bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic effects of ELISA-based segregation for control of bacterial kidney disease in Chinook salmon (Oncorhynchus tshawytscha)
Authors: Hard Jeffrey J , Elliott Diane G , Pascho Ronald J , Chase Dorothy M , Park Linda K , Winton James R , Campton Donald E
Published: January 2007

We evaluated genetic variation in ability of Chinook salmon (Oncorhynchus tshawytscha) to resist two bacterial pathogens: Renibacterium salmoninarum, the agent of bacterial kidney disease (BKD), and Listonella anguillarum, an agent of vibriosis. After measuring R. salmoninarum antigen in 499 adults by enzyme-linked immunosorbent assay (ELISA), we mated each of 12 males with high or low antigen levels to two females with low to moderate levels and exposed subsets of their progeny to each pathogen separately. We found no correlation between R. salmoninarum antigen level in parents and survival of their progeny following pathogen exposure. We estimated high heritability for resistance to R. salmoninarum (survival h2 = 0.890 ± 0.256 (mean ± standard error)) independent of parental antigen level, but low heritability for resistance to L. anguillarum (h2 = 0.128 ± 0.078). The genetic correlation between these survivals (rA = –0.204 ± 0.309) was near zero. The genetic and phenotypic correlations between survival and antigen levels among surviving progeny exposed to R. salmoninarum were both negative (rA = –0.716 ± 0.140; rP = –0.378 ± 0.041), indicating that variation in antigen level is linked to survival. These results suggest that selective culling of female broodstock with high antigen titers, which is effective in controlling BKD in salmon hatcheries, will not affect resistance of their progeny.
Larval transport, vertical distribution, and localized recruitment in anadromous rainbow smelt (Osmerus mordax)
Authors: Bradbury I R , Gardiner K , Snelgrove P VR , Campana S E , Bentzen P , Guan L
Published: January 2007

We examined larval dispersal and behaviour in rainbow smelt (Osmerus mordax) from the Salmonier River estuary, Newfoundland, during 2003–2005. Riverine ichthyoplankton surveys indicate that larval transport into the estuary is restricted to a two-week period in late June. A passive drifter experiment and the spatial distribution of larvae and juveniles suggest limited dispersal and low export from the estuary. The estuary exhibited low inflow and stratification in summer and high inflow with a stable freshwater layer in fall. Summer and fall winds are primarily onshore. We hypothesised that larval vertical swimming behaviour limits dispersal and export. Larval vertical position and swimming ability were examined through lab-based experiments conducted 0–10 and 90 days after hatching. Measurements of swim speed indicate an order of magnitude (p < 0.001) improvement in swimming capacity between larvae and juveniles. One-week after hatching, larvae displayed consistent negative geotaxis, whereas juveniles were generally deeper and displayed negative geotaxis in light and positive geotaxis in the dark. The contrasting light-mediated geotactic behavior between development stages corresponds to ontogenetic shifts in swimming abilities and seasonal changes in estuarine circulation. We suggest that the interaction between behaviour, ontogeny, and hydrography results in limited transport and a tendency for estuarine-scale recruitment, despite an extensive pelagic period.
TEMPERATURE OF NONEQUILIBRIUM LATTICE SYSTEMS
Authors: PETRI ALBERTO , DE OLIVEIRA M. J.
Published: January 2007

We investigate the thermal quench of Ising and Potts models via Monte Carlo dynamics. We find that the local distribution of the site-site interaction energy has the same form as in the equilibrium case, a result that allows us to define an instantaneous temperature θ during the systems relaxation. We also find that, after an undercritical quench, θ equals the heat bath temperature in a finite time, while the total system energy is still decreasing due to the coarsening process.
MOLECULAR DYNAMICS COMES OF AGE: 320 BILLION ATOM SIMULATION ON BlueGene/L
Authors: KADAU KAI , GERMANN TIMOTHY C. , LOMDAHL PETER S.
Published: January 2007

As computational power is increasing, molecular dynamics simulations are becoming more important in materials science, chemistry, physics, and other fields of science. We demonstrate weak and strong scaling of our classical molecular dynamics code SPaSM on Livermore's BlueGene/L architecture containing 131 072 IBM PowerPC440 processors. A maximum of 320 billion atoms have been simulated in double precision, corresponding to a cubic piece of solid copper with an edge length of 1.56 μm.
BIFURCATION OF VORTEX LINES IN QUANTUM MECHANICS
Authors: XU TAO
Published: January 2007

Topological structure of vortex line in quantum mechanics is studied and classified by Hopf index, linking number in geometry. A mechanism of generation or annihilation of vortex line is given by method of phase singularity theory. The dynamic behavior of vortex line at the critical points is discussed in detail, and three kinds of length approximation relations are given.
PROPERTIES OF ENERGY SPECTRA OF MOLECULAR CRYSTALS INVESTIGATED BY NONLINEAR THEORY
Authors: PANG XIAO-FENG , ZHANG HUAI-WU
Published: January 2007

