ppxscal/embedding_network huggingface dataset:
Defending against statistical steganalysis
Authors: Niels Provos
Venue: Proceedings of the 10th conference on USENIX Security Symposium - Volume 10 (2001)

The main purpose of steganography is to hide the occurrence of communication. While most methods in use today are invisible to an observer's senses, mathematical analysis may reveal statistical anomalies in the stego medium. These discrepancies expose the fact that hidden communication is happening. This paper presents improved methods for information hiding. One method uses probabilistic embedding to minimize modifications to the cover medium. Another method employs error-correcting codes, which allow the embedding process to choose which bits to modify in a way that decreases the likelihood of being detected. In addition, we can hide multiple data sets in the same cover medium to provide plausible deniability. To prevent detection by statistical tests, we preserve the statistical properties of the cover medium. After applying a correcting transform to an image, statistical steganalysis is no longer able to detect the presence of steganography. We present an a priori estimate to determine the amount of data that can be hidden in the image while still being able to maintain frequency count based statistics. This way, we can quickly choose an image in which a message of a given size can be hidden safely. To evaluate the effectiveness of our approach, we present statistical tests for the JPEG image format and explain how our new method defeats them.
Generation of comprehensible decision trees through evolution of training data
Authors: T. Endou, Qiangfu Zhao
Venue: Proceedings of the Evolutionary Computation on 2002. CEC '02. Proceedings of the 2002 Congress - Volume 02 (2002)

In machine learning, decision trees (DTs) are usually considered comprehensible because a reasoning process can be given for each conclusion. When the data set is large, however, the DTs obtained may become very large, and they are no longer comprehensible. To increase the comprehensibility of DTs, we have proposed several methods. For example, we have tried to evolve DTs using genetic programming (GP), with tree size as the secondary fitness measure; we have tried to initialize GP using results obtained by C4.5; and we have also tried to introduce the divide-and-conquer concept in GP, but all results obtained are still not good enough. Up to now we have tried to design good DTs from given fixed data. In this paper, we look at the problem from a different point of view. The basic idea is to evolve a small data set that can cover the domain knowledge as good as possible. From this data set, a small but good DT can be designed. The validity of the new algorithm is verified through several experiments.
Skill assessments of first electronics course
Authors: H. M. Rashid
Venue: Proceedings of the 30th Annual Frontiers in Education - Volume 02 (2000)

Industries are demanding that engineering graduates must have certain skills. The author discusses his experience in teaching an electronics course whose outcomes are expected to develop some of desirable skills. Both the instructor and the students independently assess the learning experience of the course and rate the level of skill achievements. The results of these assessments are analyzed and presented.
Interactive presentation: Pulse propagation for the detection of small delay defects
Authors: M. Favalli, C. Metra
Venue: Proceedings of the conference on Design, automation and test in Europe (2007)

This paper addresses the problems related to resistive opens and bridging faults which cannot be detected using delay fault testing because they lie out of the most critical paths. Even if the induced defect is not large enough to result in timing violations, these faults may give rise to reliability problems. To detect them, we propose a testing method that is based on the propagation of pulses within the faulty circuit and that exploits the degraded capabity of faulty paths to propagate pulses. The effectiveness of the proposed method is analyzed at the electrical level and compared with the use of reduced clock period which can detect the same class of faults. Results show similar performance in the case of resistive opens and better performance in the case of bridgings. Moreover, the proposed approach is not affected by problems on the clock distribution network.
Technical pedagogical investigation on electronic engineering educational methods in the electronic circuits area
Authors: G. O. Glas
Venue: Proceedings of the 30th Annual Frontiers in Education - Volume 01 (2000)

This paper arises from an educative investigation made in an electronic circuits course at the University of Buenos Aires. Didactic strategies were designed and started, sustained in three fundamental points: (1) computer simulation, (2) student teamwork, and (3) the guidance of the teacher as an expert, collaborating with the learning of the student. To complete the experience, multimedia software is being developed. The software is intended to support the students' knowledge construction by presenting them with new situations that could take place, helping them to think up different points of view, while promoting interaction with the teachers, with each other, and with their books and papers. The computer simulation in this experience is understood as a tool to help and make the team process easier, while allowing the students to look for their own problem-resolving strategies.
A New Content-based Image Retrieval Using Color Correlogram and Inner Product Metric
Authors: Thurdsak LEAUHATONG, Kiyoaki ATSUTA, Shozo KONDO
Venue: Proceedings of the Eight International Workshop on Image Analysis for Multimedia Interactive Services (2007)

