ppxscal/embedding_network huggingface dataset:
Chemotopological study of the fourth period mono-hydrides
Authors: Emilbus A. Uribe, Marth C. Daza, Guillermo Restrepo
Venue: Proceedings of the 9th WSEAS International Conference on Computers (2005)

We calculated 7 physico-chemical properties for the 17 fourth period mono-hydrides (E-H). We used the B3LYP/DGZVP theory level for calculating such properties. Afterwards, we applied Principal Component Analysis and Cluster Analysis to the 17 hydrides. Thus, we obtained a hierarchical classification that showed the similarity relationships among the hydrides studied. Afterwards, we extracted the similarity classes from such a hierarchical classification (dendrogram) and we built up a topological basis with those classes. Then, we evaluated the topological structure of some classifications based on the sort of chemical bond that present the different hydrides of the fourth period. The results of these evaluations showed that KH is the interior of the group of ionic hydrides and that CaH appears related to some transition metal hydrides. The topological properties of the metallic group of hydrides showed that the transition metals appear related to the ionic group one hand and to the covalent group on the other hand. Finally, ZnH appeared related to the main-group hydrides of the right side of the periodic table and it did not appear related to the transition metal hydrides.
Reasoning About Multi-Lingual Exception Handling Using RIPLS
Authors: John Ridgway, Jack C. Wileden
Venue: Electronic Notes in Theoretical Computer Science (ENTCS) (2008)

Building multi-lingual software is a practical necessity. At present, with object-oriented programming the dominant paradigm, it is common to assemble software systems comprising components written in at least two different object-oriented languages. Modern object-oriented languages provide exception handling mechanisms as a means of enriching the signatures of methods with a specification of what to do if the method ''fails'', i.e., cannot carry out its intended (normal) function for some reason. Indeed, Java and C++ (and many other object-oriented languages, including C#) have remarkably similar exception handling mechanisms. As we demonstrate, however, those exception handling mechanisms do not necessarily interoperate smoothly when used in multi-lingual software systems. We believe that our long-term goal of maximally effortless and error-free multi-lingual programming requires automated tools that are based on solid formal foundations. Toward that end, we have developed a formal language, which we call RIPLS, that can be used to rigorously study properties of multi-lingual software. In this paper, we demonstrate RIPLS and our approach by using it to study exception handling in multilingual object-oriented systems, and show how use of our methods can identify problems that standard techniques cannot. We then exhibit a correctly-working version of multi-lingual exception-handling and use our methods to confirm its correctness. Finally we discuss how experience with these RIPLS-based methods has informed our designs for automated tools that will implement correctly-working multi-lingual exception handling. This work makes a significant contribution by demonstrating that formal, theoretical foundations can be used to solve practical problems in multi-lingual software development.
On application-level approaches to avoiding TCP throughput collapse in cluster-based storage systems
Authors: Elie Krevat, Vijay Vasudevan, Amar Phanishayee, David G. Andersen, Gregory R. Ganger, Garth A. Gibson, Srinivasan Seshan
Venue: Proceedings of the 2nd international workshop on Petascale data storage: held in conjunction with Supercomputing '07 (2007)

TCP Incast plagues scalable cluster-based storage built atop standard TCP/IP-over-Ethernet, often resulting in much lower client read bandwidth than can be provided by the available network links. This paper reviews the Incast problem and discusses potential application-level approaches to avoiding it.
Dynamic Detection and Tolerance of Attacks in Storage Area Networks
Authors: Yacine Djemaiel, Noureddine Boudriga
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications - Workshops (2008)

