ppxscal/embedding_network huggingface dataset:
Middleware-based database replication: the gaps between theory and practice
Authors: Emmanuel Cecchet, George Candea, Anastasia Ailamaki
Venue: Proceedings of the 2008 ACM SIGMOD international conference on Management of data (2008)

The need for high availability and performance in data management systems has been fueling a long running interest in database replication from both academia and industry. However, academic groups often attack replication problems in isolation, overlooking the need for completeness in their solutions, while commercial teams take a holistic approach that often misses opportunities for fundamental innovation. This has created over time a gap between academic research and industrial practice. This paper aims to characterize the gap along three axes: performance, availability, and administration. We build on our own experience developing and deploying replication systems in commercial and academic settings, as well as on a large body of prior related work. We sift through representative examples from the last decade of open-source, academic, and commercial database replication systems and combine this material with case studies from real systems deployed at Fortune 500 customers. We propose two agendas, one for academic research and one for industrial R&D, which we believe can bridge the gap within 5-10 years. This way, we hope to both motivate and help researchers in making the theory and practice of middleware-based database replication more relevant to each other.
Handling data skew in parallel joins in shared-nothing systems
Authors: Yu Xu, Pekka Kostamaa, Xin Zhou, Liang Chen
Venue: Proceedings of the 2008 ACM SIGMOD international conference on Management of data (2008)

Parallel processing continues to be important in large data warehouses. The processing requirements continue to expand in multiple dimensions. These include greater volumes, increasing number of concurrent users, more complex queries, and more applications which define complex logical, semantic, and physical data models. Shared nothing parallel database management systems [16] can scale up "horizontally" by adding more nodes. Most parallel algorithms, however, do not take into account data skew. Data skew occurs naturally in many applications. A query processing skewed data not only slows down its response time, but generates hot nodes, which become a bottleneck throttling the overall system performance. Motivated by real business problems, we propose a new join geography called PRPD (Partial Redistribution & Partial Duplication) to improve the performance and scalability of parallel joins in the presence of data skew in a shared-nothing system. Our experimental results show that PRPD significantly speeds up query elapsed time in the presence of data skew. Our experience shows that eliminating system bottlenecks caused by data skew improves the throughput of the whole system which is important in parallel data warehouses that often run high concurrency workloads.
Supporting table partitioning by reference in oracle
Authors: George Eadon, Eugene Inseok Chong, Shrikanth Shankar, Ananth Raghavan, Jagannathan Srinivasan, Souripriya Das
Venue: Proceedings of the 2008 ACM SIGMOD international conference on Management of data (2008)

Partitioning is typically employed on large-scale data to improve manageability, availability, and performance. However, for tables connected by a referential constraint (capturing a parent-child relationship), the current approaches require individually partitioning each table thereby burdening the user with the task of maintaining the tables equi-partitioned, which not only is cumbersome but also error prone. This paper proposes a new partitioning method (partition by reference) that allows tables with a parent-child relationship to be logically equi-partitioned by inheriting the partition key from the parent table without duplicating the key columns. The partitioning key is resolved through an existing parent-child relationship, enforced by an active referential constraint. This logical dependency is used to automatically i) cascade partition maintenance operations performed on parent table to child tables, and ii) handle migration of child rows when partition key or parent key in parent table is updated, as a single atomic operation. This method has been introduced in Oracle Database 11gR1 with support for tables with both single level and composite partitioning methods. The paper describes the key concepts of table partitioning by reference method, discusses the design and implementation challenges, and presents an experimental study covering a usage scenario common in Information Life Cycle Management (ILM) applications.
Report on the First International Workshop on Mining Graphs and Complex Structures (MGCS'07)
Authors: Lawrence B. Holder, Xifeng Yan
Venue: ACM SIGMOD Record (2008)

