bluuebunny/crossref_metadata_2025 huggingface dataset:
Regression testing of multi-tasking real-time systems
Authors: Sundmark Daniel , Pettersson Anders , Thane Henrik
Published: January 2007

Regression testing is one of the most intricate parts of software development and maintenance. In complex multi-tasking real-time systems, task interleaving issues, deadlines and other factors further complicate this activity. In all software, however, the process of regression testing comes down to two basic activities: (1) selecting which test cases to re-execute and (2) actually performing the re-tests.The twofold contribution of this paper is the definition of the following problems: The regression test selection problem and the reproducibility problem for multi-tasking real-time system regression testing.
RTES demo system2004
Authors: Ahuja Shikha , Bapty Ted , Cheung Harry , Haney Michael , Kalbarczyk Zbigniew , Khanna Akhilesh , Kowalkowski Jim , Messie Derek , Mosse Daniel , Neema Sandeep , Nordstrom Steve , Oh Jae , Sheldon Paul , Shetty Shweta , Wang Long , Yao Di
Published: January 2007

The RTES Demo System 2004 is a prototype for reliable, fault-adaptive infrastructure applicable to commodity-based dedicated application computer farms, such as the Level 2/3 trigger for the proposed BTeV high energy physics project. This paper describes the prototype, and its demonstration at the 11th IEEE Real Time and Embedded Technology Applications Symposium, RTAS 2005.
Enabling WCET-based composition of service-based real-time applications
Authors: Estévez-Ayres Iria , García-Valls Marisol , Basanta-Val Pablo
Published: January 2007

This paper presents an approach towards a framework that enables the composition of real-time applications from existing ubiquitous services. This framework allows to announce services (specifying their QoS requirements in terms of real-time parameters, such as Worst Case Execution Time, WCET), to discover services that perform a certain functionality, and to select the set of those discovered services that will be part of the application to be created. Such service set selection is based on the fulfilment of the QoS requirements of the application. The framework supports static composition, i.e., all services required to create an application have to be discovered before launching the whole application. Finally, it is described the composition model used in the framework.
Prevention of failures due to assumptions made by software components in real-time systems
Authors: Tirumala Ajay , Crenshaw Tanya , Sha Lui , Baliga Girish , Kowshik Sumant , Robinson Craig , Witthawaskul Weerasak
Published: January 2007

Large scale real-time systems consist of hundreds of commercial off-the-shelf (COTS) and custom software components. Mismatched assumptions between software components are a prime source of failures in these systems. Further, component assumptions are often implicit due to the limitations of current software interfaces. In this work, we introduce a framework to explicitly expose assumptions in software components, and automatically verify these assumptions during system integration. We manage the propagation and composition of these assumptions in the presence of changes and upgrades to individual components.
A rule-based approach to norm-oriented programming of electronic institutions
Authors: García-Camino A. , Rodríguez-Aguilar J. A. , Sierra C. , Vasconcelos W.
Published: January 2007

Norms constitute a powerful coordination mechanism among heterogeneous agents. We propose means to specify and explicitly manage the normative positions of agents (permissions, prohibitions and obligations), with which distinct deontic notions and their relationships can be captured. Our rule-based formalism includes constraints for more expressiveness and precision and allows the norm-oriented programming of electronic institutions: normative aspects are given a precise computational interpretation. Our formalism has been conceived as a machine language to which other higher-level normative languages can be mapped, allowing their execution, as we illustrate with a selection of examples from the literature.
A classification scheme for computer program libraries
Authors: Krogh Fred T.
Published: January 2007

We hope to adopt a new classification scheme for the Collected Algorithms of the ACM and TOMS. The (incomplete) classification scheme given below indicates the direction of our thinking. Since this represents a radical departure from current schemes, it seems prudent to solicit opinions on the direction taken before proceeding further. We are also in dire need of assistance in classifications from I on. Some of these classifications will certainly be eliminated if no one thinks they are worth developing. Other classifications will be added if a good case for doing so can be made.
The components of conversion cost
Authors: Boche Ray
Published: January 2007

