ppxscal/embedding_network huggingface dataset:
Mapping fractional forest cover across the highlands of mainland Southeast Asia using MODIS data and regression tree modelling
Authors: C. Tottrup, M. S. Rasmussen, L. Eklundh, P. Jönsson
Venue: International Journal of Remote Sensing (2007)

Data from the moderate-resolution imaging spectroradiometer (MODIS) sensor, in combination with new mapping techniques, has the potential to improve regional research on tropical forest resources and land use dynamics. In this study, a supervised regression tree model was used to map fractions of (1) mature forest, (2) secondary forest, and (3) non-forest, using multi-temporal MODIS 250-m data as explanatory variables, and land cover information derived from high-spatial resolution image data as the response variables. From independent validation data, the overall mean absolute deviation of the resulting maps are estimated at 14.6% for mature forest, 21.6% for secondary forest, and 17.1% for non-forest cover. This study shows the increased potential of this new mapping technique to infer human imprints on forest cover across the highlands of mainland Southeast Asia, compared to other existing map sources.
Global and local convergence of a filter line search method for nonlinear programming
Authors: Choong Ming Chin, Abdul Halim Abdul Rashid, Khalid Mohamed Nor
Venue: Optimization Methods Software (2007)

A framework for proving global convergence for a class of line search filter-type methods for nonlinear programming is presented without assuming that the Jacobian has full rank everywhere. The underlying method is based on the filter concept where trial points are accepted, provided there is a sufficient decrease in the objective function or constraints violation function. The proposed methods solve a sequence of quadratic programming subproblems via line search techniques to induce global convergence. Under mild conditions, we will also show that the algorithm converges two step superlinearly when the iterates are near to the solution.
Selfishness, collusion and power of local search for the ADMs minimization problem
Authors: Michele Flammini, Gianpiero Monaco, Luca Moscardelli, Mordechai Shalom, Shmuel Zaks
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2008)

We consider non-cooperative games in all-optical networks where users share the cost of the used ADM switches for realizing given communication patterns. We show that the two fundamental cost sharing methods, Shapley and Egalitarian, induce polynomial converging games with price of anarchy at most 53, regardless of the network topology. Such a bound is tight even for rings. Then, we show that if collusion of at most k players is allowed, the Egalitarian method yields polynomially converging games with price of collusion between 32 and 32+1k. This result is very interesting and quite surprising, as the best known approximation ratio, that is 32+@e, can be achieved in polynomial time by uncoordinated evolutions of collusion games with coalitions of increasing size. Finally, the Shapley method does not induce well defined collusion games, but can be exploited in the definition of local search algorithms with local optima arbitrarily close to optimal solutions. This would potentially generate PTAS, but unfortunately the arising algorithm might not converge. The determination of new cost sharing methods or local search algorithms reaching a compromise between Shapley and Egalitarian is thus outlined as being a promising and worth pursuing investigating direction.
Lessons from Electrification for Identification
Authors: Marc Donner
Venue: IEEE Security and Privacy (2008)

As we've seen with the electrical system's evolution and the reengineering of the US voting system, change makes us rediscover essential assumptions and expectations about systems as well as their complexity and inherent risks. In the case of e-voting, the debate reeducated society at large about our expectations of the process, why we have such things as secret ballots, and what it takes to provide confidence that the process has been conducted fairly. With this issue of S&P, we hope that you'll be better prepared to participate in the debate over identity management and ensure that the nontechnical policy makers who will make many of the key decisions can make high-quality choices.
Legible Simplification of Textured Urban Models
Authors: Remco Chang, Thomas Butkiewicz, Caroline Ziemkiewicz, Zachary Wartell, Nancy Pollard, William Ribarsky
Venue: IEEE Computer Graphics and Applications (2008)

Traditionally, most mesh-simplification algorithms have focused on rendering complex objects with a large number of polygons. These algorithms prove to be ineffective for rendering large collections of simple models. The authors' approach relies on a new algorithm for simplifying city-sized collections of 2.5D buildings, with the goal being urban legibility.
External-memory computational geometry
Authors: M. T. Goodrich
Venue: Proceedings of the 1993 IEEE 34th Annual Foundations of Computer Science (1993)

