ppxscal/embedding_network huggingface dataset:
Low aspect-ratio porous alumina templates
Authors: M. Kokonou, C. Rebholz, K. P. Giannakopoulos, C. C. Doumanidis
Venue: Microelectronic Engineering (2008)

This article reports on the fabrication of ultra-thin (40-70nm) porous alumina films with low aspect-ratio pores on Si substrates, by anodization of very thin Al films. The pore diameter to height aspect-ratio can be accurately controlled by careful selection of the anodization conditions, followed by a chemical dissolution step that widens the pores furthermore. These ultra-thin porous alumina films were used as templates for the fabrication of metallic nanorods by deposition of metals inside the pores and complete filling of them by electron gun evaporation. Pore filling with physical deposition techniques is extremely difficult for higher aspect-ratios due to the pore-closure effect.
A Proposed Scheme for Epidemic Routing with Active Curing for Opportunistic Networks
Authors: Jonah P. Tower, Thomas D. C. Little
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications - Workshops (2008)

Opportunistic networking is emerging as a technique to exploit chance encounters among mobile nodes, and is distinct from previously studied behaviors found in sensor and ad hoc networking research. In this paper, we explore contributions in epidemic data dissemination and mobile ad hoc networks applicable to opportunistic networking, and propose an extension to prior work based on active cures. Our scheme, called SERAC, increases the rate at which cure messages are propagated in a fragmented network for the purpose of reducing the overhead of outstanding yet incompletely disseminated messages. Preliminary analyses demonstrate the feasibility of performance gains under the opportunistic networking model.
A 10Gbps analog adaptive equalizer and pulse shaping circuit for backplane interface
Authors: Kwisung Yoo, Gunhee Han, Sungmin Park
Venue: Proceedings of the 5th WSEAS International Conference on Circuits, Systems, Electronics, Control & Signal Processing (2006)

The speed of serial interface through a backplane channel suffers severe ISI (Inter Symbol Interference) caused by the limited bandwidth of the channel. In order to overcome the bandwidth limit, a pulse shaping circuit or an adaptive equalizer is used. This paper presents the comparison between two approaches. Prototype chip is designed for 10Gbps serial data communication through a 34-inch transmission line with a 0.18-??? CMOS process. The simulation and layout results show that the adaptive equalization has superior performance in power consumption, silicon area and the jitter performance.
Mitigating application-level denial of service attacks on Web servers: A client-transparent approach
Authors: Mudhakar Srivatsa, Arun Iyengar, Jian Yin, Ling Liu
Venue: ACM Transactions on the Web (TWEB) (2008)

Recently, we have seen increasing numbers of denial of service (DoS) attacks against online services and Web applications either for extortion reasons or for impairing and even disabling the competition. These DoS attacks have increasingly targeted the application level. Application-level DoS attacks emulate the same request syntax and network-level traffic characteristics as those of legitimate clients, thereby making the attacks much harder to detect and counter. Moreover, such attacks often target bottleneck resources such as disk bandwidth, database bandwidth, and CPU resources. In this article, we propose handling DoS attacks by using a twofold mechanism. First, we perform admission control to limit the number of concurrent clients served by the online service. Admission control is based on port hiding that renders the online service invisible to unauthorized clients by hiding the port number on which the service accepts incoming requests. Second, we perform congestion control on admitted clients to allocate more resources to good clients. Congestion control is achieved by adaptively setting a client's priority level in response to the client's requests in a way that can incorporate application-level semantics. We present a detailed evaluation of the proposed solution using two sample applications: Apache HTTPD and the TPCW benchmark (running on Apache Tomcat and IBM DB2). Our experiments show that the proposed solution incurs low performance overhead and is resilient to DoS attacks.
Invariant features for searching in protein fold databases
Authors: Maja Temerinac, Marco Reisert, Hans Burkhardt
Venue: International Journal of Computer Mathematics (2007)