We calculate the quantum energy spectra of molecular crystals, such as acetanilide, by using discrete nonlinear Schrodinger equation, containing various interactions, appropriate to the systems. The energy spectra consist of many energy bands, in each energy band there are a lot of energy levels including some higher excited states. The result of energy spectrum is basically consistent with experimental values obtained by infrared absorption and Raman scattering in acetanilide and can also explain some experimental results obtained by Careri et al. Finally, we further discuss the influences of variously characteristic parameters on the energy spectra of the systems.
ESSENTIAL TORI IN 3-STRING FREE TANGLE DECOMPOSITIONS OF KNOTS
Authors: MORIMOTO KANJI
Published: January 2007

In the present paper, we characterize those knot types which have 3-string essential free tangle decompositions and have essential tori in the exteriors.
SPINAL KNOTS IN LENS SPACES
Authors: DERUELLE ARNAUD , MATIGNON DANIEL
Published: January 2007

A knot in a lens is said to be spinal if it can be isotoped on a standard spine (e.g. in ℝP3, spinal knots bound a Möbius band). We prove that a Dehn surgery on a non-spinal knot in a lens space cannot produce 𝕊3. With a view to study the Dehn surgeries that produce lens spaces, the main part is devoted to finding an obstruction for a standard spine to be minimal. We consider the intersection graphs coming from a standard spine and an arbitrary surface. This obstruction is given by the existence of a generalized Scharlemann cycle.
ALL LINK INVARIANTS FOR TWO DIMENSIONAL SOLUTIONS OF YANG–BAXTER EQUATION AND DRESSINGS
Authors: AIZAWA N. , HARADA M. , KAWAGUCHI M. , OTSUKI E.
Published: January 2007

All polynomial invariants of links for two dimensional solutions of Yang–Baxter equation is constructed by employing Turaev's method. As a consequence, it is proved that the best invariant so constructed is the Jones polynomial and there exist three solutions connecting to the Alexander polynomial. Invariants for higher dimensional solutions, obtained by the so-called dressings, are also investigated. It is observed that the dressings do not improve link invariant unless some restrictions are put on dressed solutions.
A DIGITAL MODEL FRAMEWORK OF METABOLIC SYSTEM BASED ON VISIBLE HUMAN DATA SET
Authors: CUI YUNFENG , BAI JING , CHEN YINGMAO , TIAN JIAHE
Published: January 2007

Digital model of human metabolic system incorporated with real anatomical structure can be seen as an important tool in order to understand and study the processes of metabolism. This paper presented a whole body digital model framework of [18F]2-fluoro-2-deoxy-D-glucose (FDG) metabolism based on the segmented Visible Human Project (VHP) data set as the anatomical structure framework. First, the blood time-activity curve (BTAC) and the tissues time-activity curves (TTAC) were obtained from kinetic analysis. According to the obtained BTAC and TTACs, a set of corresponding values were assigned to the segmented VHP image frames. Thus a set of dynamic volume data were derived to show the 18F distribution in human body for the predetermined sampling schedule. Finally, the simulated FDG distribution was visualized by coronal, axial, and sagittal slices and volume rendering method. The model established here was especially for the metabolism of FDG; however, the modeling method is general for all tracers. The proposed model represented functional information of dynamical process of human metabolism with high visualization resolution. The results of modeling and visualization provide a useful tool for education and research on nuclear imaging, and may provide a novel technical platform for the study of pharmacokinetics.
AN APPROACH TO SURFACE RECONSTRUCTION USING UNCERTAIN DATA
Authors: PAPALEO LAURA
Published: January 2007

In a research context in which multiple and well-behaved Surface Reconstruction algorithms already exist, the main goal is not to implement a visualization toolkit able render complex object, but the implementation of methods which can improve our knowledge on the observed world. This work presents a general Surface Reconstruction framework which encapsulates the uncertainty of the sampled data, making no assumption on the shape of the surface to be reconstructed. Starting from the input points (either points clouds or multiple range images), an Estimated Existence Function (EEF) is built which models the space in which the desired surface could exist and, by the extraction of EEF critical points, the surface is reconstructed. The final goal is the development of a generic framework that is able to adapt the result to different kinds of additional information coming that is from multiple sensors.
A case study of DECnet applications and protocol performance
Authors: Chiu D.-M. , Sudama R.
Published: January 2007

