ppxscal/embedding_network huggingface dataset:
Dynamically configurable bus topologies for high-performance on-chip communication
Authors: Krishna Sekar, Kanishka Lahiri, Anand Raghunathan, Sujit Dey
Venue: IEEE Transactions on Very Large Scale Integration (VLSI) Systems (2008)

The on-chip communication architecture is a primary determinant of overall performance in complex system-on-chip (SoC) designs. Since the communication requirements of SoC components can vary significantly over time, communication architectures that dynamically detect and adapt to such variations can substantially improve system performance. In this paper, we propose FLEXBUS, a new architecture that can efficiently adapt the logical connectivity of the communication architecture and the components connected to it. FLEXBUS achieves this by dynamically controlling both the communication architecture topology, as well as the mapping of SoC components to the communication architecture. This is achieved through new dynamic bridge by-pass, and component remapping techniques. In this paper, we introduce these techniques, describe how they can be realized within modern on-chip buses, and discuss policies for run-time reconfiguration of FLEXBUS-based architectures. The techniques underlying FLEXBUS are general, and are applicable to a variety of bus standards. We have implemented FLEXBUS as an extension of the popular AMBA AHB bus, and have evaluated it using a commercial design flow. We report on experiments conducted to analyze its area, timing, and performance under a wide variety of system-level traffic profiles. We have applied FLEXBUS to two example SoC designs: 1) an IEEE 802.11 MAC processor and 2) an UMTS turbo decoder. Our results show that FLEXBUS provides gains of up to 34.55% in application data-rates over conventional architectures, with negligible area overhead and a 3.2% penalty in clock period.
Algorithms for simultaneous consideration of multiple physical synthesis transforms for timing closure
Authors: Huan Ren, Shantanu Dutt
Venue: Proceedings of the 2008 IEEE/ACM International Conference on Computer-Aided Design (2008)

We propose a post-placement physical synthesis algorithm that can apply multiple circuit synthesis and placement transforms on a placed circuit to improve the critical path delay under area constraints by simultaneously considering the benefits and costs of all transforms (as opposed to considering them sequentially after applying each transform). The circuit transforms we employ include, but are not limited to, incremental placement, two types of buffer insertion, cell resizing and cell replication. The problem is modeled as a min-cost network flow problem, in which nodes represent circuit transform options. By carefully determining the structure of the network graph and the cost of each arc, a set of near-optimal transform options can be obtained as those whose corresponding nodes in the network graph have the min-cost flow passing through them. We also tie the transform selection network graph to a detailed placement network graph with TD arc costs for cell movements. This enables our algorithms to incorporate considerations of detailed placement cost for each synthesis transform along with the basic cost of applying the transform in the circuit. We have tested our algorithms on three sets of benchmarks under 3--10% area increase constraints, and obtained up to 48% and an average of 27.8% timing improvement. Our average improvement is relatively 40% better (8.2% better by an absolute measure) than applying the same set of transforms in a good sequential order that is used in many current techniques. Considering only synthesis transforms (no replacement), our technique is relatively 50% better than the sequential approach.
Experimental data on page replacement algorithm
Authors: N. A. Oliver
Venue: Proceedings of the May 6-10, 1974, national computer conference and exposition (1974)

Although paged VM (Virtual Memory) systems are being implemented more and more, their full capabilities have not yet been realized. Early research in this field pointed to possible inefficiencies in their implementation. Subsequent studies, however, led to the conclusion that paged VM systems could provide a productive means to run large programs on small main memory, if proper techniques are employed. One of the most influential of these is the choice of an efficient page replacement algorithm (RA) to minimize page traffic between the different levels of memory.
On the choice of explicit stabilizing terms in column generation
Authors: Hatem M. T. Ben Amor, Jacques Desrosiers, Antonio Frangioni
Venue: Discrete Applied Mathematics (2009)

Column generation algorithms are instrumental in many areas of applied optimization, where linear programs with an enormous number of columns need to be solved. Although successfully employed in many applications, these approaches suffer from well-known instability issues that somewhat limit their efficiency. Building on the theory developed for nondifferentiable optimization algorithms, a large class of stabilized column generation algorithms can be defined which avoid the instability issues by using an explicit stabilizing term in the dual; this amounts at considering a (generalized) augmented Lagrangian of the primal master problem. Since the theory allows for a great degree of flexibility in the choice and in the management of the stabilizing term, one can use piecewise-linear or quadratic functions that can be efficiently dealt with using off-the-shelf solvers. The practical effectiveness of this approach is demonstrated by extensive computational experiments on large-scale Vehicle and Crew Scheduling problems. Also, the results of a detailed computational study on the impact of the different choices in the stabilization term (shape of the function, parameters), and their relationships with the quality of the initial dual estimates, on the overall effectiveness of the approach are reported, providing practical guidelines for selecting the most appropriate variant in different situations.
Dynamically reconfigurable multi-display environment for CG contents
Authors: Takashi Ohta
Venue: Proceedings of the 2008 International Conference on Advances in Computer Entertainment Technology (2008)

