ppxscal/embedding_network huggingface dataset:
Proactive Caching for Spatial Queries in Mobile Environments
Authors: Haibo Hu, Jianliang Xu, Wing Sing Wong, Baihua Zheng, Dik Lun Lee, Wang-Chien Lee
Venue: Proceedings of the 21st International Conference on Data Engineering (2005)

Semantic caching enables mobile clients to answer spatial queries locally by storing the query descriptions together with the results. However, it supports only a limited number of query types, and sharing results among these types is difficult. To address these issues, we propose a proactive caching model which caches the result objects as well as the index that supports these objects as the results. The cached index enables the objects to be reused for all common types of queries. We also propose an adaptive scheme to cache such an index, which further optimizes the query response time for the best user experience. Simulation results show that proactive caching achieves a significant performance gain over page caching and semantic caching in mobile environments where wireless bandwidth and battery are precious resources.
On the Compression of Low Rank Matrices
Authors: H. Cheng, Z. Gimbutas, P. G. Martinsson, V. Rokhlin
Venue: SIAM Journal on Scientific Computing (2005)

A procedure is reported for the compression of rank-deficient matrices. A matrix A of rank k is represented in the form $A = U \circ B \circ V$, where B is a $k\times k$ submatrix of A, and U, V are well-conditioned matrices that each contain a $k\times k$ identity submatrix. This property enables such compression schemes to be used in certain situations where the singular value decomposition (SVD) cannot be used efficiently. Numerical examples are presented.
Betting Boolean-style: a framework for trading in securities based on logical formulas
Authors: Lance Fortnow, Joe Kilian, David M. Pennock, Michael P. Wellman
Venue: Decision Support Systems (2005)

We develop a framework for trading in compound securities: financial instruments that pay off contingent on the outcomes of arbitrary statements in propositional logic. Buying or selling securities--which can be thought of as betting on or against a particular future outcome--allows agents both to hedge risk and to profit (in expectation) on subjective predictions. A compound securities market allows agents to place bets on arbitrary Boolean combinations of events, enabling them to more closely achieve their optimal risk exposure, and enabling the market as a whole to more closely achieve the social optimum. The tradeoff for allowing such expressivity is in the complexity of the agents' and auctioneer's optimization problems.We develop and motivate the concept of a compound securities market, presenting the framework through a series of formal definitions and examples. We then analyze in detail the auctioneer's matching problem. We show that, with n events, the matching problem is worst-case intractable: specifically, the problem is co-NP-complete in the divisible case and Σ2p-complete in the indivisible case. We show that the latter hardness result holds even under severe language restrictions on bids. With log n events, the problem is tractable (polynomial) in the divisible case and worst-case intractable (NP-complete) in the indivisible case. We briefly discuss matching algorithms and tractable special cases.
Radio-Triggered Wake-Up for Wireless Sensor Networks
Authors: Lin Gu, John A. Stankovic
Venue: Real-Time Systems (2005)

Power management is an important technique to prolong the lifespan of sensor networks. Many power management protocols employ wake-up/sleep schedules, which are often complicated and inefficient. We present power management schemes that eliminate such wake-up periods unless the node indeed needs to wake up. This type of wake-up capability is enabled by a new radio-triggered hardware component inspired by the observation that the wake-up radio signal contains enough energy to trigger a wake-up process. We evaluate the potential power saving in terms of the lifespan of a sensor network application, using experimental data and SPICE circuit simulations. Comparing the result with always-on and rotation-based power management schemes, we find the radio-triggered scheme saves 98% of the energy used in the always-on scheme, and saves over 70% of the energy used in the rotation-based scheme. Consequently, the lifespan increases from 3.3 days (always-on) or 49.5 days (rotation-based) to 178 days (radio-triggered). Furthermore, a store-energy technique can extend operating distance from 10 feet to 22 feet, or even longer if longer latency is acceptable. Wake-up efficiency is evaluated in NS-2 simulations, which show that radio-triggered wake-up has fewer failures, shorter latency, and consistently larger sensing laxity than rotation based wake-up. We also present amplification and radio-triggered IDs which can further enhance performance.
A spatio-temporal geometry-based model for digital documentation of historical living systems
Authors: Athanasios D. Styliadis, Michael Gr. Vassilakopoulos
Venue: Information and Management (2005)