This paper is a study based on measurements of network activities of a major site of Digital's world-wide corporate network. The study yields two kinds of results: (1) DECnet protocol performance information and (2) DECnet session statistics. Protocol performance is measured in terms of the various network overhead (non-data) packets in routing, transport and session layers. From these protocol performance data, we are able to review how effective various network protocol optimizations are; for example the on/off flow control scheme and the delayed acknowledgement scheme in the transport protocol. DECnet session statistics characterizes the workload in such a large network. The attributes of a session include the user who started it, the application invoked, the distance between the user and the application, the time span, the number of packets and bytes in each direction, and the various reasons if a session is not successfully established. Based on a large sample of such sessions, we generate distributions based on various attributes of sessions; for example the application mix, the visit count distribution and various packet number and size distributions.
From local to global: an analysis of nearest neighbor balancing on hypercube
Authors: Hong J. , Tan X. , Chen M.
Published: January 2007

This paper will focus on the issue of load balancing on a hypercube network of N processors. We will investigate a typical nearest neighbor balancing strategy - in which workloads among neighboring processors are averaged at discrete time steps. The computation model allows tasks, described by independent random variables, to be generated and terminated at all times.

We assume that the random variables at all nodes have equal expected value and their variances are bounded by a constant
d
2
, and we let the difference DIFF between the actual load on each node and the average load on the system describe the deviation of the load on a node from the global average value. The following analytical results are obtained:

The expected value of DIFF, denoted by E(DIFF), is 0.

The variance of DIFF, denoted by Var(DIFF), is independent of time
t
, and Var(DIFF)≤ 1.386

d
2

+ 0.231 log
N
.
Adaptive storage control for page frame supply in large scale computer systems
Authors: Yoshizawa Y. , Arai T.
Published: January 2007

A real storage management algorithm called Adaptive Control of Page-frame Supply (ACPS) is described. ACPS employees three strategies: prediction of the demand for real page frames, page replacement based on the prediction, and working set control. Together, these strategies constitute the real page frame allocation method, and contribute to short and stable response times in conversational processing environments.

ACPS is experimentally applied to the VOS3 operating system. Evaluation of ACPS on a real machine shows that TSS response times are not affected too strongly by king-size jobs and ACPS is successful in avoiding paging delay and thrashing. ACPS prevents extreme shortages of real storage in almost all cases.
PAM-a noniterative approximate solution method for closed multichain queueing networks
Authors: Hsieh C.-H. , Lam S. S.
Published: January 2007

Approximate MVA algorithms for separable queueing networks are based upon an iterative solution of a set of modified MVA formulas. Although each iteration has a computational time requirement of

O(MK
2
)

or less, many iterations are typically needed for convergence to a solution. (
M
denotes the number of queues and
K
the number of closed chains or customer classes.) We present some faster approximate solution algorithms that are
noniterative
. They are suitable for the analysis and design of communication networks which may require tens to hundreds, perhaps thousands, of closed chains to model flow-controlled virtual channels. Three PAM algorithms of increasing accuracy are presented. Two of them have time and space requirements of
O(MK)
. The third algorithm has a time requirement of

O(MK
2
)

and a space requirement of
O(MK)
.
A closed, cyclic, two-stage multiprogrammed system model and its diffusion approximation solution
Authors: Halachmi Baruch , Franta W. R.
Published: January 2007

In this paper attention is focused on closed multiprogrammed computer type systems. In particular, two-stage closed queueing systems are considered. The first stage can be associated with the CPU (Central Processing Unit) and the other with the I/O (Input-Output) operations. For all the models discussed.

For the first model we consider the {GI
1
/M
S
/N} system, which allows the service times of a single CPU to obey any general probability distribution, with finite variance, while the I/O servers are taken to be exponential.

The second model is an extension of the first where the concept of feedback is implemented in the CPU stage. This concept plays an important role in computer environments where the operating system includes the multiplexing or page on demand property.

The third model, the {M
S
1
/M
S
2
/N}, deals with multiprocessing computer systems where possibly more than one CPU is available, but all servers are assumed to be exponential.

In the spirit of the approximation to the GI/G/S open system, as a final model, we construct the approximate solution to the {GI
S
1
/GI
S
2
/N} closed system and discuss the circumstances under which its use is advisable. Several numerical examples for each of the models are given, each accompanied by appropriate simulation results for comparison.

It is on the basis of these comparisons that the quality of the suggested diffusion approximations can be judged. The diffusion approximating formulas should be regarded not only as a numerical technique, but also as a simplifying approach, by which deeper insight can be gained into complicated queueing systems. Considerable work remains to be done, using as a methodology the approach, given here, and several possible extensions are presented.
An event-driven data collection and analysis facility for a two-computer network
Authors: Foley James D. , McInroy John W.
Published: January 2007

In this paper we describe an event-driven data collection facility, and a general-purpose program to perform a set of analyses on the collected data. There are several features which distinguish this facility from others. First, the system being monitored is a network of loosely-coupled computers. Although there are just two computers in the network, the facility could be readily extended to larger networks. Second, the main purpose of the facility is to monitor the execution of interactive graphics application programs whose processing and data are distributed between the network's computers. Third, the data collector and analyzer are readily extendible to treat new kinds of data. This is accomplished by a data and event independent collector, and a table-driven data analyzer.
HEMI (Hybrid Events Monitoring Instrument)
Authors: Sebastian Peter R.
Published: January 2007

HEMI is an experimental instrumentation system being developed for use with the CYBER 70 and 170 Series computers in order to ascertain the extent to which an integrated approach to instrumentation is economically and technologically viable for performance measurement and evaluation purposes.

