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Articles 1 - 11 of 11
Full-Text Articles in Physical Sciences and Mathematics
Smartstore: A New Metadata Organization Paradigm With Metadata Semantic-Awareness For Next-Generation File Systems, Yu Hua, Hong Jiang, Yifeng Zhu, Dan Feng, Lei Tian
Smartstore: A New Metadata Organization Paradigm With Metadata Semantic-Awareness For Next-Generation File Systems, Yu Hua, Hong Jiang, Yifeng Zhu, Dan Feng, Lei Tian
CSE Technical Reports
Existing data storage systems based on hierarchical directory tree do not meet scalability and functionality requirements for exponentially growing datasets and increasingly complex metadata queries in large-scale file systems with billions of files and Exabytes of data. This paper proposes a novel decentralized semantic-aware metadata organization, called SmartStore, which exploits metadata semantics of files to judiciously aggregate correlated files into semantic-aware groups by using information retrieval tools. The decentralized design of SmartStore can improve system scalability and reduce query latency for both complex queries (including range and top-k queries), which is helpful to construct semantic-aware caching, and conventional filename-based point …
Ideas: An Identity-Based Security Architecture For Large-Scale And High-Performance Storage Systems, Zhongying Niu, Ke Zhou, Hong Jiang, Dan Feng, Tianming Yang
Ideas: An Identity-Based Security Architecture For Large-Scale And High-Performance Storage Systems, Zhongying Niu, Ke Zhou, Hong Jiang, Dan Feng, Tianming Yang
CSE Technical Reports
We develop IDEAS, an identity-based security architecture for large-scale and high-performance storage systems, designed to improve security, convenience and total cost of access control by merging identity management with access control in these systems. IDEAS authenticates users at each I/O node by using a single-identity certificate without the service of a centralized security server and enforces access control mechanism by using an object-based access control (OBAC) model, which is designed to address the complexity and scalability issue of security administration in large-scale storage systems. We also discuss the issue of how to identify and authenticate a large number of users …
An M-Sequence Based Steganography Model For Voice Over Ip, Lei Tian, Ke Zhou, Hong Jiang, Jin Liu, Yongfeng Huang, Dan Feng
An M-Sequence Based Steganography Model For Voice Over Ip, Lei Tian, Ke Zhou, Hong Jiang, Jin Liu, Yongfeng Huang, Dan Feng
CSE Technical Reports
Differing from applying steganography on storage cover media, steganography on Voice over IP (VoIP) must often delicately balance between providing adequate security and maintaining low latency for real-time services. This paper presents a novel real-time steganography model for VoIP that aims at providing good security for secret messages without sacrificing real-time performance. We achieve this goal by employing the well-known least-significant-bits (LSB) substitution approach to provide a reasonable tradeoff between the adequate information hiding requirement (good security and sufficient capacity) and the low latency requirement for VoIP. Further, we incorporate the m-sequence technique to eliminate the correlation among secret messages …
On Incorporating Learning Theories To Simulate A Computer-Supported Collaborative Learning Environment, Nobel Khandaker, Leen-Kiat Soh
On Incorporating Learning Theories To Simulate A Computer-Supported Collaborative Learning Environment, Nobel Khandaker, Leen-Kiat Soh
CSE Technical Reports
The success of a computer-supported collaborative learning (CSCL) environment in improving student knowledge depends on factors like student attributes (e.g., ability and motivation) and elements of the CSCL environment (e.g., group size and group formation). Better understanding of the individual and combined effects of these factors on the learning outcome of students would help: (1) researchers design better CSCL systems and (2) teachers make better decisions while carrying out CSCL sessions. To aid the researchers and teachers, we have used the observations collected and derived from published theories on individual, peer-based, and collaborative learning to design SimCoL, a multiagent-based tool …
Nmflux: Improving Degradation Behavior Of Server Applications Through Dynamic Nursery Resizing, Witawas Srisaan, Cheng Huan Jia
Nmflux: Improving Degradation Behavior Of Server Applications Through Dynamic Nursery Resizing, Witawas Srisaan, Cheng Huan Jia
CSE Technical Reports
Currently, most generational collectors are tuned to either deliver peak performance when the heap is plentiful, but yield unacceptable performance when the heap is tight or maintain good degradation behavior when the heap is tight, but deliver sub-optimal performance when the heap is plentiful. In this paper, we present NMFLUX (continuously varying the Nursery/Mature ratio), a framework that switches between using a fixed-nursery generational collector and a variable-nursery collector to achieve the best of both worlds; i.e. our framework delivers optimal performance under normal workload, and graceful performance degradation under heavy workload. We use this framework to create two generational …
Duts: Targeted Case Studies, Hui Nee Chin, Sebastian Elbaum, Matthew B. Dwyer, Matthew Jorde
Duts: Targeted Case Studies, Hui Nee Chin, Sebastian Elbaum, Matthew B. Dwyer, Matthew Jorde
CSE Technical Reports
Our previous studies of DUTs addressed research questions of effectiveness, efficiency, and robustness with respect to one software artifact, Siena, and we believe the findings generalize to similar artifacts. Still, we realize that existing studies suffer from threats to validity. Specifically, the selected artifact provided limited exposure to CR in the presence of deeper heap structures, extensive software changes, and high number of methods invocations. We start to address those threats to the validity of our findings by investigating the performance of CR in the presence of such settings.