Not long ago, the university installation I manage was asked by one of our control agencies to provide estimates of conversion time (hence cost) for a planned major upgrade of our systems. I took a deep breath, swallowed hard, and delegated full responsibility to our assistant director with strict instructions not to show me what he did. He is very good, and so I know that he will have carefully reviewed the 300 or so major programs we support, tried to assess their complexity, level of documentation, file structures, and so on. The resulting hodgepodge of subjective judgments and wild guesses would be painful to think about, even if the programs weren't in a constant state of flux. Fortunately, he is also very shrewd, and so I know how he must have arrived at our estimate. It would have gone something like this: Well, if I come up with, say, four years, people will panic and decide we can't afford to upgrade at all, and we will wind up procrastinating indefinitely with other things getting progressively worse. If I come up with an estimate of four weeks, our users will expect instant results and wonder what we've been doing all these years; we'll get the upgrade sooner, but then we'll be in serious trouble coping with every little glitch that pops up. The question then is, what is the maximum time we can allow to iron the wrinkles out of the conversion without placing the upgrade itself in jeopardy? Now, it would be "unprofessional" to estimate conversion time by licking a finger, holding it in the wind and saying, "Oh, about four months." However, once you've decided what the traffic will bear, the entries in an elaborate tabular arrangement of programs and files classified by lengths, complexities, and special difficulties, can be assigned appropriate coefficients to be multiplied, added, etc. Lo and behold, the final result is four months. (Of course, footnotes and disclaimers will reveal that conversion time and effort may vary for individual applications as scheduled use and unforseen problems demand.)
With J
Authors: Reiter Cliff
Published: January 2007

Using Red-Green-Blue triples to describe colors is common and often quite convenient. However, other color models may be more convenient or appropriate for many types of image analysis and processing. We will discuss conversion between RGB and YUV, YIQ, HSV, HLS, HSI color spaces. We create histograms of the distribution of the color components in those spaces and give examples of how to correct defects and make improvements in various color spaces.
Evolutionary computation at American Air Liquide
Authors: Harper Charles Neely
Published: January 2007

Air Liquide is the world leader in industrial and medical gases and related services. The Group offers innovative solutions based on constantly enhanced technologies. These solutions, which are consistent with Air Liquide's commitment to sustainable development, help to protect life and enable our customers to manufacture many indispensable everyday products. Founded in 1902, Air Liquide has nearly 36,000 employees and is present in more than 70 countries. Sales in 2005 totalled 10,435 million euros.
Open BEAGLE
Authors: Gagné Christian , Parizeau Marc
Published: January 2007

Numerous Evolutionary Computations (EC) software tools are now publicly available to the community - see for instance [1] and [2] for a listing of the most well known. The majority of these tools are specific to a particular EC flavor, however, only a few are truly generic EC softwares [3]. The highly diverse and adaptable nature of Evolutionary Algorithms (EA) make generic EC software tools a must-have for rapid prototyping of new approaches. As we all know, EC comprises a broad family of techniques where populations of solutions to problems are represented by some appropriate data structures (e.g. bit strings, real-valued vectors, trees, etc.) on which variation operators (e.g. mutation, crossover, etc.) are applied using iterative algorithms inspired from natural evolution. Different fitness measures can also be used, with one or several objectives, and it is possible to coevolve several species of solutions, with different species represented by possibly different data structures.
Performance and reliability
Authors: Reed Daniel A.
Published: January 2007

Legend says that Archimedes remarked, on the discovery of the lever, "Give me a place to stand and I can move the world." Today, computing pervades all aspects of society. "Science" and "computational science" have become largely synonymous, and computing is the intellectual lever that opens the pathway to discovery in diverse domains. As new discoveries increasingly lie at the interstices of traditional disciplines, computing is also the enabler for scholarship in the arts, humanities, creative practice and public policy. Equally importantly, computing supports our critical infrastructure, from monetary and communication systems to the electric power grid.With such pervasive dependence, computing system reliability and performance are ever more critical. Although the mean time before failure (MTBF) of commodity hardware components (i.e., processors, disks, memories, power supplies and networks) is high, their use in large, mission critical systems can still lead to systemic failures. Our thesis is that the "two worlds" of software -- distributed systems and sequential/parallel systems -- must meet, embodying ideas from each, if we are to build resilient systems. This talk surveys some of these challenges and presents possible approaches for resilient design, ranging from intelligent hardware monitoring and adaptation, through low-overhead recovery schemes, statistical sampling and differential scheduling and to alternative models of system software, including evolutionary adaptation.
Stardust
Authors: Thereska Eno , Salmon Brandon , Strunk John , Wachs Matthew , Abd-El-Malek Michael , Lopez Julio , Ganger Gregory R.
Published: January 2007

Performance monitoring in most distributed systems provides minimal guidance for tuning, problem diagnosis, and decision making. Stardust is a monitoring infrastructure that replaces traditional performance counters with end-to-end traces of requests and allows for efficient querying of performance metrics. Such traces better inform key administrative performance challenges by enabling, for example, extraction of per-workload, per-resource demand information and per-workload latency graphs. This paper reports on our experience building and using end-to-end tracing as an on-line monitoring tool in a distributed storage system. Using diverse system workloads and scenarios, we show that such fine-grained tracing can be made efficient (less than 6% overhead) and is useful for on- and off-line analysis of system behavior. These experiences make a case for having other systems incorporate such an instrumentation framework.
Impacts of channel variability on link-level throughput in wireless networks
Authors: Koksal Can Emre , Jamieson Kyle , Telatar Emre , Thiran Patrick
Published: January 2007