We are designing an application framework for creating graphics contents that utilize a multi-display environment. The processes store and exchange the geometry and event information via a shared space. We use a sensor to detect the placement of the displays. This enables the environment to change the number and layout of its displays dynamically.
Unsupervised view and rate invariant clustering of video sequences
Authors: Pavan Turaga, Ashok Veeraraghavan, Rama Chellappa
Venue: Computer Vision and Image Understanding (2009)

Videos play an ever increasing role in our everyday lives with applications ranging from news, entertainment, scientific research, security and surveillance. Coupled with the fact that cameras and storage media are becoming less expensive, it has resulted in people producing more video content than ever before. This necessitates the development of efficient indexing and retrieval algorithms for video data. Most state-of-the-art techniques index videos according to the global content in the scene such as color, texture, brightness, etc. In this paper, we discuss the problem of activity-based indexing of videos. To address the problem, first we describe activities as a cascade of dynamical systems which significantly enhances the expressive power of the model while retaining many of the computational advantages of using dynamical models. Second, we also derive methods to incorporate view and rate-invariance into these models so that similar actions are clustered together irrespective of the viewpoint or the rate of execution of the activity. We also derive algorithms to learn the model parameters from a video stream and demonstrate how a single video sequence may be clustered into different clusters where each cluster represents an activity. Experimental results for five different databases show that the clusters found by the algorithm correspond to semantically meaningful activities.
Counting People from Multiple Cameras
Authors: Vera Kettnaker, Ramin Zabih
Venue: Proceedings of the 1999 IEEE International Conference on Multimedia Computing and Systems - Volume 02 (1999)

We are interested in the content analysis of video from a collection of spatially distant cameras viewing a single environment. We address the task of counting the number of different people walking through such an environment, which requires that the system can identify which observations from different cameras show the same person. Our system achieves this by combining visual appearance matching with mutual content constraints between the cameras. We present results from a system with four very different camera views that counts people walking through and around a research lab.
High-Quality Multi-Mode Mipmapping Texture Compression with Alpha Map
Authors: Chih-Hao Sun, Tse-Wei Chen, You-Ming Tsao, Shao-Yi Chien
Venue: Proceedings of the 9th Pacific Rim Conference on Multimedia: Advances in Multimedia Information Processing (2008)

This paper presents a high-quality multi-mode mipmapping texture compression with alpha map (MMMTC) system. Based on wavelet transform, a hierarchical approach is adopted for mipmap in YCbCr color space to embed three levels of mipmap in a single bitstream. In addition, by inspecting the similarity between alpha channel and luminance channel, the alpha high coefficients are efficiently encoded with linear prediction from the luminance high coefficients in three modes. Simulation results show that MMMTC can provide better image quality with similar memory bandwidth for RGB channels and outperform other texture compression systems for alpha channel. VLSI implementation result shows that the hardware cost of MMMTC is similar to that of DXTC and is suitable to be integrated in GPU to provide high-quality textures with low memory bandwidth requirement.
SIPHoc: efficient SIP middleware for ad hoc networks
Authors: Patrick Stuedi, Marcel Bihr, Alain Remund, Gustavo Alonso
Venue: Proceedings of the ACM/IFIP/USENIX 2007 International Conference on Middleware (2007)

Mobile Ad Hoc Networks (MANETs) offer a flexible way to connect mobile devices to build complex infrastructures. A key issue in MANETs is session set up and management since, unlike in conventional networks, there is no centralized component to provide such a service. Yet, session set up is necessary to provide any form of communication beyond unreliable, single message communication. In this paper we describe SIPHoc, a middleware infrastructure for session set up and management in MANETs. SIPHoc provides the same interface as the SIP standard but its implementation is fully decentralized. Moreover, SIP session establishment to and from the Internet is possible as soon as a single node in the MANET has Internet access. The paper presents the architecture and implementation of SIPHoc and evaluates its performance. The experiments show that SIPHoc is message efficient and provides a low dial-to-ring delay. SIPHoc allows SIP based applications to be used in MANETs without modification. In the paper, this is demonstrated by showing how SIPHoc supports VoIP conversations within a MANET and between the MANET and end-points on the Internet.
Analysis of an interface relaxation method for composite elliptic differential equations
Authors: P. Tsompanopoulou, E. Vavalis
Venue: Journal of Computational and Applied Mathematics (2009)

