ppxscal/embedding_network huggingface dataset:
An analysis of learner arguments in a collective learning environment
Authors: Patrick Jermann, Pierre Dillenbourg
Venue: Proceedings of the 1999 conference on Computer support for collaborative learning (1999)

This contribution analyses the arguments of students in a learning activity entitled "Argue Graph". This activity is intended to make students understand the relationship between learning theories and design choices in courseware development. The analysis of arguments is centered on the effects of discussion and opinion conflict on the elaboration of arguments. We then use an adaptation of a collective intelligence model to describe the knowledge flow among people and artifacts during the learning activity. Finally, the representations produced by the system, used by students to write a synthesis and by the teacher to debrief the class are analysed in relation to metacognition. We propose to consider these representations as metacognitive tools which structure the learning activity.
A localized IP-address auto-configuration protocol for wireless ad-hoc networks
Authors: Venkata C. Giruka, Mukesh Singhal
Venue: Proceedings of the 4th international workshop on Wireless mobile applications and services on WLAN hotspots (2006)

We present a localized IP auto-con.guration protocol for wireless ad-hoc networks, called OASIS. OASIS introduces the idea of position-dependent IP-addresses using a cellular structure of the underlying network. Within a cell, nodes try to obtain a con.ict-free IP-address using a distributed mutual exclusion style algorithm. We show the correctness, and present an asymptotic analysis of the overhead of OASIS. Further, we present extensions to OASIS protocol to cope with message losses and node mobility. OASIS avoids problems due to network partitions and mergers, supports concurrent node joins/leaves, incurs localized control overhead per IP-address acquisition (independent of the number of nodes in the network), and hence it is scalable.
LogicFence: A Framework for Enforcing Global Integrity Constraints at Runtime
Authors: Shibashis Guha, Srinath Srinivasa, Saikat Mukherjee, Ranajoy Malakar
Venue: Proceedings of the 10th International Database Engineering and Applications Symposium (2006)

Large information systems (IS) comprise of several independent applications that share a common set of resources and data. Usually, there are implicit and subtle dependencies across these applications that are not specifically captured. This is especially so if the applications are bought off the shelf or are developed by independent third parties. Dependencies or global semantic constraints are difficult to discern and incorporate into the design of individual software components. Global constraints may change over time and it is usually expensive or infeasible to change individual application logic in every such situation. In order to address such an issue, we propose LogicFence, a framework that accepts a definition of global constraints and translates these constraints into primitives that are embedded into the run-time environments of application programs (currently, into the JVM of Java applications). Once here, LogicFence monitors the state of application programs and prevents the disparate instances to collectively form a globally inconsistent state.
Dynamic Travel Time Maps - Enabling Efficient Navigation
Authors: Dieter Pfoser, Nectaria Tryfona, Agnes Voisard
Venue: Proceedings of the 18th International Conference on Scientific and Statistical Database Management (2006)

Routing plays an ever-important role in a society that relies heavily on individual means of transportation. Although efficient algorithmic solutions for navigation exist, an accurate and reliable weight database that forms the basis of an acceptable algorithmic solution is missing. This work defines algorithms and data management techniques that allow the derivation of dynamic weights from collected Floating Car Data (FCD). Weights reflect the speed associated with a piece of road at a certain time. A collection of such historical data is used to capture trends in travel time behavior according to temporal variations. Based on large amounts of travel time data, edge-based weights in the form of time-varying characteristic travel times are derived. Since the available tracking data does not cover the entire road network, several methods are defined to compensate for the lack of data and to guarantee complete coverage. A dynamic weight database, the Dynamic Travel Time Map (DTTM) is defined and implemented as a spatio-temporal data warehouse to manage the characteristic travel times and to compute dynamic weights efficiently. An experimental evaluation establishes not only the efficiency of the proposed approach but also shows its applicability in a realistic context, using actual GPS vehicle tracking data for the road network of Athens, Greece.
Cyclic Storage for Fault-Tolerant Distributed Executions
Authors: Ricardo Marcelin-Jimenez, Sergio Rajsbaum, Brett Stevens
Venue: IEEE Transactions on Parallel and Distributed Systems (2006)