The fast accumulation of graph data is witnessed in a wide range of scientific and commercial domains. Typical graph data include chemical compounds, circuits, biological networks, computer networks, 2D/3D models, XML, RDF and workflows. Graph is regarded as a critical data type for knowledge discovery in bioinformatics, chemical informatics, computer vision, informational retrieval, computer security, semantic web, social science, etc., just to name a few. Unfortunately, due to the lack of graph management and mining tools, it is hard, if not impossible, for users to search and analyze any reasonably large collection of graphs. There is an imminent need for scalable methods for mining and search in graphs and other complex structures.
Genome-Scale Simulation Analysis: The Impact of Gene Deletion on the Metabolic Flux of E.coli and Its Flux-backbone
Authors: Xu Zixiang, Xie Jianming, Yang Xinan, Sun Xiao
Venue: Proceedings of the 2008 International Conference on BioMedical Engineering and Informatics - Volume 01 (2008)

Based on the gene-protein-reaction (GPR) model of E.coli_iAF1260 and the method of constraint-based analysis, we first calculated the metabolic flux distribution of E.coli_iAF1260 and defined three types of key genes (genes related to many reactions, genes related to high flux reactions, genes related to the hubs of correlated reaction sets) which related to its metabolism. Then we analyzed the impact of key gene deletion on the metabolic flux redistribution of E.coli_iAF1260 and on its high-flux backbone (HFB). We find that the deletion of these key genes will greatly affect the metabolic flux distribution but will affect flux backbone trivially. Because the in silico model of E.coli_iAF1260 is tested by many experiments, thus is credible, we can conclude that the result we get has biological significances.
A Microconductometer Utilizing Bipolar Pulse Method for Electro-Chemical Sensors
Authors: L. Fujcik, R. Vrba, R. Prokop, J. Hubalek, P. Steffan, H. Hornochova
Venue: Proceedings of the Third International Conference on Systems (2008)

The microelectronic measuring system for conductivity electro-chemical sensor measurement of liquid materials properties was designed in AMIS CMOS 0.7 mm technology. The main parts of the system are current source with switchable subranges, the sensor switches allowing change of the current polarity in compliance with the bipolar pulse method, which was developed specially for this measurement purposes at the Dept. of Microelectronics. The most important part of the system is a sensor voltage drop measuring circuit using opamp’s offset switched compensation.
A study on computer usage among secondary school students: a comparative analysis on hours spent using computers without activities connecting to internet and hours spent doing internet activities respective to genders
Authors: Suriani Hassan, Fauziah Sulaiman, Darmesah Gabda, Nortazi Sanusi
Venue: Proceedings of the 12th WSEAS International Conference on Applied Mathematics (2007)

The aim of this paper is to investigate the computer usage among secondary school students in one of a secondary school in Malaysia according on hours spent using computers without activities connecting to internet and hours spent doing internet activities. Questionnaires were given to the students, and seventy secondary school students had participated. This study involves some normal activities such as to find out (i) the value and percentage of students who had computers and internet connections at homes, (ii) the venues of the students spent time using computers without activities connecting to internet, (iii) the venues of the students spent time doing internet activities. In addition, (iv) hours spent using computers without activities connecting to internet, and (v) hours spent doing internet activities are also studied. Besides that the gender analyses based on some basic activities that can be done with computer were also analyzed. This study utilized Descriptive Statistics and Independent t-Test for the analysis methods. As for the result although more than half of the students had computers in their homes, however only half from this figure had accessed to the Internet. Many of the students also liked to use the computer whether it was connected or not connected to the internet by going to the cyber café. In addition, the hours spent on using computer weekly by male and female students were also revealed, that in many basic activities, male students were more likely to spend their valuable hours significantly sitting in front of computers doing things compared to the female students.
High-Level Modeling of Software-Management Interactions and Tasks for Autonomic Computing
Authors: Edin Arnautovic, Hermann Kaindl, Jürgen Falb, Roman Popp
Venue: Proceedings of the Fourth International Conference on Autonomic and Autonomous Systems (2008)

