OpenRaiser/Intern-Atlas huggingface dataset:
Genetic-Algorithm Seeding Of Idiotypic Networks For Mobile-Robot Navigation
Venue: arXiv cs.NE 2008
Year: 2008

Robot-control designers have begun to exploit the properties of the human immune system in order to produce dynamic systems that can adapt to complex, varying, real-world tasks. Jernes idiotypic-network theory has proved the most popular artificial-immune-system (AIS) method for incorporation into behaviour-based robotics, since idiotypic selection produces highly adaptive responses. However, previous efforts have mostly focused on evolving the network connections and have often worked with a single, pre-engineered set of behaviours, limiting variability. This paper describes a method for encoding behaviours as a variable set of attributes, and shows that when the encoding is used with a genetic algorithm (GA), multiple sets of diverse behaviours can develop naturally and rapidly, providing much greater scope for flexible behaviour-selection. The algorithm is tested extensively with a simulated e-puck robot that navigates around a maze by tracking colour. Results show that highly successful behaviour sets can be generated within about 25 minutes, and that much greater diversity can be obtained when multiple autonomous populations are used, rather than a single one.
Use of self-correlation metrics for evaluation of information properties of binary strings
Venue: arXiv cs.IT 2008
Year: 2008

It is demonstrated that appropriately chosen computable metrics based on self-correlation properties provide a degree of determinism sufficient to segregate binary strings by level of information content.
Citation Counting, Citation Ranking, and h-Index of Human-Computer Interaction Researchers: A Comparison between Scopus and Web of Science
Venue: arXiv cs.HC 2008
Year: 2008

This study examines the differences between Scopus and Web of Science in the citation counting, citation ranking, and h-index of 22 top human-computer interaction (HCI) researchers from EQUATOR--a large British Interdisciplinary Research Collaboration project. Results indicate that Scopus provides significantly more coverage of HCI literature than Web of Science, primarily due to coverage of relevant ACM and IEEE peer-reviewed conference proceedings. No significant differences exist between the two databases if citations in journals only are compared. Although broader coverage of the literature does not significantly alter the relative citation ranking of individual researchers, Scopus helps distinguish between the researchers in a more nuanced fashion than Web of Science in both citation counting and h-index. Scopus also generates significantly different maps of citation networks of individual scholars than those generated by Web of Science. The study also presents a comparison of h-index scores based on Google Scholar with those based on the union of Scopus and Web of Science. The study concludes that Scopus can be used as a sole data source for citation-based research and evaluation in HCI, especially if citations in conference proceedings are sought and that h scores should be manually calculated instead of relying on system calculations.
Estimation of available bandwidth and measurement infrastructure for Russian segment of Internet
Venue: arXiv cs.NI 2008
Year: 2008

In paper the method for estimation of available bandwidth is supposed which does not demand the advanced utilities. Our method is based on the measurement of network delay $D$ for packets of different sizes $W$. The simple expression for available bandwidth $B_{av} =(W_2-W_1)/(D_2-D_1)$ is substantiated. For the experimental testing the measurement infrastructure for Russian segment of Internet was installed in framework of RFBR grant 06-07-89074.
A Novel Approach to Formulae Production and Overconfidence Measurement to Reduce Risk in Spreadsheet Modelling
Venue: arXiv cs.HC 2008
Year: 2008

Research on formulae production in spreadsheets has established the practice as high risk yet unrecognised as such by industry. There are numerous software applications that are designed to audit formulae and find errors. However these are all post creation, designed to catch errors before the spreadsheet is deployed. As a general conclusion from EuSpRIG 2003 conference it was decided that the time has come to attempt novel solutions based on an understanding of human factors. Hence in this paper we examine one such possibility namely a novel example driven modelling approach. We discuss a control experiment that compares example driven modelling against traditional approaches over several progressively more difficult tests. The results are very interesting and certainly point to the value of further investigation of the example driven potential. Lastly we propose a method for statistically analysing the problem of overconfidence in spreadsheet modellers.
WiFly: experimenting with Wireless Sensor Networks and Virtual coordinates
Venue: arXiv cs.NI 2008
Year: 2008

