ppxscal/embedding_network huggingface dataset:
A multiview video transcoder
Authors: Baochun Bai, Janelle Harms
Venue: Proceedings of the 13th annual ACM international conference on Multimedia (2005)

Video transcoding can convert a compressed video from one format to another format. In this paper, we propose a novel multiview video transcoder, which is used for bit-rate scaling of multiple compressed synchronized video streams. Different from the traditional joint transcoder for independent multiple program transcoding, the multiview video transcoder has one unique task to decorrelate spatial redundancies among video streams. A fast disparity estimation algorithm with the GOP-based disparity search window is put forward and evaluated. The proposed multiview video transcoder can be used to design a cost-effective video acquisition and transmission system for emerging 3D video applications.
Dimension reduction algorithms in data mining, with applications
Authors: Ravi Janardan
Venue:  (2005)

This thesis concentrates on the theory, implementation, and application of dimension reduction in data mining. Many real-world applications such as text mining, image retrieval, face recognition, and microarray data analysis involve high-dimensional data, where the dimension can often run into the thousands. Traditional machine learning and data mining techniques are not effective when dealing with such high-dimensional data because of the so-called curse of dimensionality. A natural approach to deal with this problem is to apply dimension reduction as a pre-processing step. The first part of the thesis presents a dimension reduction technique for data in matrix form. The essence of the proposed algorithm is that it applies a bilinear transformation on the data. Such a bilinear transformation is particularly appropriate for data in matrix representation and often leads to lower computational costs compared to traditional algorithms. A natural application of the algorithm is in image compression and retrieval, where each image is represented in its native matrix representation. Extensive experiments performed using image data show that the proposed algorithm outperforms the traditional ones, in terms of computational time and space requirement, while maintaining competitive performance in classification. The second part of the thesis focuses on generalizing classical Linear Discriminant Analysis (LDA) to overcome problems associated with undersampled data, where the data dimension is much greater than the number of data items. The optimization criterion in classical LDA fails when the scatter matrices are singular, which is the case for undersampled problems. A new optimization criterion has been developed which is applicable to undersampled problems. The algorithms based on the proposed criterion have been shown to be very competitive in classification. The final part of the thesis considers the problem of designing an efficient and incremental dimension reduction algorithm. An LDA-based incremental dimension reduction algorithm has been developed. Unlike other LDA-based algorithms, this algorithm does not require the whole data matrix in main memory. This is desirable for large datasets. More importantly, with the insertion of new data items, the proposed algorithm can constrain the computational cost by efficient incremental updating techniques. Experiments reveal that the proposed algorithm is competitive in classification, but has much lower computational cost, especially when new data items are inserted dynamically.
Approximating Trigonometric Functions with the Laws of Sines and Cosines using the Logarithmic Number System
Authors: Mark G. Arnold
Venue: Proceedings of the 8th Euromicro Conference on Digital System Design (2005)

A new algorithm is given for computing trigonometric functions using the Logarithmic Number System (LNS). Based on the laws of sines and cosines, the algorithm uses novel addressing of ROMs with the middle-order bits of the LNS representation. Error analysis and simulation show the algorithm is accurate to 22 bits when intermediate steps are performed with 23-bit precision LNS. A VLIW software implementation having throughput of one trigonometric result every 17 cycles is suggested that uses special instructions to access small ROMs containing logarithmic sines and cosines. Also, the proposed algorithm can be implemented fully in hardware having throughput of one trigonometric result every one or two cycles using minor low-cost modi?cations to an existing LNS ALU design.
Building a visual ontology for video retrieval
Authors: L. Hollink, M. Worring
Venue: Proceedings of the 13th annual ACM international conference on Multimedia (2005)

To ensure access to growing video collections, annotation is becoming more and more important using background knowledge in the form of ontologies or thesauri is a way to facilitate annotation in a broad domain. Current ontologies are not suitable for (semi-) automatic annotation of visual resources as they contain little visual information about the concepts they describe. We investigate how an ontology that does contain visual information can facilitate annotation in a broad domain and identify requirements that a visual ontology has to meet. Based on these requirements, we create a visual ontology out of two existing knowledge corpora (WordNet and MPEG-7) by creating links between visual and general concepts. We test performance of the ontology on 40 shots of news video, and discuss the added value of each visual property.
Reactive Virtual Human System with haptic sensation and adaptive function
Authors: Seungzoo Jeong, Woong Choi, Naoki Hashimoto, Makoto Sato
Venue: Proceedings of the 2005 International Conference on Cyberworlds (2005)

