ppxscal/embedding_network huggingface dataset:
Space Searching For Intersecting Objects
Authors: D. P. Dobkin
Venue: Proceedings of the 25th Annual Symposium onFoundations of Computer Science, 1984 (1984)

Determining or counting geometric objects that intersect another geometric query object is at the core of algorithmic problems in a number of applied areas of computer science. This article presents a family of space-efficient data structures that realize sublinear query time for points, line segments, lines and polygons in the plane, and points, line segments, plaraes, and polyhedra in three dimensions.
Keep Passwords Away from Memory: Password Caching and Verification Using TPM
Authors: Hua Wang, Yao Guo, Xia Zhao, Xiangqun Chen
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications (2008)

TPM is able to provide strong secure storage for sensitive data such as passwords. Although several commercial password managers have used TPM to cache passwords, they are not capable of protecting passwords during verification. This paper proposes a new TPM-based password caching and verification method called PwdCaVe. In addition to using TPM in password caching, PwdCaVe also uses TPM during password verification. In PwdCaVe, all password-related computations are performed in the TPM. PwdCaVe guarantees that once a password is cached in the TPM, it will be protected by the TPM through the rest of its lifetime, thus eliminating the possibility that passwords might be attacked in memory. A prototype of PwdCaVe is implemented on Linux to demonstrate its feasibility.
Orthorectified image mosaic of Antarctica from 1963 Argon satellite photography: image processing and glaciological applications
Authors: K. Kim, K. C. Jezek, H. Liu
Venue: International Journal of Remote Sensing (2007)

Using the state-of-the-art digital imaging technology, extended block adjustment, orthorectification and mosaicking, individual Declassified Intelligence Satellite Argon photographic images are precisely assembled into a map quality mosaic of coastal Antarctica. The geometric accuracy of the mosaic is estimated to be approximately equivalent to the original resolution of the Argon photography, which is about 140 m. We compare the Argon mosaic with later satellite images to investigate changes in ice sheet geographic features and dynamical glaciological processes.
Policy Mapper: Administering Location-Based Access-Control Policies
Authors: Rafae Bhatti, Maria Luisa Damiani, David W. Bettis, Elisa Bertino
Venue: IEEE Internet Computing (2008)

Simplifying the administration of location-based access-control policies requires a mechanism that supports both intuitive and scalable spatial constraint specifications and a flexible enforcement architecture. Policy Mapper is an administrative tool that helps define access control at conceptual and logical levels to carry out constraint specification and enforcement. The tool also provides an Interface Definition Language that couples the two levels. Policy Mapper bridges a critical gap between the expressiveness and enforcement of spatial constraints in location-based access-control policies.
DESIGN OF DECISION TREE VIA KERNELIZED HIERARCHICAL CLUSTERING FOR MULTICLASS SUPPORT VECTOR MACHINES
Authors: Zhao Lu, Feng Lin, Hao Ying
Venue: Cybernetics and Systems (2007)

As a very effective method for universal purpose pattern recognition, support vector machine (SVM) was proposed for dichotomic classification problem, which exhibits a remarkable resistance to overfitting, a feature explained by the fact that it directly implements the principle of structural risk minimization. However, in real world, most of classification problems consist of multiple categories. In an attempt to extend the binary SVM classifier for multiclass classification, decision-tree-based multiclass SVM was proposed recently, in which the structure of decision tree plays an important role in minimizing the classification error. The present study aims at developing a systematic way for the design of decision tree for multiclass SVM. Kernel-induced distance function between datasets was discussed and then kernelized hierarchical clustering was developed and used in determining the structure of decision tree. Further, simulation results on satellite image interpretation show the superiority of the proposed classification strategy over the conventional multiclass SVM algorithms.
Greenness trends of Arctic tundra vegetation in the 1990s: comparison of two NDVI data sets from NOAA AVHRR systems
Authors: D. Stow, A. Petersen, A. Hope, R. Engstrom, L. Coulter
Venue: International Journal of Remote Sensing (2007)

