7170011
Accelerating regularized iterative ct reconstruction on commodity graphics hardware (GPU)
Iterative reconstruction algorithms augmented with regularization can produce high-quality reconstructions from few views and even in the presence of significant noise. In this paper we focus on the particularities associated with the GPU acceleration of these. First, we introduce the idea of using exhaustive benchmark tests to determine the optimal settings of various parameters in iterative algorithm, here OS-SIRT, which proofs decisive for obtaining optimal GPU performance. Then we introduce bilateral filtering as a viable and cost-effective means for regularization, and we show that GPU-acceleration reduces its overhead to very moderate levels.
2663170
A Framework for Building Privacy-Conscious Composite Web Services
The rapid growth of Web applications has prompted increasing interest in the area of composite Web services that involve several service providers. The potential for such composite Web services can be realized only if consumer privacy concerns are satisfactorily addressed. In this paper, we propose a framework that addresses consumer privacy concerns in the context of highly customizable composite Web services. Our approach involves service producers exchanging their terms-of-use with consumers in the form of "models". Our framework provides automated techniques for checking these models at the consumer site for compliance of consumer privacy policies. In the event of a policy violation, our framework supports automatic generation of "obligations" that the consumer generates for the composite service. These obligations are automatically enforced through a dynamic program analysis approach on the Web service composition code. We illustrate our approach with the implementation of two example services
156293
An efficient and backwards-compatible transformation to ensure memory safety of C programs
Memory-related errors, such as buffer overflows and dangling pointers, remain one of the principal reasons for failures of C programs. As a result, a number of recent research efforts have focused on the problem of dynamic detection of memory errors in C programs. However, existing approaches suffer from one or more of the following problems: inability to detect all memory errors (e.g., Purify), requiring non-trivial modifications to existing C programs (e.g., Cyclone), changing the memory management model of C to use garbage collection (e.g., CCured), and excessive performance overheads. In this paper, we present a new approach that addresses these problems. Our approach operates via source code transformation and combines efficient data-structures with simple, localized optimizations to obtain good performance.
1723065
An approach for realizing privacy-preserving web-based services
The past decade has witnessed a phenomenal growth in the number of users who routinely use the web to obtain information, conduct research, or carry out financial transactions. While the ability of the web to provide customized information and financial services has boosted personal and business productivity, it has raised significant concerns regarding an individual’s privacy. The privacy concerns are exacerbated further with the advent of more complex services that involve multiple service providers, as it raises the potential of personal information being shared across these providers in ways that weren’t intended by the owner of the information. To illustrate the increased privacy concerns raised by composite web-based services, consider a web-based service that allows an individual to research and order over-the-counter medication (or health supplements) at a low cost, while ensuring that there are no adverse interactions based on the individuals current prescription. Such a service will require access to the individual’s personal medical history, and will also require interaction with other entities such as web-based medical references, discount pharmacies and creditcard companies. Users may not want their personal health histories to be shared with discount pharmacies or credit card companies. Similarly, they may not want their credit card information to be shared with providers of free on-line information. Web-based service providers have long recognized the importance of addressing user privacy concerns, and taken steps to state their policies regarding the storage and use of personal user information. Unfortunately, since these policies are stated in English, they are imprecise and ambiguous, posing problems in accountability and enforceability, as well as in checking compatibility between consumer and provider policies. Indeed, the verbose nature of these policies discourage most users from even reading them! To address the above problem, we present a new approach where the consumers as well as providers can express their privacy concerns in a formal way. Specifically, consumers express their requirements in the form of policies, while providers specify their use of consumer data using models. Our approach automates compatibility checking between policies and models. If there is an incompatibility, the consumer is informed how she can refine her policies in order to use the service. If she does not want to change her policies in any way, the approach passes on additional privacy requirements to the provider. Service access can continue in case
3137385
Automatic Recognition of Logical Relations for English, Chinese and Japanese in the GLARF Framework
We present GLARF, a framework for representing three linguistic levels and systems for generating this representation. We focus on a logical level, like LFG's F-structure, but compatible with Penn Treebanks. While less finegrained than typical semantic role labeling approaches, our logical structure has several advantages: (1) it includes all words in all sentences, regardless of part of speech or semantic domain; and (2) it is easier to produce accurately. Our systems achieve 90% for English/Japanese News and 74.5% for Chinese News -- these F-scores are nearly the same as those achieved for treebank-based parsing.
58348809
A FAST SOLVER OF RADIOSITY EQUATION SYSTEMS
15359787
Task-Based Dialog Management Using An Agenda
Dialog management addresses two specific problems: (1) providing a coherent overall structure to interaction that extends beyond the single turn, (2) correctly managing mixed-initiative interaction. We propose a dialog management architecture based on the following elements: handlers that manage interaction focussed on tightly coupled sets of information, a product that reflects mutually agreed-upon information and an agenda that orders the topics relevant to task completion.
13542388
Efficient Adaptive Resource Allocation for Multiuser OFDM Systems with Minimum Rate Constraints
This paper investigates the adaptive resource allocation scheme for the downlink of multiuser OFDM systems. We focus on the problem of maximizing the overall spectral efficiency while maintaining the QoS requirements of users, including bit error rate and individual minimum rate requirements. Under the assumption of equal power allocation, an efficient algorithm is proposed to obtain the suboptimal solution of the resource allocation. In this algorithm, we first introduce some positive multipliers, one for each user, according to their minimum rate constraints (MRC), and then a parallel subcarrier-and-bit allocation scheme is designed using these multipliers with low complexity. The numerical results show that our algorithm not only substantially reduces the computational complexity of the existing algorithm, but also provides a noticeable performance improvement.
16810261
A Shared-Path-Protection Based Heuristic Algorithm for the Capacity Placement Problem in Mesh Networks
The total transmission capacity required by a transport network to satisfy demand and protect it from failures contributes significantly to its cost. Unlike SCP (spare capacity placement) scheme, JOCP (jointly optimized capacity placement) scheme could reach more optimal results since it tries to jointly optimize both working and spare capacity. However, the later is more complex and time- consuming according to previous research based on IP solution. This paper presents a heuristic algorithm MSC-JOCP, which is based on shared-path protection, to address this problem. The key idea of the algorithm is to dynamically modulate the metrics of the network's spans, so as to choose primary and backup routes given attention to load balancing as well as maximally share the spare capacity. Simulation results show that the developed scheme effectively reduces the required total capacity and enhances the network resource utilization.