The tremendous growth of 3D data models available on the Internet requires more skills for fast retrieval and classification algorithms. In particular, the problem of finding structural similarities between proteins automatically, in order to predict their functional similarity, is a challenging task. In this paper a new algebraic method for structural comparison between proteins based on invariant features computed by group integration with spherical harmonics and D-Wigner matrices is proposed. Our goal is to achieve good classification without alignment by using intrinsic, pose invariant features. We compare our method to DALI, PRIDE and the Gauss Integral method in a classification and search task. Additionally we provide a Web interface to test the proposed method.
Product flow analysis in distribution networks with a fixed time horizon
Authors: M. T. Wynn, C. J. Fidge, A. H. M. ter Hofstede, M. Dumas
Venue: Proceedings of the thirty-first Australasian conference on Computer science - Volume 74 (2008)

The movement of items through a product distribution network is a complex dynamic process which depends not only on the network's static topology but also on a knowledge of how each node stores, handles and forwards items. Analysing this time-dependent behaviour would normally require a simulation algorithm which maintains a globally-synchronised system state. For a certain class of problem, however, where the simulation is required to stop in a consistent state but not necessarily maintain consistency at all times, we show that an algorithm that makes localised decisions only is sufficient. As a motivating example we consider the practical problem of product recalls, in which our primary concern is the state of the distribution network at a specific time after a batch of suspect items was released, but we do not necessarily care about intermediate states leading up to the final one.
'Now everything looks like a game': mobile phones and location-based games
Authors: Debra Polson, Colleen Morgan
Venue: Proceedings of the 4th international conference on mobile technology, applications, and systems and the 1st international symposium on Computer human interaction in mobile technology (2007)

This paper explores how we may transform peoples' perceived access to cultural participation by exploiting the possible relationships between place, play and mobile devices. It presents SCOOT; a location-based game in order to investigate how aspects of game-play can be employed to evoke at once playful and culturally meaningful experiences of place. In particular this paper is concerned with how the portable, communicative and social affordances of mobile phones are integral to making a "now everything looks like a game" experience.
Distributed Autonomous System Based Design Technique to Enhance Synchronization Productivity in Simulations
Authors: Asad Waqar Malik, Shoab A. Khan
Venue: Proceedings of the 2008 Second Asia International Conference on Modelling & Simulation (AMS) (2008)

In this paper we analyzed Chandy-Misra null message algorithm and proposed and implemented autonomous grouping technique to improve the performance. Our primary goal is to minimize the synchronization overhead in conservative parallel simulation by reducing the number of null messages over the network. Exchange of large number of null messages effect the performance of simulation and liable to congestion. Different techniques has been proposed most of them are simulation dependent. The performance of null message algorithm highly depends upon lookahead value. The smaller the lookahead the more number of messages transmitted during the simulation. We presented an autonomous grouping approach to reduce the number of synchronization messages sent out of the system.
An early software engineering approach to teaching cs1, cs2 and ai
Authors: T. M. Rao, Sandeep Mitra
Venue: Proceedings of the 39th SIGCSE technical symposium on Computer science education (2008)

We propose the use of a new design-first approach called Problem Stereotypes and Solution Frameworks, for teaching CS1 and CS2. A problem stereotype is a category of problems that can be solved using similar techniques. A solution framework is a typical solution to a problem, parts of which can be reused to solve other problems of this stereotype. Students are introduced to a stereotype through a selection of related problems, and common features among these are identified. Homework problems are selected from the same stereotype, with students expected to follow the "recipe" provided by the given examples to generate their own solutions. Using this approach reduces the stress level for beginner students, and prevents them falling prey to the "CS is HARD" myth. We present the results of our experience with this approach in two introductory classes and an upper-division Artificial Intelligence (AI) class at SUNY Brockport.
Optimal operational strategy for hybrid renewable energy system using genetic algorithms
Authors: Juhari Ab. Razak, Kamaruzzaman Sopian, Zulkifli Mohd Nopiah, Azami Zaharim, Yusoff Ali
Venue: Proceedings of the 12th WSEAS International Conference on Applied Mathematics (2007)