For making software systems autonomic, it is important to understand and model software-management tasks. Each such task contains typically many interactions between the administrator and the software system.We propose to model software-management interactions and tasks in the form of a discourse between the administrator and the software system. Such discourse models are based on insights from theories of human communication. This should make them "natural" for humans to define and understand. While it may be obvious that such discourse models cover software-management interactions, we found that they may also represent major parts of the related tasks. Our well-defined models of interactions and tasks as well as their operationalization should facilitate their execution and automation.
Combining visual dictionary, kernel-based similarity and learning strategy for image category retrieval
Authors: Philippe Henri Gosselin, Matthieu Cord, Sylvie Philipp-Foliguet
Venue: Computer Vision and Image Understanding (2008)

This paper presents a search engine architecture, RETIN, aiming at retrieving complex categories in large image databases. For indexing, a scheme based on a two-step quantization process is presented to compute visual codebooks. The similarity between images is represented in a kernel framework. Such a similarity is combined with online learning strategies motivated by recent machine-learning developments such as active learning. Additionally, an offline supervised learning is embedded in the kernel framework, offering a real opportunity to learn semantic categories. Experiments with real scenario carried out from the Corel Photo database demonstrate the efficiency and the relevance of the RETIN strategy and its outstanding performances in comparison to up-to-date strategies.
A unified approach to BER analysis of synchronous downlink CDMA systems with random signature sequences in fading channels with known channel phase
Authors: M. Moinuddin, A. U. H. Sheikh, A. Zerguine, M. Deriche
Venue: EURASIP Journal on Advances in Signal Processing (2008)

A detailed analysis of the multiple access interference (MAI) for synchronous downlink CDMA systems is carried out for BPSK signals with random signature sequences in Nakagami-m fading environment with known channel phase. This analysis presents a unified approach as Nakagami-m fading is a general fading distribution that includes the Rayleigh, the one-sided Gaussian, the Nakagami-q, and the Rice distributions as special cases. Consequently, new explicit closed-form expressions for the probability density function (pdf) of MAI and MAI plus noise are derived for Nakagami-m, Rayleigh, one-sided Gaussian, Nakagami-q, and Rician fading. Moreover, optimum coherent reception using maximum likelihood (ML) criterion is investigated based on the derived statistics of MAI plus noise and expressions for probability of bit error are obtained for these fading environments. Furthermore, a standard Gaussian approximation (SGA) is also developed for these fading environments to compare the performance of optimum receivers. Finally, extensive simulation work is carried out and shows that the theoretical predictions are very well substantiated.
New results on dynamic planar point location
Authors: S. W. Cheng, R. Janardan
Venue: Proceedings of the 31st Annual Symposium on Foundations of Computer Science (1990)

A point location scheme is presented for an n-vertex dynamic planar subdivision whose underlying graph is only required to be connected. The scheme uses O(n) space and yields an O(log/sup 2/n) query time and an O(log n) update time. Insertion (respectively, deletion) of an arbitrary k-edge chain inside a region can be performed in O(k log(n+k)) (respectively, O(k log n)) time. The scheme is then extended to speed up the insertion/deletion of a k-edge monotone chain to O(log/sup 2/n log log n+k) time (or O(log n log log n+k) time for an alternative model of input), but at the expense of increasing the other time bounds slightly. All bounds are worst case. Additional results include a generalization to planar subdivisions consisting of algebraic segments of bounded degree and a persistent scheme for planar point location.
An effective edge-directed frequency filter for removal of aliasing in upsampled images
Authors: Artur Rataj
Venue: Machine Graphics Vision International Journal (2006)

