bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-Term Protective Immune Response Elicited by Vaccination with an Expression Genomic Library ofToxoplasma gondii
Authors: Fachado Alberto , Rodriguez Alexandro , Molina Judith , Silvério Jaline C. , Marino Ana P. M. P. , Pinto Luzia M. O. , Angel Sergio O. , Infante Juan F. , Traub-Cseko Yara , Amendoeira Regina R. , Lannes-Vieira Joseli
Published: August 2003

Immunization of BALB/c mice with an expression genomic library ofToxoplasma gondiiinduces a Th1-type immune response, with recognition of severalT. gondiiproteins (21 to 117 kDa) and long-term protective immunity against a lethal challenge. These results support further investigations to achieve a multicomponent anti-T. gondiiDNA vaccine.
Induction of T Helper Type 1 Responses by a Polysaccharide Deacetylase fromCryptococcus neoformans
Authors: Biondo Carmelo , Beninati Concetta , Bombaci Mauro , Messina Luciano , Mancuso Giuseppe , Midiri Angelina , Galbo Roberta , Teti Giuseppe
Published: August 2003

A 25-kDa cryptococcal deacetylase (d25) was found here to induce cell proliferation, as well as secretion of interleukin 2 and gamma interferon, but not interleukin 4, in spleen cells from d25-immunized orCryptococcus neoformans-infected mice. The gamma interferon, but not the interleukin 2, response was required for the protective activities of d25 immunization in a murine cryptococcosis model.
Host Cell Fate on
Cryptosporidium parvum
Egress from MDCK Cells
Authors: Elliott David A. , Clark Douglas P.
Published: August 2003

Cryptosporidium parvum
is an intracellular protozoan parasite that causes a severe diarrheal illness of unclear etiology. Also unclear is the fate of the host cell upon parasite egress. We show in an MDCK cell model that the host cell is killed upon parasite egress; this death is necrotic, rather than apoptotic, in nature.
Characterization of a ComE3 Homologue Essential for DNA Transformation in
Helicobacter pylori
Authors: Yeh Yu-Ching , Lin Tzu-Lung , Chang Kai-Chih , Wang Jin-Town
Published: August 2003

To find genes involved in natural competence in
Helicobacter pylori
, we used a bioinformatics database search and found two transformation-related open reading frames (ORFs): a
comE3
homologue (HP1361 ORF) of
Bacillus subtilis
and a
comL
homologue (HP1378 ORF) of
Neisseria gonorrhoeae
. We failed to obtain an HP1378 ORF knockout mutant, while an HP1361 ORF knockout mutant was obtained by transposon shuttle mutagenesis. The DNA transformation abilities of both natural transformation and electroporation were severely impaired (frequency, <10
−9
) in the HP1361
−
mutant. Complementation with a pHel2 vector carrying the HP1361 ORF restored the capabilities of natural competence (to a frequency of 4.21 × 10
−7
) and electroporation (to 3.62 × 10
−7
). The HP1361
−
mutant showed impairment in DNA binding and uptake. The results suggest that HP1361 is a
comE3
homologue and is required for DNA binding and uptake during DNA transformation.
Therapeutic cloning research and ethical oversight
Authors: Spriggs M
Published: August 2003

Cloning Trevor, a story about therapeutic cloning research, appeared in the June issue ofThe Atlantic Monthly. The story gives a human face to the people whom therapeutic cloning could benefit. It presents an argument for government funding and it puts the usual calls for a moratorium on embryonic stem cell research to allow for more debate, in a less favourable light. The story also highlights some problems with ethical oversight.
MRSA in the Netherlands: preventive measure raises a moral issue
Authors: Gebhardt D O E
Published: August 2003

In the Netherlands the incidence of methicillin resistantStaphylococcus aureus(MRSA) infections in hospitals is surprisingly low when compared to that of neighbouring countries. It is believed that this favourable condition is caused by stringent precautionary measures such as complete isolation of the patients. In one case the nurse taking care of such patients was herself MRSA positive. This condition changed and she became MRSA negative after removal (at her request) of her tonsils. The question is raised how far one should go to protect patients when the preventive measures taken may endanger the health of those who take care of them.
Extending preimplantation genetic diagnosis: medical and non-medical uses
Authors: Robertson J A
Published: August 2003