We study analytically and experimentally the throughput of the packetized time-varying discrete erasure channel with feedback, which closely captures the behavior of many practical physical layers. We observe that the channel variability at different time scales affects the link-level throughput positively or negatively depending on its time scale. We show that the increased variability in the channel at a time scale smaller than a single packet increases the link-level throughput, whereas the variability at a time scale longer than a single packet reduces it. We express the throughput as a function of the number of transmissions per packet and evaluate it as in terms of the cumulants of the samples of the stochastic processes, which model the channel. We also illustrate our results experimentally using mote radios.
GPS scheduling
Authors: Lieshout P. , Mandjes M. , Borst S.
Published: January 2007

We consider a system with two service classes with heterogeneous traffic characteristics and Quality-of-Service requirements. The available bandwidth is shared between the two traffic classes in accordance with the Generalized Processor Sharing (GPS) discipline. GPS-based scheduling algorithms, such as Weighted Fair Queueing, provide a popular mechanism for service differentiation among heterogeneous traffic classes. While the performance of GPS for given weights has been thoroughly examined, the problem of selecting weight values that maximize the traffic-carrying capacity, has only received limited attention so far. In the present paper, we address the latter problem for the case of general Gaussian traffic sources. Gaussian models cover a wide variety of both long-range dependent and short-range dependent processes, and are especially suitable at relatively high levels of aggregation. In particular, we determine the realizable region, i.e., the combinations of traffic sources that can be supported for given Quality-of-Service requirements in terms of loss and delay metrics. The results yield the remarkable observation that simple priority scheduling strategies achieve nearly the full realizable region.
1
.
NetQuest
Authors: Song Han Hee , Qiu Lili , Zhang Yin
Published: January 2007

In this paper, we present NetQuest, a flexible framework for large-scale network measurement. We apply
Bayesian experimental design
to select active measurements that maximize the amount of information we gain about the network path properties subject to given resource constraints. We then apply
network inference
techniques to reconstruct the properties of interest based on the partial, indirect observations we get through these measurements.By casting network measurement in a general Bayesian decision theoretic framework, we achieve flexibility. Our framework can support a variety of design requirements, including (i) differentiated design for providing better resolution to certain parts of the network, (ii) augmented design for conducting additional measurements given existing observations, and (iii) joint design for supporting multiple users who are interested in different parts of the network. Our framework is also
scalable
and can design measurement experiments that span thousands of routers and end hosts.We develop a toolkit that realizes the framework on PlanetLab. We conduct extensive evaluation using both real traces and synthetic data. Our results show that the approach can accurately estimate network-wide and individual path properties by only monitoring within 2-10% of paths. We also demonstrate its effectiveness in providing differentiated monitoring, supporting continuous monitoring, and satisfying the requirements of multiple users.
Robust traffic matrix estimation with imperfect information
Authors: Zhao Qi , Ge Zihui , Wang Jia , Xu Jun
Published: January 2007

Estimation of traffic matrices, which provide critical input for network capacity planning and traffic engineering, has recently been recognized as an important research problem. Most of the previous approaches infer traffic matrix from either SNMP link loads or sampled NetFlow records. In this work, we design novel inference techniques that, by statistically correlating SNMP link loads and sampled NetFlow records, allow for much more accurate estimation of traffic matrices than obtainable from either information source alone, even when sampled NetFlow records are available at only a subset of ingress. Our techniques are practically important and useful since both SNMP and NetFlow are now widely supported by vendors and deployed in most of the operational IP networks. More importantly, this research leads us to a new insight that SNMP link loads and sampled NetFlow records can serve as "error correction codes" to each other. This insight helps us to solve a challenging open problem in traffic matrix estimation, "How to deal with dirty data (SNMP and NetFlow measurement errors due to hardware/software/transmission problems)?" We design techniques that, by comparing notes between the above two information sources, identify and remove dirty data, and therefore allow for accurate estimation of the traffic matrices with the cleaned dat.We conducted experiments on real measurement data obtained from a large tier-1 ISP backbone network. We show that, when full deployment of NetFlow is not available, our algorithm can improve estimation accuracy significantly even with a small fraction of NetFlow data. More importantly, we show that dirty data can contaminate a traffic matrix, and identifying and removing them can reduce errors in traffic matrix estimation by up to an order of magnitude. Routing changes is another a key factor that affects estimation accuracy. We show that using them as the a priori, the traffic matrices can be estimated much more accurately than those omitting the routing change. To the best of our knowledge, this work is the first to offer a comprehensive solution which fully takes advantage of using multiple readily available data sources. Our results provide valuable insights on the effectiveness of combining flow measurement and link load measurement.
An efficient algorithm for the exact analysis of multiclass queueing networks with large population sizes
Authors: Casale Giuliano
Published: January 2007

