ppxscal/embedding_network huggingface dataset:
Checking Emptiness of Non-Deterministic Regular Types with Set Operators
Authors: Lunjin Lu
Venue: Electronic Notes in Theoretical Computer Science (ENTCS) (2008)

An algorithm to decide the emptiness of a regular type expression with set operators given a set of parameterized type definitions is presented. The algorithm generalizes previous work in that tuple distributivity is not assumed and set operators are permitted in type expressions.
ITSSIP: Interval-parameter two-stage stochastic semi-infinite programming for environmental management under uncertainty
Authors: P. Guo, G. H. Huang, L. He, B. W. Sun
Venue: Environmental Modelling Software (2008)

In this study, an interval-parameter two-stage stochastic semi-infinite programming (ITSSIP) method is developed for municipal solid waste (MSW) management under uncertainty. In order to better account for uncertainties, the uncertainties are expressed with discrete intervals, functional intervals and probability distributions. The ITSSIP method integrates the two-stage stochastic programming (TSP), interval programming (IP), chance-constrained programming (CCP) and semi-infinite programming (SIP) within a general optimization framework. ITSSIP has infinite constraint because it uses functional intervals with time (s) being an independent variable. At the same time, ITSSIP also presents probability distribution information. The ITSSIP method can incorporate pre-regulated MSW management policies directly into its optimization process to analyze various policy scenarios having different economic penalties when the promised amounts are not delivered. The model is applied to a MSW management system with three waste treatment facilities, three cities and three periods. As an extension of mathematical programming methods, the developed ITSSIP approach has advantages in uncertainty reflection and policy analysis. Firstly, ITSSIP can help generate optimal solutions for decision variables under different levels of waste-generation rate and different levels of constraint-violation probability, which are informative for decision makers; secondly, it has the capability in addressing the parameter's dynamic feature, i.e., variations of the parameters with time; this could hardly be reflected in the previous methods. The obtained solutions are useful for decision makers to obtain insight regarding the tradeoffs between environmental, economic and system-reliability criteria.
Modelling of atmospheric impairments in stratospheric communications
Authors: Gorazd Kandus, Mihael Mohorčič, Erich Leitgeb, Tomaž Javornik
Venue: Proceedings of the 2nd WSEAS International Conference on Circuits, Systems, Signal and Telecommunications (2008)

Stratospheric communication systems operating in the millimetre frequency bands are subject to atmospheric impairments caused by rain and scintillation. In this paper we address propagation channel modelling of these atmospheric impairments. In particular, we present a rain fading and a scintillation fading channel model for stratospheric communications. Rain fading is modelled according to the modified DLR segment approach for generating channel attenuation time series taking into consideration the specifics of stratospheric communication systems, namely the variable elevation angle and different carrier frequency. Additional fading due to scintillation, which may be harmful in deep fades caused by the rain, is modelled by adjusting the satellite scintillation channel model so that the amount of scintillation fading is correlated to the attenuation caused by the rain. The two models were implemented in a software tool enabling generation of the propagation channel attenuation time series for the fixed and the mobile stratospheric communication systems.
Short-Term MPEG-4 AVC Bandwidth Prediction for Broadband Cable Networks
Authors: Laetitia Lanfranchi, Benny Bing
Venue: Proceedings of the Communication Networks and Services Research Conference (2008)

In this paper, we propose and evaluate the accuracy of a new traffic model that predicts, in the short term, the size of the B-frames of MPEG-4 AVC compressed video. To quantify the prediction accuracy, a model for the prediction error is also proposed. In a broadband cable network, the prediction model can be employed by a cable headend to provision video bandwidth efficiently or more importantly, reduce bit rate variability and bandwidth requirements via selective B-frame dropping, thereby minimizing buffering requirements and packet losses at the set top box. It will be shown that the model provides highly accurate prediction for a wide variety of video types, in particular, high action and regular movies encoded in high quality resolution. This is an important benefit since high motion MPEG videos demand the highest bandwidth and generate the widest range of bit rate requirements. Although the prediction model is very simple to implement, this paper also proposes two methods to simplify its operation further without sacrificing prediction accuracy.
A Comparison of Cluster and Grid Configurations Executing Image Processing Tasks in a Local Network
Authors: Giorgia de Oliveira Mattos, Rafael Dueire Lins, Andrei de Araújo Formiga, Francisco Heron de Carvalho Jr.
Venue: Proceedings of the Seventh International Conference on Networking (2008)

The use of clusters and grids for high-performance applications has become widespread lately. In general, one associates clusters with dedicated LANs and grids with WANs and internets. This paper reports the results of a comparative analysis between cluster and grid performance when executing a load-balanced, image processing application in a local-area network. The results obtained show almost no difference in total execution times, indicating that grid software may be used advantageously in LANs to run similar load-balanced applications.
A discriminative framework for clustering via similarity functions
Authors: Maria-Florina Balcan, Avrim Blum, Santosh Vempala
Venue: Proceedings of the 40th annual ACM symposium on Theory of computing (2008)