New uses of preimplantation genetic diagnosis (PGD) to screen embryos prior to transfer raise ethical, legal, and policy issues that deserve close attention. Extensions for medical purposes, such as to identify susceptibility genes, late onset disease, and human leukocyte antigen (HLA) matching, are usually ethically acceptable. Whether embryo screening for gender, perfect pitch, or other non-medical characteristics are also acceptable depends upon the parental needs served and the harm posed to embryos, children, and society. Speculations about potential future uses of PGD should not prevent otherwise acceptable current uses of PGD.
Bach to the future: response to: Extending preimplantation genetic diagnosis: medical and non-medical uses
Authors: Ashcroft R
Published: August 2003

Professor Robertson sketches an elegant framework for policy evaluation and regulation of the use of preimplantation genetic diagnosis for various medical, medical related, and non-medical purposes. In criticism of his position, I argue that the distinction between policy and ethics upon which his argument relies is highly unstable, and the approach taken to ethical evaluation of particular parental interests leaves open many issues which the policy approach would hope to exclude. In conclusion I argue that while his position ultimately fails, the onus is on his critics to come up with a viable and satisfying alternative.
Confidentiality and the ethics of medical ethics
Authors: Rogers W A , Draper H
Published: August 2003

In this paper we consider the use of cases in medical ethics research and teaching. To date, there has been little discussion about the consent or confidentiality requirements that ought to govern the use of cases in these areas. This is in marked contrast to the requirements for consent to publish cases in clinical journals, or to use personal information in research. There are a number of reasons why it might be difficult to obtain consent to use cases in ethics. Many cases concern people who are incompetent, and thus unable to give consent. Often the material is of a sensitive nature, it is not clear who should give consent, or the ethicist has no access to those involved. We argue that the use of cases in ethics research and teaching can be justified by appeal to the public interest argument, and suggest a number of areas for discussion and clarification.
Actionvinaction: a case history in ethics
Authors: Berry P
Published: August 2003

The motives behind the author’s decision to resuscitate a patient are examined. This is prompted by the realisation that he ignored the man’s apparent wish not to be saved for fear of criticism from both relatives and colleagues. The way in which decisions are made when the interests of the doctor and the patient clash are briefly explored. Self interest may play a more significant role than is commonly accepted.
“Cold calling” in psychiatric follow up studies: is it justified?
Authors: Tyrer P , Seivewright H , Ferguson B , Johnson T
Published: August 2003

Background:The ethics of cold calling—visiting subjects at home without prior appointment agreed—in follow up research studies has received little attention although it is perceived to be quite common. We examined the ethical implications of cold calling in a study of subjects with defined neurotic disorders followed up 12 years after initial assessment carried out to determine outcome in terms of symptoms, social functioning, and contact with health services. The patients concerned were asked at original assessment if they would agree to be followed up subsequently and although they agreed no time limit was put on this.

Objectives:To decide if cold calling was ethically justifiable and, if so, to set guidelines for researchers.

Design:The study was a cohort study of patients with neurotic disorder treated initially for 10 weeks in a randomised controlled trial.

Findings:At follow up by a research medical practitioner 18 of the 210 patients had died and of the remaining 192 patients 186 (97%) were seen or had a telephone interview. Four patients refused and two others did not have interviews but agreed to some data being obtained. However, only 104 patients (54%) responded to letters inviting them to make an appointment or to refuse contact and the remainder were followed up by cold calling, with most patients agreeing readily to the research interview. The findings illustrate the dilemma of the need to get the maximum possible data from such studies to achieve scientific validity (and thereby justify the ethics of the study) and the protection of subjects’ privacy and autonomy.

Conclusions:More attention needs to be paid to consent procedures if cold calling is to be defended on ethical grounds but it is unreasonable to expect this to be obtained at the beginning of a research study in a way that satisfies the requirements for informed consent. A suggested way forward is to obtain written consent for the research at the time that cold calling takes place before beginning the research.
The implications of starvation induced psychological changes for the ethical treatment of hunger strikers
Authors: Fessler D M T
Published: August 2003

Objective:To evaluate existing ethical guidelines for the treatment of hunger strikers in light of findings on psychological changes that accompany the cessation of food intake.