The findings in this report reveal that the performance of the …
Efficient Power Management Of Heterogeneous Soft Real-Time Clusters, Leping Wang, Ying Lu
Efficient Power Management Of Heterogeneous Soft Real-Time Clusters, Leping Wang, Ying Lu
CSE Technical Reports
With growing cost of electricity, the power management of server clusters has become an important problem. However, most previous researchers only address the challenge in homogeneous environments. Considering the increasing popularity of heterogeneous systems, this paper proposes an efficient algorithm for power management of heterogeneous soft real-time clusters. It is built on simple but effective mathematical models. When deployed to a new platform, the software incurs low configuration cost because no extensive performance measurements and profiling are required. To strive for efficiency, a threshold-based approach is adopted. In this paper, we systematically study this approach and its design decisions.
Proceedings Work-In-Progress Session Of The 14th Real-Time And Embedded Technology And Applications Symposium, 22-24 April, 2008 St. Louis, Usa, Ying Lu
CSE Technical Reports
The Work-In-Progress session of the 14th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS '08) presents papers describing contributions both to state of the art and state of the practice in the broad field of real-time and embedded systems. The 25 accepted papers were selected from 27 submissions. This proceedings is also available as University of Nebraska–Lincoln Technical Report TR-UNL-CSE-2008-0003, at
http://lakota.unl.edu/facdb/csefacdb/TechReportArchive/TR-UNL-CSE-2008-0003.pdf
Special thanks go to the General Chairs – Scott Brandt and Frank Mueller and Program Chairs – Chenyang Lu and Christopher Gill for their support and guidance. Special thanks also go to the Work-In-Progress Program Committee Members …
Loss-Rate Based Reliable Data Transport Mechanism For Dynamic Event Sensing In Wireless Sensor Networks, Yuyan Xue, Byrav Ramamurthy, Yong Wang
Loss-Rate Based Reliable Data Transport Mechanism For Dynamic Event Sensing In Wireless Sensor Networks, Yuyan Xue, Byrav Ramamurthy, Yong Wang
CSE Technical Reports
Many wireless sensor network (WSN) transport protocols proposed in recent studies focus on providing end-to- end reliability as in TCP. However, traditional end-to-end reliability is energy and time consuming for common loss tolerant applications in WSNs. In this paper, we propose a Loss Tolerant Reliable (LTR) data transport mechanism for dynamic Event Sensing (LTRES) in WSNs. In LTRES, a reliable event sensing requirement at the transport layer is dynamically determined by the sink. A distributed source rate adaptation mechanism is designed, incorporating a loss rate based lightweight congestion control mechanism, to regulate the data traffic injected into the network so …
Farmer: A Novel Approach To File Access Correlation Mining And Evaluation Reference Model For Optimizing Peta-Scale File System Performance, Peng Xia, Dan Feng, Hong Jiang, Lei Tian, Fang Wang
Farmer: A Novel Approach To File Access Correlation Mining And Evaluation Reference Model For Optimizing Peta-Scale File System Performance, Peng Xia, Dan Feng, Hong Jiang, Lei Tian, Fang Wang
CSE Technical Reports
File correlations have become an increasingly important consideration for performance enhancement in peta-scale storage systems. Previous studies on file correlationsmainly concern with two aspects of files: file access sequence and semantic attribute. Based on mining with regard to these two aspects of file systems, various strategies have been proposed to optimize the overall system performance. Unfortunately, all of these studies consider either file access sequences or semantic attribute information separately and in isolation, thus unable to accurately and effectively mine file correlations, especially in large-scale distributed storage systems.
This paper introduces a novel File Access coRrelation Mining and Evaluation Referencemodel …
Network Coding For Wdm All-Optical Multicast, Eric D. Manley, Jitender S. Deogun, Lisong Xu, Dennis R. Alexander
Network Coding For Wdm All-Optical Multicast, Eric D. Manley, Jitender S. Deogun, Lisong Xu, Dennis R. Alexander
CSE Technical Reports
Network coding has become a useful means for achieving efficient multicast, and the optical community has started to examine its application to optical networks. However, a number of challenges, including limited processing capability and coarse bandwidth granularity, need to be overcome before network coding can be effectively used in optical networks. In this paper, we address some of these problems. We consider the problem of finding efficient routes to use with coding, and we study the effectiveness of using network coding for optical-layer dedicated protection of multicast traffic. We also propose architectures for all-optical circuits capable of performing the processing …