The primary objective of this study was to compare the sensitivity of two different normalized difference vegetation index (NDVI) time series derived from Local Area Coverage (LAC) and Global Areal Coverage (GAC) data sets of the National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) satellite system. This comparison was conducted in the context of analysing spatiotemporal patterns of Arctic tundra vegetation greenness change in the 1990s within the North Slope of Alaska. A second objective was to examine patterns of greenness change with respect to the distribution of vegetation association types. An 8 km spatial resolution NDVI series was produced by the Global Inventory Modeling and Mapping Studies (GIMMS) group at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center based on a GAC data set and corrected for stratospheric aerosol effects from the eruption of Mt Pinatubo. The LAC (1 km spatial resolution) NDVI time series was generated through recalibration and fine-tuning of image registration of a twice-monthly time series produced by the US Geological Survey, and was cross-calibrated with the GIMMS data set to reduce stratospheric aerosol effects from the Mt Pinatubo eruption. While the general patterns of pixels exhibiting significant increase in seasonally integrated NDVI over the 1990s were similar from both data sets, many of the more localized areas of more rapidly increasing greenness (i.e. 'hotspots') between 1990 and 1999 were lost with the product from the GIMMS data set. The majority of the 'hotspots' of greenness increase within the North Slope region are located in the southern portions of the foothills physiographic province and within vegetation units composed primarily of prostrate or dwarf shrubs with a mixture of graminoid species. Notably fewer hotspots of greenness increase were detected in Arctic tundra areas of the Seward Peninsula and none in the Chukotka Peninsula of the Russian Far East, an area that had not experienced the same warming trend in the 1990s and preceding decades as the Alaskan Arctic.
Fast and lean self-stabilizing asynchronous protocols
Authors: G. Itkis, L. Levin
Venue: Proceedings of the 35th Annual Symposium on Foundations of Computer Science (1994)

We consider asynchronous general topology dynamic networks of identical nameless nodes with worst-case transient faults. Starting from any faulty configuration, our protocols self-stabilize any computation in time polynomial in the (unknown) network diameter. This version sacrifices some diversity of tasks and efficiency for simplicity and clarity of details. Appendix gives more efficient procedures in less detail.
Events and Sightings
Authors: Chigusa Kita, Thomas J. Misa, William Aspray, David Walden Robert M. Price
Venue: IEEE Annals of the History of Computing (2008)

Conference—History of Nordic Computing; IT History Society; Norsk Data—40th-anniversary celebrations; Control Data's 50th anniversary; Obituary—Tadahiro Sekimoto
A socio-cognitive framework for designing interactive IR systems: Lessons from the Neanderthals
Authors: Charles Cole
Venue: Information Processing and Management: an International Journal (2008)

The article analyzes user-IR system interaction from the broad, socio-cognitive perspective of lessons we can learn about human brain evolution when we compare the Neanderthal brain to the human brain before and after a small human brain mutation is hypothesized to have occurred 35,000-75,000 years ago. The enhanced working memory mutation enabled modern humans (i) to decode unfamiliar environmental stimuli with greater focusing power on adaptive solutions to environmental changes and problems, and (ii) to encode environmental stimuli in more efficient, generative knowledge structures. A sociological theory of these evolving, more efficient encoding knowledge structures is given. These new knowledge structures instilled in humans not only the ability to adapt to and survive novelty and/or changing conditions in the environment, but they also instilled an imperative to do so. Present day IR systems ignore the encoding imperative in their design framework. To correct for this lacuna, we propose the evolutionary-based socio-cognitive framework model for designing interactive IR systems. A case study is given to illustrate the functioning of the model.
Estimation of trustworthiness for P2P systems in a collusive attack
Authors: Fumiaki Sato
Venue: International Journal of Web and Grid Services (2008)