Representations used in digital documentation applications today usually assume a world that only exists in the present. Information contained within a database may be added-to or modified over time, but change through time is seldom maintained. This limitation of current IT has recently received attention, given the increasingly urgent need to understand geographical processes and cause-and-effect inter-relationships between human activities and the environment. Models proposed for the representation of spatio-temporal data are extensions of traditional raster and vector representations that can be seen as location-or feature-based, respectively, and are therefore best organized for performing, either location- or feature-based queries. In this paper, a new spatio-temporal data model suitable for digital documentation of historical living systems (artefacts, monuments and sites) is defined: it is based on 3D geometry and intended to facilitate analysis of temporal relationships and patterns of 3D modeling changes through time. This is particularly useful to both IT and IS managers, researchers and practitioners. It is shown that time-based queries related to 3D models of objects can be processed in an efficient and straightforward manner using the model. Finally, analytical time efficiency estimations are given, showing that the model is also an efficient and compact representation of spatio-temporal information.
Improved channel-aware MAC protocols for wireless local area networks: Research Articles
Authors: Zhihui Chen, Ashfaq Khokhar
Venue: Wireless Communications Mobile Computing (2005)

This paper studies the fading properties of the communication channel assumed in wireless local area networks (WLANs) and devises efficient channel-aware protocols for the distributed coordination function (DCF) and the point coordination function (PCF), the two modes of communication defined in the IEEE standard for WLAN. Our simulations show that the proposed PCF protocol improves the channel capacity usage up to 14&percnt; and the proposed DCF protocol improves the channel capacity up to 90&percnt;, when compared with standard IEEE 802.11 implementations, depending on the loss rate and temporal characteristics of the wireless channel. The proposed protocols introduce minimum computational overhead. We also show that, compared with standard DCF protocol defined in IEEE 802.11, the proposed DCF protocol can lower the SNR requirements for a given packet error rate thus potentially extending the battery life of portable devices that use WLAN.. Copyright &copy; 2004 John Wiley & Sons, Ltd.
Analysis and experimental verification of the linear correlation of the operation condition among the bifurcation points of current-mode-controlled buck&ndash;boost converter: Research Articles
Authors: K. W. Eric Cheng, M. Liu
Venue: International Journal of Circuit Theory and Applications (2005)

The operation parameter of the buck&ndash;boost converter is examined for its boundary of the first flip bifurcation. It is found that the parameters exhibit a linear relation for the same parameter at another bifurcation point. The bifurcation parameters also have a linear correlation between them. Theoretical analysis is presented to explain how this can occur. Simulation and experimental results at 20 kHz are used to present these novel results. Copyright &copy; 2005 John Wiley & Sons, Ltd.
Pitch estimation of speech signal based on adaptive lattice notch filter
Authors: Joon-Hyuk Chang, Nam Soo Kim, Sanjit K. Mitra
Venue: Signal Processing (2005)

A novel approach to pitch estimation of speech signals using an adaptive lattice notch filter (ALNF) is proposed. Based on a good convergence property and an unbiased frequency estimate with respect to the noise variance, the pitch period is estimated using the ALNF. Simulation results have verified that the ALNF is very effective in estimating the pitch period of the given speech signal under background noise environments.
A system for document markup and organisation
Authors: Shazia Akhtar, John Dunnion, Ronan G. Reilly
Venue: Proceedings of the 2004 international symposium on Information and communication technologies (2004)

In this paper, we present a system for marking up text documents into XML on a Self-Organising Map (SOM). The system organises pre-tagged XML documents on the Self-Organising Map such that the documents similar in content are placed closer to each other. Then, by employing the inductive learning algorithm C5.0, the system learns markup rules from the nearest SOM neighbours of a new unmarked document. Experiments with the system on a number of document corpora demonstrate that our approach is promising.
Change of memory formation according to STDP in a continuous-time neural network model
Authors: Hidenori Watanabe, Masataka Watanabe, Kazuyuki Aihara, Shunsuke Kondo
Venue: Systems and Computers in Japan (2004)

Gerstner and colleagues have proposed a learning rule in which the incrementation of synaptic weight is adjusted according to the time difference between neuron firing and spike arrival. In this study, a continuous-time associative memory model is constructed by using a learning rule based on that idea, and the functions of the learning rule are investigated. First, a continuous-time associative memory model is constructed on the basis of the learning rule in continuous time, in which the neuron can store memory as the synchronous firing dynamics of the neuron. A result is presented in which multiple memory patterns can be recalled simultaneously under the proposed model. Then, using the proposed learning rule, an attempt is made to compose a nesting structure formed by arbitrary memory patterns. Based on the above series of results, it is shown that the learning rule has the function of modifying the memory storage structure according to changes in the environment. &copy; 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(12): 57&ndash;66, 2004; Published online in Wiley InterScience (). DOI 10.1002&sol;scj.10324
A Characterization of Web Data Sources to Facilitate E-Commerce Transactions
Authors: Chima Adiele
Venue: Proceedings of the International Conference on Information Technology: Coding and Computing (ITCC'05) - Volume I - Volume 01 (2005)