Design:Electronic databases were searched for (a) editorials and ethical proclamations on hunger strikers and their treatment; (b) studies of voluntary and involuntary starvation, and (c) legal cases pertaining to hunger striking. Additional studies were gathered in a snowball fashion from the published material cited in these databases. Material was included if it (a) provided ethical or legal guidelines; (b) shed light on psychological changes accompanying starvation, or (c) illustrated the practice of hunger striking. Authors’ observations, opinions, and conclusions were noted.

Conclusions:Although the heterogeneous nature of the sources precluded statistical analysis, starvation appears to be accompanied by marked psychological changes. Some changes clearly impair competence, in which case physicians are advised to follow advance directives obtained early in the hunger strike. More problematic are increases in impulsivity and aggressivity, changes which, while not impairing competence, enhance the likelihood that patients will starve themselves to death.
Physicians’s reports on the impact of living wills at the end of life in Japan
Authors: Masuda Y , Fetters M D , Hattori A , Mogi N , Naito M , Iguchi A , Uemura K
Published: August 2003

Context:A growing number of Japanese people have completed advance directives, especially living wills, even though there is no legislation recognising such documents and little empirical research on their impact on clinical care at the end of life in Japan.

Objectives:To investigate physicians’ attitudes about living wills and their experiences with patients who had completed a living will and later died.

Design:Self administered survey and qualitative study using open question and content analysis.

Setting:Japan.

Participants:Physicians known to have cared for a patient who had presented a living will prior to death.

Measurements:The physician’s response to receiving a living will, communication about the living will, the impact of the living will on clinical care, demographics, and their opinion on advance directives, especially living wills.

Main results:Fifty five per cent of respondents approved of advance directives in general, and 34% had more opportunities to communicate with a patient and his/her family after receiving the living will. Sixty nine per cent of the physicians who received a living will did not, however, change their course of therapy as a consequence of receiving the living wills. Based on the analysis, we identified three areas of concern in the comments on living wills: (1) concerns relative to patients, physicians, and families; (2) social context, and (3) clinical and administrative concerns. The physicians raised various topics for discussion; they tended to describe the issues from a clinical perspective.

Conclusions:Our identified areas of concern should prove helpful in better understanding the clinical and ethical implications of living wills in Japan.
Investigating the origin of AIDS: some ethical dimensions
Authors: Martin B
Published: August 2003

The theory that AIDS originated from contaminated polio vaccines raises a number of challenging issues with ethical dimensions. TheJournal of Medical Ethicsdealt with a submission about the theory a decade ago; subsequent developments have raised further issues. Four areas of contention are addressed: whether the theory should be investigated; whether anyone should be blamed; whether defamation actions are appropriate, and whether the scientific community has a responsibility to examine unorthodox theories.
Medicine as an essentially contested concept
Authors: McKnight C
Published: August 2003

W B Gallie’s notion of essentially contested concepts remains of philosophical interest. I argue that medicine is one such concept and look at the consequences of this as regards the inappropriateness of looking for definitions and necessary and sufficient conditions to settle debates about what medicine is and is not.
THz Technology: An Overview
Authors: Siegel P. H.
Published: August 2003

THz technology applications, sensors and sources are briefly reviewed. Emphasis is placed on the less familiar components, instruments or subsystems. Science drivers, some historic background and future trends are discussed.
Two-Terminal Active Devices for Terahertz Sources
Authors: Haddad G. I. , East J. R. , Eisele H.
Published: August 2003

The terahertz frequency range of the electromagnetic spectrum holds great promise for many applications including sensing, imaging, and communications. However, the availability of solid-state sources with reasonable power levels is well recognized as one of the major obstacles for systems applications in this frequency range. Here, the state of the art of active two-terminal devices is reviewed and high-lighted with some exemplary experimental results. The potential, capabilities, and limitations of two-terminal devices regarding power generation at terahertz frequencies are discussed. Furthermore, a new device is described that has the potential of circumventing some of the limitations of existing devices.
Multiplier and Harmonic Generator Technologies for Terahertz Applications
Authors: Weikle R. M. , Crowe T. W. , Kollberg E. L.
Published: August 2003