We introduce an efficient algorithm for the exact analysis of closed multiclass product-form queueing network models with large population sizes. We adopt a novel approach, based on linear systems of equations, which significantly reduces the cost of computing normalizing constants. With the proposed algorithm, the analysis of a model with
N
circulating jobs of multiple classes requires essentially the solution of
N
linear systems with order independent of population sizes.A distinguishing feature of our approach is that we can immediately apply theorems, solution techniques, and decompositions for linear systems to queueing network analysis. Following this idea, we propose a block triangular form of the linear system that further reduces the requirements, in terms of both time and storage, of an exact analysis. An example illustrates the efficiency of the resulting algorithm in presence of large populations.
Transient analysis of tree-Like processes and its application to random access systems
Authors: Van Velthoven J. , Van Houdt B. , Blondia C.
Published: January 2007

A new methodology to assess transient performance measures of tree-like processes is proposed by introducing the concept of tree-like processes with marked time epochs. As opposed to the standard tree-like process, such a process marks part of the time epochs by following a set of Markovian rules. Our interest lies in obtaining the system state at the
n
-th marked time epoch as well as the mean time at which this
n
-th marking occurs. The methodology transforms the transient problem into a stationary one by applying a discrete Erlangization and constructing a reset Markov chain. A fast algorithm, with limited memory usage, that exploits the block structure of the reset Markov chain is developed and is based, among others, on Sylvester matrix equations and fast Fourier transforms. The theory of tree-like processes generalizes the well-known paradigm of Quasi-Birth-Death Markov chains and has various applications. We demonstrate our approach on the celebrated Capetanakis-Tsybakov-Mikhailov (CTM) random access protocol yielding new insights on its initial behavior both in normal and overload conditions.
An analytical model for cache replacement policy performance
Authors: Guo Fei , Solihin Yan
Published: January 2007

Due to the increasing gap between CPU and memory speed, cache performance plays an increasingly critical role in determining the overall performance of microprocessor systems. One of the important factors that a affect cache performance is the cache replacement policy. Despite the importance, current analytical cache performance models ignore the impact of cache replacement policies on cache performance. To the best of our knowledge, this paper is the first to propose an analytical model which predicts the performance of cache replacement policies. The input to our model is a simple circular sequence profiling of each application, which requires very little storage overhead. The output of the model is the predicted miss rates of an application under different replacement policies. The model is based on probability theory and utilizes Markov processes to compute each cache access' miss probability. The model realistic assumptions and relies solely on the statistical properties of the application, without relying on heuristics or rules of thumbs. The model's run time is less than 0.1 seconds, much lower than that of trace simulations. We validate the model by comparing the predicted miss rates of seventeen Spec2000 and NAS benchmark applications against miss rates obtained by detailed execution-driven simulations, across a range of different cache sizes, associativities, and four replacement policies, and show that the model is very accurate. The model's average prediction error is 1.41%,and there are only 14 out of 952 validation points in which the prediction errors are larger than 10%.
Robust network connectivity
Authors: Peserico Enoch , Rudolph Larry
Published: January 2007

This work analyzes the connectivity of large diameter networks where every link has an independent probability p of failure. We give a (relatively simple) topological condition that guarantees good connectivity between regions of such a network. Good connectivity means that the regions are connected by nearly as many disjoint, fault-free paths as there are when the entire network is fault-free. The topological condition is satisfied in many cases of practical interest, even when two regions are at a distance much larger than the expected "distance between faults", 1/p. We extend this result to networks with failures on nodes, as well as geometric radio networks with random distribution of nodes in a deployment area of a given topography.A rigorous formalization of the intuitive notion of "hole" in a (not necessarily planar) graph is at the heart of our result and our proof. Holes, in the presence of faults, degrade connectivity in the region "around" them to a distance that grows with the size of the hole and the density of faults. Thus, to guarantee good connectivity between two regions even in the presence of faults, the intervening network should not only sport multiple paths, but also not too many large holes.Our result essentially characterizes networks where connectivity depends on the "big picture" structure of the network, and not on the local "noise" caused by faulty or imprecisely positioned nodes and links.
Throughput performance of popular JMS servers
Authors: Menth Michael , Henjes Robert , Zepfel Christian , Gehrsitz Sebastian
Published: January 2007