HEMI takes advantage of the distributed CYBER computer architecture. This consists of a pool of Peripheral Processors (PPs) - (mainly dedicated to I/O and system tasks) while the CPU capabilities are reserved mostly for computation; Central Memory constitutes the communications link.

HEMI uses one of the PPs as its major processor. A hardware data acquisition front end is interfaced to one of the I/O channels and driven by the PP. Hardware probes sample events at suitable testpoints, while the PP has software access to Central Memory (Operating System tables and parameters), Status Registers, I/O Channel Flags, etc.

A data reduction package is used to produce a variety of reports from the data collected. A limited on-line data reduction and display capability is also provided.

This paper will describe the current status of the project as well as anticipated applications of HEMI.
Interpretive analysis of computer system performance
Authors: Cox Springer W.
Published: January 2007

A typical performance evaluation consists of the identification of resources, the definition of system boundaries, the measurement of external and internal performance variables, and finally the interpretation of data and projection of system performance to hypothetical environments. These projections may be used to estimate the cost savings to be expected when changes are made to the system.

The fundamental external performance measures such as response time and thruput are intimately related, but may be defined differently depending on how the system is defined. They can be analyzed with respect to the internal performance measures (such as activities, queue lengths and busy times) by applying one or more interpretations such as: absolute utilizations, normalized busy times, system profiles, analysis of response, workload relaxation, and resource consumption hyperplanes. These models, which are generally free of assumptions regarding interarrival and service time distributions, can be adjusted to represent potential changes to the system. Then the interpretations may be used to evaluate the predicted external performance measures.
The computer capacity curve - a prerequisite for computer performance evaluation and improvement
Authors: Brotherton D. E.
Published: January 2007

Measurements of themselves have tended to concentrate on specific computer configuration components (e.g., CPU load, channel load, disk data set contention, problem program optimization, operating system optimization, etc.) rather than at the total computer configuration level. As a consequence, since these components can have a high degree of interaction, the requirement currently exists for a workable configuration performance concept which will reflect the configuration performance change that is the resultant of single or multiple component change. It is the author's opinion that such a concept will provide management and measurement specialists a planning and analysis tool that can be well Used in evaluating the costs. It is to this configuration performance concept that this paper is addressed, and the concept by my choosing is named “The Computer Capacity Curve.”
The value of CPU utilization as a criterion for computer system usage
Authors: Erikson Warren J.
Published: January 2007

It is generally agreed that a computer system's CPU utilization means little by itself, but there has been only a limited amount of research to determine the value of CPU utilization when used with other performance measures. This paper focuses on time-sharing systems (or similar systems such as some remote batch systems) as viewed by someone who wants to minimize the mean cost per job run on the system.

The paper considers cost per job to include both the computer cost (as allocated among all the jobs run on the system) and the user cost (where user cost is the time spent waiting for a response from the system multiplied by the user's wage rate). Given this approach, cost per job is a function of some constants (user wage rate, computer system cost, and mean processing time per job) and only one variable (CPU utilization). The model thus developed can be used to determine the optimum CPU utilization for any system. It can also be used to determine the value of different tuning efforts.
Applied quality assurance methodology
Authors: Pfau Pamela R.
Published: January 2007

What is the charter of a Quality Assurance (Q.A.) department? What are the activities? How are they undertaken? What is the impact of Quality Assurance upon a software product?

The structure and operating philosophy of the department are explained in this report as is the definition of the work cycle as applied to a new release of a software product. Comments are made about the interaction between departments: product development, product maintenance, publications, education, field support, product management, marketing, product distribution and quality assurance. While this is a description of the activities of a company involved in developing and marketing software products, the concepts apply to techniques and practices which would also be beneficial to any data processing department that develops in-house application software.
Software Configuration Management
Authors: Bersoff Edward H. , Henderson Vilas D. , Siegel Stan G.
Published: January 2007

This paper is about discipline. It is about discipline that managers should apply to software development. Why is such discipline needed? Quite simply because the software industry has traditionally behaved in an undisciplined manner—doing its own thing. The products that the industry has turned out have typically

Contained other than what was expected (usually less, rather than more);

Been delivered much later than scheduled;

Cost more than anticipated;

Been poorly documented; and

If you have been involved in any of the situations quoted above, then this paper may be of some help. In short, if you are now, or intend to be, a software seller or buyer, then you should benefit from an understanding of Software Configuration Management. Lest you think that you are not now, or ever will be, a software seller or buyer—keep in mind that the recent technology explosion in electronic component miniaturization has placed the era of personalized computing at hand. In that context, nearly everyone may be considered a potential seller or buyer of software.