In this paper we give new techniques for designing efficient algorithms for computational geometry problems that are too large to be solved in internal memory. We use these techniques to develop optimal and practical algorithms for a number of important large-scale problems. We discuss our algorithms primarily in the context of single processor/single disk machines, a domain in which they are not only the first known optimal results but also of tremendous practical value. Our methods also produce the first known optimal algorithms for a wide range of two-level and hierarchical multilevel memory models, including parallel models. The algorithms are optimal both in terms of I/O cost and internal computation.
Partitions of a graph into paths with prescribed endvertices and lengths
Authors: Hikoe Enomoto, Katsuhiro Ota
Venue: Journal of Graph Theory (2000)

For a graph G, let &sigma;2(G) denote the minimum degree sum of a pair of nonadjacent vertices. We conjecture that if |V(G)|&thinsp;=&thinsp;n&thinsp;=&thinsp;&Sigma;ki&thinsp;=&thinsp;1 ai and &sigma;2(G)&thinsp;&ge;&thinsp;n&thinsp;+&thinsp;k&thinsp;-&thinsp;1, then for any k vertices v1, v2,&hellip;, vk in G, there exist vertex-disjoint paths P1, P2,&hellip;, Pk such that |V(Pi)|&thinsp;=&thinsp;ai and vi is an endvertex of Pi for 1&thinsp;&le;&thinsp;i&thinsp;&le;&thinsp;k. In this paper, we verify the conjecture for the cases where almost all ai&thinsp;&le;&thinsp;5, and the cases where k&thinsp;&le;&thinsp;3. &copy; 2000 John Wiley & Sons, Inc. J Graph Theory 34: 163&ndash;169, 2000
Spectral norm of random matrices
Authors: Van H. Vu
Venue: Combinatorica (2007)

In this paper, we present a new upper bound for the spectral norm of symmetric random matrices with independent (but not necessarily identical) entries. Our results improve an earlier result of F&#x00fc;redi and Koml&#x00f3;s.
Protocol completion incentive problems in cryptographic Vickrey auctions
Authors: Phillip G. Bradford, Sunju Park, Michael H. Rothkopf, Heejin Park
Venue: Electronic Commerce Research (2008)

Despite attractive theoretical properties, Vickrey auctions are seldom used due to the risk of information revelation and fear of cheating. CVAs (Cryptographic Vickrey Auctions) have been proposed to protect bidders' privacy or to prevent cheating by the bid taker. This paper focuses on incentive issues for certain CVAs. First, it defines the CVAs of interest and identifies ideal goals for this class of CVAs. One of the criteria identifies an incentive problem that is new to the literature on CVAs, the disincentive of bidders to complete the protocol once they have learned that they lost the auction. Any auction protocol that requires losing bidders to do additional work after learning they have lost the auction must provide the losers with proper incentives to follow the protocol. Second, this paper shows that for a class of CVAs, some losers must continue to participate even though they know they have lost. Finally, it describes two new CVA protocols that solve the protocol-completion incentive problem. Both protocols use bidder-bidder comparisons based on a modified Yao's Millionaires' protocol. The first protocol performs O(n 2) bidder-bidder comparisons, while the second protocol performs O(n) comparisons.
Affine invariance study of edge detection algorithms by means of PICASSO 2 system
Authors: I. V. Gribkov, P. P. Koltsov, N. V. Kotovich, A. A. Kravchenko, A. S. Kutsaev, A. S. Osipov, A. V. Zakharov
Venue: Proceedings of the 6th WSEAS International Conference on Signal, Speech and Image Processing (2006)

The system PICASSO 2 has been designed for a comparative evaluation of image processing algorithms. In this paper, the system is used to study the stability of edge detection under affine transformations (shifts, rotations and scalings) of the objects being tested. Six edge detectors (by Canny, Rothwell, Heitger, Black, Smith and Iverson) have been applied to the images from PICASSO 2 data set and the outputs were compared using several performance metrics. In particular, our results show the unstable behavior of all six methods on the edges of varying contrast.
The consecutive-4 digraphs are Hamiltonian
Authors: Gerard J. Chang, Frank K. Hwang, Li-Da Tong
Venue: Journal of Graph Theory (1999)