The color correlogram is a simple statistical descriptor of a color image that has been widely used for content-based image retrieval (CBIR) systems. To measure similarity between two images using the correlogram, the traditional approaches use the relative distance. In this paper, to improve performance of the CBIR systems, the inner product metric is used to measure similarity of images instead of the relative distance. Results of experiments proved that the CBIR using the inner product metric has better performance than the one using the relative distance.
Experiences with interdisciplinary based design teams
Authors: M. H. Morgan
Venue: Proceedings of the 28th Annual Frontiers in Education - Volume 01 (1998)

Within most academic settings design courses are taught in isolation. Typically each separate academic unit or department teaches its own version of design that is for the most part very narrow in scope and presentation. Such approaches overlook the interdisciplinary character of the design process and are not representative of the type of design experiences students will encounter in industry. In the latter setting, a team will generally consist of individuals with very diverse backgrounds and experiences. The purpose of such an arrangement is to make the design process as inclusive as possible. In this paper, we describe the development of an interdisciplinary-based design approach that addresses the above concern.
Dual Ownership: Access Management for Shared Item Information in RFID-enabled Supply Chains
Authors: Alexander Ilic, Florian Michahelles, Elgar Fleisch
Venue: Proceedings of the Fifth IEEE International Conference on Pervasive Computing and Communications Workshops (2007)

RFID tags combined with globally unique numbering schemes such as the Electronic Product Code (EPC) help standardizing the communication along the supply chain. Participants generate and share item information to collectively build digital lifecycle records. Yet, the challenge of efficient access management for item-level information still remains open. This paper introduces a novel concept for data access management, called Dual Ownership. The model grants access control to parties that can prove the physical possession of an item. RFID technology hereby tracks the transitions of physical possession to translate them to data access permissions. This paper describes the concept of Dual Ownership and discusses its implications.
7.95mW 2.4GHz Fully-Integrated CMOS Integer N Frequency Synthesizer
Authors: Debashis Mandal, T. K. Bhattacharyya
Venue: Proceedings of the 20th International Conference on VLSI Design held jointly with 6th International Conference: Embedded Systems (2007)

A fully-integrated, ZigBee standard complaint, frequency synthesizer in the frequency range of 2.4- 2.4835GHz with frequency resolution of 5MHz, is designed in 0.18 Êm epi-CMOS process and silicon performance is measured. Integer-N architecture is chosen for implementation. It consumes 7.95mW of power at 1.8V supply and core area is 0.75 x 0.65mm2. The measured phase-noises are -81.55dBc/Hz and -108.55dBc/Hz at 100kHz and 1MHz offset, respectively, with low settling time less than 25 us.
A Comparison of SYN Flood Detection Algorithms
Authors: Matt Beaumont-Gay
Venue: Proceedings of the Second International Conference on Internet Monitoring and Protection (2007)

The problem of detecting distributed denial of ser- vice (DDoS) attacks, and particularly SYN flood at- tacks, has received much attention in current literature. A variety of algorithms for detecting such attacks have been published. Researchers have tested their own algorithms using traces containing real or synthetic attacks, and have reported good results based on those tests. However, the traces used and parameters of the attacks seen or generated vary greatly between published works. This paper compares three published SYN flood detection algorithms using traces collected from the UCLA Computer Science Department network and synthetic attacks in an Emulab network. The algorithms vary significantly in the speed at which they detect the start and end of attacks, their false positive and false negative rates, the types of non- DDoS activity they detect, and other properties. Their qualitative strengths and weaknesses are discussed, and suggestions are made for enhancements.
The interception approach to reliable distributed CORBA objects
Authors: P. Narasimhan, L. E. Moser, P. M. Melliar-Smith
Venue: Proceedings of the 3rd conference on USENIX Conference on Object-Oriented Technologies (COOTS) - Volume 3 (1997)

The Eternal system is a CORBA 2.0-compliant system that enhances the CORBA standard with replication and thus fault tolerance. The novel interception approach implemented in the Eternal system involves capturing IIOP-specific system calls made by the ORB, and subsequently mapping these calls onto a reliable multicast group communication system. The motivation for the use of this approach is that fault tolerance is transparent to the application objects, as well as to the ORB, and that any commercial ORB can be used with no internal modification. The interception approach exploits the performance of the underlying multicast group communication system to provide good performance.
Adaptive suppression of narrowband digital interferers from spread spectrum signals
Authors: H. V. Poor
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 02 (1996)

