ppxscal/embedding_network huggingface dataset:
On-chip differentiation of human mesenchymal stem cells into adipocytes
Authors: X. F. Ni, C. Crozatier, L. Sensebé, A. Langonne, L. Wang, Y. Fan, P. G. He, Y. Chen
Venue: Microelectronic Engineering (2008)

A microfluidic chip was designed to produce with four different cell densities after seeding has been fabricated by soft lithography. It consists of eight parallel chambers with a single inlet and a single outlet. Each chamber was divided into four compartments, separated by a row of pillars. Human mesenchymal stem cells (hMSCs) were first grown on-chip using a normal culture medium for one day. Then, the differentiation of hMSCs into adipocytes was successfully induced by the perfusion of a differentiation medium for 14days. The results showed that the differentiation rate of hMSCs in the chip critically depends on the initial cell density. Typically, with the increase of the cell density from 800 to 5000cells/cm^2, the differentiation rate increases from 21% to 41%.
Maximum Likelihood Rate Estimation: With Applications in Image and Video Compression
Authors: Koohyar Minoo, Truong Nguyen
Venue: Proceedings of the Data Compression Conference (2008)

To overcome the computational complexity in making optimized rate-distortion coding decisions (due to the calculation of actual rate) we propose a rate estimation scheme based on the Maximum Likelihood Parameter Estimation (MLPE) method. We derive separate rate estimation expressions for sending: the significance map (SM) and the absolute values and the signs of nonzero code words (R~sm , Rnz av _~ and Rnz s , and respectively). For this derivation we have assumed a uniform quantization scheme with (extended) dead zone which is the most practiced coding scenario for image and video coding schemes today.
Recovering surface reflectance and multiple light locations and intensities from image data
Authors: S. Xu, A. M. Wallace
Venue: Pattern Recognition Letters (2008)

We present a method to recover the reflectance of objects and the parameters of multiple lights using a 3D image acquired by a depth sensor and a stereo intensity pair. Experimental evaluation shows the ability to recover varying diffuse and constant specular reflectance parameters from object images, and simultaneously the locations and intensities of up to three distinct light sources.
Ultra Mobile Broadband Technology Overview
Authors: Michael Wang
Venue: Proceedings of the Communication Networks and Services Research Conference (2008)

This presentation gives in-depth discussion on these issues in Ultra Mobile Broadband communication systems. Topics include: 1. Frame structure, channelization and resource management; 2. Adaptive coding and modulation with HARQ; 3. Interference management: dynamic fractional frequency reuse and power control; 4. Handoff: (1) Disjoint forward and reverse links and intra-carrier handoff; (2) Beacons and inter-carrier handoff; 5. Multi antenna techniques: MIMO spatial multiplexing, single code word and multi code word transmissions, MMSE and MMSE-SIC receivers, spatial rank predication, precoding, beamforming, SDMA, and MIMO pilots; 6. Preamble design, system acquisition and determination;
Efficient Monte Carlo based incremental statistical timing analysis
Authors: Vineeth Veetil, Dennis Sylvester, David Blaauw
Venue: Proceedings of the 45th annual Design Automation Conference (2008)

Modeling and accuracy difficulties exist with traditional SSTA analysis and optimization methods. In this paper we describe methods to improve the efficiency of Monte Carlo-based statistical static timing analysis. We propose a Stratification + Hybrid Quasi Monte Carlo (SH-QMC) approach to reduce the number of samples required for Monte Carlo based SSTA. Our simulations on benchmark circuits up to 90K gates show that the proposed method requires 23.8X fewer samples on average to achieve comparable accuracy in timing estimation as a random sampling approach. Results on benchmark circuits also show that when SH-QMC is performed with multiple parallel threads on a quad core processor, the approach is faster than traditional SSTA with comparable accuracy. SH-QMC scales better than traditional SSTA with circuit size. We also propose an incremental approach to recompute a percentile delay metric after ECO. The results show that on average only 1.4% and 0.7% of original samples need to be evaluated for exact recomputation of the 95th percentile and 99th percentile delays, after sample size reduction using SH-QMC.
A compressed self-index using a Ziv---Lempel dictionary
Authors: Luís M. Russo, Arlindo L. Oliveira
Venue: Information Retrieval (2008)