Problems of clustering data from pairwise similarity information are ubiquitous in Computer Science. Theoretical treatments typically view the similarity information as ground-truth and then design algorithms to (approximately) optimize various graph-based objective functions. However, in most applications, this similarity information is merely based on some heuristic; the ground truth is really the unknown correct clustering of the data points and the real goal is to achieve low error on the data. In this work, we develop a theoretical approach to clustering from this perspective. In particular, motivated by recent work in learning theory that asks "what natural properties of a similarity (or kernel) function are sufficient to be able to learn well?" we ask "what natural properties of a similarity function are sufficient to be able to cluster well?" To study this question we develop a theoretical framework that can be viewed as an analog of the PAC learning model for clustering, where the object of study, rather than being a concept class, is a class of (concept, similarity function) pairs, or equivalently, a property the similarity function should satisfy with respect to the ground truth clustering. We then analyze both algorithmic and information theoretic issues in our model. While quite strong properties are needed if the goal is to produce a single approximately-correct clustering, we find that a number of reasonable properties are sufficient under two natural relaxations: (a) list clustering: analogous to the notion of list-decoding, the algorithm can produce a small list of clusterings (which a user can select from) and (b) hierarchical clustering: the algorithm's goal is to produce a hierarchy such that desired clustering is some pruning of this tree (which a user could navigate). We develop a notion of the clustering complexity of a given property (analogous to notions of capacity in learning theory), that characterizes its information-theoretic usefulness for clustering. We analyze this quantity for several natural game-theoretic and learning-theoretic properties, as well as design new efficient algorithms that are able to take advantage of them. Our algorithms for hierarchical clustering combine recent learning-theoretic approaches with linkage-style methods. We also show how our algorithms can be extended to the inductive case, i.e., by using just a constant-sized sample, as in property testing. The analysis here uses regularity-type results of [FK] and [AFKK].
Senescence-Associated β-Galactosidase as a Senescence Biomarker Showed in Rat Hippocampus
Authors: Y. Q. Geng, J. T. Guan, B. H. Wang, X. H. Xu, Y. C. Fu
Venue: Proceedings of the 2008 International Conference on BioMedical Engineering and Informatics - Volume 01 (2008)

Objective: To investigated the activity of SA-β-GAL in rat hippocampus at different ages. Method: Hippocampus of 6, 18 and 24 month-age rats were observed by histochemical staining for SA-β-GAL and cytochemical staining for SA-β-GAL on prolong cultured hippocampal neurons. Results: SA-β-GAL activity elevated in hippocampal pyramidal cells of CA3 region with advanced age. The upregulated SA-β-GAL activity was accompanied by an increase prolong period of cultured hippocampal neurons. Interestingly, the staining of SA-β-GAL was strikingly low in dentate gyrus, where the granules cells neurogenesis of rat from 6 to 18 and 24 month-age. Conclusion: These results suggested that SA-β-GAL showed the senescent neurons in hippocampus, moreover, SA-β-GAL is probably a potential tool to detect the neurogenesis pool in adult brain.
Formal verification of concurrent scheduling strategies using TLA
Authors: Gudmund Grov, Greg Michaelson, Andrew Ireland
Venue: Proceedings of the 13th International Conference on Parallel and Distributed Systems - Volume 02 (2007)

There is a high demand for correctness for safety critical systems, often requiring the use of formal verification. Simple, well-understood scheduling strategies ease verification but are often very inefficient. In contrast, efficient concurrent schedulers are often complex and hard to reason about. This paper shows how the Temporal Logic of Action (TLA) can be used to formally reason about a wellunderstood scheduling strategy in the process of implementening a more efficient one. This is achieved by formally verifying that the efficient strategy preserves all properties, in particular the behaviour, of the simpler strategy. The approach is illustrated with the Hume programming language, which is based on concurrent rich automata. We introduce an efficient extension to the Hume scheduler, and prove that it preserves the behaviour of the standard Hume scheduler.
Architecture leadership and management in globally distributed software development
Authors: Raghvinder S. Sangwan, Johannes Ros
Venue: Proceedings of the first international workshop on Leadership and management in software architecture (2008)