Experimentation is important when designing communication protocols for Wireless Sensor Networks. Lower-layers have a major impact on upper-layer performance, and the complexity of the phenomena can not be entirely captured by analysis or simulation. In this report, we go through the complete process, from designing an energy-efficient self-organizing communication architecture (MAC, routing and application layers) to real-life experimentation roll-outs. The presented communication architecture includes a MAC protocol which avoids building and maintaining neighborhood tables, and a geographically-inspired routing protocol over virtual coordinates. The application consists of a mobile sink interrogating a wireless sensor network based on the requests issued by a disconnected base station. After the design process of this architecture, we verify it functions correctly by simulation, and we perform a temporal verification. This study is needed to calculate the maximum speed the mobile sink can take. We detail the implementation, and the results of the off-site experimentation (energy consumption at PHY layer, collision probability at MAC layer, and routing). Finally, we report on the real-world deployment where we have mounted the mobile sink node on a radio-controlled airplane.
Exploring Human Factors in Spreadsheet Development
Venue: arXiv cs.HC 2008
Year: 2008

In this paper we consider human factors and their impact on spreadsheet development in strategic decision-making. This paper brings forward research from many disciplines both directly related to spreadsheets and a broader spectrum from psychology to industrial processing. We investigate how human factors affect a simplified development cycle and what the potential consequences are.
Risk Management for Complex Calculations: EuSpRIG Best Practices in Hybrid Applications
Venue: arXiv cs.HC 2008
Year: 2008

As the need for advanced, interactive mathematical models has increased, user/programmers are increasingly choosing the MatLab scripting language over spreadsheets. However, applications developed in these tools have high error risk, and no best practices exist. We recommend that advanced, highly mathematical applications incorporate these tools with spreadsheets into hybrid applications, where developers can apply EuSpRIG best practices. Development of hybrid applications can reduce the potential for errors, shorten development time, and enable higher level operations. We believe that hybrid applications are the future and over the course of this paper, we apply and extend spreadsheet best practices to reduce or prevent risks in hybrid Excel/MatLab applications.
Excelsior: Bringing the Benefits of Modularisation to Excel
Venue: arXiv cs.SE 2008
Year: 2008

Excel lacks features for modular design. Had it such features, as do most programming languages, they would save time, avoid unneeded programming, make mistakes less likely, make code-control easier, help organisations adopt a uniform house style, and open business opportunities in buying and selling spreadsheet modules. I present Excelsior, a system for bringing these benefits to Excel.
Local Approximation Schemes for Topology Control
Venue: arXiv cs.DS 2008
Year: 2008

This paper presents a distributed algorithm on wireless ad-hoc networks that runs in polylogarithmic number of rounds in the size of the network and constructs a linear size, lightweight, (1+ε)-spanner for any given ε> 0. A wireless network is modeled by a d-dimensional α-quasi unit ball graph (α-UBG), which is a higher dimensional generalization of the standard unit disk graph (UDG) model. The d-dimensional α-UBG model goes beyond the unrealistic ``flat world'' assumption of UDGs and also takes into account transmission errors, fading signal strength, and physical obstructions. The main result in the paper is this: for any fixed ε> 0, 0 < α\le 1, and d \ge 2, there is a distributed algorithm running in O(\log n \log^* n) communication rounds on an n-node, d-dimensional α-UBG G that computes a (1+ε)-spanner G' of G with maximum degree Δ(G') = O(1) and total weight w(G') = O(w(MST(G)). This result is motivated by the topology control problem in wireless ad-hoc networks and improves on existing topology control algorithms along several dimensions. The technical contributions of the paper include a new, sequential, greedy algorithm with relaxed edge ordering and lazy updating, and clustering techniques for filtering out unnecessary edges.
Data Fusion Trees for Detection: Does Architecture Matter?
Venue: arXiv cs.IT 2008
Year: 2008