We have proposed a human-scale interaction system (i.e. Reactive Virtual Human System) with haptic sensation. This system is composed of a wire-based haptic interface and an immersive virtual environment(VE). Based on the framework, we realized Virtual Catch Ball that a user can play a virtual human with a feeling of contacting real ball. To make a database of virtual human's natural reaction, we implemented ReactiveMotion Capture System that can capture movements with physical reaction in close interpersonal engagements. In this paper, we will further show the system's extended function that new motions can reflect on virtual human's behavioral structure by a on-line motion capture. It will be a practical way to produce various motion patterns during playing, and to enforce virtual human's adaptive function.
High-order/spectral methods for transient wave equations
Authors: Tian Xiao
Venue:  (2004)

In this thesis, several novel numerical methods are developed to solve two important systems, Maxwell's equations and the acoustic equations. These methods belong to two categories: finite-difference time-domain (FDTD) based methods and spectral time-domain based methods. They are shown by numerical experiments to have some distinguished features and behave better in most applications than conventional approaches. It is well known that the staircasing approximation in the conventional FDTD method for modeling curved objects is limited in accuracy to the first order. Two new methods, the enlarged cell method (ECM) to model curved conducting objects, and the staggered upwind embedded boundary (SUEB) method to model material interfaces, are put forward to overcome such large approximation errors. The ECM does not need to reduce the time step to ensure numerical stability for small irregular cells near the boundary. Therefore, it is more efficient than the recently-proposed conformal FDTD, and moreover, it incurs a smaller dispersion error. The SUEB method embeds the boundary in a simple staggered Cartesian grid and employs upwind conditions to correctly represent the physical conditions of the interfaces. Both methods only require modifying the finite-difference stencils around the boundaries to preserve the second-order accuracy. As a result, they are much more efficient than the conventional FDTD for curved objects. Recently spectral time-domain methods, such as the well-known discontinuous Galerkin method (DGM), have drawn abundant attention due to their exponential convergence. Unfortunately, the accuracy is usually dominated by geometry representation rather than spectral approximation. For the widely-used linear simplex grids, the first-order approximation to curved geometries leads to at best a second-order solution no matter how accurate the schemes are applied. For this reason we introduced an efficient staggered second-order time-stepping technique instead of high-order Runge-Kutta methods to avoid the waste of time-integration effort. In addition, to achieve higher-order accuracy, the DGM on a more accurate grid, the quadratic (second-order) simplex grid, is developed. To further maximize the advantages of the high-order/spectral methods, a novel framework is developed to combine a series of spectral methods with different orders and elements. Such a hybrid spectral method is optimal for complex problems.
Distributed File System Virtualization Techniques Supporting On-Demand Virtual Machine Environments for Grid Computing
Authors: Ming Zhao, Jian Zhang, Renato J. Figueiredo
Venue: Cluster Computing (2006)

This paper presents a data management solution which allows fast Virtual Machine (VM) instantiation and efficient run-time execution to support VMs as execution environments in Grid computing. It is based on novel distributed file system virtualization techniques and is unique in that: (1) it provides on-demand cross-domain access to VM state for unmodified VM monitors; (2) it enables private file system channels for VM instantiation by secure tunneling and session-key based authentication; (3) it supports user-level and write-back disk caches, per-application caching policies and middleware-driven consistency models; and (4) it leverages application-specific meta-data associated with files to expedite data transfers. The paper reports on its performance in wide-area setups using VMware-based VMs. Results show that the solution delivers performance over 30% better than native NFS and with warm caches it can bring the application-perceived overheads below 10% compared to a local-disk setup. The solution also allows a VM with 1.6 GB virtual disk and 320 MB virtual memory to be cloned within 160 seconds for the first clone and within 25 seconds for subsequent clones.
Predictive modeling of streaming servers
Authors: Michele Covell, Sumit Roy, Beomjoo Seo
Venue: ACM SIGMETRICS Performance Evaluation Review (2005)

In this paper, we describe our approach to deriving saturation models for streaming servers from vector-labeled training data. If a streaming server is driven into saturation by accepting too many clients, the quality of service degrades across the sessions. The actual saturating load on a streaming server depends on the detailed characteristics of the client requests: the content location (local disk or stream relay), the relative popularity, and the bit and packet rates [1]. Previous work in streaming-server models has used carefully selected, low-dimensional measurements, such as client jitter and rebuffering counts [2], or server memory usage [3]. In contrast, we collect 30 distinct low-level measures and 210 nonlinear derivative measures each second. This provides us with robustness against outliers, without reducing sensitivity or responsiveness to changes in load. Since the measurement dimensionality is so high, our approach requires the modeling and learning framework described in this paper.
Multiple Layer Clustering of Large Software Systems
Authors: Bill Andreopoulos, Aijun An, Vassilios Tzerpos, Xiaogang Wang
Venue: Proceedings of the 12th Working Conference on Reverse Engineering (2005)