Due to the increasing amount of data handled by business applications and the need of an easy way to access data by multiple servers, Storage Area Networks (SANs) have been proposed as a solution to be deployed in enterprises networks. Despite their advantages, a set of security issues are related to these next generation high speed network architectures and that may be a threat to the performance and the availability of such networks. In this paper, we propose an intrusion detection and tolerance system that ensures protection of the SANs against attacks. The proposed solution is based on: a) the management of two areas (virtual area and protected area) at each storage node; b) the cooperation of detection modules running on each SAN component; and c) the use of distributed set of rules that are updated and managed in a secure manner. A case study is given to illustrate the proposed system capabilities in terms of intrusion detection and tolerance.
A Near-Zero Run-Time Energy Overhead within a Computation Outsourcing Framework for Energy Management in Mobile Devices
Authors: Ahmed Abukmail, Abdelsalam (Sumi) Helal
Venue: Proceedings of the Fifth International Conference on Information Technology: New Generations (2008)

In order to support run-time computation outsourcing to save energy, a certain amount of overhead has to be incurred to facilitate appropriate communication. As computation outsourcing is a methodology for saving energy on mobile devices, the amount of overhead incurred must be kept to a minimum. In this work, we support our compile-time methodology to facilitate the outsourcing of intensive computation with a run-time monitoring system that consumes an extremely low amount of energy (near-Zero). This near-Zero overhead resulted from analyzing the code at compile-time rather than run-time execution and profiling. The compile-time strategy utilized in our work analyzes the code at multiple levels of abstraction (High, Medium, and Low). The result of the analysis, which takes advantage of a real-time systems technique that calculates the maximum number of loop iterations, hence giving us a worst-case execution time for each loop within the benchmark application, allows for a fine-grain analysis of our benchmark. Resulting from analyzing the code, a client/server version of the applications is produced. As a result of producing this client/server version, certain run-time support has to take place on both the machine executing the client (the mobile device) as the machine executing the server. Our experimental results as performed on a Sharp Zaurus, utilizing Wi-Fi as a means of communication, showed tremendous energy saving while incurring a near-Zero run-time overhead.
Ankle Actuation for Limit Cycle Walkers
Authors: D.G.E. Hobbelen, M. Wisse
Venue: International Journal of Robotics Research (2008)

Limit Cycle Walkers are bipeds that exhibit a stable cyclic gait without requiring local controllability at all times during gait. Well-known example are McGeer's &#x201C;Passive Dynamic Walkers&#x201D;, but the concept expands to actuated bipeds as involved in this study. Current state-of-the-art Limit Cycle Walkers excel in being very energy efficient, but their ability to handle disturbances (i.e. disturbance rejection) is still limited. A way to improve this ability while maintaining low energy consumption is the use of ankle actuation, which has so far seen few applications in this type of walker. In this paper we study the effect of (1) applying (passive) stiffness in the ankle joint, (2) applying control in the stance ankle based only on local sensor information and (3) modulating ankle push-off. For all three strategies the paper shows how they influence energy use and disturbance rejection of a simple point mass walking model, a more realistic model and a physical prototype. We find that applying a passive ankle spring that results in premature heel rise is energetically optimal and gives an actuation pattern that largely resembles that of humans. Local stance ankle control and ankle push-off modulation can improve the disturbance rejection of a Limit Cycle Walker by at least 60%, without increasing its energy use. These findings are substantiated by showing that our prototype is able to handle large disturbances such as a step-down of 5% of its leg length, while walking efficiently at a mechanical cost of transport of 0.09.
Some Connection Problems with BitTorrent
Authors: Dongliang Guan, Jiangtao Wang, Hui Chen, Jun Dong
Venue: Proceedings of the Seventh International Conference on Networking (2008)

In this paper we released some connection problems with BitTorrent (BT) that we have founded in our four months' experimental study. One connection per IP address is usually used by network application software for flow fairness. However if one connection per IP address is configured with BT there will be some problems in connection setup, which induces some peers not to find some of others even the number of total peers is small. These problems are caused by some bugs in the current BT. All of these problems will be detailed in this paper and modified source codes are also given. We hope this work be helpful for some researchers' experimental study, perfect BT's real use, and arouse similar project's attention to these connection problems.
Non-anchored Unified Naming for Ubiquitous Computing Environments
Authors: Yoo Chul Chung, Dongman Lee
Venue: Proceedings of the 2008 Sixth Annual IEEE International Conference on Pervasive Computing and Communications (2008)