We consider the problem of decentralized detection in a network consisting of a large number of nodes arranged as a tree of bounded height, under the assumption of conditionally independent, identically distributed observations. We characterize the optimal error exponent under a Neyman-Pearson formulation. We show that the Type II error probability decays exponentially fast with the number of nodes, and the optimal error exponent is often the same as that corresponding to a parallel configuration. We provide sufficient, as well as necessary, conditions for this to happen. For those networks satisfying the sufficient conditions, we propose a simple strategy that nearly achieves the optimal error exponent, and in which all non-leaf nodes need only send 1-bit messages.
A General Rate Duality of the MIMO Multiple Access Channel and the MIMO Broadcast Channel
Venue: arXiv cs.IT 2008
Year: 2008

We present a general rate duality between the multiple access channel (MAC) and the broadcast channel (BC) which is applicable to systems with and without nonlinear interference cancellation. Different to the state-of-the-art rate duality with interference subtraction from Vishwanath et al., the proposed duality is filter-based instead of covariance-based and exploits the arising unitary degree of freedom to decorrelate every point-to-point link. Therefore, it allows for noncooperative stream-wise decoding which reduces complexity and latency. Moreover, the conversion from one domain to the other does not exhibit any dependencies during its computation making it accessible to a parallel implementation instead of a serial one. We additionally derive a rate duality for systems with multi-antenna terminals when linear filtering without interference (pre-)subtraction is applied and the different streams of a single user are not treated as self-interference. Both dualities are based on a framework already applied to a mean-square-error duality between the MAC and the BC. Thanks to this novel rate duality, any rate-based optimization with linear filtering in the BC can now be handled in the dual MAC where the arising expressions lead to more efficient algorithmic solutions than in the BC due to the alignment of the channel and precoder indices.
An Indirect Genetic Algorithm for Set Covering Problems
Venue: arXiv cs.NE 2008
Year: 2008

This paper presents a new type of genetic algorithm for the set covering problem. It differs from previous evolutionary approaches first because it is an indirect algorithm, i.e. the actual solutions are found by an external decoder function. The genetic algorithm itself provides this decoder with permutations of the solution variables and other parameters. Second, it will be shown that results can be further improved by adding another indirect optimisation layer. The decoder will not directly seek out low cost solutions but instead aims for good exploitable solutions. These are then post optimised by another hill-climbing algorithm. Although seemingly more complicated, we will show that this three-stage approach has advantages in terms of solution quality, speed and adaptability to new types of problems over more direct approaches. Extensive computational results are presented and compared to the latest evolutionary and other heuristic approaches to the same data instances.
On the Application of Hierarchical Coevolutionary Genetic Algorithms: Recombination and Evaluation Partners
Venue: arXiv cs.NE 2008
Year: 2008

This paper examines the use of a hierarchical coevolutionary genetic algorithm under different partnering strategies. Cascading clusters of sub-populations are built from the bottom up, with higher-level sub-populations optimising larger parts of the problem. Hence higher-level sub-populations potentially search a larger search space with a lower resolution whilst lower-level sub-populations search a smaller search space with a higher resolution. The effects of different partner selection schemes amongst the sub-populations on solution quality are examined for two constrained optimisation problems. We examine a number of recombination partnering strategies in the construction of higher-level individuals and a number of related schemes for evaluating sub-solutions. It is shown that partnering strategies that exploit problem-specific knowledge are superior and can counter inappropriate (sub)fitness measurements.
A Recommender System based on Idiotypic Artificial Immune Networks
Venue: arXiv cs.NE 2008
Year: 2008