A compressed full-text self-index for a text T, of size u, is a data structure used to search for patterns P, of size m, in T, that requires reduced space, i.e. space that depends on the empirical entropy (H k or H 0) of T, and is, furthermore, able to reproduce any substring of T. In this paper we present a new compressed self-index able to locate the occurrences of P in O((m + occ)log u) time, where occ is the number of occurrences. The fundamental improvement over previous LZ78 based indexes is the reduction of the search time dependency on m from O(m 2) to O(m). To achieve this result we point out the main obstacle to linear time algorithms based on LZ78 data compression and expose and explore the nature of a recurrent structure in LZ-indexes, the $${\mathcal{T}}_{78}$$ suffix tree. We show that our method is very competitive in practice by comparing it against other state of the art compressed indexes.
Nearest hyperdisk methods for high-dimensional classification
Authors: Hakan Cevikalp, Bill Triggs, Robi Polikar
Venue: Proceedings of the 25th international conference on Machine learning (2008)

In high-dimensional classification problems it is infeasible to include enough training samples to cover the class regions densely. Irregularities in the resulting sparse sample distributions cause local classifiers such as Nearest Neighbors (NN) and kernel methods to have irregular decision boundaries. One solution is to "fill in the holes" by building a convex model of the region spanned by the training samples of each class and classifying examples based on their distances to these approximate models. Methods of this kind based on affine and convex hulls and bounding hyperspheres have already been studied. Here we propose a method based on the bounding hyperdisk of each class - the intersection of the affine hull and the smallest bounding hypersphere of its training samples. We argue that in many cases hyperdisks are preferable to affine and convex hulls and hyperspheres: they bound the classes more tightly than affine hulls or hyperspheres while avoiding much of the sample overfitting and computational complexity that is inherent in high-dimensional convex hulls. We show that the hyperdisk method can be kernelized to provide nonlinear classifiers based on non-Euclidean distance metrics. Experiments on several classification problems show promising results.
Enhancing software engineering education: a creative approach
Authors: Mario Žagar, Ivana Bosnić, Marin Orlić
Venue: Proceedings of the 2008 international workshop on Software Engineering in east and south europe (2008)

Research in software engineering (SE) shows that freshly graduated students are usually not prepared to deal with problems occurring at the workplace. It is important to teach them how to construct the knowledge and solve the problems faced with. In this paper, we present two approaches used in SE courses at the University of Zagreb, Croatia: One approach is a distributed project-based course, where students from Croatia and Sweden work on the projects together, going through the whole life-cycle of creating a software product, while solving different problems, from technical obstacles to handling cultural differences. The other approach focuses on self-constructing the knowledge and presenting it to other students, with students' discussions and a group project in the end of the course. Both approaches enable the practicing of soft skills which in most cases are not adequately represented in SE education.
Enforcing appropriate process execution for exploiting idle resources from outside operating systems
Authors: Yoshihisa Abe, Hiroshi Yamada, Kenji Kono
Venue: ACM SIGOPS Operating Systems Review (2008)

