ppxscal/embedding_network huggingface dataset:
Robust TCP stream reassembly in the presence of adversaries
Authors: Sarang Dharmapurikar, Vern Paxson
Venue: Proceedings of the 14th conference on USENIX Security Symposium - Volume 14 (2005)

There is a growing interest in designing high-speed network devices to perform packet processing at semantic levels above the network layer. Some examples are layer-7 switches, content inspection and transformation systems, and network intrusion detection/prevention systems. Such systems must maintain per-flow state in order to correctly perform their higher-level processing. A basic operation inherent to per-flow state management for a transport protocol such as TCP is the task of reassembling any out-of-sequence packets delivered by an underlying unreliable network protocol such as IP. This seemingly prosaic task of reassembling the byte stream becomes an order of magnitude more difficultto soundly execute when conducted in the presence of an adversary whose goal is to either subvert the higher-level analysis or impede the operation of legitimate traffic sharing the same network path. We present a design of a hardware-based high-speed TCP reassembly mechanism that is robust against attacks. It is intended to serve as a module used to construct a variety of network analysis systems, especially intrusion prevention systems. Using trace-driven analysis of out-of-sequence packets, we first characterize the dynamics of benign TCP trafficand show how we can leverage the results to design a reassembly mechanism that is efficient when dealing with non-attack traffic. We then refine the mechanism to keep the system effective in the presence of adversaries. We show that although the damage caused by an adversary cannot be completely eliminated, it is possible to mitigate the damage to a great extent by careful design and resource allocation. Finally, we quantify the trade-off between resource availability and damage from an adversary in terms of Zombie equations that specify, for a given configuration of our system, the number of compromised machines an attacker must have under their control in order to exceed a specified notion of "acceptablecollateral damage."
User Security Behavior on Wireless Networks: An Empirical Study
Authors: Tim Chenoweth, Robert Minch, Sharon Tabor
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

Wireless networks are rapidly becoming ubiquitous but are often insecure and leave users responsible for their own security. We empirically study whether users are successfully securing their client computers when using wireless networks. Automated techniques are used that scan users' machines after they associate with a university wireless network. This determines whether a firewall is being used and what TCP ports are open. Results show that over 9% of 3,331 unique computers scanned were not using a properly configured firewall. In addition, almost 9% had at least one TCP port open, with almost 6% having open ports with significant security implications. We also found and discuss cases where connected computers were compromised by Trojan programs such as SubSeven and NetBus. We discuss the generalizability of our results to other potentially insecure wireless networks, and suggestions for further research.
Efficient ML estimation of the shape parameter for generalized Gaussian MRFs
Authors: S. S. Saquib
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 04 (1996)

A certain class of Markov random fields (MRF) known as generalized Gaussian MRFs (GGMRF) have been shown to yield good performance in modeling the a priori information in Bayesian image reconstruction and restoration problems. Though the ML estimate of temperature T of a GGMRF has a closed form solution, the optimal estimation of the shape parameter p is a difficult problem due to the intractable nature of the partition function. We present a tractable scheme for ML estimation of p by an off-line numerical computation of the log of the partition function. In image reconstruction or restoration problems, the image itself is not known. To address this problem, we use the EM algorithm to compute the estimates directly from the data. For efficient computation of the expectation step, we propose a fast simulation technique and a method to extrapolate the estimates when the simulations are terminated prematurely prior to convergence. Experimental results show that the proposed methods result in substantial savings in computation and superior quality images.
On the performance of interference canceller based I/Q imbalance compensation
Authors: M. Valkama
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 05 (2000)

In quadrature receivers, unavoidable imbalances in the analog front-end between the I- and Q-branches result in finite and usually insufficient rejection of the image frequency band. This causes the image signal to appear as interference on top of the desired signal. Both analog and digital techniques to compensate the effects of I/Q imbalance have been presented in the literature. In this paper, we carry out a detailed performance analysis of the interference cancellation based imbalance compensation structure utilizing baseband digital signal processing. Also simulation results are provided for comparison. The results indicate that the interference canceller based solution can offer adequate performance for most communication applications.
Morphological richness offsets resource demand- experiences in constructing a POS tagger for Hindi
Authors: Smriti Singh, Kuhoo Gupta, Manish Shrivastava, Pushpak Bhattacharyya
Venue: Proceedings of the COLING/ACL on Main conference poster sessions (2006)