The immune system is a complex biological system with a highly distributed, adaptive and self-organising nature. This paper presents an Artificial Immune System (AIS) that exploits some of these characteristics and is applied to the task of film recommendation by Collaborative Filtering (CF). Natural evolution and in particular the immune system have not been designed for classical optimisation. However, for this problem, we are not interested in finding a single optimum. Rather we intend to identify a sub-set of good matches on which recommendations can be based. It is our hypothesis that an AIS built on two central aspects of the biological immune system will be an ideal candidate to achieve this: Antigen-antibody interaction for matching and idiotypic antibody-antibody interaction for diversity. Computational results are presented in support of this conjecture and compared to those found by other CF techniques.
Concurrent Composition and Algebras of Events, Actions, and Processes
Venue: arXiv cs.LO 2008
Year: 2008

There are many different models of concurrent processes. The goal of this work is to introduce a common formalized framework for current research in this area and to eliminate shortcomings of existing models of concurrency. Following up the previous research of the authors and other researchers on concurrency, here we build a high-level metamodel EAP (event-action-process) for concurrent processes. This metamodel comprises a variety of other models of concurrent processes. We shape mathematical models for, and study events, actions, and processes in relation to important practical problems, such as communication in networks, concurrent programming, and distributed computations. In the third section of the work, a three-level algebra of events, actions and processes is constructed and studied as a new stage of algebra for concurrent processes. Relations between EAP process algebra and other models of concurrency are considered in the fourth section of this work.
A Type System for Data-Flow Integrity on Windows Vista
Venue: arXiv cs.CR 2008
Year: 2008

The Windows Vista operating system implements an interesting model of multi-level integrity. We observe that in this model, trusted code can be blamed for any information-flow attack; thus, it is possible to eliminate such attacks by static analysis of trusted code. We formalize this model by designing a type system that can efficiently enforce data-flow integrity on Windows Vista. Typechecking guarantees that objects whose contents are statically trusted never contain untrusted values, regardless of what untrusted code runs in the environment. Some of Windows Vista's runtime access checks are necessary for soundness; others are redundant and can be optimized away.
Performance Evaluation of Multiple TCP connections in iSCSI
Venue: arXiv cs.NI 2008
Year: 2008

Scaling data storage is a significant concern in enterprise systems and Storage Area Networks (SANs) are deployed as a means to scale enterprise storage. SANs based on Fibre Channel have been used extensively in the last decade while iSCSI is fast becoming a serious contender due to its reduced costs and unified infrastructure. This work examines the performance of iSCSI with multiple TCP connections. Multiple TCP connections are often used to realize higher bandwidth but there may be no fairness in how bandwidth is distributed. We propose a mechanism to share congestion information across multiple flows in ``Fair-TCP'' for improved performance. Our results show that Fair-TCP significantly improves the performance for I/O intensive workloads.
The Sizes of Optimal q-Ary Codes of Weight Three and Distance Four: A Complete Solution
Venue: arXiv cs.IT 2008
Year: 2008

This correspondence introduces two new constructive techniques to complete the determination of the sizes of optimal q-ary codes of constant weight three and distance four.
Fourier Spectra of Binomial APN Functions
Venue: arXiv cs.DM 2008
Year: 2008

In this paper we compute the Fourier spectra of some recently discovered binomial APN functions. One consequence of this is the determination of the nonlinearity of the functions, which measures their resistance to linear cryptanalysis. Another consequence is that certain error-correcting codes related to these functions have the same weight distribution as the 2-error-correcting BCH code. Furthermore, for fields of odd degree, our results provide an alternative proof of the APN property of the functions.
Artificial Immune Systems Tutorial
Venue: arXiv cs.NE 2008
Year: 2008