This paper is about the discipline called Software Configuration Management (SCM). The objective of SCM is to assist the software seller in achieving product integrity and to assist the software buyer in obtaining a product that has integrity.
Relating software requirements and design
Authors: Peters Lawrence
Published: January 2007

Software development is a process which has evolved into a number of phases. Although the names of the phases and some of their characteristics differ from contractor to contractor and customer to customer, the functional similarities among sets of phases cannot be ignored. The basic software development scenario depicted by these phases starts with problem identification and definition, requirements specification, design, code, test, and installation and maintenance. Although some “smearing&rdquo of one phase activity into other(s) may occur, this represents the basic flow. However, it is just that smearing which occurs between requirements and design that we wish to explore here.

Identifying or defining problems and solving problems are viewed by many to be separate, distinguishable activities. They are complementary in that one identifies what must be done (requirements) while the other depicts how it will be done (design). But software designers complain bitterly that requirements are poorly defined while customers and analysts often complain that the design is not responsive to the problem(s) as they perceive it. Somehow software designers end up discovering previously unknown requirements and end up solving a problem which is foreign to the customer. Is there a workable mechanism to reduce this difficulty?
A software quality assurance experiment
Authors: Benson J. P. , Saib S. H.
Published: January 2007

An experiment was performed to evaluate the ability of executable assertions to detect programming errors in a real time program. Errors selected from the categories of computational errors, data handling errors, and logical errors were inserted in the program. Assertions were then written which detected these errors. While computational errors were easily detected, data handling and logical errors were more difficult to locate. New types of assertions will be required to protect against these errors.
Simulation of a distributed system for performance modelling
Authors: Bennett David A. , Landauer Christopher A.
Published: January 2007

A distributed system of cooperating minicomputers is simulated by AIMER (Automatic Integration of Multiple Element Radars) to model and analyze the behavior of a radar tracking system. Simulation is applied in the AIMER project in an attempt to model a network of minicomputers to discover a maximally flexible network architecture. Because building the tracking system out of real hardware would not result in a flexible enough testbed system, the proposed configuration is represented by a software emulation. The instruction sets of the individual processors are emulated in order to allow separation of the measurement facilities from the execution of the system. The emulation is supported by a Nano-data QM-1 micro and nano-programmable host. Extensive performance monitoring hooks have been built into the emulation system which allow small performance perturbations to become visible.

The tracking network is controlled by a combination firmware operating system and a special emulated virtual control machine. The tracking algorithms run on virtual machines whose instruction sets and computational throughput can be parameterized when the model is generated, or dynamically by an operator during a run.

The radar and ground truth environments for the tracking system are simulated with logic resident in one of the emulated machines, allowing these functions to be monitored as accurately as the tracking algorithms.

The use of this simulation technique has resulted in an extremely flexible testbed for the development of distributed radar tracking system models. The testbed itself can be quickly tailored to other application problems.
Survey of analytic queueing network models of computer systems
Authors: Kienzle Martin G. , Sevcik K. C.
Published: January 2007

A number of case studies involving the use of queueing network models to investigate actual computer systems are surveyed. After suggesting a framework by which case studies can be classified, we contrast various parameter estimation methods for specifying model parameters based on measurement data. A tabular summary indicates the relationships among nineteen case studies.
Evaluation methods in SARA—the graph model simulator
Authors: Razouk Rami R. , Vernon Mary , Estrin Gerald
Published: January 2007

The supported methodology evolving in the SARA (System ARchitects' Apprentice) system creates a design frame-work on which increasingly powerful analytical tools are to be grafted. Control flow analyses and program verification tools have shown promise. However, in the realm of the complex systems which interest us there is a great deal of research and development to be done before we can count on the use of such powerful tools. We must always be prepared to resort to experiments for evaluation of proposed designs.