In Peer-to-Peer (P2P) systems, it is an important problem to evaluate the trustworthiness of the peer for safe communications. In many existing methods, the trustworthiness is computed based on the reputation feedback of the peer. Especially, the method using the maximum likelihood estimation can compute a stochastic estimation value from comparatively little feedback information. Moreover, even if a lie is included in the feedback, the trustworthiness is calculated with an acceptable accuracy. However, this method does not have enough strength in a collusive attack. This paper proposes a new estimation method in consideration of a collusive rate of the peer. Moreover, it proposes an algorithm which calculates trustworthiness by proposing the method of presuming a collusive rate from the similarity of the feedback of each peer. This method was evaluated by the simulation. As a result, trustworthiness was presumed at a higher accuracy when there was a collusive attack.
General Shape Generation by Contouring Fractals and Applying Linear Boundary Regression
Authors: Carsten Oertel, Peter Bock
Venue: Proceedings of the 36th Applied Imagery Pattern Recognition Workshop (2007)

The ALISA Component Module (ACM) has been developed as a general-purpose shape classifier for objects in Digital Transmissive Images (DTIs). The Component Module classifies contoured DTIs intended to reveal the internal structures of objects and to facilitate feature extraction. The ACM is trained with exemplars of regions-of-interest (ROIs) representing object components. While the ACM has demonstrated robust classification performance for a few application domains, its performance as a general shape classifier remains to be determined. Therefore, a set of general shapes is needed to measure the ACM's performance as a general shape classifier. This paper presents a novel approach to generating such a set of shapes by contouring randomly generated fractal images and selecting subsets of contours analogous to ROIs of objects in DTIs. Linear boundary regression (LBR) is postulated as a post-process to accommodate the generation of contoured ROIs more closely resembling contours of human-made objects in DTIs.
Challenges on the road to exascale computing
Authors: Tilak Agerwala
Venue: Proceedings of the 22nd annual international conference on Supercomputing (2008)

Supercomputing systems have made great strides in recent years as the extensive computing needs of cutting-edge engineering work and scientific discovery have driven the development of more powerful systems. The first teraflop computer, ASCI Red, came on the scene in late 1996, and now a machine must achieve 5.9 teraflops to gain entry to the very bottom of the Top500 supercomputing list. With the emergence of petascale supercomputers expected in 2008 or 2009, we have set our sights on the increased capacity and expected muscle of exascale computing. This has also been the focus of organizations such as the Institute for Advanced Architectures jointly launched at Sandia and Oak Ridge National Laboratories. However, the challenges of exascale computing will not be solved by the technologies of today. If today's most power and energy efficient supercomputer was linearly scaled to the exascale level, it would consume around 200MWatts of power, contain over 60 million cores, and require over 400M dollars of memory. Such a system will present significant problems in management and programmability as current bounds of parallelism are tested. Data accessibility will also be a significant issue as our ability to sense, generate and calculate on data is growing faster than our ability to access, manage and even "store" that data. These problems only get worse as the systems computational power scales up. In this talk, I will discuss exascale computing challenges to be overcome in the areas of power, architecture, programmability, management, and data accessibility.
Automatic DC operating point computation and design plan generation for analog IPs
Authors: Ramy Iskander, Marie-Minerve Louërat, Andreas Kaiser
Venue: Analog Integrated Circuits and Signal Processing (2008)

DC operating point computation is inescapable for both knowledge-based and simulation-based analog synthesis. In this perspective, this article presents the automatic computation of DC operating point and the¿generation of suitable design plans for analog IPs. The analog IP is built as a hierarchy of subcircuits inside our dedicated framework CAIRO+. Leaf subcircuits are known as devices and higher-level subcircuits are known as modules. Each subcircuit is represented by a dependency graph. The¿dependency graph expresses electrical dependencies of circuit parameters on a selected set of design parameters. The dependency graph of the analog IP is constructed, in a hierarchical bottom-up approach, by merging graphs of children devices and modules. The graph is converted to a directed acyclic graph (DAG) by detecting and removing existing directed cycles. The resulting DAG is the design plan for the analog IP. Upon construction, the DAG is executed, in a top-down approach, to compute the DC operating point and the dimensions of the transistors. The computed DC operating point is compared to a DC simulation to ensure its correctness. The proposed methodology has been successfully applied to size and bias two analog IPs: a single-ended two-stage operational amplifier and a␣differential cascode current-mode integrator. The results prove the efficiency and accuracy of the proposed methodology.
Generating random spanning trees
Authors: A. Broder
Venue: Proceedings of the 30th Annual Symposium on Foundations of Computer Science (1989)