Raster images can have a range of various distortions related to their raster structure. Their upsampling might in effect substantially reveal the raster structure of the original image, known as aliasing. The upsampling itself may introduce aliasing into the upsampled image as well. The presented method attempts to remove the aliasing using frequency filters based on discrete fast Fourier transform, and applied directionally in certain regions placed along the edges in the image. As opposed to some anisotropic smoothing methods, the presented algorithm aims to selectively reduce the aliasing only, preserving the sharpness of image details. The method can be used as a post processing filter along with various upsampling algorithms. It was experimentally shown that the method can improve the visual quality of the upsampled images.
Cryptanalysis of an Extension of the Hill Cipher
Authors: Indivar Gupta, Jasbir Singh, Roopika Chaudhary
Venue: Cryptologia (2007)

B. Thilaka and K. Rajalakshmi [2] propose extensions of Hill Cipher using affine transformation and polynomial transformation to make it more secure. In this article, we show that these extensions of Hill Cipher are prone to cryptanalytic attacks. We have proposed known plaintext attack for cryptanalizing ciphers based on the modified Hill Cipher system. We illustrate the method with the help of examples and show that the suggested modifications in Hill Cipher do not make it significantly stronger.
Software Architecture for Ground Control Station for Unmanned Aerial Vehicle
Authors: Mladjan Jovanovic, Dusan Starcevic
Venue: Proceedings of the Tenth International Conference on Computer Modeling and Simulation (2008)

UAV (Unmanned Aerial Vehicle) performs various kinds of missions such as mobile tactical reconnaissance, surveillance, law enforcement, search and rescue, land management, environmental monitoring, disaster management. UAV is a complex and challenging system to develop. It operates autonomously in unknown and dynamically changing environment. This requires different types of subsystems to cooperate. In order to realize all functionalities of the UAV, the software part becomes very complex real-time system expected to execute real-time tasks concurrently. This paper describes proposed software architecture for GCS (Ground Control Station) for lightweight UAV purpose-built for medium-scale reconnaissance and surveillance missions in civil area. The overall system architecture and implementation are described.
A heuristic fault tolerant control for nonlinear MIMO systems using neural networks
Authors: Jose Noriega
Venue: Proceedings of the 2nd WSEAS International Conference on Electronics, Control and Signal Processing (2003)

This paper describes a fault tolerant control algarithm based on a simple integrater and a neural network model for a multiple-input multiple-output (MIMO) nonlinear system. Two situations are considered. First, the system is working under normal operation parameters and the control vector is computed only by the minimisation of the performance index using the gradient descent rule. Second, assuming that a fault in any actuator gain will degrade the controller performance, a threshold is expected to detect the fault and initiate a fault compensation procedure.
An epistemic dynamic model for tagging systems
Authors: Klaas Dellschaft, Steffen Staab
Venue: Proceedings of the nineteenth ACM conference on Hypertext and hypermedia (2008)

In recent literature, several models were proposed for reproducing and understanding the tagging behavior of users. They all assume that the tagging behavior is influenced by the previous tag assignments of other users. But they are only partially successful in reproducing characteristic properties found in tag streams. We argue that this inadequacy of existing models results from their inability to include user's background knowledge into their model of tagging behavior. This paper presents a generative tagging model that integrates both components, the background knowledge and the influence of previous tag assignments. Our model successfully reproduces characteristic properties of tag streams. It even explains effects of the user interface on the tag stream.
Impact of polarization and incidence of the ASAR sensor on coastline mapping: example of Gabon
Authors: N. Baghdadi, R. Pedreros, N. Lenotre, T. Dewez, M. Paganini
Venue: International Journal of Remote Sensing (2007)

Coastline mapping is of great interest in many different applications. In this Letter, we analyse the effect of the polarization and the incidence angle of the new Advanced Synthetic Aperture Radar (ASAR) sensor on coastline detection. Results indicate a marked dependence of the incidence angle and polarization on the delimitation between land and sea. At low incidence angles (
On the regularity of maps
Authors: Gareth A. Jones, J. Mary Jones, Jürgen Wolfart
Venue: Journal of Combinatorial Theory Series B (2008)