Idle resources can be exploited not only to run important local tasks such as data replication and virus checking, but also to make contributions to society by participating in open computing projects like SETI@home [2]. When executing background processes to utilize such valuable idle resources, we need to explicitly control them so that the user will not be discouraged from exploiting idle resources by foreground performance degradation. Unfortunately, common priority-based schedulers lack such explicit execution control. In addition, to encourage active use of idle resources, a mechanism for controlling background processes should not require modifications to the underlying operating system or user applications. If such modifications are required, the user may be reluctant to employ the mechanism. In this paper, we argue that we can reasonably detect resource contention between foreground and background processes and properly control background process execution at the user level. We infer the existence of resource contention from the approximated resource shares of background processes. Our approach takes advantage of dynamically instrumented probes, which are becoming increasingly popular, in estimating the resource shares. Also, it considers different resource types in combination and can handle varied workloads, including multiple background processes. We show that our system effectively avoids the performance degradation of foreground activities by suspending background processes in an appropriate fashion. Our system keeps the increase in foreground execution time due to background processes below 16.9%, or much lower in most of our experiments. Also, we extend our approach to address undesirable resource allocations to CPU-intensive processes that can occur in multiprocessor environments.
An Agent-Based Simulation of SOA-Ready Devices
Authors: Stamatis Karnouskos, Mian Mohammad Junaid Tariq
Venue: Proceedings of the Tenth International Conference on Computer Modeling and Simulation (2008)

In the future Internet of Things, intelligent embedded devices are expected to not only offer their functionality as a web service, but also to be able to discover and cooperate with other devices and services in a peer-to-peer way. The new capabilities of the emerging infrastructure will have a significant impact on industrial applications, services and business practices. In this paper we explore the simulation of such an infrastructure composed of heterogeneous web-service enabled (SOA-ready) devices with the help of a multi-agent system.
Visualization of unfavorable interactions in protein folds
Authors: Christian X. Weichenberger, Piotr Byzia, Manfred J. Sippl
Venue: Bioinformatics (2008)

Summary: Three dimensional structures of proteins contain errors which often originate from limitations of the experimental techniques employed. Such errors frequently result in unfavorable atomic interactions. Here we present a new web service, called Interaction Viewer, for the visualization and correction of such errors. We show how the Interaction Viewer is used in combination with the NQ-Flipper service to spot strained asparagine and glutamine rotamers and we emphasize the convenience of this service in correcting such errors. Availability: The web service is integrated with the NQ-Flipper service and accessible at http://flipper.services.came.sbg.ac.at Contact: sippl@came.sbg.ac.at
Effect of Packet Shuffler on Parallel TCP Stream Network
Authors: Yutaka Sugawara, Takeshi Yoshino, Hiroshi Tezuka, Mary Inaba, Kei Hiraki
Venue: Proceedings of the Seventh International Conference on Networking (2008)

With the rapid progress of high-performance cluster applications, data transfer between clusters in distant locations becomes more important. But, it is known that it is not easy to get good performance of data transfer using parallel TCP streams on long distance high bandwidth network. In this paper, we microscopically observe parallel TCP streams on 10 gigabit Ethernet (10GbE) network with a bottleneck, then propose, implement, and evaluate Packet Shuffler which balances the throughput of parallel streams. We implement both network analyzer and Packet Shuffleron the multiple-purpose network hardware framework TGNLE-1 which also we designed.
From social power to social importance
Authors: Guido Boella, Luigi Sauro, Leendert van der Torre
Venue: Web Intelligence and Agent Systems (2007)

In this paper we introduce a method to measure the social importance of an agent in a multiagent system, using a directed graph representing dependencies among agents to achieve their goals, so-called dependence graphs pioneered by Castelfranchi, Conte and Sichman. Our measure is derived from van den Brink and Gilles' &beta;-measure to rank agents, using a directed graph representing an abstract dominance relation among agents. In particular, we show how to define power structures and dependence networks from the goals and skills of individual agents, and how to adapt the &beta;-measure for such dependence networks based on their topological properties. Moreover, we show that our notion of social importance can be given an intuitive meaning: it measures the discontent of the other agents in case the agent would leave the society.
A Traffic Analysis of Authentication Methods for Proxy Mobile IPv6
Authors: Jong-Hyouk Lee, Tai-Myoung Chung
Venue: Proceedings of the 2008 International Conference on Information Security and Assurance (isa 2008) (2008)