The author describes a probabilistic algorithm that, given a connected, undirected graph G with n vertices, produces a spanning tree of G chosen uniformly at random among the spanning trees of G. The expected running time is O(n log n) per generated tree for almost all graphs, and O(n/sup 3/) for the worst graphs. Previously known deterministic algorithms are much more complicated and require O(n/sup 3/) time per generated tree. A Markov chain is called rapidly mixing if it gets close to the limit distribution in time polynomial in the log of the number of states. Starting from the analysis of the above algorithm, it is shown that the Markov chain on the space of all spanning trees of a given graph where the basic step is an edge swap is rapidly mixing.
Global cloud top height and thermodynamic phase distributions as obtained by SCIAMACHY on ENVISAT
Authors: A. A. Kokhanovsky, M. Vountas, V. V. Rozanov, W. Lotz, H. Bovensmann, J. P. Burrows
Venue: International Journal of Remote Sensing (2007)

Global cloud top height spatial distribution as obtained using highly spectrally resolved (≈0.42 nm) SCIAMACHY on ENVISAT measurements in the oxygen A-band is presented. Also the global cloud phase index map is given. The results were derived using semi-analytical cloud retrieval algorithms developed by the authors specifically for SCIAMACHY cloud retrievals. The algorithm is applicable for clouds having an optical thickness larger than 5. Therefore, only thick cloud fields were selected for this study. We found that the global average cloud top height is close to 6 km and the most frequent value of the phase index is close to 0.8.
Some new results on the algebraic characterizations of an equality constrained optimization problem equivalent to the transportation problem
Authors: Süleyman safak, Mustafa özel, Hamza Bulut, S. Aysun Bulut
Venue: International Journal of Computer Mathematics (2007)

An equality constrained optimization problem equivalent to the transportation problem with m sources and n destinations is described. The optimality condition and some algebraic characterizations of the problem are investigated using its Hessian matrix. In addition, several algebraic characterizations of an equivalent case of the transportation problem are given using the spectral decomposition and generalized inverses of its coefficient matrix. It is shown that the transportation problem and its equivalent case have common algebraic characterizations.
The nonholonomic redundancy of second-order nonholonomic mechanical systems
Authors: Guang-Ping He, Zhi-Yong Geng
Venue: Robotics and Autonomous Systems (2008)

The nonholonomic redundancy of second-order nonholonomic mechanical systems is investigated. It has been verified that the self-motion can be implemented demonstrably by some nonholonomic mechanical systems such as the underactuated redundant manipulators. An exponentially stabilization control method is proposed for a class of underactuated manipulators, of which the number of actuated joints is no less than that of the passive joints. It has been shown that this class of underactuated manipulators are completely controllable when the dynamic coupling of the underactuated manipulators is non-degenerated and the up-boundary of the inputs is large enough. By the proposed control method, we exhibit this class manipulators with zero weight can realize the ''self-motion'' as a full-actuated redundant one. As a typical application, the problem of path tracking with suppressing vibration is investigated for the underactuated redundant manipulators. It is revealed that the vibration of the underactuated redundant manipulator can be converted into an internal resonance that is compatible with the ''self-motion'', while it leads to no vibration at the end-effector of the manipulator. Some numerical simulations by a planar four-DOF underactuated manipulator with two actuated joints and two passive joints show the effectiveness of the accurate trajectory control method and the value of the self-motion compatible internal resonance.
Using web2.0 Software and Mobile Devices for Creating Shared Understanding among Virtual Learning Communities
Authors: Jari Laru, Sanna Järvelä
Venue: Proceedings of the Fifth IEEE International Conference on Wireless, Mobile, and Ubiquitous Technology in Education (2008)