Globally distributed software development is inherently difficult. The fundamental problem is that communication, coordination and control mechanisms that operate so naturally and invisibly in co-located projects are not available or not as effective for distributed teams. Maintaining a shared up-to-date understanding of the system under design among distributed teams separated by physical, temporal, and cultural distances, therefore, becomes challenging. Under such circumstances the role of a project architect takes on an added significance. The architect must bridge the gaps that exist among the distributed teams especially those with interrelated tasks. Bridging gaps across teams requires proactive effort to create, among distributed teams, a shared level of understanding of the system context, its problem domain and an overarching vision of the system to be designed. We call this a shared project context. Establishing a shared project context goes a long way in creating architectural artifacts, understanding dependencies across software elements of the architecture and the allocation of their development to the distributed teams. Lack of such a context leads to the creation of multiple realities promoting ignorance, confusion and frustration, which subsequently undermine mutual trust and make inter-team communications less effective. This vicious cycle leads to dysfunctional teams, inefficiencies in the project and ultimately to poorly designed architectures.
Computing difference-differential dimension polynomials by relative Gröbner bases in difference-differential modules
Authors: Meng Zhou, Franz Winkler
Venue: Journal of Symbolic Computation (2008)

In this paper we present a new algorithmic approach for computing the Hilbert function of a finitely generated difference-differential module equipped with the natural double filtration. The approach is based on a method of special Grobner bases with respect to ''generalized term orders'' on N^mxZ^n and on difference-differential modules. We define a special type of reduction for two generalized term orders in a free left module over a ring of difference-differential operators. Then the concept of relative Grobner bases w.r.t. two generalized term orders is defined. An algorithm for constructing these relative Grobner bases is presented and verified. Using relative Grobner bases, we are able to compute difference-differential dimension polynomials in two variables.
Transmission power loss impacts on the oligopoly competitive electricity market
Authors: Yuchao Ma, Chuanwen Jiang, Zhijian Hou
Venue: Proceedings of the 9th International Conference on Circuits (2005)

Until now, the transmission power loss is disregarded in most literature that focuses on the gaming behaviors of the producers in the electricity market. This paper proposed supply function game model considering the power flow loss of the transmission network. The model is composed of the upper-level optimization problem of the producer's surplus for generation firms and the lower-level optimization of the market system surplus. Since the two-level optimization model is termed as Mathematical Programming with Equilibrium Constraints, (MPEC) problem, the penalty factor approach is used to solve the MPEC. The simulation results find that, not only in the perfect competition market but also in the supply function equilibrium based oligopoly market, the power flow loss impacts from the electricity network will drive the total transactions and the market efficiency decreased in relatively large extent with respect to the power flow loss disregarded model.
Research of Information Technology Security in the Financial Industry
Authors: Bin Xia, Hui Bai, Bin Pan
Venue: Proceedings of the First International Workshop on Knowledge Discovery and Data Mining (2008)

After describing the security condition of the information technology in financial industries, this paper systematically summarizes its basic influence elements on basis of introducing the concept of information technology risks in financial industries, and analyzes relationship of information technology risk factors. Finally, in view of these existence risk factors, guidelines for managing information technology risks in financial industries have been proposed.
An Access Control Model for Web-Services That Supports Delegation and Creation of Authority
Authors: Mitsuhiro Mabuchi, Yasushi Shinjo, Akira Sato, Kazuhiko Kato
Venue: Proceedings of the Seventh International Conference on Networking (2008)

We present a new access control model for XML Web-Services that provides users with two kinds of authorities: the authority to delegate their authorities to other users and the authority to create new authorities based on their own authorities. We developed this model by introducing capability-based access control to Web services. A capability consists of an object identifier and the list of permitted operations for that object. We map an authority of a Web-Services object to a capability of the object and express the capability as a description in Web Services Description Language (WSDL). Delegation of an authority corresponds to distribution of a capability, which is done by passing a WSDL description. Creation of a new authority corresponds to generating a restricted capability based on an original capability, which is done by stacking an object on an original object. Stacking objects also makes it possible to add new functions to existing Web-Services objects without modifying the existing objects. We demonstrate the effectiveness of the proposed model using a schedule management application, which enables a project leader to delegate his or her tasks to subordinates by comparing it with Google Calendar. We also show that the execution times of stackable objects are acceptable by comparing them with typical Internet delay.
Efficient Synchronization in Message Passing Systems
Authors: Gurdip Singh, Ye Su
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications (2008)

The problem of synchronization can be formulated in terms of rules constraining the occupancy of regions in different processes, where a region is a block of code whose execution may require synchronization. In this region synchronization problem, the region occupancy rules (or the synchronization policy) can be specified using a global invariant. The task of a region synchronization algorithm is to constrain the region entry and exit of processes in a manner that satisfies the global invariant. This paper proposes efficient algorithms for region synchronization in message passing systems. In particular, we propose extensions of two existing mutual exclusion algorithms to solve the region synchronization problem. We show that our algorithms are message efficient and satisfy the property of absence of unnecessary synchronization. We show that many existing synchronization problems such asgroup mutual exclusion, readers/writers, committee coordination, and barrier can be specified as instances of the region synchronization problem, and hence our algorithms can be used to solve a large class of problems.
Bantam: a customizable, java-based, classroom compiler
Authors: Marc L. Corliss, E. Christopher Lewis
Venue: Proceedings of the 39th SIGCSE technical symposium on Computer science education (2008)