Du, Hsu, and Hwang conjectured that consecutive-d digraphs are Hamiltonian for d = 3, 4. Recently, we gave an infinite class of consecutive-3 digraphs, which are not Hamiltonian. In this article we prove the conjecture for d = 4. &copy; 1999 John Wiley & Sons, Inc. J Graph Theory 31: 1&ndash;6, 1999.
Renewal model of mobile data services through user experience analysis
Authors: Sun-Joo Jun, Min-Jeong Kim
Venue: Proceedings of the 9th international conference on Human computer interaction with mobile devices and services (2007)

In this paper, we introduced real renewal examples of KTF's mobile data service. At the time of development, we focused on user analysis and tried to improve the existing mobile data service based on user's opinion. After the new mobile data service was launched based on user experience analysis, the customers were satisfied with the newly developed mobile data service. We expect that new mobile data service would make continuous revenue streams and contribute to image up the company.
Managing Model Evolution Using the CCBM Approach
Authors: Audrey Occello, Anne-Marie Dery-Pinna, Michel Riveill, Günter Kniesel
Venue: Proceedings of the 15th Annual IEEE International Conference and Workshop on the Engineering of Computer Based Systems (2008)

With the adoption of MDE, application evolution is facilitated. Instead of modifying each deployed version, the application is modified only once at the model level and then regenerated for each platform. On the other hand, to manage application complexity, models are partitioned and then integrated together to form larger ones. However most of modeling approaches use an integration mechanism based on merging existing models that makes it difficult to manage application evolution in a modular and incremental way. As an alternative, we propose the Collaborative Component Based Model approach (CCBM) that leverages software components principles and focuses on the specification of how models collaborate with each other. This paper presents how the proposed approach contributes to integrate and manage change of models incrementally by preserving defined collaborations during the whole life-cycle of an application, from initial, very loosely specified interactions, through step-wise refinements, to the final concretization to a component implementation.
Performance of wavelet based Multi-Chip Rate DS-CDMA signals over multi-path Nakagami-m fading channels
Authors: Ertan Öztürk
Venue: Wireless Communications Mobile Computing (2008)

Multi-Chip Rate-Direct Sequence-Code Division Multiple Access (MCR-DS-CDMA) technique using scaled chip waveforms has been designed as an alternative to multi-data rate DS-CDMA techniques having constant chip rates. In this work, the probability of error (Pe) expression for MCR-DS-CDMA signals is derived over multi-path Nakagami-m fading channels to investigate the effects of chip waveforms on it. This paper also proposes the use of orthogonal wavelets as chip waveforms of MCR-DS-CDMA signals over the considered channel. For numerical calculations, Daubechies-22 (D22) wavelet is used because its side lobes are 40&thinsp;dB below its main lobe in frequency domain. D22 is compared with a Square Root Raised Cosine (SRRC) chip waveform. In the numerical calculations, only first four scales of the chip waveforms relating to four different chip-data rates are considered. The results for the Pe performance and the capacity (the number of user per Hertz for a same Pe level) show that D22 significantly outperforms the SRRC chip waveform at all data rates, due to low cross correlations among different scales of orthogonal wavelets. Besides, by increasing the number of scales, the advantage of the use of orthogonal wavelets will increase furthermore. Copyright &copy; 2007 John Wiley & Sons, Ltd.
Design of the Implantable Artificial Lung using Computational Fluid Dynamics
Authors: Gi-Beum Kim, Mun-Yong Lee, Seol-Hee Jeon, Md. Mizanur Rahman, Woo-Suk Chong, Min-Ho Kim, Seong-Jong Kim, Suck-Ju Yoon, In-Shick Kim, Jin-Shang Kim, Hyung-Sub Kang, Chul-Un Hong
Venue: Proceedings of the 2008 International Conference on BioMedical Engineering and Informatics - Volume 02 (2008)