In this paper we report our work on building a POS tagger for a morphologically rich language- Hindi. The theme of the research is to vindicate the stand that- if morphology is strong and harnessable, then lack of training corpora is not debilitating. We establish a methodology of POS tagging which the resource disadvantaged (lacking annotated corpora) languages can make use of. The methodology makes use of locally annotated modestly-sized corpora (15,562 words), exhaustive morpohological analysis backed by high-coverage lexicon and a decision tree based learning algorithm (CN2). The evaluation of the system was done with 4-fold cross validation of the corpora in the news domain (www.bbc.co.uk/hindi). The current accuracy of POS tagging is 93.45% and can be further improved.
Faster Placer for Island-Style FPGAs
Authors: Pritha Banerjee, Susmita Sur-Kolay
Venue: Proceedings of the International Conference on Computing: Theory and Applications (2007)

In this paper, we propose a placement method for island-style FPGAs, based on fast yet very good initial placement followed by refinement using ultra-low temperature Simulated Annealing. The initial placement is the keystone of the method and the steps to obtain it are: top down coarse partitioning, allocation of partitions to regions on FPGA array, placement of logic blocks within each region and finally the IOs. The solutions thus obtained require 66% fewer moves i.e. about 3x speed-up during final iterative refinement by simulated annealing, whereas the quality of solution is on the average within 2% of optimal. The critical path length obtained after routing does not degrade for the set of 9 benchmark circuits.
Searching the Visual Web
Authors: Sixto Ortiz Jr.
Venue: Computer (2007)

Given the rapidly expanding increase in the online multimedia content that users can find on the Internet, researchers are looking for ways to offer improved image- and video-search techniques.
Connecting Industrial Controllers to the Internet through Software Composition in Web Application Servers
Authors: Herwig Mannaert, Philip Huysmans, Paul Adriaenssens
Venue: Proceedings of the Second International Conference on Internet and Web Applications and Services (2007)

The automation of all business processes and network management functions, and the web-enabling of those information systems, is proceeding at a rapid pace. It seems inevitable that the monitoring and control of most industrial equipment and industrial controllers, shall become web-based as well. In general, this industrial equipment is controlled through binary protocols, and is not able to support modern Internet standards such as XML. In this contribution, a structured framework is presented to web-enable the monitoring and control of various types of industrial equipment. It is both based on open software standards and component models, and on dedicated architectural design patterns. In order to describe the framework and its detailed design patterns, this contribution builds upon a recently proposed technique for the elaboration of architectural descriptions. The implementation of several management systems for various types of industrial equipment is described, and the results are discussed.
The case for compressed caching in virtual memory systems
Authors: Paul R. Wilson, Scott F. Kaplan, Yannis Smaragdakis
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (1999)

Compressed caching uses part of the available RAM to hold pages in compressed form, effectively adding a new level to the virtual memory hierarchy. This level attempts to bridge the huge performance gap between normal (uncompressed) RAM and disk. Unfortunately, previous studies did not show a consistent benefit from the use of compressed virtual memory. In this study, we show that technology trends favor compressed virtual memory--it is attractive now, offering reduction of paging costs of several tens of percent, and it will be increasingly attractive as CPU speeds increase faster than disk speeds. Two of the elements of our approach are innovative. First, we introduce novel compression algorithms suited to compressing in-memory data representations. These algorithms are competitive with more mature Ziv-Lempel compressors, and complement them. Second, we adaptively determine how much memory (if at all) should be compressed by keeping track of recent program behavior. This solves the problem of different programs, or phases within the same program, performing best for different amounts of compressed memory.
A new survivor memory management method in Viterbi decoders: trace-delete method and its implementation
Authors: Suk-Jin Jung
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 06 (1996)

The well known methods for survivor path storage and decoding are the register-exchange method (REM) and the trace-back method (TBM). The REM is conceptually simple, but it is not appropriate for VLSI implementation because it requires large power consumption and large chip area. The TBM is the preferred method in the VLSI implementation of Viterbi decoders (VD) having large constraint length and high performance. However, the TBM requires last-in-first-out (LIFO) buffer and has to use multiple read operations for high speed operation. This multiple operation results in complex control logic. In this paper, we propose a new survivor memory management method called trace-delete method (TDM) and realize this algorithm in hardware (H/W) for VLSI implementation and we compare the TDM with the TBM in terms of latency, the number of memory elements, and the requirements of control logic. The main advantage of the proposed method can be found as short latency and less requirements on additional control logic. Especially, if we combine the TDM with block interleaving the implementation is even simpler than the TBM. The method is studied with particular relevance to HDTV.
Real-Time Network Virtual Military Simulation System
Authors: Yi-Haur Shiau, Shin-Jye Liang
Venue: Proceedings of the 11th International Conference Information Visualization (2007)