Off-grid settlements require efficient, reliable and cost-effective renewable energy as alternative to the power supplied by diesel generator. Techno-economic analysis is required to find the optimum renewable energy system in the long run. This paper reviews the application of genetic algorithms in optimization of hybrid system consisting of pico hydro system, solar photovoltaic modules, diesel generator and battery sets. It is intended to maximize the use of renewable system while limiting the use of diesel generator. Daily load demand is assumed constant for derivation of annual load. Power derived from the hybrid should be able to meet the demand. Local weather data is used and analyzed to assess the technical and economic viability of utilizing the hybrid system. Optimization of the system will be based on the component sizing and the operational strategy. Genetic algorithms programming is used to evaluate both conditions in minimizing the total net present cost for optimum configuration. Manufacturer data for the hybrid components is used in calculation of sizing to represent actual power derivation. Several operation strategies will be considered while forming the vectors for optimum strategy. Random selection of sizing and strategy is used to initiate the solution for the problem which will have the lowest total net present cost. Sensitivity analysis is also performed to optimize the system at different conditions.
Addressing performance analysis of Taiwan's international hotels by using an integrated approach
Authors: Ching-Cheng Shen, Kun-Lin Hsieh
Venue: Proceedings of the 6th WSEAS International Conference on Systems Theory & Scientific Computation (2006)

International hotels in Taiwan had met an imbalance characteristic between market supply and demand. Such situation had led the performance analysis to be became an important issue. In this study, we proposed an integrated approach incorporating fuzzy set theory and data envelope analysis (DEA) to address the problem of performance analysis. The efficiency ratio computed from our proposed approach can be more appropriate, reliable and practical than using the other DEA models. The study examines formulations of DEA efficiency including how three DEA efficiency measurement methods work and why alternative methods have evolved, especial for the advantages of using the proposed approach will being taken into consideration. Finally, an illustrative example owing to Taiwan's International Hotels are taken to demonstrate the rationality and feasibility of the proposed approach.
A Root-Finding Method for Assessing SRAM Stability
Authors: Rouwaida Kanj, Zhuo Li, Rajiv Joshi, Frank Liu, Sani Nassif
Venue: Proceedings of the 9th international symposium on Quality Electronic Design (2008)

In this paper, we propose a closed form method to evaluate the read stability of an SRAM cell via quartic root finding. By utilizing a simplified MOSFET device model, we model SRAM cell stability by a system of quartic equations. The algebraic nature of the equations along with simplified region boundaries provide the insight that only a few combinations of device operating regions correspond to the stability of the cell, instead of 729 combinations in the brutal force approach. Such an insight not only makes it possible to have a quick “litmus test” to determine cell stability under variability, but also significantly speeds up the analysis, compared to a traditional SPICE approach. Experimental results using industrial bulk CMOS models show that the results are in excellent agreement with SPICE results and 65X faster.
Towards a user-oriented environment for web services composition
Authors: Mahmoud M. Elgayyar, Sascha J. Alda, Armin B. Cremers
Venue: Proceedings of the 4th international workshop on End-user software engineering (2008)

Current web services composition engines like ActiveBPEL provide only facilities to create static workflow compositions. Once a workflow is deployed and started, the constructs that represent the workflow cannot be altered subsequently. In fact, only administrator could re-define a workflow at any time. We claim, however, that such an admin-based deployment is not sufficient. For future application scenarios, we see a need for adapting workflow compositions in a personalized manner even at runtime of the deployed workflow. According to this idea, regular end-users should be able to adapt a workflow for accommodating new requirements. Based on our review for the component-based tailoring methods, the paper presents the multi-tier architecture TailorBPEL that supports the tailoring of personalized BPEL-based workflow compositions. We believe that such architecture is significant for having highly flexible and adaptable service-oriented architectures that are considered for the adoption to user-centric application scenarios.
Chordal graphs, interval graphs, and wqo
Authors: Guoli Ding
Venue: Journal of Graph Theory (1998)