Code-division multiple-access (CDMA) implemented with direct-sequence spread-spectrum signaling is among the most promising multiplexing technologies for cellular telecommunications services. We consider the application of the minimum-mean-square-error (MMSE) multiuser detection technique to the problem of suppressing the digital narrowband interference (NBI) from spread spectrum signals. The MMSE multiuser detector can be implemented using a blind adaptive method, which is ideally suited for use in the NBI suppression framework. This application requires the treatment of a single narrowband digital signal as a group of related, virtual spread-spectrum signals with very simple spreading codes. This model gives a special structure to the matrices appearing in the optimization problem implied by the MMSE criterion, and this structure is exploited to develop and analyze a practical adaptive algorithm. The major contribution of this paper beyond the previous work in the field of NBI suppression is the development of this adaptive algorithm that can exploit the advantages of multiuser detection in suppressing narrowband digital interference from spread-spectrum networks.
Assessment of a Mobile Agent Based Routing Protocol for Mobile Ad-hoc Networks
Authors: Lei Liang, Peter Graham
Venue: Proceedings of the 21st International Conference on Advanced Information Networking and Applications Workshops - Volume 01 (2007)

Ad-hoc networking allows users to form temporary wireless networks without existing infrastructure. Each node acts both as host and router and must therefore be willing to forward packets for other nodes. This is done using a Mobile Ad-hoc NETwork (MANET) routing protocol. Frequent topology changes make such routing challenging. Existing protocols include Dynamic Source Routing (DSR) [3], the Cluster-Based Routing Protocol (CBRP) [5], and the Ad hoc On-demand Distance Vector (AODV) [11] protocol, among others. Using existing protocols, however, some nodes may be unduly loaded and end-to-end delay may be high. Further, existing protocols are hard to upgrade once they are in use. To address these problems, a new routing protocol, MARP, using mobile agents is presented. Mobile agents are software entities that can move between network nodes and execute programs they carry with them wherever they are running. Our agent-based algorithm implements a demand-based protocol that provides efficient routing at the application layer. A proof of concept implementation has been developed using Aglets [6] and simulated to evaluate its performance. The details of the protocol and its performance are reported in this paper.
Fast Algorithms for Heavy Distinct Hitters using Associative Memories
Authors: Nagender Bandi, Divyakant Agrawal, Amr El Abbadi
Venue: Proceedings of the 27th International Conference on Distributed Computing Systems (2007)

Real-time detection of worm attacks, port scans and Distributed Denial of Service (DDoS) attacks, as network packets belonging to these security attacks flow through a network router, is of paramount importance. In a typical worm attack, a worm infected host tries to spread the worm by scanning a number of other hosts thus resulting in significant number of network connections at an intermediate router. Detecting such attacks amounts to finding all hosts that are associated with unusually high number of other hosts, which is equivalent to solving the classic heavy distinct hitter problem over data streams. While several heavy distinct hitter solutions have been proposed and evaluated in a standard CPU setting, most of the above applications typically execute on special networking architectures called Network Processing Units (NPUs). These NPUs interface with special associative memories known as the Ternary Content Addressable Memories (TCAMs) to provide gigabit rate forwarding at network routers. In this paper, we describe how the integrated architecture of NPU and TCAMs can be exploited to develop high-speed solutions for heavy distinct hitters.
Comparing the performance of web server architectures
Authors: David Pariag, Tim Brecht, Ashif Harji, Peter Buhr, Amol Shukla, David R. Cheriton
Venue: ACM SIGOPS Operating Systems Review (2007)

In this paper, we extensively tune and then compare the performance of web servers based on three different server architectures. The &mu;server utilizes an event-driven architecture, Knot uses the highly-efficient Capriccio thread library to implement a thread-per-connection model, and WatPipe uses a hybrid of events and threads to implement a pipeline-based server that is similar in spirit to a staged event-driven architecture (SEDA) server like Haboob. We describe modifications made to the Capriccio thread library to use Linux's zero-copy sendfile interface. We then introduce the SY mmetric Multi-Processor Event Driven (SYMPED) architecture in which relatively minor modifications are made to a single process event-driven (SPED) server (the &mu;server) to allow it to continue processing requests in the presence of blocking due to disk accesses. Finally, we describe our C++ implementation of WatPipe, which although utilizing a pipeline-based architecture, excludes the dynamic controls over event queues and thread pools used in SEDA. When comparing the performance of these three server architectures on the workload used in our study, we arrive at different conclusions than previous studies. In spite of recent improvements to threading libraries and our further improvements to Capriccio and Knot, both the event-based &mu;server and pipeline-based Wat-Pipe server provide better throughput (by about 18%). We also observe that when using blocking sockets to send data to clients, the performance obtained with some architectures is quite good and in one case is noticeably better than when using non-blocking sockets.
A State-Based Programming Model and System for Wireless Sensor Networks
Authors: Urs Bischoff, Gerd Kortuem
Venue: Proceedings of the Fifth IEEE International Conference on Pervasive Computing and Communications Workshops (2007)