We show that, whereas a finite map is regular if and only if its automorphism group and monodromy group are isomorphic as abstract groups, for infinite maps this condition is necessary but not sufficient, and we need the stronger condition that they should be isomorphic as permutation groups. We illustrate this with examples of maps based on Grigorchuk's group and the modular group.
Effective SAP SD, 1 edition
Authors: D. Rajen Iyer
Venue:  (2007)

- Understand and use SAP SD effectively and efficiently - Apply SAP SD to your own company?s business model and make it work for you. - A reference guide for the SAP SD professional - Learn all aspects of SD functionality and essential technical details SAP SD, the leading sales and distribution solution is a complex product that is often not fully understood. This book helps you fully leverage your SD implementation as it clarifies how SD works through explanations and practical examples. Understand how SD works from a functional and a technical perspective. Discover how SD integrates and interacts with other key SAP modules and understand how it relates to BadIs, BAPIs and IDocs. An in-depth, practical resource, this book is your one-stop resource for SAP SD. Highlights Include: - Master Data Applications - Key Techniques - Supply Chain Extension of SD - Financial and Controlling Interface - Reporting and Analytics - Special Order Processing - Data transfer, Notification, Interchange and Interface - E-Sales and Distribution - Enhancements, Upgrades, and Extension
A Unified Threat Model for Assessing Threat in Web Applications
Authors: Xiaohong Li, Ke He
Venue: Proceedings of the 2008 International Conference on Information Security and Assurance (isa 2008) (2008)

This paper presents a unified threat model for assessing threat in web applications. We extend the threat tree model with more semantic and context information about threat to form the new model which is used to analyze and evaluate threat in the software design stage. We utilize historical statistical information contained in this model to design threat mitigation schemes. The threat assessing results and mitigation schemes can be used to direct secure coding and testing. This makes it possible to design threat-resistant web applications by means of detecting and mitigating threat in the early software design stage.
Sorting out sorting: the sequel
Authors: David Furcy, Thomas Naps, Jason Wentworth
Venue: Proceedings of the 13th annual conference on Innovation and technology in computer science education (2008)

Ronald Baecker's Sorting Out Sorting (SOS) set the stage for much of what has followed in the evolution of algorithm visualization (AV). That period of evolution has now spanned over a quarter century, and we have learned much about how to effectively use AV. This paper addresses how we can incorporate that knowledge into a new rendition of SOS, which we call SOS - The Sequel. In this sequel we attempt to transform Baecker's original video into a highly interactive multimedia learning resource delivered over the Web using Macromedia Flash. The paper describes the design and use of this new resource and reports on a small empirical study designed to measure its effectiveness.
Dual-Channel Access Mechanism for Cost-Effective NoC Design
Authors: Shijun Lin, Li Su, Depeng Jin, Lieguang Zeng
Venue: Proceedings of the Second ACM/IEEE International Symposium on Networks-on-Chip (2008)

In this paper, we propose dual-channel access mechanism to design cost-effective NoC based on 2D-mesh topology. Compared with traditional single-channel access mechanism, our scheme greatly increases the throughput and cuts down the average latency with reasonable implementation cost, especially when the traffic load is high.
Fast matching algorithms for points on a polygon
Authors: O. Marcotte
Venue: Proceedings of the 30th Annual Symposium on Foundations of Computer Science (1989)

The complete graph induced by a set of 2n points on the boundary of a polygon is considered. The edges are assigned weights equal to the Euclidean distance between their endpoints if the endpoints see each other in the polygon, and + infinity otherwise. An O(n log n)-time algorithm is obtained for finding a minimum-weight perfect matching in this graph if the polygon is convex, and an O(n log/sup 2/n)-time algorithm if the polygon is simple but nonconvex. The assignment problem for a convex polygon is solved in time O(n log n), and O(n alpha (n)) and O(n alpha (n) log n) time bounds are obtained for the verification problem on convex and nonconvex polygons, respectively, where alpha (n) is the functional inverse of the Ackermann function.