Let precedes, equal to be the induced-minor relation. It is shown that, for every t, all chordal graphs of clique number at most t are well-quasi-ordered by precedes, equal to. On the other hand, if the bound on clique number is dropped, even the class of interval graphs is not well-quasi-ordered by precedes, equal to. &copy; 1998 John Wiley & Sons, Inc. J Graph Theory 28: 105&ndash;114, 1998
Rethink the sync
Authors: Edmund B. Nightingale, Kaushik Veeraraghavan, Peter M. Chen, Jason Flinn
Venue: ACM Transactions on Computer Systems (TOCS) (2008)

We introduce external synchrony, a new model for local file I/O that provides the reliability and simplicity of synchronous I/O, yet also closely approximates the performance of asynchronous I/O. An external observer cannot distinguish the output of a computer with an externally synchronous file system from the output of a computer with a synchronous file system. No application modification is required to use an externally synchronous file system. In fact, application developers can program to the simpler synchronous I/O abstraction and still receive excellent performance. We have implemented an externally synchronous file system for Linux, called xsyncfs. Xsyncfs provides the same durability and ordering-guarantees as those provided by a synchronously mounted ext3 file system. Yet even for I/O-intensive benchmarks, xsyncfs performance is within 7&percnt; of ext3 mounted asynchronously. Compared to ext3 mounted synchronously, xsyncfs is up to two orders of magnitude faster.
Evaluation of the B-method for determining actual evapotranspiration in a boreal forest from MODIS data
Authors: J. M. Sánchez, V. Caselles, R. Niclós, E. Valor, C. Coll, T. Laurila
Venue: International Journal of Remote Sensing (2007)

Boreal forests occupy about 11% of the terrestrial surface and represent an important contribution to global energy balance. The ground measurement of daily evapotranspiration (LEd) is very difficult due to the limitations on experiments. The objective of this paper is to present and explore the applicability of the B-method for monitoring actual LEd in these ecosystems. The method shown in this paper allows us to determine the surface fluxes over boreal forests on a daily basis from instantaneous information registered in a conventional meteorological tower, as well as the canopy temperature (T c) retrieved by satellite. Images collected by the MODIS (moderate resolution imaging spectroradiometer) on board EOS-Terra have been used for this study. The parameters of the model were calibrated from the SIFLEX-2002 (Solar Induced Fluorescence Experiment 2002) campaign dataset in a northern boreal forest in Finland. A study of these parameters was made on an hourly basis in order to make the method applicable, not only at midday but within an interval of 7 h around it. This is an important advance with respect to the original formulation of this approach since the overpass time of satellites can be very variable. The comparison between T c ground measured with a thermal infrared radiometer, and T c retrieved from land surface temperature (LST) MODIS data, showed an estimation error of ±1.4°C for viewing angles from 5 to 60°. A complete sensitivity analysis was carried out and an estimation error of about ±35%, corresponding to the interval 10.00-11.00 h UTC, was shown as the lowest in LEd retrieval. Finally, the method was validated over the study site using 21 MODIS images for 2002 and 2003. The results were compared with eddy-correlation ground measurements. An accuracy of ±1.0 mm/day and an overestimation of 0.3 mm/day were shown in the LEd retrieval.
Half-Overlap Subchannel Filtered MultiTone Modulation with the Small Delay
Authors: Pavel Silhavy
Venue: Proceedings of the Seventh International Conference on Networking (2008)

In this contribution an analysis of MultiCarrier Modulation (MCM) is realized. The features of Discrete MultiTone modulation (DMT), Orthogonal Frequency Division Multiplexing (OFDM) and alternative modulation based on filter bank - Filtered MultiTone (FMT) will be mentioned. Based on this study the half sub-channel overlapped Filtered MultiTone Modulation will be introduced.
Expected gene-order distances and model selection in bacteria
Authors: Daniel Dalevi, Niklas Eriksen
Venue: Bioinformatics (2008)