The theoretical analysis on both the continuous (differential) and the discrete (linear algebra) levels of an interface relaxation method for solving elliptic differential equations is presented. The convergence of the method for 1-dimensional problems is proved. The region of convergence and the optimal values for the relaxation parameters involved are determined for model problems. Numerical data for 1- and 2-dimensional problems that confirm the theoretical results, exhibit the effectiveness of the method and elucidate its characteristics are presented.
Defining the security required for WAP based mobile ticket sales
Authors: Alex Pandelidis
Venue: Proceedings of the 2006 International Conference on Privacy, Security and Trust: Bridge the Gap Between PST Technologies and Business Services (2006)

M-commerce has not really been used to its full potential as of yet. With the advent of more powerful cell phones and PDAs entering the market there is an opportunity for more innovative marketing techniques to come into play. Currently to perform any kind of commerce in the mobile environment, users are required to use the WAP system to communicate with the internet. However the WAP system presents its own problems because there is a sever lack of security due to the nature of the operations. These issues are perhaps what have prevented mobile commerce from becoming a realistic solution. In the future there is promise of new technologies will address some of the security issues that have been presented within a WAP based mobile commerce system.
A Framework for P2P Botnets
Authors: Su Chang, Linfeng Zhang, Yong Guan, Thomas E. Daniels
Venue: Proceedings of the 2009 WRI International Conference on Communications and Mobile Computing - Volume 03 (2009)

Botnets are the most serious danger facing the Internet and enterprise networks. To effectively protect against botnets, researchers should not only focus on known botnets, but also the inherent relationships among them and those botnets to appear in the future. In this paper, we first propose a framework capable of characterizing the inherent relationships between all different kinds of current (existing and suggested in the literature) botnets as well as worms. Based on the proposed framework, we predict a new botnet that we call the Loosely Coupled Peer-to-Peer (P2P) Botnet (lcbot), which is stealthy and can be considered as a combination of existing P2P botnet structures. We conduct experiments to compare the performances between lcbot and other P2P botnets in the literature, and gain insight understanding of P2P botnets. We also discuss potential mechanisms to detect the existence of P2P botnets. To the best of our knowledge, we are the first to propose the framework for botnets, the lcbot concept in P2P botnet research.
Space-Efficient Algorithm for Image Rotation
Authors: Tetsuo Asano, Shinnya Bitou, Mitsuo Motoki, Nobuaki Usui
Venue: IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (2008)

This paper presents an algorithm for rotating a subimage in place without using any extra working array. Due to this constraint, we have to overwrite pixel values by interpolated values. Key ideas are local reliability test which determines whether interpolation at a pixel is carried out correctly without using interpolated values, and lazy interpolation which stores interpolated values in a region which is never used for output images and then fills in interpolated values after safety is guaranteed. It is shown that linear interpolation is always safely implemented. An extension to cubic interpolation is also discussed.
A survey of evaluation techniques used in augmented reality studies
Authors: Andreas Dünser, Raphaël Grasset, Mark Billinghurst
Venue: ACM SIGGRAPH ASIA 2008 courses (2008)

In this paper we report on an initial survey of user evaluation techniques used in Augmented Reality (AR) research. To identify all papers which include AR evaluations we reviewed research publications between the years 1993 and 2007 from online databases of selected scientific publishers. Starting with a total of 6071 publications we filtered the articles in several steps which resulted in 165 AR related publications with user evaluations. These publications were classified in two different ways: according to the evaluation type used following an earlier literature survey classification scheme; and according to the evaluation methods or approach used. We present the results of out literature survey, provide a comprehensive list of references of the selected publications, and discuss some possible research opportunities for future work.
On Trace-Expressible Behaviour of Petri Nets
Authors: Joanna Jółkowska, Edward Ochmański
Venue: Fundamenta Informaticae (2008)

We propose a trace-based approach to description behaviours of concurrent systems. First, we define the independency relation induced by arbitrary transition system, forming this way an asynchronous transition system. Then we introduce the notion of traceability of transition systems and study some decision problems, related to computing independency and deciding traceability for basic classes of Petri nets. Main results: traceability is decidable for place/transition nets and undecidable in broader classes of nets - inhibitor, reset and transfer nets.
A Green's function approach to the study of the conduction properties of electron transport through CNT/trans-PA/CNT system
Authors: N. Shahtahmasebi, H. Milani Moghaddam, S. A. Ketabi
Venue: Proceedings of the 6th conference on Microelectronics, nanoelectronics, optoelectronics (2007)

