carriers can be image, video, sound or text data. In this paper, a novel scheme is proposed...
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While NAND flash memories have rapidly increased in both capacity and performance and are increasingly used as a storage device in many embedded systems, their reliability has decreased both because of increased densi...
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ISBN:
(纸本)9781605586274
While NAND flash memories have rapidly increased in both capacity and performance and are increasingly used as a storage device in many embedded systems, their reliability has decreased both because of increased density and the use of multi-level cells (MLC). Current MLC technology only specifies the minimum requirement for an error correcting code (ECC), but provides no additional protection in hardware. However, existing flash file systems such as YAFFS and JFFS2 rely upon ECC to survive small numbers of bit errors, but cannot survive the larger numbers of bit errors or page failures that are becoming increasingly common as flash file systems scale to multiple gigabytes. We have developed a flash memory file system, RCFFS, that increases reliability by utilizing algebraic signatures to validate data and Reed-Solomon codes to correct erroneous or missing data. Our file system allows users to adjust the level of reliability they require by specifying the number of redundancy pages for each erase block,allowing them to dynamically trade off reliability and storage overhead. By integrating error mitigation with advanced features such as fast mounting and compression, we show, via simulation in NANDsim, that our file system can outperform YAFFS and JFFS2 while surviving flash memory errors that would cause data loss for existing flash file systems. Copyright 2009 ACM.
Reward is the simplest way to motivate students in education. It can encourage students to learn and get immediate achievement. Moreover, it is also has potential to construct students' intrinsic motivation. Howev...
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High-Level fusion systems based on the JDL model are relatively immature. Current solutions lack a comprehensive ability to manage multi-source data in a multi-dimensional vector space, and generally do not integrate ...
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Community Question Answering (QA) portals contain questions and answers contributed by hundreds of millions of users. These databases of questions and answers are of great value if they can be used directly to answer ...
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ISBN:
(纸本)9781605583907
Community Question Answering (QA) portals contain questions and answers contributed by hundreds of millions of users. These databases of questions and answers are of great value if they can be used directly to answer questions from any user. In this research, we address this collaborative QA task by drawing knowledge from the crowds in community QA portals such as Yahoo! Answers. Despite their popularity, it is well known that answers in community QA portals have unequal quality. We therefore propose a quality-aware framework to design methods that select answers from a community QA portal considering answer quality in addition to answer relevance. Besides using answer features for determining answer quality, we introduce several other quality-aware QA methods using answer quality derived from the expertise of answerers. Such expertise can be question independent or question dependent. We evaluate our proposed methods using a database of 95K questions and 537K answers obtained from Yahoo! Answers. Our experiments have shown that answer quality can improve QA performance significantly. Furthermore, question dependent expertise based methods are shown to outperform methods using answer features only. It is also found that there are also good answers not among the best answers identified by Yahoo! Answers users. Copyright 2009 ACM.
This work elucidates the evolution of three generations of the laboratory information system in the National Taiwan University Hospital, which were respectively implemented in an IBM Series/1 minicomputer, a client/se...
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Clinical MRI images are generally corrupted by random noise during acquisition with blurred subtle structure features. Many denoising methods have been proposed to remove noise from corrupted images at the expense of ...
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We show the design and implementation of a robot controller with a unique locomotion system. We demonstrate that a discrete-event simulation based design provides a cost-effective, flexible, open workflow for modular ...
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ISBN:
(纸本)9789639799455
We show the design and implementation of a robot controller with a unique locomotion system. We demonstrate that a discrete-event simulation based design provides a cost-effective, flexible, open workflow for modular robotic development. The robot is designed to translate against a vertical surface using cables fixed at one end that can wind on motor-controlled spools attached to the robot. This architecture was implemented first as a regressively tested simulation within CD++ then ported to Real-time CD++. Using the NXT++ interface library, a hardware implementation of the robot using Lego® Mindstorms™ was shown to be controllable.
This paper presents a new method of capturing digital ink for pen-based computing. Current technologies such as tablets, ultrasonic and the Anoto pens rely on special mechanisms for locating the pen tip, which result ...
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