Proxy Mobile IPv6 has been proposed to enable a network-based mobility support which does not require a mobilehost to be involved in mobility signaling. In the Proxy Mobile IPv6 specification, an authentication procedure is required as an initial part of registration for network access. However, the current specification does not provide the authentication procedure explicitly. Thus, in this paper, we propose authentication methods classified based on security level. Due to the limited resource of wireless networks, we analyze authentication traffic in terms of cost. The presented performance evaluation results demonstrate the impacts of each authentication method.
Dynamic multi-process information flow tracking for web application security
Authors: Susanta Nanda, Lap-Chung Lam, Tzi-cker Chiueh
Venue: Proceedings of the 2007 ACM/IFIP/USENIX international conference on Middleware companion (2007)

Although there is a large body of research on detection and prevention of such memory corruption attacks as buffer overflow, integer overflow, and format string attacks, the web application security problem receives relatively less attention from the research community by comparison. The majority of web application security problems originate from the fact that web applications fail to perform sanity checks on inputs from the network that are eventually used as operands of security-sensitive operations. Therefore, a promising approach to this problem is to apply proper checks on tainted portions of the operands used in security-sensitive operations, where a byte is tainted if it is data/control dependent on some network packet(s). This paper presents the design, implementation and evaluation of a dynamic checking compiler called WASC, which automatically adds checks into web applications used in three-tier internet services to protect them from the most common two types of web application attacks: SQL- and script-injection attack. In addition to including a taint analysis infrastructure for multi-process and multi-language applications, WASC features the use of SQL and HTML parsers to defeat evasion techniques that exploit interpretation differences between attack detection engines and target applications. Experiments with a fully operational WASC prototype show that it can indeed stop all SQL/script injection attacks that we have tested. Moreover, the end-to-end latency penalty associated with the checks inserted by WASC is less than 30% for the test web applications used in our performance study.
Merging neural networks and topological models to re-engineer construction drawings
Authors: Volker Berkhahn, Sandra Tilleke
Venue: Advances in Engineering Software (2008)

In this paper an approach is presented to digitize a drawing, to build up geometric and topologic models, to recognise construction parts and to interpret dimension lines and inscriptions. All recognized parts are transformed into a three-dimensional geometric model which provides all necessary geometric information for a product model. The recognition process of construction parts is based on a line search and topological analysis, which are not suitable for the recognition of drawing inscriptions and hand writings. Because dimension inscriptions deliver significant information about the dimensions of construction parts, a neural Kohonen network is implemented and adapted in order to recognise inscription text. Finally the gained information about dimensions is related to significant details of construction parts.
Energy-efficient connected-coverage in wireless sensor networks
Authors: Ionut Cardei, Mihaela Cardei
Venue: International Journal of Sensor Networks (2008)

This paper addresses the target coverage problem inWireless Sensor Networks (WSNs). Communication and sensing consume energy, therefore, efficient power management can extend network lifetime. In this paper, we consider a large number of sensors randomly deployed to monitor a number of targets. Each target may be redundantly covered by multiple sensors. To conserve energy, we organise sensors in sets activated sucessively. In this paper, we introduce the Connected Set Covers (CSC) problem that has as objective finding a maximum number of set covers such that each sensor node to be activated is connected to the Base Station (BS). A sensor can participate in multiple sensor sets, but the total energy spent in all sets is constrained by the initial energy reserves. We show that the CSC problem is NP-complete and we propose three solutions: an Integer Programming (IP)-based solution, a greedy approach and a distributed and localised heuristic. Simulation results that validate our approaches are also presented.
News Briefs
Authors: Linda Dailey Paulson
Venue: Computer (2008)

Topics covered include "open source" hardware that lets users build devices, a fast wireless data-transfer approach, a haptic vest that makes games more realistic, and techniques for embedding circuits and displays in contact lenses.
An effective algorithm of motif finding problem
Authors: Yong Chen, Guojun Li
Venue: International Journal of Bioinformatics Research and Applications (2008)