Users and developers require some way to identify by human readable names the many resources that comprise a ubiquitous computing environment. In addition, naming in such environments should work well despite ad~hoc situations, and it should also provide context-based naming. This paper describes the Non-anchored Unified Naming (NUN) system, which satisfies these requirements. It is based on relative naming among resources and provides the ability to name arbitrary types of resources. By having resources themselves take part in naming, resources are able to contribute their specialized knowledge into the name resolution process, making context-dependent mapping of names to resources possible.
Achieving programming model abstractions for reconfigurable computing
Authors: David Andrews, Ron Sass, Erik Anderson, Jason Agron, Wesley Peck, Jim Stevens, Fabrice Baijot, Ed Komp
Venue: IEEE Transactions on Very Large Scale Integration (VLSI) Systems (2008)

This paper introduces hthreads, a unifying programming model for specifying application threads running within a hybrid computer processing unit (CPU)/field-programmable gate-array (FPGA) system. Presently accepted hybrid CPU/FPGA computational models--and access to these computational models via high level languages--focus on programming language extensions to increase accessibility and portability. However, this paper argues that new high-level programming models built on common software abstractions better address these goals. The hthreads system, in general, is unique within the reconfigurable computing community as it includes operating system and middleware layer abstractions that extend across the CPU/FPGA boundary. This enables all platform components to be abstracted into a unified multiprocessor architecture platform. Application programmers can then express their computations using threads specified from a single POSIX threads (pthreads) multithreaded application program and can then compile the threads to either run on the CPU or synthesize them to run within an FPGA. To enable this seamless framework, we have created the hardware thread interface (HWTI) component to provide an abstract, platform-independent compilation target for hardware-resident computations. The HWTI enables the use of standard thread communication and synchronization operations across the software/hardware boundary. Key operating system primitives have been mapped into hardware to provide threads running in both hardware and software uniform access to a set of sub-microsecond, minimal-jitter services. Migrating the operating system into hard-ware removes the potential bottleneck of routing all system service requests through a central CPU.
Effect of Triangular Routing in Mixed IPv4/IPv6 Networks
Authors: Teerapat Sanguankotchakorn, Preeda Jaiton
Venue: Proceedings of the Seventh International Conference on Networking (2008)

The triangular routing is one of the main problem in MIPv4. It leads to many attendant problems, namely the increment of impact of possible network partitions, load on the network and delay in delivering packets. The next generation IPv6 is designed to overcome this kind of problems. However, IPv4 and IPv6 are anticipated to coexist for a period of time. In addition, during IPv4 to IPv6 transition period, when Network Address Translation Protocol Translation (NAT-PT) is used to connect IPv4 and IPv6 networks together, the triangular routing cannot be avoided. In this research, we study the effect of triangular routing and Mobile IP-Application Layer Gateway (MIP-ALG) in mixed IPv4/IPv6 networks using NS-2 simulator. Three traffic models, namely HTTP, FTP and VoIP, are used in our simulation. The performance evaluation criteria are throughput and mean end-to-end delay. The simulation results show that the triangular routing degrades the performance of the mixed IPv4/IPv6 network. It is obvious that triangular routing reduces the peak throughput of HTTP and FTP traffics while it does not affect peak throughput of VoIP traffic. The mean end-to-end delay for HTTP, FTP and VoIP increase 45.45%, 47.61% and 52.74%, respectively. Finally, it is found that MIP-ALG can reduce the triangular routing effect, when direction of transmitting data is from IPv6 to MIPv4 network.
A nearly optimal sensor placement algorithm for boundary coverage
Authors: Andrea Bottino, Aldo Laurentini
Venue: Pattern Recognition (2008)