Harmonic generation based on frequency multipliers has proven to be the most successful and widely used solid-state technology for generating power at submillimeter wavelengths. Over the last several years, the development of new device technologies, implementation of innovative circuits, and application of advanced integrated-circuit processing techniques to frequency multiplier design have resulted in unprecedented levels of performance throughout the submillimeter-wave frequency band. This paper reviews the technological innovations, device options, circuit architectures, and fabrication technologies that have made harmonic generation such a successful approach to source development in the submillimeter spectrum.
Submicron InP-based HBTs for Ultra-high Frequency Amplifiers
Authors: Urteaga M. , Krishnan S. , Scott D. , Wei Y. , Dahlstrom M. , Lee S. , Rodwell M. J. W.
Published: August 2003

Transistor bandwidths are approaching terahertz frequencies. Paramount to high speed transistor operation is submicron device scaling. High bandwidths are obtained with heterojunction bipolar transistors by thinning the base and collector layers, increasing emitter current density, decreasing emitter contact resistivity, and reducing the emitter and collector junction widths. In mesa HBTs, minimum dimensions required for the base contact impose a minimum width for the collector junction, frustrating device scaling. We have fabricated HBTs with narrow collector junctions using a substrate transfer process. HBTs with submicron collector junctions exhibit extremely high fmaxand high gains in mm-wave ICs. Transferred-substrate HBTs have obtained record 21 dB unilateral power gain at 100 GHz. Recently-fabricated devices have shown unbounded unilateral power gain from 40-110 GHz, and fmaxcannot be extrapolated from measuremente. However, these devices exhibited high power gains at 220 GHz, the frequency limit of presently available microwave network analyzers. Demonstrated amplifier ICs in the technology include reactively tuned amplifiers at 175 GHz, lumped and distributed amplifiers with bandwidths to 85 GHz, and W-band power amplifiers.
THz Generation by Photomixing in Ultrafast Photoconductors
Authors: Brown E. R.
Published: August 2003

This article reviews the fundamental concepts, technology, and recent developments on the topic of THz photomixers made from low-temperature-grown GaAs, ErAs:GaAs, and ErAs:InGaAs. It is designed to be comprehensive and useful both to students and to engineers and scientists new to the THz field.
Silicon-Germanium Quantum-Cascade Lasers
Authors: Kelsall Robert W. , Soref Richard A.
Published: August 2003

The prospects and advantages of silicon germanium quantum cascade lasers are discussed, from both physical and technological perspectives. A range of Si/SiGe intersubband laser configurations are discussed, for both edge and surface emission. Recent experimental activity on mid- and far-infrared devices is reviewed, and the value of detailed theoretical tools for heterostructure design is highlighted. Steps towards silicon optoelectronic integration are also considered.
Plasma Wave Electronics
Authors: Shur Michael S. , Ryzhii Victor
Published: August 2003

Plasma waves are oscillations of electron density in time and space. In deep submicron field effect transistors plasma wave frequencies lie in the terahertz range and can be tuned by applied gate bias. Since the plasma wave frequency is much larger that the inverse electron transit time in the device, it is easier to reach "ballistic" regimes for plasma waves than for electrons moving with drift velocities. In the ballistic regime, no collisions of electrons with impurities or lattice vibrations occur on a time scale on the order of the plasma oscillation period, and the device channel acts as a resonant cavity for the plasma waves, making possible tunable resonant detection or even emission of the electromagnetic radiation in the terahertz range. We review the theory of plasma waves in field effect transistors; discuss instabilities of these waves in different device structures and their applications for detection and generation of the terahertz radiation.
T-Ray Sensing and Imaging
Authors: Mickan S. P. , Zhang X.-C.
Published: August 2003

Terahertz (THz) radiation occupies part of the electromagnetic spectrum between the infrared and microwave bands. Until recently, technology at THz frequencies was under-developed compared to the rest of the electromagnetic spectrum, leaving a gap between millimeter waves and the far-infrared (FIR). In the past decade, interest in the THz gap has been increased by the development of ultrafast laser-based T-ray systems and their demonstration of diffraction-limited spatial resolution, picosecond temporal resolution, DC-THz spectral bandwidth and signal-to-noise ratios above 104.