The Java Messaging Service (JMS) facilitates communication among distributed software components according to the publish/subscribe principle. If the subscribers install filter rules on the JMS server, JMS can be used as a message routing platform, but it is not clear whether its message throughput is sufficiently high to support large-scale systems. In this paper, we investigate the capacity of three high performance JMS server implementations: FioranoMQ, SunMQ, and WebsphereMQ. In contrast to other studies, we focus on the message throughput in the presence of filters and show that filtering reduces the performance significantly. We present models for the message processing time of each server and validate them by measurement.
A characterization of a java-based commercial workload on a high-end enterprise server
Authors: Steiner Ian M. , Shuf Yefim
Published: January 2007

While past studies with simple Java benchmarks like SPECjvm98 and SPECjbb2000 have been integral in advancing the industry, this paper illustrates some of the characteristics of a more complex and realistic 3-Tier J2EE (Java 2 Enterprise Edition) commercial workload, SPECjAppServer2004.
In the course of this study, we both validate and disprove certain assumptions commonly made by researchers about Java workloads. For instance, on a tuned system having a heap of the appropriate size, the fraction of CPU time spent on garbage collection (GC) for this complex workload is small (<2%) compared to commonly studied benchmarks like SPECjbb2000 and SPECjvm98.
In addition to high-level statistics on garbage collection and the execution profile, detailed hardware performance characteristics, such as the branch misprediction rates and lock contention, are evaluated and used to motivate future research directions. We also use statistical correlation to evaluate and compare the relative significance of different hardware events to the overall performance of the system.
On the visualization of the DNA sequence and its nucleotide content
Authors: Mylläri Aleksandr , Salakoski Tapio , Pasechnik Alexey
Published: January 2007

Visual inspection can help reveal patterns that would be computationally rather difficult to reveal. We consider three different algorithms for visualizations of a DNA sequence and its nucleotide content: random walk, fractal and visualization based on the entropy-like parameters calculated using a sliding window. We present a program that uses these three methods and visualizes either the whole of a given sequence, or specified fragments. It also provides facilities to compare visualizations obtained for different sequences/fragments. Random walk visualization considers the sequence symbol-by-symbol; the other two methods also take into account how well nucleotides are "mixed" in the sequence. It allows an easy visualization of repeated patterns, segments with a high/low content of some nucleotides, such as CG-islands, etc. The program also helps to identify regions of interest for further study.
Gerunds and representations
Authors: Bernecky Robert , Hui Roger K. W.
Published: January 2007

Gerunds, verbal forms that can be used as nouns, are recognized as having utility in the realm of programming languages. We show that gerunds can be viewed as arrays of atomic representations of verbs (functions), in a way which is consistent with the syntax and semantics of APL, and which allows verbs to be first class objects in the language. We define derivations of verbs from gerunds in the J dialect of APL, and show how these derivations provide control structures for sequencing, selection (in the sense of generalized forms of CASE or SWITCH statements and IF/THEN/ELSE), iteration (DO UNTIL), recursion, and parallel computation (MIMD, or Multiple Instruction, Multiple Data). We conclude with alternative representations of verbs which are useful in other contexts.
APL technology of computer simulation
Authors: Boozin A. Yu , Pospelov I. G.
Published: January 2007

The advantages and disadvantages of APL language usage for computer simulation are considered. The language has been actively used in the Computing Center for the last ten years for simulation of socio-economic systems. The original software package was developed with the aid of APL★PLUS/PC. This package makes simulation research easy and helps to get the results in graphical form.
An N-dimensional data structure in support of electronic data interchange (EDI) translation
Authors: Brigham Georges , Shaw Edward
Published: January 2007

A method is described by which data in a database system are named using sets. The sets exist in an n-dimensional data space in which each axis represents a homogeneous set and all axes (sets) are orthogonal. Data are represented as mathematical functions of relationships between the sets. Data are named using an ordered combination of the names of the sets. An executable language is used to describe relationships between the sets and to query the database. This methodology lends itself quite conveniently to APL and currently forms the foundation for a robust commercial application performing electronic data interchange (EDI) translation.
An interactive data analysis system developed under APL
Authors: Day Peter I.
Published: January 2007

Unocal Science & Technology Division has used STSC APL*PLUS to build a software package --- PC-LogIC --- for analyzing data from oil-wells. Such data is routinely gathered from a variety of electrical, mechanical, and nuclear sensors lowered into the well-bore and, for our purposes, can be regarded as coincident depth-series vectors. PC-LogIC was designed to allow the data analyst to perform two key tasks: rapid "visualizing" of the data; and selecting algorithms and parameters for interpreting the data.APL has been used to fulfill two different needs. At a fundamental level, there is one set of algorithms that actually performs the data analysis. At a higher level, not necessarily tied to the type of data being analyzed, is a second set of functions that provides an interactive interface between the user, the data and the interpretation algorithms. This interface is provided through menus that operate in both text and graphics mode, through text-entry panels, and through an extensive series of graphical routines. In text mode operation, considerable use has been made of □WIN and related functions under keyboard control, whereas in graphics mode □G-style graphics have been used, with mouse control provided through □INT 51. A demonstration of PC-LogIC, concentrating on the higher-level interface, will be given on a 386/AT-compatible machine.
Using boolean of integer arrays to analyze networks
Authors: Fordyce Kenneth , Morreale Mario , Jantzen Jan , Sullivan Gerald
Published: January 2007