This paper describes a fundamental SARA tool, the graph model simulator. During top-down refinement of a design, the simulator is used to test consistency between the levels of abstraction. During composition, known building blocks are linked together and the composite graph model is tested relative to the lowest top-down model. Design of test environments is integrated with the multilevel design process. The SARA methodology is exemplified through design of a higher level building block to do a simple FFT.
Software reliability modeling accounting for program size variation due to integration or design changes
Authors: Musa J. D. , Iannino A.
Published: January 2007

Estimation of software reliability quantities has traditionally been on stable systems; i.e., systems that are completely integrated and are not undergoing design changes. Also, it is assumed that test results are completely inspected for failures. This paper describes a method for relaxing the foregoing conditions by adjusting the lengths of the intervals between failures experienced in tests as compensation. The resulting set of failure intervals represents the set that would have occured for a stable system in its final configuration with complete inspection. The failure intervals are then processed as they would be for a complete system. The approach is developed for the execution time theory of software reliability, but the concepts could be applied to many other models the estimation of quantities of interest to the software manager are illustrated.
Evaluation of concurrent physical database reorganization through simulation modeling
Authors: Söderlund Lars
Published: January 2007

The performance of a database system commonly deteriorates due to degradation of the database's physical data structure. The structure degradation is a consequence of the normal operations of a general database management system.

When system performance has degraded below acceptable limits the database must be reorganized. In conventional, periodic reorganization the database, or part of it, is taken off line while the data structure is being reorganized.

This paper presents results from a study where it is shown that concurrent reorganization, i.e. a continous reorganization of the physical data structure while application processes have full access to the database, is an attractive alternative to conventional reorganization.

The paper also presents a solution to a methodological problem concerning the simulation of a system which has activities with extremely varying durations.
Interface design as a prosthesis for an individual with a brain injury
Authors: Cole Elliot , Dehdashti Parto
Published: January 2007

This is a case study demonstrating how interface design was applied to make personal productivity software accessible and appropriate for an individual with learning disabilities from a head injury. Substantial customization was required, and nine months of data are presented.
User models of the circuit design process
Authors: Colgan Lynne , Rankin Paul , Brouwer-Janse Maddy
Published: January 2007

To aid in the design of both a CAD system and its user interface, studies of circuit designers using a prototyped system resulted in several user model diagrams depicting the analogue circuit design process. The relative merits of this approach and its affect on the system design are discussed.
Bringing natural language information retrieval out of the closet
Authors: Harman Donna , Candela Gerald
Published: January 2007

A prototype information retrieval system was developed that gives users fast and easy access to textual information. This system uses a statistical ranking methodology that allows a user to input a query using only natural language, such as a sentence or a noun phrase, with no special syntax required. The system returns a set of text titles or descriptions, ranked in order of likely relevance to the query. The user can then select one or more titles for further examination of the corresponding text. The prototype was tested by over forty users, all proficient in doing manual research in the subject area, but few proficient in doing online research. The system was very fast, providing response times on the order of one second for searching a gigabyte of data and was also very effective, retrieving at least one relevant record within the first ten records retrieved for 53 out of 68 test queries. All users were able to get satisfactory results within a short time after seeing a demonstration, and those that had never used an online retrieval system did as well as those with experience. This is in sharp contrast to Boolean based retrieval systems where continual use is necessary to obtain consistently good results.
Multimedia interaction with image database systems
Authors: Kato Toshikazu , Kurita Takio , Shimogaki Hiroyuki
Published: January 2007

A picture is worth a thousand words. Images are good media to communicate with an image database system. Multimedia interaction enables users to give multimedia information to the system as well as to receive it from the system[1, 2]. Visual interface must be able to interpret several kinds of multimedia information related with computer and human vision. For example, the system should recognize the words on subjective impression as well as the sketches we draw as the keys for retrieval.
Some systems, applications and models I have known
Authors: Sevcik Kenneth C.
Published: January 2007

Being named recipient of the 2004 ACM Sigmetrics Achievement Award has done several things to me. It brought me surprise that I would be singled out from the many people who have made significant and sustained contributions to the field of performance evaluation. It also brought me deep appreciation for all the students and colleagues with whom I have worked and come to know as friends over the years. Finally, it has caused me to ponder and reminisce about many of the research projects and consulting studies in which I have participated.In this talk, I will describe various systems I have used and studied, various applications of interest, and various models that I, and others, have used to try to gain insights into the performance of systems. Some lessons of possible future relevance that emerge from this retrospective look at a wide variety of projects are the following:

Exact Answers Are Overrated -- While exact solutions of mathematical models are intellectually satisfying, they are often not needed in practice.

Analytic Models Have a Role -- Analytic models can be used to obtain quick and inexpensive answers to performance questions in many situations where neither simulation nor experimentation are feasible.

Assumptions Matter -- Subtle changes to the assumptions that underlie an analytic model can substantially alter the conclusions reached based on the model.