The biological immune system is a robust, complex, adaptive system that defends the body from foreign pathogens. It is able to categorize all cells (or molecules) within the body as self-cells or non-self cells. It does this with the help of a distributed task force that has the intelligence to take action from a local and also a global perspective using its network of chemical messengers for communication. There are two major branches of the immune system. The innate immune system is an unchanging mechanism that detects and destroys certain invading organisms, whilst the adaptive immune system responds to previously unknown foreign cells and builds a response to them that can remain in the body over a long period of time. This remarkable information processing biological system has caught the attention of computer science in recent years. A novel computational intelligence technique, inspired by immunology, has emerged, called Artificial Immune Systems. Several concepts from the immune have been extracted and applied for solution to real world science and engineering problems. In this tutorial, we briefly describe the immune system metaphors that are relevant to existing Artificial Immune Systems methods. We will then show illustrative real-world problems suitable for Artificial Immune Systems and give a step-by-step algorithm walkthrough for one such problem. A comparison of the Artificial Immune Systems to other well-known algorithms, areas for future work, tips & tricks and a list of resources will round this tutorial off. It should be noted that as Artificial Immune Systems is still a young and evolving field, there is not yet a fixed algorithm template and hence actual implementations might differ somewhat from time to time and from those examples given here.
On Ritt's decomposition Theorem in the case of finite fields
Venue: arXiv cs.SC 2008
Year: 2008

A classical theorem by Ritt states that all the complete decomposition chains of a univariate polynomial satisfying a certain tameness condition have the same length. In this paper we present our conclusions about the generalization of these theorem in the case of finite coefficient fields when the tameness condition is dropped.
Stateless and Delivery Guaranteed Geometric Routing on Virtual Coordinate System
Venue: arXiv cs.NI 2008
Year: 2008

Stateless geographic routing provides relatively good performance at a fixed overhead, which is typically much lower than conventional routing protocols such as AODV. However, the performance of geographic routing is impacted by physical voids, and localization errors. Accordingly, virtual coordinate systems (VCS) were proposed as an alternative approach that is resilient to localization errors and that naturally routes around physical voids. However, VCS also faces virtual anomalies, causing their performance to trail geographic routing. In existing VCS routing protocols, there is a lack of an effective stateless and delivery guaranteed complementary routing algorithm that can be used to traverse voids. Most proposed solutions use variants of flooding or blind searching when a void is encountered. In this paper, we propose a spanning-path virtual coordinate system which can be used as a complete routing algorithm or as the complementary algorithm to greedy forwarding that is invoked when voids are encountered. With this approach, and for the first time, we demonstrate a stateless and delivery guaranteed geometric routing algorithm on VCS. When used in conjunction with our previously proposed aligned virtual coordinate system (AVCS), it out-performs not only all geometric routing protocols on VCS, but also geographic routing with accurate location information.
Unified storage systems for distributed Tier-2 centres
Venue: arXiv cs.DC 2008
Year: 2008

The start of data taking at the Large Hadron Collider will herald a new era in data volumes and distributed processing in particle physics. Data volumes of hundreds of Terabytes will be shipped to Tier-2 centres for analysis by the LHC experiments using the Worldwide LHC Computing Grid (WLCG). In many countries Tier-2 centres are distributed between a number of institutes, e.g., the geographically spread Tier-2s of GridPP in the UK. This presents a number of challenges for experiments to utilise these centres efficaciously, as CPU and storage resources may be sub-divided and exposed in smaller units than the experiment would ideally want to work with. In addition, unhelpful mismatches between storage and CPU at the individual centres may be seen, which make efficient exploitation of a Tier-2's resources difficult. One method of addressing this is to unify the storage across a distributed Tier-2, presenting the centres' aggregated storage as a single system. This greatly simplifies data management for the VO, which then can access a greater amount of data across the Tier-2. However, such an approach will lead to scenarios where analysis jobs on one site's batch system must access data hosted on another site. We investigate this situation using the Glasgow and Edinburgh clusters, which are part of the ScotGrid distributed Tier-2. In particular we look at how to mitigate the problems associated with ``distant'' data access and discuss the security implications of having LAN access protocols traverse the WAN between centres.