A critical computational requirement for many of the decision technologies in the fields of operations research (PERT/CPM, Markov chains, decision trees, Bayesian analysis, MRP, simulation, …), artificial intelligence (evidential reasoning, truth maintenance systems, propositional logic, rule based inference, frames and semantic nets, …), and decision support systems (worksheet or financial planning models, data / entity models, …) is the development and manipulation of a function network or directed graph describing the relationship between "variables", "objects", or "actors" involved in the application of the decision technology to a specific problem. The manipulation of such networks or graphs using Boolean matrices and vector of integer vectors is well known in portions of the APL community (see bibliography), but intertwined with specific applications and spread out across a variety sources (some of which are difficult to obtain). This paper succinctly and simply describes the basics of manipulating a function network with Boolean matrices and integer vectors including focusing networks, finding circular conditions (A depends on B, B depends on C, C depends on A, therefore A depends on A, …), and grouping functions based on relative independence to identify parallel computational opportunities and substantially reduces the non-procedural aspect of the problem.
Psycho-biographical analysis with APL
Authors: Kondrashev Andrew V. , Kronik Alexander A.
Published: January 2007

This paper deals with computer methods of psychological age measuring, psycho-biographical express-diagnostics of personality, and data analysis with APL.
The dual structure of ordered trees
Authors: Langlet Gérard A.
Published: January 2007

Although they were described by K. Iverson in his 1962 book [1], ordered trees have never been implemented as APL objects. However, APL2 as well as ISO-APL, provide many facilities to handle them. This paper illustrates with simple examples, the duality between the tree-structure and what will be presented as an "object-oriented definition structure". APL functions are proposed to facilitate the conversion of one form into the other one. Trees have great utility in data base processing, as well in science, as in business applications. Interfaces with the "outer world" - e.g. word processors, or LISP and PROLOG can become easy to build with the help of this simple concept of duality.
APLITDS
Authors: Spinicci Carlo Alberto
Published: January 2007

In spite of its tremendous expressive power, APL lacks a convenient environment for developing large, interactive systems. The workspace structure prevents easy sharing of code and the realization of user interfaces is at least as difficult as in other languages. This paper describes an integrated development environment that attempts to overcome these limitations.
Automated SQL documentation using APL2
Authors: Swain Rexford H.
Published: January 2007

An application programmer working with APL2 and SQL/DS will often want to investigate and/or document the definitions of SQL tables and views, particularly when working with tables created by others. Unlike conventional APL file systems, SQL "knows" quite a bit about the objects it is storing, but this information is scattered throughout several system catalogs. An APL2 tool which combines and neatly formats available information about a table is presented.Interpretation of this information may point out conditions which are causing SQL to perform less than optimally. Some issues which influence SQL performance are considered, and some general guidelines for improving performance are suggested.Some familiarity with APL2 and SQL is assumed."SQL" should be understood to mean IBM's SQL/DS for VM systems. But other SQL-based database managers, such as DB2, are very similar.
Comparison of the functional power of APL2 and FORTRAN 90
Authors: Willhoft Robert G.
Published: January 2007

APL and Fortran, although very different, share the challenge of remaining "competitive" in the light of an onslaught of "modern" computer languages. To meet this challenge, both have attempted to enhance their position by adding significant new features to their language. For example, APL2 is an extension of APL.Fortran has also attempted to meet the challenges of modern programming by developing a new Fortran standard called Fortran 90. This standard revises many areas of Fortran, but this paper will only concentrate on those that affect the computational power of Fortran. Many of the changes were motivated by the increased use of vector and array "supercomputers." Therefore, array features, the ability to act on entire arrays instead of individual elements, are an important part of this new standard. In doing this work, the Fortran community looked to APL as an example of a powerful array language.This paper will answer several questions regarding this new standard. First, from a computational or functional point of view, what are the major features of Fortran 90? Next, how do these features compare with APL2? And finally, what can APL2 learn from the Fortran 90 work?
Assembler utility functions for APL2/PC
Authors: Ylinen Tauno
Published: January 2007

Some general guidelines are discussed on why and how to develop utility functions in assembler for the APL2/PC environment. Assembler utility functions may replace some most heavily used idiomatic APL auxiliary functions and boost the efficiency of APL applications. About twenty such functions are presented, some of them perhaps useful as temporary extensions of the APL2/PC interpreter. The collection of assembler utility functions is available in the public domain, and should be extended by the joint efforts of the international APL community.
Toward a lexicon of musical APL2 phrases (invited)
Authors: Jordan Stanley , Frils Erik S.
Published: January 2007