After considering all the methods of analysis, simulation and experimentation, my recommendation for the very best means to attain substantially improved computer system performance is: Wait thirty years!
How to identify and estimate the largest traffic matrix elements in a dynamic environment
Authors: Soule Augustin , Nucci Antonio , Cruz Rene , Leonardi Emilio , Taft Nina
Published: January 2007

In this paper we investigate a new idea for traffic matrix estimation that makes the basic problem less under-constrained, by deliberately changing the routing to obtain additional measurements. Because all these measurements are collected over disparate time intervals, we need to establish models for each Origin-Destination (OD) pair to capture the complex behaviours of internet traffic. We model each OD pair with two components: the diurnal pattern and the fluctuation process. We provide models that incorporate the two components above, to estimate both the first and second order moments of traffic matrices. We do this for both stationary and cyclo-stationary traffic scenarios. We formalize the problem of estimating the second order moment in a way that is completely independent from the first order moment. Moreover, we can estimate the second order moment without needing any routing changes (i.e., without explicit changes to IGP link weights). We prove for the first time, that such a result holds for any realistic topology under the assumption of
minimum cost routing
and
strictly positive link weights
. We highlight how the second order moment helps the identification of the top largest OD flows carrying the most significant fraction of network traffic. We then propose a refined methodology consisting of using our variance estimator (without routing changes) to identify the top largest flows, and estimate only these flows. The benefit of this method is that it dramatically reduces the number of routing changes needed. We validate the effectiveness of our methodology and the intuitions behind it by using real aggregated sampled netflow data collected from a commercial Tier-1 backbone.
Uncooperative congestion control
Authors: Chandrayana Kartikeya , Kalyanaraman Shivkumar
Published: January 2007

Traditionally uncooperative rate control schemes have implied open loop protocols such as UDP, CBR, etc. In this paper we show that closed loop uncooperative rate control schemes also exist and that the current AQM proposals cannot efficiently control their mis-behavior. Moreover, these proposals require that AQM be installed at all routers in the Internet which is not only expensive but requires significant network upgrade.In this paper we show that management of uncooperative flows need not be coupled with AQM design but can be viewed as edge based policing question. In this paper we propose an analytical model for managing uncooperative flows in the Internet by re-mapping their utility function to a target range of utility functions. This mapping can be achieved by transparently manipulating congestion penalties conveyed to the uncooperative users.The most interesting aspect of this research is that this task can be performed at the edge of the network with little state information about uncooperative flows. The proposed solution is independent of the buffer management algorithm deployed on the network. As such it works with Drop-Tail queues as well as any AQM scheme. We have analyzed the framework and evaluated it on various single and multi-bottleneck topologies with both Drop-Tail and RED. Our results show that the framework is robust and works well even in presence of background traffic and reverse path congestion.
Document classification, indexing and abstracting may be inherently difficult problems
Authors: Fraenkel Aviezri S.
Published: January 2007

The main features of document indexing are abstracted. It is shown that the easy part of indexing, namely the question whether there is a bounded number of descriptors for indexing a document is NP-complete. Thus even the most efficient algorithm for exact indexing is not, at least at the present time, bounded by a polynomial-time function.
Progress report on project information bridge
Authors: Wessel Andrew E.
Published: January 2007

Project Information Bridge is a West German Federal Ministry for Research and Technology supported project. It has been conducted in cooperation with the Gesellschaft für Information und Dokumentation (Society for Information and Documentation) (GID) and the various data base hosts in West Germany. Its goal was to develop and test a working prototype of an add-on package for existing IR systems.This report covers the time period from October 1981 through March 1983 during which the prototype was successfully developed and tested. The principal emphasis was to provide users with search formulation aids applicable to specific document files searchable using differing IR systems. Aids for thesaurus construction for natural language words and for file construction and indexing have not at this date been tested. Should tests be completed prior to the conference date, information concerning these topics will be presented at the conference.
On-Line Personal Bibliographic Retrieval System
Authors: Fayen Emily G. , Baird Susan B.
Published: January 2007

The Norris Cotton Cancer Center (NCCC) On-Line Personal Bibliographic Retrieval System was developed to assist researchers at the Center in managing personal or project-related collections of reference materials. The system supports on-line entry, storage, and retrieval of bibliographic citations for collections of books, journal articles, reprints, reports, manuscripts, other documents, and audio-visual materials.The NCCC system is intended for relatively small collections of materials (under 10,000 items) and is not intended to duplicate or compete in any way with MEDLARS, CANCERLINE, or any of the other on-line bibliographic retrieval services. It is similar in concept to Mitre's SHOEBOX (1), but is much less complex and requires far less computer resources. The major advantage of the NCCC system is that it is simple, small, and easy to use.None of the techniques used in developing the NCCC system is particularly new or innovative. Rather, several well-known approaches to bibliographic retrieval were combined to produce a system that was easy and inexpensive to develop and is easy and inexpensive to use. The system is now running on the Dartmouth College Computing system's equivalent of a Honeywell 66/DPS-3. The programs are all written in BASIC.
SIGART Member Dissertation Abstracts
Authors: Vandenbrande Jan H.
Published: January 2007