This paper introduces the Bantam Java compiler project, a new language and compiler designed specifically for the classroom Bantam Java, the source programming language, is a small subset of the Java language, which is a commonly-used language in introductory programming courses. Because Bantam Java is similar to Java, it leverages the student's existing intuition and the student can automatically apply what they learn in the course directly to Java. The Bantam Java project is also customizable (it supports several tools and targets), which gives instructors flexibility in designing course assignments. Finally, the Bantam Java compiler project includes a free, comprehensive, student manual which can be used in conjunction with any compiler textbook.
Multi-sensor image registration based on intensity and edge orientation information
Authors: Yong Sun Kim, Jae Hak Lee, Jong Beom Ra
Venue: Pattern Recognition (2008)

This paper presents a method for registering multi-sensor images such as visible and infrared images. Registration is achieved by iteratively minimizing an objective function through updating transformation parameters of deformation. A new entropy-based objective function is proposed on the basis of a 3-D joint histogram incorporating intensity information and edge orientation information. To complement the entropy-based objective function, a weighting function is also introduced through the use of a coincidence measure of edge orientations. Experimental results show that the proposed method provides more robust registration results than the existing approaches.
Divide, Compress and Conquer: Querying XML via Partitioned Path-Based Compressed Data Blocks
Authors: Wilfred Ng, Ho-Lam Lau, Aoying Zhou
Venue: World Wide Web (2008)

We propose a novel partition path-based (PPB) grouping strategy to store compressed XML data in a stream of blocks. In addition, we employ a minimal indexing scheme called block statistic signature (BSS) on the compressed data, which is a simple but effective technique to support evaluation of selection and aggregate XPath queries of the compressed data. We present a formal analysis and empirical study of these techniques. The BSS indexing is first extended into effective cluster statistic signature (CSS) and multiple-cluster statistic signature (MSS) indexing by establishing more layers of indexes. We analyze how the response time is affected by various parameters involved in our compression strategy such as the data stream block size, the number of cluster layers, and the query selectivity. We also gain further insight about the compression and querying performance by studying the optimal block size in a stream, which leads to the minimum processing cost for queries. The cost model analysis provides a solid foundation for predicting the querying performance. Finally, we demonstrate that our PPB grouping and indexing strategies are not only efficient enough to support path-based selection and aggregate queries of the compressed XML data, but they also require relatively low computation time and storage space when compared with other state-of-the-art compression strategies.
Practical weak-atomicity semantics for java stm
Authors: Vijay Menon, Steven Balensiefer, Tatiana Shpeisman, Ali-Reza Adl-Tabatabai, Richard L. Hudson, Bratin Saha, Adam Welc
Venue: Proceedings of the twentieth annual symposium on Parallelism in algorithms and architectures (2008)

As memory transactions have been proposed as a language-level replacement for locks, there is growing need for well-defined semantics. In contrast to database transactions, transaction memory (TM) semantics are complicated by the fact that programs may access the same memory locations both inside and outside transactions. Strongly atomic semantics, where non transactional accesses are treated as implicit single-operation transactions, remain difficult to provide without specialized hardware support or significant performance overhead. As an alternative, many in the community have informally proposed that a single global lock semantics [18,10], where transaction semantics are mapped to those of regions protected by a single global lock, provide an intuitive and efficiently implementable model for programmers. In this paper, we explore the implementation and performance implications of single global lock semantics in a weakly atomic STM from the perspective of Java, and we discuss why even recent STM implementations fall short of these semantics. We describe a new weakly atomic Java STM implementation that provides single global lock semantics while permitting concurrent execution, but we show that this comes at a significant performance cost. We also propose and implement various alternative semantics that loosen single lock requirements while still providing strong guarantees. We compare our new implementations to previous ones, including a strongly atomic STM.[24]
Software pre-patterns as architectural knowledge
Authors: Gerald Bortis, André van der Hoek
Venue: Proceedings of the 3rd international workshop on Sharing and reusing architectural knowledge (2008)

Christopher Alexander's introduction of patterns inspired their application in fields such as software engineering. However, their current realization deviates from his original intent in how and when they are used. In this paper, we contrast Alexander's concept of patterns to their current realization in software engineering and suggest a new approach to creating patterns which are broader and can be applied at the early phases of the design process, and thus adhere to Alexander's original intent as a format for capturing and sharing important design knowledge.