Given a set V of active components in charge of a distributed execution, a storage scheme is a sequence B_{0}, B_{1}, \ldots, B_{b-1} of subsets of V, where successive global states are recorded. The subsets, also called blocks, have the same size and are scheduled according to some fixed and cyclic calendar of b steps. During the i\rm th step, block B_{i} is selected. Each component takes a copy of its local state and sends it to one of the components in B_i, in such a way that each component stores (approximately) the same number of local states. Afterward, if a component of B_{i} crashes, all of its stored data is lost and the computation cannot continue. If there exists a block with no failed components in it, then a recent global state can be retrieved and the computation does not need to start over from the very beginning. The goal is to design storage schemes that tolerate as many crashes as possible, while trying to have each component participating in as few blocks as possible and, at the same time, working with large blocks (so that a component in a block stores a small number of local states). In this paper, several such schemes are described and compared in terms of these measures.
Constrained Global Optimization by Constraint Partitioning and Simulated Annealing
Authors: Benjamin W. Wah, Yixin Chen, Andrew Wan
Venue: Proceedings of the 18th IEEE International Conference on Tools with Artificial Intelligence (2006)

In this paper, we present constraint-partitioned sim- ulated annealing (CPSA), an algorithm that extends our previous constrained simulated annealing (CSA) for constrained optimization. The algorithm is based on the theory of extended saddle points (ESPs). By decomposing the ESP condition into multiple neces- sary conditions, CPSA partitions a problem by its constraints into subproblems, solves each indepen- dently using CSA, and resolves those violated global constraints across the subproblems. Because each subproblem is exponentially simpler and the number of global constraints is very small, the complexity of solving the original problem is significantly reduced. We state without proof the asymptotic convergence of CPSA with probability one to a constrained global minimum in discrete space. Last, we evaluate CPSA on some continuous constrained benchmarks.
A comparative study of shunt hybrid and shunt active power filters for single-phase applications: simulation and experimental validation
Authors: Salem Rahmani, Kamal Al-Haddad, Hadi Youssef Kanaan
Venue: Mathematics and Computers in Simulation (2006)

The aim of this paper is to compare the performance of the single-phase shunt active power filter (SPSAPF) and the single-phase shunt hybrid power filter (SPSHPF) that adopt both an indirect current control scheme with a unipolar pulse width modulation (U-PWM) strategy. The SPSHPF topology includes, in addition to the components of the SPSAPF, a power factor correction capacitor connected in series with a transformer. The primary winding of the transformer is connected to the single-phase voltage-source inverter which is the main part of the filter. The indirect current control technique that is implemented for both filters is based on extracting the source current reference from the distorted waveform of the load current. The U-PWM control technique is based on comparing simultaneously a triangular high frequency carrier signal with a slow-varying regulation signal and its opposite. The double comparison process results in the gate signals for the semiconductors. A laboratory prototype for each filter is built. It is demonstrated that the rating of the inverter used in the SPSHPF is three to four times lower than the one corresponding to the SPSAPF In addition, the performance of the SPSHPF is found to be much better than that of the SPSAPF as far as the line current distortion is concerned.
Experiences on automatically assessed algorithm simulation exercises with different resubmission policies
Authors: Lauri Malmi, Ville Karavirta, Ari Korhonen, Jussi Nikander
Venue: Journal on Educational Resources in Computing (JERIC) (2005)

In this paper, we present our experiences in using two automatic assessment tools, TRAKLA and TRAKLA2, in a second course of programming. In this course, 500--700 students have been enrolled annually during the period 1993--2004. The tools are specifically designed for assessing algorithm simulation exercises in which students simulate the working of algorithms at a conceptual level. Both of these tools allow students to resubmit their solutions after getting feedback. However, the resubmission policy has changed considerably during the period. Those changes reflect the students performance in the exercises. We conclude that an encouraging grading policy, i.e., the more exercises they solve the better grades they achive, combined with an option to resubmit the solution is a very important factor promoting students' learning. However, in order to prevent aimless trial-and-error problem solving method, the number of resubmissions allowed per assignment should be carefully controlled.
A new congestion control algorithm for layered multicast in heterogeneous multimedia dissemination
Authors: Qiang Liu, Jeng-Neng Hwang
Venue: Proceedings of the 2003 International Conference on Multimedia and Expo - Volume 1 (2003)

Layered multicast is a promising technique for disseminating adaptive-quality audio/video to multiple heterogeneous receivers. Congestion control in a layered multicast scheme is very important to support heterogeneity and scalability. Previous works on congestion control use packet loss, delay, and receiving rate to infer whether there is spare capacity along the path, which suffers from slow convergence, lack of inter-session fairness or TCP-fairness, layer oscillations, and loss induced by the join experiments. In this paper, we propose a layered multicast bandwidth inference congestion (BlC) control, which use delay increasing trend detection to infer the spare capacity. The major contribution of this paper is introducing the source probe organization and effective spare capacity inference by delay trend detection algorithm. We evaluate BIC for a large variety of scenarios and show that it converges fast to the optimal link utilization and can adapt to network dynamics effectively. We also show that BIC is stable, inter-session fair and fair to competing TCP traffics.
An Improved FSM Method for Web-based Applications
Authors: Xunmei Gu, Guoxin Song, Qingyi Li
Venue: Proceedings of the International Conference on Computational Inteligence for Modelling Control and Automation and International Conference on Intelligent Agents Web Technologies and International Commerce (2006)