Using a tight-binding model and methods based on Green's function theory and Löwdin's partitioning technique, we numerically investigate the effects of the coupling strength CNT/molecule, the length of the molecule and the properties of metallic single-walled carbon nanotube(CNT) on the electronic transmission through a CNT/molecule/CNT system, as a full carbon transistor model. We rely on Landauer formalism as the basis for studying the conductance properties of this system. The dependence of the conductance on the above basic parameters of the system, are investigated. Our calculations show that the conductance is sensitive to the CNT/molecule coupling and exponentially decreases with the increase of the length of the molecule, and the parameters of CNT also play an important role in overall conductance of the system.
Offline and online aspects of defragmenting the module layout of a partially reconfigurable device
Authors: Sándor P. Fekete, Jan C. van der Veen, Ali Ahmadinia, Diana Göhringer, Mateusz Majer, Jürgen Teich
Venue: IEEE Transactions on Very Large Scale Integration (VLSI) Systems (2008)

Modern generations of field-programmable gate arrays (FPGAs) allow for partial reconfiguration. In an online context, where the sequence of modules to be loaded on the FPGA is unknown beforehand, repeated insertion and deletion of modules leads to progressive fragmentation of the available space, making defragmentation an important issue. We address this problem by proposing an online and an offiine component for the defragmentation of the available space. We consider defragmenting the module layout on a reconfigurable device. This corresponds to solving a 2-D strip packing problem. Problems of this type are NP-hard in the strong sense, and previous algorithmic results are rather limited. Based on a graph-theoretic characterization of feasible packings, we develop a method that can solve 2-D defragmentation instances of practical size to optimality. Our approach is validated for a set of benchmark instances. We also discuss a simple strategy for dealing with online scenarios, called "least-interference fit" (LIF); we give a number of analytic results that allow a comparison of LIF with the best offline solution, and demonstrate that it works well on benchmark instances of moderate size.
H-P2PSIP: Interconnection of P2PSIP domains for global multimedia services based on a hierarchical DHT overlay network
Authors: Isaias Martinez-Yelmo, Alex Bikfalvi, Ruben Cuevas, Carmen Guerrero, Jaime Garcia
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2009)

The IETF P2PSIP WG is currently standardising a protocol for distributed multimedia services combining the media session functionality of SIP and the decentralised distribution and localisation of resources in peer-to-peer networks. The current P2PSIP scenarios only consider the infrastructure for the connectivity inside a single domain. This paper proposes an extension of the current work to a hierarchical multi-domain scenario: a two level hierarchical peer-to-peer overlay architecture for the interconnection of different P2PSIP domains. The purpose is the creation of a global decentralised multimedia services in enterprises, ISPs or community networks. We present a study of the routing performance and routing state in the particular case of a two-level distributed hash table hierarchy that uses Kademlia. The study is supported by an analytical model and its validation by a peer-to-peer simulator.
A framework for mitigating attacks against measurement-based adaptation mechanisms in unstructured multicast overlay networks
Authors: Aaron Walters, David Zage, Cristina Nita Rotaru
Venue: IEEE/ACM Transactions on Networking (TON) (2008)

Many multicast overlay networks maintain application-specific performance goals by dynamically adapting the overlay structure when the monitored performance becomes inadequate. This adaptation results in an unstructured overlay where no neighbor selection constraints are imposed. Although such networks provide resilience to benign failures, they are susceptible to attacks conducted by adversaries that compromise overlay nodes. Previous defense solutions proposed to address attacks against overlay networks rely on strong organizational constraints and are not effective for unstructured overlays. In this work, we identify, demonstrate and mitigate insider attacks against measurement-based adaptation mechanisms in unstructured multicast overlay networks. We propose techniques to decrease the number of incorrect adaptations by using outlier detection and limit the impact of malicious nodes by aggregating local information to derive global reputation for each node. We demonstrate the attacks and mitigation techniques through real-life deployments of a mature overlay multicast system.
Managing and Mining Uncertain Data
Authors: Charu C. Aggarwal
Venue: Advances In Database Systems (2009)

Managing and Mining Uncertain Data, a survey with chapters by a variety of well known researchers in the data mining field, presents the most recent models, algorithms, and applications in the uncertain data mining field in a structured and concise way. This book is organized to make it more accessible to applications-driven practitioners for solving real problems. Also, given the lack of structurally organized information on this topic, Managing and Mining Uncertain Data provides insights which are not easily accessible elsewhere. Managing and Mining Uncertain Data is designed for a professional audience composed of researchers and practitioners in industry. This book is also suitable as a reference book for advanced-level students in computer science and engineering, as well as the ACM, IEEE, SIAM, INFORMS and AAAI Society groups.