Network virtual reality is an advanced, distributed interactive and collaborative computer graphics technology for presenting information and exploring data in the 3D virtual environment. In this paper, a real-time network virtual military simulation system is developed. The Digital Terrain Model and SPOT images of the Geographic Information System are integrated with the weather simulation of the particle system to construct a 3D virtual environment. The main features of the system include (1) ROAMing is used to construct and visualize the 3D virtual environment, (2) particle system is employed to simulate the weather conditions, (3) physical, gravity and collision detection are adopted to fulfill the realistic interactions, and (4) network communications is supported for distributed multi-users. Several computer graphics accelerating schemes, such as real-time optimally adapting meshes, view frustum culling, level-of-detail, are used to speedup the rendering, and dead reckoning to reduce the flow rate of network to make the distributed real-time VR feasible.
Integration of micro-electro-mechanical deformable mirrors in doped fiber amplifiers
Authors: D. Bouyge, A. Crunteanu, D. Sabourdy, P. Blondy, V. Couderc, J. Lhermite, L. Grossard, A. Barth&#x00e9;lemy
Venue: Microsystem Technologies (2007)

We present a simple technique to produce active Q-switching in various types of fiber amplifiers by active integration of electrostatic actuated deformable metallic micro-mirrors. The optical MEMS (MOEMS) device acts as one of the laser cavity reflectors and, at the same time, as switching/modulator element. We aim to obtain laser systems emitting short, high-power pulses and having variable repetition rate. The electro-mechanical behavior of bridge-type membranes was simulated by using electrostatic and modal 3D finite element analysis (FEA). The results of the simulations fit well with the experimental mechanical, electrical and thermal measurements of the components. In order to decrease the sensitiveness to fiber-mirror alignment we are developing novel optical devices based on stressed-metal cantilever-type geometry that allow mirror deflections up to 50&#x00a0;&#x03bc;m with increased reflectivity discrimination during actuation.
Constraint-based sentence compression an integer programming approach
Authors: James Clarke, Mirella Lapata
Venue: Proceedings of the COLING/ACL on Main conference poster sessions (2006)

The ability to compress sentences while preserving their grammaticality and most of their meaning has recently received much attention. Our work views sentence compression as an optimisation problem. We develop an integer programming formulation and infer globally optimal compressions in the face of linguistically motivated constraints. We show that such a formulation allows for relatively simple and knowledge-lean compression models that do not require parallel corpora or large-scale resources. The proposed approach yields results comparable and in some cases superior to state-of-the-art.
Mobile Agent for Efficient Routing among Source Nodes in Wireless Sensor Networks
Authors: Elhadi Shakshuki, Xinyu Xing, Haroon Malik
Venue: Proceedings of the Third International Conference on Autonomic and Autonomous Systems (2007)

In wireless sensor network, a lot of sensory traffic with redundancy is produced due to massive node density and their diverse placement. This causes the decline of scarce network resources such as bandwidth and energy, thus decreasing the lifetime of sensor network. Recently, mobile agent is proposed as a solution to overcome these problems. Mobile agent accounts for performing data processing and making data aggregation decisions at nodes rather than bring data back to a central processor (sink). Using this approach, redundant sensory data will be eliminated. However, carrying a huge amount of aggregated data among source nodes, using mobile agent, requires immensely planned routing. This is to avoid hastily burning source nodes energy in interest region. Towards this end, we propose a novel approach to achieve optimal routing path for mobile agent. Our proposed approach has two folds. Firstly, Dijkstra's algorithm is used to generate a complete graph to connect all source nodes. Secondly, genetic algorithm is performed on a completed graph to generate best approximated route. To demonstrate the feasibility of our approach, formal analysis and experimental results are presented.
A transparent checkpoint facility on NT
Authors: Johny Srouji, Paul Schuster, Maury Bach, Yulik Kuzmin
Venue: Proceedings of the 2nd conference on USENIX Windows NT Symposium - Volume 2 (1998)

With the increased use of networks of NT workstations for long-running engineering applications, process checkpointing and process migration can avoid wasted computer cycles and improve system utilization. The problem we solve is how to capture and reconstruct process state transparently and efficiently without affecting the correctness of the application. A checkpoint facility enables the intermediate state of a process to be saved to a file. Users can later resume execution of the process from the checkpoint file. This prevents the loss of data generated by long-running processes due to program or system failures, and it also facilitates debugging when the bug appears after the program has executed for a long time. This paper describes the implementation of a checkpoint library that permits users to save temporary state of long-running multi-threaded programs on a Windows/NT system and to resume execution from the checkpointed state at a later time. Our Windows implementation is the first such implementations that we are aware of for this operating system. Our implementation is portable, maintains good performance, and is transparent. The checkpoint facility is currently used in several major internal projects at Intel.
Efficient evaluation of the LVCSR search space using the NOWAY decoder
Authors: S. Renals
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 01 (1996)