Recognition of machining features such as holes, slots and pockets is essential for the fully automatic manufacture of mechanical parts. This thesis discusses an experimental feature recognizer that uses a blend of artificial intelligence (AI) and computational geometry techniques. The recognizer is implemented in a rapid prototyping test bed consisting of the Knowledge Craft (TM) AI environment tightly coupled with the PADL-2 solid modeler, running under Unix on a SUN 3/260 computer. It is capable of finding features with interacting volumes (e.g., two crossing slots), and takes into account nominal shape information, tolerancing and other available data.
Effects of channel blocking on the performance of shared disk pack in a multi-computer system
Authors: Raffi Abbas
Published: January 2007

In a multi-computer environment where several computers share packs of disk drives, the architecture of the disk controller can have significant effect on the throughput of the disk pack. In a simple configuration a controller can allow access to only one disk in the pack at a time, and effectively block other channels from accessing other disks in the pack. A desirable alternative is to be able to access different disks of the same pack simultaneously from different channels. Motivated by the presence of a mixed hardware in an installation to support both configurations, an attempt is made to model each system and produce analytical and simulation results to compare their relative performances. It is predicted that under the prevalent conditions in the installation, a complete switchover to either system should not give rise to significant performance change.
Trace Driven modeling
Authors: Sherman Stephen W.
Published: January 2007

Trace Driven modeling is a technique that combines measurement and simulation in order to create an accurate model of a computer system. This paper extends the review and overview of trace driven modeling presented in a previous paper [15] by Sherman and Browne. The technique of trace driven modeling is defined and examined. Several simulation studies that used the technique of trace driven modeling and appeared after the studies discussed in [15] are briefly examined.
Associative mass storage for database
Authors: Wolf G.
Published: January 2007

Two types of associative mass storage for use in database systems, have been introduced in this paper, they are

I
Hybrid associative storage
For use as an associative primary storage, it comprise a storing “basement” and an associative surface matrix. The suggested configuration has a capacity of up to 64 megabytes and a search rate of the order of 2 to 8 gigabytes per second. As well as associative operation, it is also suitable for extremely fast sorting.

II
Hardware hash coding system
A hardware structure provides associative access to conventional, numerically addressed storage media. The prefered application is for quasi-associative access to data in secondary storages.

Associative mass storages systems differ in their characteristics and complement each other. Together they form the hardware building blocks of a database system.
A neighbor connected processor network for performing relational algebra operations
Authors: Bratbergsengen Kjell , Larsen Rune , Risnes Oddvar , Aandalen Terje
Published: January 2007

In a data base computer consisting of cells with processing capability, the desired goal is to achieve an execution time - for each data base operation - to be inversely proportional to the number of cells. Using rings as a basic building block, we have constructed different intercell communication networks. The capacity of the communication network have been analyzed under the workload of relational algebra operations. A k-dimensional network of intersecting rings, each of 2 or 3 cells have been found to give the highest processing capacity per cell in the network. Here k is log
2
C, where C is the total number of cells.

A simple wiring scheme for k-dimensional network of 2 cells per ring has been presented. For this type of network, we have also described the routing logic, and given an estimate of the queueing delay.
A medium level compiler generating microcode
Authors: Marti Jed B. , Kessler Robert R.
Published: January 2007

Described is a medium level language and compiler which generates microcode for the Burroughs 1800. The language significantly aids implementation of microcode interpreters for this machine.
Experience with a high level micromachine simulator
Authors: Schleimer S. , Meyers W. J.
Published: January 2007

As part of a microcoding project, we developed a simulator that offers a relatively high level view of a micromachine. The simulator supports all out a few features of the hardware, and provides a more friendly environment for the microprogrammer. In addition, the simulator supports a number of microprogramming conventions at a level inaccessible to the hardware. The simulator was implemented in a high level language, which contributed to its timely delivery and flexibility and did not detract from its efficiency. The simulator has been used to validate all of our microcode, with considerable success. Over 98% of microcode bugs have been found during simulation. The credibility of our microcode by the time it reaches hardware has also improved the detection and correction of hardware bugs.
Direct execution of C-string compiler texts
Authors: Bridges Charles W. , Abd-alla Abd-Elfattah Mohamed
Published: January 2007

High level language (HLL) computer architectures refer to those computers which are designed to accept either HLL source texts directly or intermediate texts preprocessed and prepared by HLL compilers. This paper investigates the direct execution of three C-string formats: duos, triples, and quadruples. Software simulators are developed which directly execute these C-string formats on an IBM 3033 architecture. The simulators are then executed for each of the C-string formats, testing the efficiency of each directly executed language (DEL) format for various workloads, on different mainframe architectures, and for five different HLL's. The results demonstrate that triples are the most efficient DEL format in support of most HLL texts on large-scale mainframes.