This chapter reviews the development, the state of the art and the applications of T-ray spectrometers. Continuous-wave (CW) THz-frequency sources and detectors are briefly introduced in comparison to ultrafast pulsed THz systems. An emphasis is placed on experimental applications of T-rays to sensing and imaging, with a view to the continuing advance of technologies and applications in the THz band.
Multistatic Reflection Imaging with Terahertz Pulses
Authors: Dorney Timothy D. , Symes William W. , Mittleman Daniel M.
Published: August 2003

Recent advances in the technique of terahertz time-domain spectroscopy have led to the development of the first fiber-coupled room-temperature broadband terahertz sources and detectors. The fiber coupling permits the repositioning of the emitter and receiver antennas without loss of temporal calibration or alignment, thus enabling multistatic imaging. We describe a new imaging method which exploits this new capability. This technique emulates the data collection and image processing procedures developed for geophysical prospecting. We use a migration procedure to solve the inverse problem; this permits us to reconstruct the location, shape, and refractive index of targets. We show examples for both metallic and dielectric model targets, and we perform velocity analysis on dielectric targets to estimate the refractive indices of imaged components. These results broaden the capabilities of terahertz imaging systems, and also demonstrate the viability of the THz system as a test bed for the exploration of new seismic processing methods.
Orbifolding Frobenius Algebras
Authors: Kaufmann Ralph M.
Published: August 2003

We study the general theory of Frobenius algebras with group actions. These structures arise when one is studying the algebraic structures associated to a geometry stemming from a physical theory with a global finite gauge group, i.e. orbifold theories. In this context, we introduce and axiomatize these algebras. Furthermore, we define geometric cobordism categories whose functors to the category of vector spaces are parameterized by these algebras. The theory is also extended to the graded and super-graded cases. As an application, we consider Frobenius algebras having some additional properties making them more tractable. These properties are present in Frobenius algebras arising as quotients of Jacobian ideal, such as those having their origin in quasi-homogeneous singularities and their symmetries.
Jensen's Trace Inequality in Several Variables
Authors: Hansen Frank , Pedersen Gert K.
Published: August 2003

For a convex, real function f, we present a simple proof of the formula [Formula: see text] valid for each tuple (x1,…, xm) of symmetric matrices in [Formula: see text] and every unital column (a1,…, am) of matrices, i.e. [Formula: see text]. This is the standard Jensen trace ine-quality. If f ≥ 0 it holds also for the unbounded trace on [Formula: see text], where [Formula: see text] is an infinite-dimensional Hilbert space. We then investigate the more general case where τ is a densely defined, lower semi-continuous trace on a C*-algebra [Formula: see text] and f is a convex, continuous function of n variables, and show that we have the inequality [Formula: see text] for every family of abeliann-tuples [Formula: see text], i.e. tuples of self-adjoint elements in [Formula: see text] such that [xik, xjk] = 0 for all i, j and k, where 1 ≤ k ≤ m, and every unital m-column (a1,…, am) in [Formula: see text], provided that the elements [Formula: see text] also form an abelian n-tuple. We even establish this result for weak* measurable, self-adjoint, abelian fields (xit)t∈T, 1 ≤ i ≤ n, i.e. [xit, xjt] = 0 for all i, j and t, and weak* measurable, unital column field (at)t∈T in [Formula: see text] paired with any trace or trace-like functional φ, i.e. one that contains the n-tuple (presumed abelian) with elements [Formula: see text] in its centralizer. This takes the form of the inequality [Formula: see text] We also study functions of n variables that are monotone increasing in each variable, and show in two important cases that [Formula: see text] whenever [Formula: see text] and [Formula: see text] are abelian n-tuples with xi ≤ yi for each i and φ is a trace or a trace-like functional.
Correspondences and Approximation Properties for von Neumann Algebras
Authors: Kraus Jon
Published: August 2003