Identification of the short DNA sequence motif, which serves as binding targets for transcription factors, is a fundamental problem in both computer science and molecular biology. Especially, finding the subtle motifs with variable gaps is more challenging. In this paper, a new algorithm is presented, which explores some new strategies. Based on a neighbourhood set concept, a new probability matrix is defined, which can capture the target motifs effectively. An iterative restart strategy is used, by which we can use several similar motifs' information to detect the real motif to demonstrate the effectiveness of our algorithm. We test it on several kinds of data and compare it with some other current representation algorithms. Simulation shows that the algorithm can effectively detect the subtle motifs.
Evaluating Performance and Fault Tolerance in a Virtual Large-Scale Disk
Authors: Erianto Chai, Minoru Uehara, Hideki Mori
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications (2008)

Recently, the exchange of data has increased with progress in information technology. The capacity of for storing data is also increasing. However, even if the capacity of global storage becomes extremely large, the capacity of local storage is always limited. Moreover, storage of files larger then the available local storage is impossible. This paper discusses use of a network to construct a cheap, high trust and PB class, decentralized storage system using many hundreds of PCs in an educational environment. The performance of this ‘large-scale virtual disk’ is investigated both during normal operation and in instances of failure.
Generation of isospectral graphs
Authors: Lorenz Halbeisen, Norbert Hungerbühler
Venue: Journal of Graph Theory (1999)

We discuss a discrete version of Sunada's Theorem on isospectral manifolds, which allows the generation of isospectral simple graphs, i.e., nonisomorphic simple graphs that have the same Laplace spectrum. We also consider additional boundary conditions and Buser's transplantation technique applied to a discrete situation. &copy; John Wiley & Sons, Inc. J Graph Theory 31: 255&ndash;265, 1999
Frequency analysis to facilitate the recognition of images
Authors: Yin He, Xin Yan, Lyn Bartram
Venue: Proceedings of the 5th symposium on Applied perception in graphics and visualization (2008)

Content based image retrieval is an approach for facilitating the searching and browsing of large image collections. In this approach, image analysis is conducted on low level visual properties extracted from the image. We believed that in order to create an effective image retrieval system, visual perception must be taken into account. We conjectured that a technique which employs both M and P pathways would be more effective in the discrimination and search tasks of thumbnails. While the P pathway representations are easy to judge by observing color and shape, assessment of M pathway is possible through spatial frequency filtering. In order to validate this claim, a study was conducted to look at how manipulating spatial frequency composition of thumbnails affects visual search time. Thumbnails were sorted using frequency analysis and a user study measured recognition time, correctness of response, and number of repeated trials.
A pricing information service for grid computing
Authors: Alexandru Caracas, Jörn Altmann
Venue: Proceedings of the 5th international workshop on Middleware for grid computing: held at the ACM/IFIP/USENIX 8th International Middleware Conference (2007)

This paper addresses two shortcomings that exist in the area of pricing Grid services in an economic Grid environment. The first shortcoming is that there are no standards for pricing schemes, caused by a large difference in the units that are traded (e.g. CPU cycles or virtual clusters) in Grid computing. The second shortcoming is the lack of a model for managing the pricing of informational elements (e.g. software applications) and computational elements (e.g. virtual machines, which comprise resources such as CPU, memory, disk space, network bandwidth). This paper presents a pricing service for Grid computing services, which resolves the shortcomings by introducing a general pricing scheme for informational and computational elements. We describe the functional requirements, architecture, and the interfaces of the pricing service. The pricing service allows expressing the proposed general pricing scheme as an XML document, which can be linked to service level agreements. Contrary to other proposals on pricing, the pricing service is separated from the functionality of metering, accounting, and payment. To validate the concept of a pricing information service, we portray two Utility Computing scenarios.