An artificial implantable lung would be a useful device to support ARDS patients awaiting lung transplantation. In this study, the characteristic of fluid flow in the new type lung assist devices has been established using CFD. According to the modeling, it is believed that the tangential type module would be more beneficial to the fluid flow, and 2 ports would influence better than 1 port. However, such results are simple modeling by CFD, and therefore need to be confirmed by actual experiments.
Workspaces associated to assembly modes of the 5r planar parallel manipulator
Authors: Erik Macho, Oscar Altuzarra, Charles Pinto, Alfonso Hernandez
Venue: Robotica (2008)

The aim of this paper is to show how it is possible to obtain for the 5R planar parallel manipulator the complete workspace associated with each solution of the direct kinematic problem or assembly mode. The workspaces associated with the different inverse kinematic problem solutions or working modes are joined and the robot moves from one to another without losing the control. An exhaustive analysis of the complete workspace and singular positions of the 5R planar parallel manipulator with two active joints is presented. Furthermore, application of these principles to path planning will be explained.
Towards fully polymeric MEMS: Fabrication and testing of PEDOT/PSS strain gauges
Authors: Udo Lang, Philipp Rust, Jurg Dual
Venue: Microelectronic Engineering (2008)

In recent years first commercial devices based on organic electronic materials entered the market. Recent market studies mention the necessity to include sensors in the design of organic electronic devices in order to broaden the range of applications. It is therefore essential to identify potential organic sensor materials and to develop processes and methods to structure and characterize them. Widely used in organic electronics is the complex of the intrinsically conductive polymer poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate acid (PEDOT/PSS). In this paper we first present a lift-off process for patterning thin PEDOT/PSS films. Crucial deposition parameters are systematically investigated and subsequently a reliable micropatterning process defined. Then a design for fully polymeric pressure sensors made from polyimide (PI) membranes and PEDOT/PSS strain sensors is proposed. Preliminary test results as proof-of-concept are finally shown.
Proceedings of the 4th international workshop on Predictor models in software engineering
Venue: International Conference on Software Engineering (2008)

It is our great pleasure to welcome you to PROMISE 2008 - the 4th International Workshop on Predictor Models in Software Engineering. This year's workshop continues its tradition of being the premier forum for presentation of research results and experience reports in the area of predictor models applied to software engineering. The theme for this year's workshop is Bridging Research and Industry. Key questions for the workshop are -- How might PROMISE and other researchers better align with the realities of industry? -- How can industry make effective use of research ideas? In keeping with this theme, we have two keynote speakers from industry. Dr. Murray Cantor is an IBM Distinguished Engineer and the governance solutions lead on the IBM Rational Software CTO team. Mr. Chris Beal is a Sun Microsystems Senior Staff Engineer working with Solaris Revenue Product Engineering. We are pleased that PROMISE has become an international event. Our call for papers attracted submissions from Asia, Canada, Europe, and the United States. The program committee accepted over a dozen papers covering a variety of topics, including models related to fault prediction, effort estimation, and requirements engineering. One feature that sets this workshop apart from others is the PROMISE repository of software data sets that are publicly available for research purposes. The repository currently has 57 data sets and has grown at an average rate of 44% annually over the last 3.5 years.
A "Gap Bridger"
Authors: Richard Rashid
Venue: ACM SIGMOD Record (2008)

I knew Jim Gray as a colleague, a friend and an employee. He created the first Microsoft Research group outside of our initial research lab in Redmond, WA. Jim's impact on industry and science was not limited to his own area of research. He championed new ways of thinking about how computer science and information processing could be integrated into other areas of research. In so doing; he will have a lasting impact on the rate of progress in many disciplines. His success stemmed not just from what he knew and what he could do with his knowledge, but also from who he was as a person. Jim was a "Gap Bridger" -- someone who could connect people, groups, companies and disciplines.
Smoothing dissimilarities to cluster binary data
Authors: David B. Hitchcock, Zhimin Chen
Venue: Computational Statistics Data Analysis (2008)