E-commerce involves business activities that deal with the exchange of values for goods and services on the Internet where all transactions are carried out electronically. These activities consist of different operations that depend on data. Web data emanate from data sources that are inherently distributed and potentially heterogeneous. However, Web users, and indeed, participants of e-commerce transactions desire access to data without necessarily understanding the intricacies of the underlying data sources. Unfortunately, data infrastructure has not been a major focus of e-commerce research. In this paper, we characterize e-commerce data sets to reveal the storage requirements and other data management needs of such data. We specify a common-term vocabulary to make explicit the content of data, and hence, facilitate the integration of e-commerce data sets. Central to the semantic description of data is a filter mechanism that recognizes a context schema.
Your Coffee Shop Doesn't Use Two-Phase Commit
Authors: Gregor Hohpe
Venue: IEEE Software (2005)

Asynchronous processing models can be highly efficient but are not without challenges. If the real world writes the best stories, then maybe we can learn something from Starbucks about designing successful asynchronous messaging solutions.
Dynamic web log session identification with statistical language models
Authors: Xiangji Huang, Fuchun Peng, Aijun An, Dale Schuurmans
Venue: Journal of the American Society for Information Science and Technology (2004)

We present a novel session identification method based on statistical language modeling. Unlike standard time-out methods, which use fixed time thresholds for session identification, we use an information theoretic approach that yields more robust results for identifying session boundaries. We evaluate our new approach by learning interesting association rules from the segmented session files. We then compare the performance of our approach to three standard session identification method--the standard timeout method, the reference length method, and the maximal forward reference method--and find that our statistical language modeling approach generally yields superior results. However, as with every method, the performance of our technique varies with changing parameter settings. Therefore, we also analyze the influence of the two key factors in our language-modeling-based approach: the choice of smoothing technique and the language model order. We find that all standard smoothing techniques, save one, perform well, and that performance is robust to language model order.
Schema Matching Using Duplicates
Authors: Alexander Bilke, Felix Naumann
Venue: Proceedings of the 21st International Conference on Data Engineering (2005)

Most data integration applications require a matching between the schemas of the respective data sets. We show how the existence of duplicates within these data sets can be exploited to automatically identify matching attributes. We describe an algorithm that first discovers duplicates among data sets with unaligned schemas and then uses these duplicates to perform schema matching between schemas with opaque column names. Discovering duplicates among data sets with unaligned schemas is more difficult than in the usual setting, because it is not clear which fields in one object should be compared with which fields in the other. We have developed a new algorithm that efficiently finds the most likely duplicates in such a setting. Now, our schema matching algorithm is able to identify corresponding attributes by comparing data values within those duplicate records. An experimental study on real-world data shows the effectiveness of this approach.
Type synthesis of 3-DOF reducible translational mechanisms
Authors: Feng Gao, Yong Zhang, Weimin Li
Venue: Robotica (2005)

Motion coupling is one of the typical characters of parallel robots. This makes it complicated to control the parallel robots. Therefore, the design of parallel mechanisms with decoupled motions is an important and challenging issue in the parallel robotic field. However, research in this field, including the definition and type synthesis theory, is weak or lacking. In this paper, the reducible correlation between the input and the output of 3-DOF translational mechanisms with decoupled motions is investigated and the definition of this topic is presented. A new parameter named Gf coordinate is propsed for the synthesis of 3-DOF reducible translational mechanisms. The type synthesis theory for this kind of mechanisms is obtained and some reducible mechanisms are synthesized.
A Flexible Software Architecture for Hybrid Tracking
Authors: Miguel Ribo, Markus Brandner, Axel Pinz
Venue: Journal of Robotic Systems (2004)

Fusion of vision-based and inertial pose estimation has many high-potential applications in navigation, robotics, and augmented reality. Our research aims at the development of a fully mobile, completely self-contained tracking system, that is able to estimate sensor motion from known 3D scene structure. This requires a highly modular and scalable software architecture for algorithm design and testing. As the main contribution of this paper, we discuss the design of our hybrid tracker and emphasize important features: scalability, code reusability, and testing facilities. In addition, we present a mobile augmented reality application, and several first experiments with a fully mobile vision-inertial sensor head. Our hybrid tracking system is not only capable of real-time performance, but can also be used for offline analysis of tracker performance, comparison with ground truth, and evaluation of several pose estimation and information fusion algorithms. &copy; 2004 Wiley Periodicals, Inc.
An adaptive object model with dynamic role binding
Authors: Tetsuo Tamai, Naoyasu Ubayashi, Ryoichi Ichiyama
Venue: Proceedings of the 27th international conference on Software engineering (2005)