Locating visual sensors in 2D can be often modeled as an Art Gallery problem. Tasks such as surveillance require observing or ''covering'' the interior of a polygon with a minimum number of sensors or ''guards''. For other tasks, such as inspection and image based rendering, observing the boundaries of the environment is sufficient. As Interior Covering (IC), also Edge Covering (EC) is NP-hard, and no finite algorithm is known for its exact solution. Approximate EC solutions are provided by many heuristic algorithms, but their performances with respect to optimality (minimum number of sensors) is unknown. In this paper, we propose a new EC sensors location technique. The algorithm is incremental, and converges toward the optimal solution. It refines an initial approximation provided by an integer covering algorithm (IEC) where each edge is observed entirely by at least one sensor. A lower bound for the number of sensors, specific of the polygon considered, is used at each step for evaluating the quality of the current solution, and a set of rules are provided for performing a local refinement to reduce the computational burden. The algorithm has been implemented, and tests over hundreds of random polygons show that it supplies solutions very close to and often coincident with the lower bound, and then suboptimal or optimal. In addition, the approximate starting solutions provided by the IEC algorithms are, on the average, close to optimum. The tight lower bound can also be used for testing other EC sensor location algorithms. Running times allow dealing with polygons with up to a few hundreds of edges, which appears adequate for many practical cases. An enhanced version of the algorithm, also taking into account range and incidence constraints, has also been implemented and tested.
Energy efficiency measurement for multimedia audio decoding on embedded systems
Authors: Chu-Hsing Lin, Chih-Hsiong Shih, Jung-Chun Liu, Mao-Hua Cheng, Yan-Wei Lee
Venue: Proceedings of the 2nd international conference on Ubiquitous information management and communication (2008)

Handheld devices with embedded systems are massively used in modern times due to their characteristics of portability and convenience. In addition to the basic general functions, video and audio capabilities are also indispensable to embedded systems. The performance of application software running on embedded devices is limited to the optimization process done by the manufacturers. In this paper, we analyze the energy consumption of multimedia audio decoding on embedded systems. Given the electric power analysis results, we are able to compress audio data with the best energy conservation ability to replay on embedded systems. By fine tuning audio compression settings of various popular codecs, an energy efficient suggestion is provided for devices with embedded systems.
Those Who Will Not Learn From History...
Authors: Greg Wilson
Venue: Computing in Science and Engineering (2008)

Much of today's thinking about computational science education is shaped by the needs of the high-performance minority and the perspective of academic computer science. What most working scientists actually need is basic software development skills. Focusing attention on this will be the best way to make the long-promised computational revolution a reality.
Design of a dynamic distributed mobile computing environment
Authors: Wen-Yew Liang, Yu-Ming Hsieh, Zong-Ying Lyu
Venue: Proceedings of the 13th International Conference on Parallel and Distributed Systems - Volume 02 (2007)

Many of the embedded systems have integrated the features of multimedia, networking, and mobility in a device. With the capability of wireless communication, mobile devices can be connected to share information, and even more, work together to accomplish a more complex job. In this paper, a novel distributed mobile computing model based on the concept of dynamic task group is proposed. Through this dynamic distributed mobile computing (Dynamic-DMC) model, computing resources can be added and removed dynamically according to the availability of the resources. An environment supporting the Dynamic-DMC model, called D2MCE, has also been implemented. In D2MCE, a shared memory abstraction layer is provided for the purpose of easy programming. An example D2MCE program is also given in this paper. The Dynamic-DMC model and the D2MCE implementation can also be used in traditional cluster computing. Initial result shows that the performance of D2MCE is acceptable.
Fast periodic graph exploration with constant memory
Authors: Leszek Gąsieniec, Ralf Klasing, Russell Martin, Alfredo Navarra, Xiaohui Zhang
Venue: Journal of Computer and System Sciences (2008)