The notion of the amenability of a locally compact group has been extended in various ways. Two weaker versions of amenability, weak amenability and the approximation property, have been defined for locally compact groups (by Haagerup and Haagerup and Kraus, respectively) and Bekka has defined a notion of amenability for representations of locally compact groups. Correspondences can be viewed as a generalization of representations of such groups. Using this viewpoint, Ananthraman–Delaroche has defined a notion of (left) amenability for correspondences. In this paper, we define notions of weak amenability and the approximation property for correspondences (and representations of locally compact groups), and obtain various results concerning these notions. Ananthraman–Delaroche showed that if N ⊂ M is an inclusion of von Neumann algebras, and if the associated inclusion correspondence is left amenable, then various approximation properties of N (semidiscreteness, the weak* completely bounded approximation property, and the weak* operator approximation property) are shared by M. We show that if this correspondence has the (weaker) approximation property, then if N has the weak* operator approximation property, so does M. An application of this result to crossed products is also given.
Sustainability of External Imbalances: The Case of Malaysia
Authors: Lau Evan , Baharumshah Ahmad Zubaidi
Published: August 2003

The understanding of the sustainable external imbalances over the 1961-2001 for Malaysia is presented in this paper. The empirical results clearly show that inflows and outflows share a common stochastic trend prior to the 1997 Asian crisis while in the post-crisis period the current account surpluses are on an unsustainable path. Our findings highlight the important role of imports (mainly intermediate inputs) in exports. For an economy that depends on export promotion for its growth process, imports are important in restoring external imbalances to its sustainable steady state path. As illustrated by the recent crisis, the large depreciation of the ringgit contributed to a decline in imports and for an economy that is highly dependent on imported capital, this means an economic slowdown.
The Effect of Government on Economic Growth in Fiji
Authors: Doessel D. P. , Valadkhani Abbas
Published: August 2003

This paper investigates the empirical relationship between the size of government and the process of economic growth in Fiji. The results reported here present a mixed picture, in that the model estimated specifies two different effects of the government sector on economic growth. Using annual time series data for the period 1964–1999, it is found that government expenditure exerts a strong beneficial impact on economic growth. However, marginal factor productivity in the government sector is found to be lower than that of the private sector. The reasons for this low productivity are two-fold: the result of the lack of market incentives and signals in the public sector and the involvement of Fiji's government in some activities which may be rationalised in terms of the socio-political objectives of the Fijian government. While recognising that there may be factors which may hinder the process of efficiency in the private sector, it can be argued that by shifting factors of production from the low productivity (government) sector to the high productivity (private) sector, the rate of growth of GNP will increase.
Orthodox Economics and Economists: Strengths and Weaknesses
Authors: Ng Yew-Kwang
Published: August 2003

Economics is a very powerful discipline that focuses on some important aspects of our life, in particular, constrained maximization equilibrium in resource allocation. However, orthodox economics based on simplified models and many economists much captured by such models have too narrow a focus, ignoring many important factors including the importance of competition for relative standing, environmental disruption, and behaviour patterns inconsistent with the narrow concept of rationality. Economics has also become excessively formalistic, sacrificing relevance for technical sophistication. Extensions of economics to overcome these weaknesses have been and are being made. The incorporation of these advances will make economics more useful. But more time and resources may be needed to train economists properly.
How Did the Bank of Thailand Respond to Capital Inflows before a Crisis? Sterilization and Base Money in the 1990's
Authors: Inoguchi Masahiro
Published: August 2003

This paper explores how the Bank of Thailand (BOT) responded to capital inflows through sterilization and how it changed base money before the Asian crisis. There has been no general consensus on this subject and many previous studies have not considered the definition of sterilization. In this paper, sterilization is defined as the sale of domestic assets by a central bank in order to offset an increase in base money due to the purchase of foreign assets. When the BOT does not sell domestic assets but instead changes the value of accounts that are not counted in base money on the liabilities side of the balance sheet, it can keep base money fixed without sterilization. The results of this analysis are that the BOT kept base money constant after 1994 by means of sterilization and the manipulation of liabilities not counted in base money, while prior to 1994, there was incomplete sterilization and base money was not fixed.
The Silicon Lattice Accelerator
Authors: Spencer James E.
Published: August 2003