Cluster analysis attempts to group data objects into homogeneous clusters on the basis of the pairwise dissimilarities among the objects. When the data contain noise, we might consider performing a smoothing operation, either on the data themselves or on the dissimilarities, before implementing the clustering algorithm. Possible benefits to such pre-smoothing are discussed in the context of binary data. We suggest a method for cluster analysis of binary data based on ''smoothed'' dissimilarities. The smoothing method presented borrows ideas from shrinkage estimation of cell probabilities. Some simulation results are given showing that improvement in the accuracy of the clustering result is obtained via smoothing, especially in the case in which the observed data contain substantial noise. The method is illustrated with an example involving binary test item response data.
A general approach for building combinational P automata
Authors: Huan Long, Yuxi Fu
Venue: International Journal of Computer Mathematics (2007)

In traditional automata theory, the closure with respect to certain operations is one of the most investigated properties, especially the methods of constructing automata for certain operations among the given sub-automata. However, up to now less effort has been addressed to this question for P automata. As an improvement on earlier results, we introduce P automata with communication and active membrane rules working in the initial mode (CAIP). We present methods for constructing automata that recognize the Union, the Concatenation, the Kleene Closure, or the ω Closure of the given languages which are represented by some P automata. We also show that for any language denoted by a regular expression, we can readily construct a CAIP automaton corresponding to it.
Alternatives in evaluating multimedia in secondary school science teaching
Authors: Johannes C Cronjé, Johann Fouche
Venue: Computers Education (2008)

While different approaches to evaluation will yield different results, depending on the purpose of the evaluation this article describes an evaluation approach that was aimed at investigation the mental models of users of the programme. The study was driven by questions about the differences in mental models of the instructional designers and the learners, the time learners spent working through the program and the observable changes in their mental models. In this design experiment, a program was developed to teach basic principles of electricity. Three boys and three girls one each of high, medium and low achievement in science were selected from an advantaged urban school, and a similar sample was taken from a disadvantaged rural school. They were asked to draw their impressions of various concepts of electricity and then allowed free access to the program, where they could visit any section even if they had not completed a previous one. Afterwards they were asked to draw sketches again. Other instruments included an opinion questionnaire and observation of the learners working with a ''think aloud'' protocol. It was found that there were considerable differences in the mental models of the learners and designers about what to expect from computer-based learning. While navigational freedom allowed fast learners to move through work that they knew already, weaker learners tended to get lost. The sketches that learners made before and after exposure to the program provided valuable insights into the growth of their understanding of the concepts.
A new vegetation index derived from the pattern decomposition method applied to Landsat-7/ETM+ images in Mongolia
Authors: K. Muramatsu, Y. Xiong, S. Nakayama, F. Ochiai, M. Daigo, M. Hirata, K. Oishi, B. Bolortsetseg, D. Oyunbaatar, I. Kaihotsu
Venue: International Journal of Remote Sensing (2007)

The goal of this study was to estimate vegetation coverage and map the land-cover in an experimental field (60×60 km) near Mandalgobi, Mongolia using Landsat-7/ETM+ data for ground truthing in the Advanced Earth Observing Satellite II (ADEOS-II) Mongolian Plateau Experiment (AMPEX). We measured soil moisture, vegetation coverage, and vegetation moisture in the field at 49 grid points around the time that the Aqua satellite passed over the area. We also surveyed the land-cover in the field. Using ground-based data and characteristics of spectral reflectance, we attempted to extract vegetation information from satellite data using the pattern decomposition method, which is a type of spectral mixture analysis. This method uses normalized spectral shapes as endmembers, which do not change between scenes. We defined an index using the pattern decomposition coefficients to analyse sparsely vegetated areas. The index showed a linear relationship with vegetation coverage. The vegetation coverage was estimated for the study site, and the average coverage at the site was 21.4%. Land-cover types were classified using the index and the pattern decomposition coefficients; the kappa coefficient was 0.75. The index was useful for estimating vegetation coverage and land-cover mapping for semiarid areas.