To achieve the goal of realizing object adaptation to environments, a new role-based model Epsilon and a language EpsilonJ is proposed. In Epsilon, an environment is defined as a field of collaboration between roles and an object adapts to the environment assuming one of the roles. Objects can freely enter or leave environments and belong to multiple environments at a time so that dynamic adaptation or evolution of objects is realized. Environments and roles are the first class constructs at runtime as well as at model description time so that separation of concerns is not only materialized as a static structure but also observed as behaviors. Environments encapsulating collaboration are independent reuse components to be deployed separately from objects. In this paper, the Epsilon model and the language are explained with some examples. The effectiveness of the model is illustrated by a case study on the problem of integrated systems. Implementation of the language is also reported.
Translation Disambiguation in Mixed Language Queries
Authors: Percy Cheung, Pascale Fung
Venue: Machine Translation (2004)

Code-switching is very common among bilingual speakers. Spoken queries by these speakers are typically in mixed language. In this paper, we propose an unsupervised method for mixed-language query understanding, using only a monolingual corpus and a bilingual dictionary. Secondary-language words mixed in a primary-language query are translated into words in the primary language. We found that using a single disambiguation feature for translation is more effective than using multiple features, provided this feature is based on the most salient seed-word, chosen automatically by con¿dence scoring. We propose and compare four types of disambiguation features that are based on context seed-words. A baseline method uses the nearest neighboring seed-word as disambiguation feature. Multiple-context seed-word voting is also proposed in order to enlarge the context window. On the other hand, merely using the inverse-distance as weights on context words degrades the performance as it runs counter to the potential underlying syntactic relations between words. Our ¿nal proposal is a solution that uses multiple-context seed-words and the translation candidates of all mixed language words to select a single most salient seed-word for translation disambiguation. The translation disambiguation accuracy for this feature is at 83.7% for all words in the ATIS spontaneous speech query database, and 66.7% for content words.
A tree-based approach to clustering XML documents by structure
Authors: Gianni Costa, Giuseppe Manco, Riccardo Ortale, Andrea Tagarelli
Venue: Proceedings of the 8th European Conference on Principles and Practice of Knowledge Discovery in Databases (2004)

We propose a novel methodology for clustering XML documents on the basis of their structural similarities. The idea is to equip each cluster with an XML cluster representative, i.e. an XML document subsuming the most typical structural specifics of a set of XML documents. Clustering is essentially accomplished by comparing cluster representatives, and updating the representatives as soon as new clusters are detected. We present an algorithm for the computation of an XML representative based on suitable techniques for identifying significant node matchings and for reliably merging and pruning XML trees. Experimental evaluation performed on both synthetic and real data shows the effectiveness of our approach.
FLUX: A logic programming method for reasoning agents
Authors: Michael Thielscher
Venue: Theory and Practice of Logic Programming (2005)

FLUX is a programming method for the design of agents that reason logically about their actions and sensor information in the presence of incomplete knowledge. The core of FLUX is a system of Constraint Handling Rules, which enables agents to maintain an internal model of their environment by which they control their own behavior. The general action representation formalism of the fluent calculus provides the formal semantics for the constraint solver. FLUX exhibits excellent computational behavior due to both a carefully restricted expressiveness and the inference paradigm of progression.
Clinical requirements engineering
Authors: Stephen Fickas
Venue: Proceedings of the 27th international conference on Software engineering (2005)

In this paper, I make a case for integration of requirements engineering (RE) with clinical disciplines. To back my case, I look at two examples that employ a clinical RE approach, first, that of introducing email into the life of a brain-injured individual, and second, introducing digital darkroom tools into my life. The former uses a Brownfield approach by starting with an existing clinical process, cognitive rehabilitation, and then defining an RE process that fits. The latter uses a Greenfield approach that postulates a new clinical RE process that focuses on the problems some of us have using digital darkroom tools.
XJ: facilitating XML processing in Java
Authors: Matthew Harren, Mukund Raghavachari, Oded Shmueli, Michael G. Burke, Rajesh Bordawekar, Igor Pechtchanski, Vivek Sarkar
Venue: Proceedings of the 14th international conference on World Wide Web (2005)

The increased importance of XML as a data representation format has led to several proposals for facilitating the development of applications that operate on XML data. These proposals range from runtime API-based interfaces to XML-based programming languages. The subject of this paper is XJ, a research language that proposes novel mechanisms for the integration of XML as a first-class construct into Java™. The design goals of XJ distinguish it from past work on integrating XML support into programming languages --- specifically, the XJ design adheres to the XML Schema and XPath standards. Moreover, it supports in-place updates of XML data thereby keeping with the imperative nature of Java. We have built a prototype compiler for XJ, and our preliminary experiments demonstrate that the performance of XJ programs can approach that of traditional low-level API-based interfaces, while providing a higher level of abstraction.