Software clustering algorithms presented in the literature rarely incorporate in the clustering process dynamic information, such as the number of function invocations during runtime. Moreover, the structure of a software system is often multi-layered, while existing clustering algorithms often create flat system decompositions. This paper presents a software clustering algorithm called MULICsoft that incorporates in the clustering process both static and dynamic information. MULICsoft produces layered clusters with the core elements of each cluster assigned to the top layer. We present experimental results of applying MULICsoft to a large open-source system. Comparison with existing software clustering algorithms indicates that MULICsoft is able to produce decompositions that are close to those created by system experts.
Evaluating Human Factors in Augmented Reality Systems
Authors: Mark A. Livingston
Venue: IEEE Computer Graphics and Applications (2005)

Augmented reality has been a part of computer graphics methodology for decades. A number of prototype augmented reality systems have shown the possibilities this paradigm creates. This article explores the challenges created by human factors when implementing augmented reality systems.
Smooth Handoff with Enhanced Packet Buffering-and-Forwarding in Wireless/Mobile Networks
Authors: Chun-Ting Chou, Kang G. Shin
Venue: Proceedings of the Second International Conference on Quality of Service in Heterogeneous Wired/Wireless Networks (2005)

Packet buffering-and-forwarding is a simple but essential mechanism and has been widely used with other mechanisms to provide seamless handoffs in many wireless/mobile networks. However, some undesirable side effects of this mechanism, if not managed appropriately, can easily diminish its effectiveness in providing seamless inter-cell transitions during a handoff. We first examine these side effects and show how inappropriate buffer management by a mobility agent could affect the TCP performance. The throughput of TCP is then studied with special emphasis on the effects of a handoff. We enhance the conventional buffering-and-forwarding by proposing the Last-Come- First-Drop (LCFD) buffer management policy (to be employed by mobility agents) and post-handoff acknowledgement suppression (to be used by mobile nodes). Our enhancements are backward compatible and suitable for the gradual/incremental deployment. By deriving an analytical model and conducting numerical analysis, we show that our scheme can improve the TCP throughput up to 30%. Finally, we conduct the ns-2 based simulation to confirm these numerical results, and demonstrate the applicability of the analytic model for predicting TCP throughput in other handoff schemes.
Deriving User Interface from Ontologies: A Model-Based Approach
Authors: Ben Liu, Hejie Chen, Wei He
Venue: Proceedings of the 17th IEEE International Conference on Tools with Artificial Intelligence (2005)

In this paper we present an approach to derive User Interface (UI) from ontologies. It automatically generates UI according to declarative model specifications, and the UI helps a novice user to construct valid queries against a Knowledge Base (KB). The UI represents queries by OWL, and then transfers them to concrete applications for matchmaking. A novel aspect of our approach is that the ontological KB used by UI generator is exactly the one used by applications; hence the refining of ontologies needs not refining UI. Further, during a user-machine interaction session, the system eliminates every illegal option that engenders a clash in the KB, so the consistent checking of user inputs is accomplished as a side effect. It boosts the development of a knowledge dense system, as the building of a KB in progress, the UI is generated simultaneous.
DesCOTS-EV: A Tool for the Evaluation of COTS Components
Authors: Carme Quer, Xavier Franch, Xavier Lopez-Pelegrin
Venue: Proceedings of the 13th IEEE International Conference on Requirements Engineering (2005)

In the last years, some methods have been proposed for dealing with COTS component selection. In all of them, a key point is the comparison of the user requirements, which drive the selection process, with the capabilities of the evaluated COTS. Quality models are a means to obtain structured descriptions of COTS domains. Once built, COTS in a domain may be evaluated with respect to the quality entities included therein, quality requirements may be stated with respect to the quality model, and the classical factorrequirement negotiation process may be used for the selection of the most appropriate COTS.
Sufficient Conditions for Nesting the Reachable Sets of Two Smooth Control Systems of Constant Rank and Linear in Phase Variables
Authors: M. V. Topunov
Venue: Automation and Remote Control (2005)

Sufficient conditions for nesting the reachable sets of smooth control systems of constant rank and linear in phase variables are formulated. Sets that are reachable from an arbitrary point in time T and in a time not greater than T are determined. Examples are given.
Data broadcast scheduling: models, algorithms, and analysis
Authors: Weizhen Mao
Venue:  (2005)