This article further develops and analyses the large vocabulary continuous speech recognition (LVCSR) search strategy reported by Renals and Hochberg (see Proc. ICASSP '95, p.596-9, 1995). In particular, the posterior-based phone deactivation pruning approach has been extended to include phone-dependent thresholds and an improved estimate of the least upper bound on the utterance log-probability has been developed. Analysis of the pruning procedures and of the search's interaction with the language model has also been performed. Experiments were carried out using the ARPA North American Business News task with a 20,000 word vocabulary and a trigram language model. As a result of these improvements and analyses, the computational cost of the recognition process performed by the NOWAY decoder has been substantially reduced.
Drowning in data: digital library architecture to support scientific use of embedded sensor networks
Authors: Christine L. Borgman, Jillian C. Wallis, Matthew S. Mayernik, Alberto Pepe
Venue: Proceedings of the 7th ACM/IEEE-CS joint conference on Digital libraries (2007)

New technologies for scientific research are producing a deluge of data that is overwhelming traditional tools for data capture, analysis, storage, and access. We report on a study of scientific practices associated with dynamic deployments of embedded sensor networks to identify requirements for data digital libraries. As part of continuing research on scientific data management, we interviewed 22 participants in 5 environmental science projects to identify data types and uses, stages in their data life cycle, and requirements for digital library architecture. We found that scientists need continuous access to their data from the time that field experiments are designed through final analysis and publication, thus reflecting a broader notion of "digital library." Six categories of requirements are discussed: the ability to obtain and maintain data in the field, verify data in the field, document data context for subsequent interpretation, integrate data from multiple sources, analyze data, and preserve data. Three digital library efforts currently underway within the Center for Embedded Networked Sensing are addressing these requirements, with the goal of a tightly coupled interoperable framework that, in turn, will be a component of cyberinfrastructure for science.
Multi-agent based control and reconfiguration for restoration of distribution systems with distributed generators
Authors: Noel N. Schulz
Venue:  (2006)

Restoration entails the development of a plan consisting of opening or closing of switches, which is called reconfiguration. This dissertation proposes the design of a fast and efficient service restoration with a load shedding method for land-based and ship systems, considering priority of customers and several other system operating constraints. Existing methods, based on centralized restoration schemes that require a powerful central computer, may lead to a single point of failure. This research uses a decentralized scheme based on agents. A group of agents created to realize a specific goal by their interactions is called a Multi-Agent System (MAS). Agents and their behaviors are developed in Java Agent DEvelopment Framework (JADE) and the power system is simulated in the Virtual Test Bed (VTB). The large-scale introduction of Distributed Generators (DGs) in distribution systems has made it increasingly necessary to develop restoration schemes considering DG. The separation of utility causes the system to decompose into electrically isolated islands with generation and load imbalance that can have severe consequences. Automated load shedding schemes are essential for systems with DGs, since the disconnection of the utility can lead to instability much faster than an operator intervention can repair. Load shedding may be the only option to maintain the island when conditions are so severe as to require correction by restoration schemes. Few algorithms have been reported for the problem of maintaining the island, even though load shedding has been reported for power systems using under-frequency and under-voltage criteria. This research proposes a new operational strategy for sudden generator-load imbalance due to loss of utility that dynamically calculates the quantity of load to be shed for each island and the quantity of load that can be restored. Results presented in this dissertation are among the first to demonstrate a state-of-the-art MAS for load shedding under islanded conditions and restoration of the shed loads. The load shedding and restoration schemes developed here have behaviors that can incorporate most of the distribution topologies. Achieving service restoration with DG is complicated but new automated switch technologies and communications make MAS a better scheme than existing schemes.
On proof-test intervals for safety functions implemented in software
Authors: Alena Griffiths
Venue: Proceedings of the eleventh Australian workshop on Safety critical systems and software - Volume 69 (2007)

Given a target probability of functional failure on demand for a system, a corresponding dangerous failure rate for the system can be derived, provided that a proof-test interval for the function is known. IEC 61508, and related standards, requires that this calculation be performed, for certain kinds of systems that are required to provide safety functionality on demand. This paper explains why it is necessary to consider what constitutes a proof-test interval for a function, and then considers what this means for software. We show that there are several problems with the proof-test concept, as applied to software, and describe the problems this presents to practitioners wanting to derive safety integrity levels for system safety functions.