Both the programming environment and the notation of APL2 have proven useful in music theory and computer music. APL2 expressions can generate, test, and modify data structures representing musical syntax (actual passages or songs) or musical semantics (facts, ideas, or relationships in music). In this paper our primary concern is syntax-oriented. We examine a few basic parameters of music, introduce data structures that capture essential features of these parameters, and explore some useful expressions. Within these expressions we find several typical "musical objects" and some common transformations on these objects. Most of the expressions are simple, but their musical results are far from trivial. This only underscores the power of APL2.
Control of large scale computing systems
Authors: Diao Yixin , Hellerstein Joseph L. , Parekh Sujay
Published: January 2007

The rapidly increasing scale of computing systems means that it is vitally important to address the scaling challenges in the control of computing systems. We introduce a framework for describing the control problems for large scale computing systems that expand along two dimensions: the scale of the target system and the scale of the policy. Using this framework, we present control architectures that span a range from centralized schemes to distributed solutions. We further identify several research challenges related to issues such as target systems latencies and policy decomposition.
Program optimization
Authors: Gasser Sidney B.
Published: January 2007

Sandia Laboratories has established a consulting service designed to improve the overall efficiency of Fortran production programs in use by the scientific community. Since this service was inaugurated in May, 1971, approximately 40 jobs have been reviewed for optimization with varying degrees of success. In several instances it was not possible to improve the operating efficiency of a given program. However, in most cases it has been possible to achieve worthwhile reductions in the use of critical machine resources (primary attention is directed at use of central processor time and allocation of central memory). Average reduction of CPU usage is approximately 30% with one recorded instance of a 97% reduction.This paper addresses the problems encountered in launching and promoting a program optimization service in an open shop environment among users with widely varying levels of programming to indicate the method used to isolate and correct the sections of code that preempt the vital computer resources.
Performance measurement in a university computing facility
Authors: Draper M. D. , Teorey T. J.
Published: January 2007

Methods of software performance monitoring and data reduction, recently implemented at the University of Wisconsin, have been successfully used to provide a meaningful set of information for management decision making. Emphasis in performance measurement has been placed on I/O request data, resource utilization, user and system file usage summaries, and individual job accounting statistics.The major goals at Wiscon in have been to maximize system through put and to reduce turnaround time for small jobs, while keeping turnaround for larger jobs within a reasonable limit. Over a two year period throughput was increased by a factor of two and mean turnaround time was decreased by a factor of ten.Although implemented for a specific system, the UNIVAC 1108, the overall approach is applicable to a wide range of general purpose multiprogramming time sharing systems. The description of the data collection and analysis facility emphasizes this generality.
GIR'05 2005 ACM workshop on geographical information retrieval
Authors: Jones Christopher B. , Purves Ross
Published: January 2007

Geographical information retrieval (GIR) is concerned with the problems of finding information resources that relate to particular geographical locations. Until recently most web search engines have treated geographical terminology within user queries in the same way as other terminology. This can often result in failure to find relevant documents and in the retrieval of irrelevant documents. There are several reasons for this. For example, there are many different places with the same name, so unless the query contains a unique set of geographical terms, documents referring to the wrong place may be retrieved. There are many uses of place names in the names of people and organisations with the consequence that search depending on naive exact matching of terms may retrieve such documents even though they may not relate to the named place. It is also the case that queries may include spatial prepositions, such as near or outside, which will not be interpreted intelligently by the search engine. Thus relevant documents may not be found because the user's query did not contain explicit references to the places that match the query expression, in the sense of being, for example, near, inside or north of a named place. It is also the case that conventional search engines lack other desirable facilities for geographical search such as relevance ranking that takes account of geographical proximity and the ability to use interactive maps to specify a query and to visualise the results.
Relevance feedback at INEX 2005
Authors: Crouch Carolyn J.
Published: January 2007

Relevance feedback in the INEX environment is addressed by several papers in the proceedings of the INEX 2005 Workshop [1]. The most extensive discussion is provided by Schenkel and Theobald [2]. Mihajlovic,
et. al.
[3], and Sauvagnat,
et. al.
[4], describe approaches to relevance feedback in specific sections of papers devoted to discussions of multiple INEX tasks. For detailed descriptions of the systems and methods used and results obtained in each case, see the papers cited.
Data mining for improved cardiac care
Authors: Rao R. Bharat , Krishnan Sriram , Niculescu Radu Stefan
Published: January 2007