We consider the problem of periodic exploration of all nodes in undirected graphs by using a finite state automaton called later a robot. The robot, using a constant number of states (memory bits), must be able to explore any unknown anonymous graph. The nodes in the graph are neither labelled nor coloured. However, while visiting a node v the robot can distinguish between edges incident to it. The edges are ordered and labelled by consecutive integers 1,...,d(v) called port numbers, where d(v) is the degree of v. Periodic graph exploration requires that the automaton has to visit every node infinitely many times in a periodic manner. In this paper, we are interested in minimisation of the length of the exploration period. In other words, we want to minimise the maximum number of edge traversals performed by the robot between two consecutive visits of a generic node, in the same state and entering the node by the same port. Note that the problem is unsolvable if the local port numbers are set arbitrarily, see [L. Budach, Automata and labyrinths, Math. Nachr. 86 (1978) 195-282]. In this context, we are looking for the minimum function @p(n), such that, there exists an efficient deterministic algorithm for setting the local port numbers allowing the robot to explore all graphs of size n along a traversal route with the period @p(n). Dobrev et al. proved in [S. Dobrev, J. Jansson, K. Sadakane, W.-K. Sung, Finding short right-hand-on-the-wall walks in graphs, in: Proc. 12th Colloquium on Structural Information and Communication Complexity, SIROCCO 2005, in: Lecture Notes in Comput. Sci., vol. 3499, Springer, Berlin, 2005, pp. 127-139] that for oblivious robots @p(n)==2n-2 holding for any robot.
Robust approach for suburban road segmentation in high-resolution aerial images
Authors: D. Guo, A. Weeks, H. Klee
Venue: International Journal of Remote Sensing (2007)

The goal of this research is to develop an algorithm that accurately segments high-resolution images, where linear features, such as roads, are corrupted by noise. In high-resolution images, there are two types of noises that are obstacles to road segmentation. Noise could be within road areas (such as cars, water, differences in composite road surface mix) or unwanted contents outside road areas, like buildings and trees. To remove unwanted contents, the geographical information from the United States Geographical Survey (USGS) is used. The USGS provides a collection of road centre line information that has been collected for many years and can be used to limit the area for road segmentations close to roads. In this paper, a standard process was developed to align the USGS geographical information with the high-resolution images. USGS geographical data is used to eliminate background clutter that is disjunct from roads. The road segmentation process is then reduced to dealing with automobile traffic, shadows and pavement colour discontinuity within road areas. In order to achieve reliable road segmentation in the presence of these objects, the mean-shift clustering approach is used within the hue-saturation-intensity (HSI) space. Conditional morphological image processing techniques are also used to significantly improve the segmentation results. The proposed method results in the average accuracy of road segmentation above 85%.
How to Think About Algorithms
Authors: Jeff Edmonds
Venue:  (2008)

There are many algorithm texts that provide lots of well-polished code and proofs of correctness. This book is not one of them. Instead, this book presents insights, notations, and analogies to help the novice describe and think about algorithms like an expert. By looking at both the big picture and easy step-by-step methods for developing algorithms, the author helps students avoid the common pitfalls. He stresses paradigms such as loop invariants and recursion to unify a huge range of algorithms into a few meta-algorithms. Part of the goal is to teach the students to think abstractly. Without getting bogged with formal proofs, the book fosters a deeper understanding of how and why each algorithm works. These insights are presented in a slow and clear manner accessible to second- or third-year students of computer science, preparing them to find their own innovative ways to solve problems.
Learning dissimilarities by ranking: from SDP to QP
Authors: Hua Ouyang, Alex Gray
Venue: Proceedings of the 25th international conference on Machine learning (2008)

We consider the problem of learning dissimilarities between points via formulations which preserve a specified ordering between points rather than the numerical values of the dissimilarities. Dissimilarity ranking (d-ranking) learns from instances like "A is more similar to B than C is to D" or "The distance between E and F is larger than that between G and H". Three formulations of d-ranking problems are presented and new algorithms are presented for two of them, one by semidefinite programming (SDP) and one by quadratic programming (QP). Among the novel capabilities of these approaches are out-of-sample prediction and scalability to large problems.