Functional size measurement (FSM) methods are intended to measure the size of software by qualifying the functional user requirements of the software. COSMIC-FFP is a common ISO-standardized FSM method. According to the dynamic characteristic of Web-based applications, this paper presents a COSMIC-FFP-like method to measure the functional size of Web-based applications. Through experiment, it is proved that this extended method is effective.
PeerCluster: A Cluster-Based Peer-to-Peer System
Authors: Xin-Mao Huang Cheng-Yue Chang Ming-Syan Chen
Venue: IEEE Transactions on Parallel and Distributed Systems (2006)

This paper proposes a cluster-based peer-to-peer system, called PeerCluster, for sharing data over the Internet. In PeerCluster, all participant computers are grouped into various interest clusters, each of which contains computers that have the same interests. The intuition behind the system design is that by logically grouping users interested in similar topics together, we can improve query efficiency. To efficiently route and broadcast messages across/within interest clusters, a hypercube topology is employed. In addition, to ensure that the structure of the interest clusters is not altered by arbitrary node insertions/deletions, we have devised corresponding JOIN and LEAVE protocols. The complexities of these protocols are analyzed. Moreover, we augment PeerCluster with a system recovery mechanism to make it robust against unpredictable computer/network failures. Using an event-driven simulation, we evaluate the performance of our approach by varying several system parameters. The experimental results show that PeerCluster outperforms previous approaches in terms of query efficiency, while still providing the desired functionality of keyword-based search.
Legislating Entrepreneurship: An Oxymoron?
Authors: Shane Greenstein
Venue: IEEE Micro (2006)

Can the passage of a federal law help entrepreneurs? Columnist Shane Greenstein is a skeptic.
A java library for simulating contact centers
Authors: Eric Buist, Pierre L'Ecuyer
Venue: Proceedings of the 37th conference on Winter simulation (2005)

ContactCenters is a Java library for writing contact center simulators. It supports multi-skill and blend contact centers with complex and arbitrary routing, dialing policies, and arrival processes. The programmer can alter the simulation logic in many ways, without modifying the source code of the library. A simulator can interoperate with other libraries, e.g., for optimization and statistical analysis. Performance, flexibility, and extensibility are the main goals of its design and implementation. In this paper, we present the general architecture of the library, its main components and their interaction. We give an example of a contact center simulator and provide comparisons with a widely used commercial simulation system also offering facilities for contact center simulation.
Mental imagery, language and gesture: multimodal access to human communication
Authors: Francis Quek
Venue: Proceedings of the 2005 NICTA-HCSNet Multimodal User Interaction Workshop - Volume 57 (2006)

Human communication and interaction are inherently multimodal. Speech, prosody, gesture, gaze, facial displays, and body posture are involved in the communicative act. Hence, understanding witting or unwitting visual displays is critical to both the analysis and synthesis of human communicative behaviour.One path from multimodal behaviour to language is bridged by the underlying mental imagery. This visuospatial imagery, for a speaker, relates not to the elements of syntax, but to the units of thought that drive the expression (vocal utterance and visible display). The basic idea is that mental imagery is integral to language production, and non-verbal behaviour (gesture, gaze, facial expression) informs us of this imagery. This gives us a handle to extract information on human discourse from a multimedia record of multimodal language performance. The question becomes what computable features of behaviour are informative about imagery and the organization of the discourse.We shall see a feature-decomposition approach that facilitates cross-modal analysis at the level of discourse planning and conceptualization. We shall discuss our experimental framework and cite concrete examples of features that provide computational access to discourse structure. We shall also see several examples of how these principles may be applied in such domains as meeting analysis and distance tutoring.
Emerging Mobile Technologies and Issues
Authors: S. R. Subramanya
Venue: Proceedings of the International Symposium on Collaborative Technologies and Systems (2006)