Cardiovascular Disease (CVD) is the single largest killer in the world. Although, several CVD treatment guidelines have been developed to improve quality of care and reduce healthcare costs, for a number of reasons, adherence to these guidelines remains poor. Further, due to the extremely poor quality of data in medical patient records, most of today's healthcare IT systems cannot provide significant support to improve the quality of CVD care (particularly in chronic CVD situations which contribute to the majority of costs).We present REMIND, a Probabilistic framework for Reliable Extraction and Meaningful Inference from Nonstructured Data. REMIND integrates the structured and unstructured clinical data in patient records to automatically create high-quality structured clinical data. There are two principal factors that enable REMIND to overcome the barriers associated with inference from medical records. First, patient data is highly redundant -- exploiting this redundancy allows us to deal with the inherent errors in the data. Second, REMIND performs inference based on external medical domain knowledge to combine data from multiple sources and to enforce consistency between different medical conclusions drawn from the data -- via a probabilistic reasoning framework that overcomes the incomplete, inconsistent, and incorrect nature of data in medical patient records.This high-quality structuring allows existing patient records to be mined to support guideline compliance and to improve patient care. However, once REMIND is configured for an institution's data repository, many other important clinical applications are also enabled, including: quality assurance; therapy selection for individual patients; automated patient identification for clinical trials; data extraction for research studies; and to relate financial and clinical factors. REMIND provides value across the continuum of healthcare, ranging from small physician practice databases to the most complex hospital IT systems, from acute cardiac care to chronic CVD management, and to experimental research studies. REMIND is currently deployed across multiple disease areas over a total of 5,000,000 patients across the US.
Championing of an LTV model at LTC
Authors: Freeman Edmund , Melli Gabor
Published: January 2007

In this paper we report on the successful implementation of a lifetime value (LTV) forecasting system at a large telecommunications company (LTC). While some research results have been reported elsewhere on the technical challenges of modeling customer value, our experience suggests that a data mining system implementation can expect to encounter several organizational challenges that can impinge on its success. We provide a background on the application, and then analyze several success factors.
Frequent closed itemset based algorithms
Authors: Yahia S. Ben , Hamrouni T. , Nguifo E. Mephu
Published: January 2007

As a side effect of the digitalization of unprecedented amount of data, traditional retrieval tools proved to be unable to extract hidden and valuable knowledge. Data Mining, with a clear promise to provide adequate tools and/or techniques to do so, is the discovery of hidden information that can be retrieved from datasets. In this paper, we present a structural and analytical survey of frequent closed itemset (FCI) based algorithms for mining association rules. Indeed, we provide a structural classification, in four categories, and a comparison of these algorithms based on criteria that we introduce. We also present an analytical comparison of FCI-based algorithms using benchmark dense and sparse datasets as well as "worst case" datasets. Aiming to stand beyond classical performance analysis, we intend to provide a focal point on performance analysis based on memory consumption and advantages and/or limitations of optimization strategies, used in the FCI-based algorithms.
Experimenting with a trace-driven simulator of a batch computing system
Authors: Waldbaum G.
Published: January 2007

Measures of the performance of multiprogrammed systems frequently exhibit considerable instability with respect to workload characteristics. As a result, an evaluator of a change to a multiprogrammed system should investigate the effect of this change under different workloads and draw conclusions by means of statistical methods. This paper describes how such an evaluation is performed with a trace-driven simulator of the Watson Research Center's batch computing system. Two simulation experiments are described, one dealing with the number of printers and the other with the number of initiators.
Hardware techniques
Authors: Warner Dudley
Published: January 2007

Warner:
It is becoming increasingly evident that computer systems are not performing anywhere near as well as they should; recent statistics indicate that the average CPU is active only 30% of the time, with many clocked at 10% and lower. It seems that in trying to give computer systems the versatility required by a multiprogramming environment, we have been ignoring the fact that they must also be efficient. In general, today's systems are poorly coordinated and wasteful, with the CPU idle much of the time, and little overlap between CPU and peripherals. The price of this kind of inefficiency is high, especially in terms of job turnaround time and system throughput rate.
Multimodal natural language platform supporting cellular phones
Authors: Mitchell Stella , Pavlovski Christopher J. , Smith Braam , Stavropoulos Harry , Wood David
Published: January 2007

As 3
rd
Generation (3G) networks emerge they provide not only higher data transmission rates, but also the ability to transmit both voice and low latency data simultaneously. This capability can be leveraged to provide a multimodal user interface. We describe the end-to-end architecture of our implementation of a multimodal application (voice and graphical user interface) that uses Natural Language Understanding in the speech interface combined with a WAP browser to perform mobile office functions on a cellular phone. A novel aspect of the multimodal platform is that no software is required to be installed on the mobile device. The feasibility of our approach is demonstrated by a successful trial with 50 users over a 3G mobile network. We outline our framework, present the results and observations made during the trial.