Motivation: The evolutionary distance inferred from gene-order comparisons of related bacteria is dependent on the model. Therefore, it is highly important to establish reliable assumptions before inferring its magnitude. Results: We investigate the patterns of dotplots between species of bacteria with the purpose of model selection in gene-order problems. We find several categories of data which can be explained by carefully weighing the contributions of reversals, transpositions, symmetrical reversals, single gene transpositions and single gene reversals. We also derive method of moments distance estimates for some previously uncomputed cases, such as symmetrical reversals, single gene reversals and their combinations, as well as the single gene transpositions edit distance. Contact: ner@math.chalmers.se Supplementary information: Supplementary data are available at Bioinformatics online.
A replication oriented approach to event based middleware over structured peer to peer networks
Authors: Mohammad Reza Selim, Yuichi Goto, Jingde Cheng
Venue: Proceedings of the 5th international workshop on Middleware for pervasive and ad-hoc computing: held at the ACM/IFIP/USENIX 8th International Middleware Conference (2007)

Due to efficient event dissemination and mobility support, event based middlewares are gaining popularity in pervasive computing environments. However, loss of events caused by broker/client failures or unreliable network connections is a common problem in existing event based middlewares. Middlewares providing support to critical distributed systems must be reliable enough not to lose published events. In this paper, we present the design of REM, a large scale Replication based type and attribute oriented Event Middleware over structured peer to peer (p2p) network. REM safeguards event losses by replicating the states of a broker in the neighboring overlay nodes. REM provides lossless mobility support to the clients even in a highly dynamic environment.
Enhanced web session mobility based on SIP
Authors: W. Munkongpitakkun, S. Kamolphiwong, S. Sae-Wong
Venue: Proceedings of the 4th international conference on mobile technology, applications, and systems and the 1st international symposium on Computer human interaction in mobile technology (2007)

Web-based session mobility system is capability of moving HTTP session from one device to another device without interrupted and seamless web access, User may be continue using web applications at the same point on a new device without re-login or re-type any information. Web application working on HTTP is stateless protocol. A number of approaches to track web application sessions were presented, for example server-based, proxy-based and client-base. In our recently work we have proposed Web-based session mobility using SIP (Session Initiation Protocol). In this mechanism SIP URL is used instead of IP address of the destination device. This will allow more flexible of finding a target device to move on. By using SIP, we have shown some significant advantages over other schemes, e.g. more benefits, and yet, more simplicity. Moreover, most benefits hold by SIP can be achieved, e.g. present service, call forwarding, call parking. This makes our proposed mechanism more attractive. We have shown how to implement web-based session mobility in real world. In this paper, we have proposed some enhancements of web session mobility based on SIP.
Subspace based feature selection for pattern recognition
Authors: Serkan Gunal, Rifat Edizkan
Venue: Information Sciences: an International Journal (2008)

Feature selection is an essential topic in the field of pattern recognition. The feature selection strategy has a direct influence on the accuracy and processing time of pattern recognition applications. Features can be evaluated with either univariate approaches, which examine features individually, or multivariate approaches, which consider possible feature correlations and examine features as a group. Although univariate approaches do not take the correlation among features into consideration, they can provide the individual discriminatory power of the features, and they are also much faster than multivariate approaches. Since it is crucial to know which features are more or less informative in certain pattern recognition applications, univariate approaches are more useful in these cases. This paper therefore proposes subspace based separability measures to determine the individual discriminatory power of the features. These measures are then employed to sort and select features in a multi-class manner. The feature selection performances of the proposed measures are evaluated and compared with the univariate forms of classic separability measures (Divergence, Bhattacharyya, Transformed Divergence, and Jeffries-Matusita) on several datasets. The experimental results clearly indicate that the new measures yield comparable or even better performance than the classic ones in terms of classification accuracy and dimension reduction rate.