Previously, the generalized luminosity ℒ was defined and calculated for all incident channels based on an NLC e+ e- design. Alternatives were then considered to improve the differing beam-beam effects in the e- e-, eγ and γγ channels. One example was tensor beams composed of bunchlets nijk implemented with a laser-driven, silicon accelerator based on micromachining techniques. Problems were considered and expressions given for radiative broadening due to bunchlet manipulation near the final focus to optimize luminosity via charge enhancement, neutralization or bunch shaping. Because the results were promising, we explore fully integrated structures that include sources, optics (for both light and particles) and acceleration in a common format - an accelerator-on-chip. Acceptable materials (and wavelengths) must allow velocity synchronism between many laser and electron pulses with optimal efficiency in high radiation environments. There are obvious control and cost advantages that accrue from using silicon structures if radiation effects can be made acceptable and the structures fabricated. Tests related to deep etching, fabrication and radiation effects on candidate amorphous and crystalline materials show Si (λL > 1.2μ m ) and fused SiO 2(λL > 0.3μ m ) to be ideal materials.
An Evaluation of Knowledge Engineering Approaches to the Maintenance of Evolutionary Software
Authors: Chandra C. , Ramamoorthy C. V.
Published: August 2003

Reverse engineering and reengineering are two major research challenges in the software maintenance process. Reverse engineering is the process of rederiving the specification of a program; and reengineering is the process of modifying an already existing software to add additional functionalities or to correct any malfunction. The difficulty in these tasks are that software development commonly involves many software engineers with implicit assumptions about the behavior of each module. These assumptions are not documented and often leads to inconsistencies in the code. During reverse engineering, such assumptions may not be uncovered. These assumptions usually have complex dependencies, and are the cause of a lot of bugs when the software is reengineered. Many approaches and prototype tools have been developed to address these issues. Reverse engineering and automated program understanding tools have been developed to support the reverse engineering tasks; while various theoretical works on structural program analysis and programs for automated ripple effect analysis have attempted to deal with the reengineering process. These works can be classified into two main types of approaches: those using shallow knowledge or knowledge about the structure of the system and those utilizing deep knowledge or knowledge about the semantics and behavior of the software system. In this paper, we attempt to survey works that have been done under these two broad categories of approaches to deal with the software maintenance tasks, evaluate the strengths and drawbacks of each approach, and attempt to draw a conclusion on the advantages and disadvantages of the two main lines of approaches.
The Design of an Expert System for Domain Knowledge Engineering and Decision Making: A Case Study in the Criminal Justice System
Authors: Agyapong Owusu-Ansah , Bobbie Patrick O.
Published: August 2003

In this paper, we discuss a tool for eliciting domain knowledge (specification) of a decision support system. In particular, we focus on a decision support software system (DSS) which employs domain knowledge of recidivism in the juvenile justice system. Using the elicited domain knowledge, the DSS tool uses deductive reasoning techniques to make inferences and provide suggestive courses of action to support the investigatory functions of police, attorneys, or probation officials. The motivation for developing the system is manifold:

(1) the activities of the officials are repetitive and their procedures mostly manual;

(2) investigations usually result in large volume of biographical data;

(3) the need to link several, related case files;

(4) officials seldom have concurrent access to case files — causing delays in resolving cases in the court system; among others.