Inherent in the field of data broadcasting is a communication problem in which a server is to transmit a subset of data items in response to requests received from clients. The intent of the server is to optimize metrics quantifying the quality of service the system provides. This method of data dissemination has proved to be an efficient means of delivering information in asymmetric environments demanding massive scalability. Of critical importance in such a system is the algorithm used by the server to construct a schedule of item broadcasts. Due to the real-time nature of this problem, performances of heuristics designed to construct such schedules are heavily dependent on request instances. Thus it is challenging to establish the quality of one algorithm over another. Though several scheduling methods have been developed, these algorithms have been studied with a reliance on probabilistic assumptions and little emphasis on analytical results. In contrast, we provide a formal treatment of the data broadcast scheduling problem in which analytical methods are applied, complemented by simulation experiments. Utilizing a worst-case technique known as competitive analysis, we establish bounds on the performance of various algorithms in the context of several different broadcast models. We describe results in three different settings. Minimizing the total wait time of all requests with a single channel and multiple database items we establish the competitive ratios for two well-known algorithms, First Come First Served (FCFS) and Most Requests First (MRF) to be equal, and provide a general lower bound for all algorithms in this context. We describe simulation results that indicate the superior performance of MRF over FCFS on average. Minimizing two conflicting metrics, the total wait time and total broadcast cost, with a single channel and single database item we develop two on-line algorithms, establish their competitive ratios, and provide an optimal off-line algorithm used to simulate the impact of various parameters on the performance of both on-line heuristics. Finally, we extend the previous model by including multiple database items and establish a lower bound to a greedy algorithm for this context.
Heuristic and Distributed QoS Route Discovery for Mobile Ad hoc Networks
Authors: Peng Fu, Jingtao Li, Deyun Zhang
Venue: Proceedings of the The Fifth International Conference on Computer and Information Technology (2005)

The Quality of service (QoS) routing has been receiving increasingly intensive attention in the mobile ad hoc networks (MANETs) fields, but it is difficult to solve the problem for the nature of MANETs such as performance constraints and dynamic network topology. In order to increase the probability of success in finding QoS feasible paths and reduce average cost in flooding path discovery scheme of the traditional MANETs routing protocols, we proposed a heuristic and distributed route discovery method named RLGAMAN that supports QoS requirement for MANETs in this paper. This method integrates the route discovery scheme with a reinforcement learning (RL) method that only utilizes the local information for the dynamic network environment; and the route expand scheme based on genetic algorithms (GA) method to avoid the problem of stagnation route. We investigate the performance of the RLGAMAN by simulation experiment bed in NS2. Compared with the traditional method, the experiment results showed the network performance is improved obviously, and RLGAMAN is efficient and effective.
The Fundamental Role of Hop Distance in IEEE802.11 Multi-Hop Ad Hoc Networks
Authors: Yan Gao, Dah-Ming Chiu, John C. S. Lui
Venue: Proceedings of the 13TH IEEE International Conference on Network Protocols (2005)

In wireless networks, it is well understood what throughput can be achieved by nodes who can hear each other (i.e. nodes within a single cell)[1, 3]. The effects of nodes beyond the sensing range (known as hidden nodes) on a sender are complicated and difficult to analyze. Consequently, how to analytically model multi-hop adhoc networks, specially networks based on the popular IEEE802.11 standards remains largely open. In a recent paper [2], the throughput of a particular wireless network topology (linear network with a given number of hidden nodes) has been derived analytically. In this paper, we unify previous results on single-cell models, and results characterizing different types of hidden node interference and the analysis of [2], to derive a general solution for throughput given a linear network of arbitrary density and transmission distance between source and destination nodes. An important insight from our model is that there is a certain transmission distance, which is less than the maximum transmission distance, that optimizes throughput in such networks. This result is verified using ns-2 simulation with both single as well as multiple flows.
Improved Collision Detection Algorithm for Soft Tissue Deformable Models
Authors: M. A. Padilla Castaneda, F. Arambula Cosio
Venue: Proceedings of the Sixth Mexican International Conference on Computer Science (2005)

The virtual 3D models of human organs in surgery simulation must reproduce the complex viscoelastic deformable behavior of living soft tissue during interaction with virtual surgical tools. Collision detection is a crucial task for modelling and real-time simulation of surgical interactions. Few techniques for collision detection between moving bodies that involve tissue cutting and deformations have been reported. In this paper, we present an improved Quinlan algorithm for collision detection suitable for real-time tissue cutting and deformation simulation. We also present an example of the use of the algorithm in a prostate surgery simulation system.
A Better Algorithm for Uniform Metrical Task Systems with Few States
Authors: Wolfgang Bein, Lawrence Larmore, John Noga
Venue: Proceedings of the 8th International Symposium on Parallel Architectures,Algorithms and Networks (2005)

We give a randomized algorithm( the "Wedge Algorithm") of competitiveness \frac{3}{2}H_k- \frac{1}{{2K}} for any metrical task system on a uniform space of K points, for any k \ge 2, where H_k = \sum\nolimits_{i = 1}^k \frac{1}{i}, the k^th This algorithm has better competitiveness than Irani-Seidan algorithm if k ia smaller than 10^8. The algorithm is better by a factor of 2 if k \le 47.