In our recent research we have explored possibilities to scaffold collaborative learning in higher education with wireless networks and mobile tools. The pedagogical ideas are grounded on concepts of collaborative learning, including the socially shared origin of cognition, as well as self-regulated learning theory. This poster will demonstrate how social software and mobile devices can be used for facilitating socially shared collaboration and community building.
Discrete computer tomography based on rotating projection algorithm
Authors: J. G. Vázquez Luna, A. Grebennikov, T. Valencia Perez, M. Najera Enriquez
Venue: Proceedings of the 2nd WSEAS International Conference on Computer Engineering and Applications (2008)

Computer tomography is used efficiently in different applied areas. This approach requires scanning the object and image reconstruction, using, for example, the inversion of the Radon transform. It seems necessary for difficult structures and can be realized in sufficiently fast manner. We consider in this paper the situation, when the investigating object has the discrete structure, so its reconstruction consists only in localization of some elements with different characteristic inside of the homogeneous (or quasi homogeneous) substance in the considered region. We propose for this case the "Discrete Tomography" based on Rotating Projection algorithm with a little number of scanning angles. This algorithm do not requires application of some inverse transforms. It simplifies the image reconstruction. Proposed approach is faster in its computer realization, gives possibility to reduce the time of the radiation treatment. The good properties of the developed algorithm are demonstrated on simulated numerical examples.
Net Neutrality... Seriously this Time
Authors: Daniel J. Weitzner
Venue: IEEE Internet Computing (2008)

Discriminatory disruption of certain Internet communications protocols, and the recent truce between Comcast and BitTorrent, has caused much debate. At the root of the matter is a very basic question about how Comcast's action relates to the fundamental technical and institutional agreements that make the Internet work. A closer look at what Comcast did, along with the legitimate operational problems that certain types of traffic cause in networks, help explain the challenge the Internet community now faces.
A New Service Level Agreement Model for Best-Effort Traffics in IP over WDM
Authors: Hung-Yi Chang, Pi-Chung Wang, Chia-Tai Chan, Chun-Liang Lee
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications - Workshops (2008)

In this paper, we propose a new SLA model for best effort IP traffic over WDM networks. This model jointly considers two QoS metrics, workable traffic volume and availability, as SLA parameters. We devise an algorithm of integer programming to minimize operation cost for the incremental traffic.
On non-Hamiltonian circulant digraphs of outdegree three
Authors: Stephen C. Locke, Dave Witte
Venue: Journal of Graph Theory (1999)

We construct infinitely many connected, circulant digraphs of outdegree three that have no Hamiltonian circuit. All of our examples have an even number of vertices, and our examples are of two types: either every vertex in the digraph is adjacent to two diametrically opposite vertices, or every vertex is adjacent to the vertex diametrically opposite to itself. &copy; 1999 John Wiley & Sons, Inc. J Graph Theory 30: 319&ndash;331, 1999
Pairwise constraint propagation by semidefinite programming for semi-supervised classification
Authors: Zhenguo Li, Jianzhuang Liu, Xiaoou Tang
Venue: Proceedings of the 25th international conference on Machine learning (2008)

We consider the general problem of learning from both pairwise constraints and unlabeled data. The pairwise constraints specify whether two objects belong to the same class or not, known as the must-link constraints and the cannot-link constraints. We propose to learn a mapping that is smooth over the data graph and maps the data onto a unit hypersphere, where two must-link objects are mapped to the same point while two cannot-link objects are mapped to be orthogonal. We show that such a mapping can be achieved by formulating a semidefinite programming problem, which is convex and can be solved globally. Our approach can effectively propagate pairwise constraints to the whole data set. It can be directly applied to multi-class classification and can handle data labels, pairwise constraints, or a mixture of them in a unified framework. Promising experimental results are presented for classification tasks on a variety of synthetic and real data sets.