The emerging 3rd generation (3G) mobile systems are expected to provide a wide variety of voice and data services, supporting data rates of up to 2 Mbps. The next generation mobile/cellular systems are being designed to operate on a core IP (Internet Protocol) network, supporting all the popular operating systems and software applications. They are expected to support mobile rates of 100 Mbps, and fixed rates of 1Gbps. Also, the mobile phones have been transformed from mere voice communication devices to advanced communication devices (voice, text and video messaging). In addition, they have acquired features of consumer electronics (with built-in cameras, MP3 players, video capture and play), and computing (email, Web access, spread sheets). The emerging and future mobile systems facilitate the provision of rich multimedia content services, such as TV broadcasts, video streaming, music, video telephony, multimedia messaging, Web browsing, mobile commerce, and (multi-party) games, mobile collaboration, and several location-based services. The worldwide mobile content market is expected reach $59 Billion by 2009, according to Juniper Research. The development and deployment of content, applications, and services have been transforming from being technology-centric to being content-centric and user-centric. The ultimate objective of mobile content and services is to provide the users with a rich experience in a convenient and cost-effective manner, and to provide the mobile vendors, operators, and service providers with appropriate ROI (return on investment).
Shadow Removal Based on Shadow Direction and Shadow Attributes
Authors: Yinghua Lu, Huijie Xin, Jun Kong, Bingbing Li, Yan Wang
Venue: Proceedings of the International Conference on Computational Inteligence for Modelling Control and Automation and International Conference on Intelligent Agents Web Technologies and International Commerce (2006)

Moving shadow removal is critical for robust moving object tracking system. A shadow removal algorithm based on shadow attributes is presented in this paper. The direction of shadow is estimated first, and then shadow points are sampled based on the direction of shadow. At last the shadow attributes is calculated using the sampled shadow points. The shadow is removed based on shadow attributes. Experimental results are presented to show that our algorithm is better than some other methods.
Multilevel routing with jumper insertion for antenna avoidance
Authors: Tsung-Yi Ho, Yao-Wen Chang, Sao-Jie Chen
Venue: Integration, the VLSI Journal (2006)

As technology advances into nanometer territory, the antenna problem has caused significant impact on routing tools. The antenna effect is a phenomenon of plasma-induced gate oxide degradation caused by charge accumulation on conductors. It directly influences reliability, manufacturability and yield of VLSI circuits, especially in deep-submicron technology using high-density plasma. Furthermore, the continuous increase of the problem size of IC routing is also a great challenge to existing routing algorithms. In this paper, we propose a novel framework for multilevel full-chip routing with antenna avoidance using built-in jumper insertion approach. Compared with the state-of-the-art multilevel routing, the experimental results show that our approach reduced 100% antenna-violated gates and results in fewer wirelength, vias, and delay increase.
Designing a Video-on-Demand System for a Brazilian High Speed Network
Authors: L. Souza, A. Ripoll, X. Y. Yang, P. Hernandez, F. Cores
Venue: Proceedings of the 26th IEEE International ConferenceWorkshops on Distributed Computing Systems (2006)

Despite the availability of video-on-demand (VoD) services in a number of cities around the world, the large-scale deployment of VoD services has not been widely explored due to economic constraints. The high complexity founded in these systems makes the design process very difficult. This study presents a VoD system design for a highspeed metropolitan network, based on ATM technology, located in Brazil. To accomplish this goal, we have utilized our own simulation-based tool for VoD design called VODSim. This tool allows VoD research on any VoD platform, simulating the complete flow path followed by requests from clients to servers passing through the network infrastructure, allowing the configuration and tuning of multiple system parameters. Using VODSim, we analyse possible VoD architectures for the proposal environment (i.e. Centralized-server, Independent-servers, One-level-proxies and Distributedservers), studying key-parameters that have influence in system design. Experimental results show that Distributed-server architecture is the one that adjusts better to the analyzed infrastructure, improving streaming capacity by 16%, 25% and 28% more than One-level-proxies, Centralized and Independent-servers respectively. Taking in account future growth in VoD system, the Distributed-server even provides an unlimited scalability through new local network incorporation and using P2P techniques.
HHMSM: a hierarchical hybrid multicast stream merging scheme for large-scale video-on-demand systems
Authors: Hai Jin, Dafu Deng
Venue: Proceedings of the 2003 International Conference on Multimedia and Expo - Volume 1 (2003)

The key performance bottleneck for large-scale video-on-demand (VoD) systems is the server bandwidth, which controls the number of clients a video server can support. Two existing stream scheduling schemes can save server bandwidth significantly by using multicast method to transmit video data: the batching scheme and the patching scheme. However, the batching scheme results in long start-up latency and high reneging probability. The patching scheme does not work well at high client request rates due to mass retransmission for same video data. In this paper, we propose a hierarchical hybrid multicast stream merging scheme, called HHMSM, which can save server bandwidth significantly over a wide range of client request rates. Furthermore, the start-up latency raised by the HHMSM scheme is far less than that of the batching scheme.
Guest Editor's Introduction: The State of Web Security
Authors: Mike Andrews
Venue: IEEE Security and Privacy (2006)

Today's Internet is a rapidly evolving place. What were once the hot technologies (gopher, FTP, telnet) are quickly being replaced by others (RSS, AJAX, SOAP). Such is the same with security; whereas in the '90s most attacks targeted networks, today most target the applications that run on top of them.