Sensor networks are one important building block towards the realisation of context-aware applications. Suitable communication protocols and middleware solutions are necessary to facilitate the development of sensor network applications. Additionally, the vast number of nodes in sensor networks necessitates a new programming model for application developers. Commonly used programming abstractions force the programmer to express the global behaviour of a network in terms of local actions taken at individual nodes. We argue that global programming abstractions are needed to express global behaviour of a network. We present RuleCaster, a novel state-based programming framework for sensor network applications. RuleCaster provides a high-level language for application definition, a compiler that splits the high-level specification into individual tasks and assigns them to the nodes, and a service-based middleware that provides the interface for collaborative execution of these tasks.
Case study resources for an ethics and computing course
Authors: K. Bowyer
Venue: Proceedings of the Frontiers in Education Conference,1997. on 27th Annual Conference. Teaching and Learning in an Era of Change. - Volume 01 (1997)

Case studies can be an effective part of an ethics and computing course. However, it is often time-consuming for the instructor to build a list of good case studies. This is especially true if the instructor wants to use real-life incidents for the cases. Even for the instructor who prefers to use "anonymized" or "synthetic" case studies, a compilation of real incidents provides a good starting point for creating realistic cases. This paper provides brief descriptions of real case study incidents which have been classroom-tested in an undergraduate "ethics and computing" course. Special effort is made to include incidents with themes that are sometimes given less coverage relative to, for example, hacking or software piracy.
Adaptive Appearance Model for Object Contour Tracking in Videos
Authors: Mohand Said Allili, Djemel Ziou
Venue: Proceedings of the Fourth Canadian Conference on Computer and Robot Vision (2007)

In this paper, we propose a novel object tracking algorithm in video sequences. The formulation of the object tracking is based on variational calculus, where an adaptive parametric mixture model is used for object features representation. The tracking is based on matching the object mixture models between successive frames of the sequence by using active contours while adapting the mixture model to varying object appearance changes due to illumination conditions and camera geometry. The implementation of the method is based on level set active contours which allow for automatic topology changes and stable numerical schemes. We validate our approach on examples of object tracking performed on real video sequences.
Controlling a Wheelchair Indoors Using Thought
Authors: Brice Rebsamen, Etienne Burdet, Cuntai Guan, Haihong Zhang, Chee Leong Teo, Qiang Zeng, Christian Laugier, Marcelo H. Ang Jr.
Venue: IEEE Intelligent Systems (2007)

The idea of controlling objects or machines through thought is moving from science fiction to reality. This article presents the first working prototype of a brain-controlled wheelchair that can navigate in a typical office or hospital environment. The wheelchair is based on a slow but safe brain-controlled interface using the P300 signal detected from electroencephalography. The authors adapted the system's control strategy to the interface's measured performance. To circumvent the problem caused by the interface's low information rate, a motion guidance strategy provides safe, efficient control without complex sensors or sensor processing. Experiments demonstrated that healthy subjects can safely control the wheelchair in an office-like environment without training.This article is part of a special issue on Interacting with Autonomy.
Express virtual channels: towards the ideal interconnection fabric
Authors: Amit Kumar, Li-Shiuan Peh, Partha Kundu, Niraj K. Jha
Venue: Proceedings of the 34th annual international symposium on Computer architecture (2007)

Due to wire delay scalability and bandwidth limitations inherent in shared buses and dedicated links, packet-switched on-chip interconnection networks are fast emerging as the pervasive communication fabric to connect different processing elements in many-core chips. However, current state-of-the-art packet-switched networks rely on complex routers which increases the communication overhead and energy consumption as compared to the ideal interconnection fabric. In this paper, we try to close the gap between the state-of-the-art packet-switched network and the ideal interconnect by proposing express virtual channels (EVCs), a novel flow control mechanism which allows packets to virtually bypass intermediate routers along their path in a completely non-speculative fashion, thereby lowering the energy/delay towards that of a dedicated wire while simultaneously approaching ideal throughput with a practical design suitable for on-chip networks. Our evaluation results using a detailed cycle-accurate simulator on a range of synthetic traffic and SPLASH benchmark traces show upto 84% reduction in packet latency and upto 23% improvement in throughput while reducing the average router energy consumption by upto 38% over an existing state-of-the-art packet-switched design. When compared to the ideal interconnect, EVCs add just two cycles to the no-load latency, and are within 14% of the ideal throughput. Moreover, we show that the proposed design incurs a minimal hardware overhead while exhibiting excellent scalability with increasing network sizes.