Developing a software system to support the investigation and decision making of criminal cases is in itself a daunting task, which makes the system specification a critical input to the development process. Hence, the correctness of the resultant domain knowledgebase and the underlying deductive/support system depends on logically consistent and sound methods. In the paper, we describe the rationale for developing the DSS system, why we focus on the criminal (juvenile) justice system, the methodology for eliciting DSS domain knowledge, and a scenario of what we are implementing as a proof-of-concept system. A series of elicitation sessions which epitomize the DSS system are discussed in the article.
REINAS: A Real-Time System for Managing Environmental Data
Authors: Rosen Eric C. , Haining Theodore R. , Long Darrell D. E. , Mantey Patrick E. , Wittenbrink Craig M.
Published: August 2003

Managing scientific data is a challenging task, and many of the problems it presents have yet to be adequately solved. The Real-time Environmental Information Network and Analysis System (REINAS) is an operational solution to the problem of collecting and distributing environmental data in a real-time context, as well as supporting data acquisition, retrieval, visualization and long-term data maintenance. The system is built around one or more databases and has been developed to support both real-time and retrospective regional scale environmental science. Continuous real-time data is acquired from dispersed sensors and input to a logically integrated but physically distributed system. The database engine provides a powerful structure to handle data management, but current database technology can have difficulty meeting the performance requirements that a large real-time environmental system demands. The REINAS architecture and current status is described in detail, including the challenges that were addressed in the construction of an operational system which includes a regional wireless instrumentation network comprised of over 200 instrument platforms and 1500 sensor streams producing real-time data of interest to thousands of users.
Distributed Systems Management Software-in-the-Loop
Authors: Krämer Bernd J. , Koch Thomas
Published: August 2003

IT experts expect open distributed processing to become the predominant computing infrastructure in the late nineties. All computer supported work places of large enterprises and organizations will then be networked and will be integrated into cross-regional and cross-sector business and information processes. The size and complexity of such applications, the local autonomy, distribution and heterogeneity of participating subsystems, and their asynchronous interaction, however, require new architectures, strategies, and tools for their technical management. In previous work we placed a production rule interpreter into the monitoring, decision, control action loop to provide flexible, operational semantics of well-understood management policies. In this article we extend this work in two directions. First we map the structure and dynamic behavior of policies into a graph representation. This semantic representation enables a systematic prediction of the effects of policy executions and allows for a better impact analysis in case of policy changes. Then we introduce a declarative event definition mechanism. It supports a causal and temporal correlation of individual events and serves to instantiate and adapt a predefined generic event handler to the specific needs of the actual management application. Such event handlers join in the interaction between monitoring agents and policy interpreter. By event correlation they may reduce the number of events triggering management actions significantly and help to filter secondary events.
Scientific Data Mining: A Case Study
Authors: Chang Chia-Yo , Wang Jason T. L. , Chang Roger K.
Published: August 2003

Scientific data mining is the activity of finding significant information in scientific data. This paper presents an example of scientific data mining: the discovery of approximately common patterns in RNA secondary structures. We represent an RNA secondary structure by an ordered labeled tree based on a previously proposed scheme. The patterns in the trees are substructures that can differ in both substitutions and deletions/insertions of nodes of the trees. Our techniques incorporate approximate tree matching algorithms and novel heuristics for discovery and optimization. Experimental results obtained by running these algorithms on both generated data and RNA secondary structures show the good performance of the algorithms. It is shown that the optimization heuristics speed up the discovery algorithm by a factor of 10. Moreover, our optimized approach is 100,000 times faster than the brute force method.
A Fast 3-D Visualization Methodology Using Characteristic Views of Objects
Authors: Hwang Soochan , Cho Sang-Young , Wang Taehyung , Sheu Phillip C.-Y.
Published: August 2003

This paper describes a 3-D visualization method based on the concept of characteristic views (CVs). The idea of characteristic views was derived based on the observation that the infinite possible views of a 3-D object can be grouped into a finite number of equivalence classes so that within each class all the views are isomorphic in the sense that they have the same line-junction graphs. To visualize the changes of scenes in real time, the BSP tree algorithm is known to be efficient in a static environment in which the viewpoint can be changed easily. However, if a scene consists of many objects and each object consists of many polygons, the time complexity involved in traversing a BSP tree increases rapidly so that the original BSP tree algorithm may not be efficient. The method proposed in this paper is object-oriented in the sense that, for all viewpoints, at the preprocessing stage the ordering for displaying the objects is determined. At run time, the objects are displayed based on a pre-calculated ordering according to the viewpoint. In addition, a CV is used as a basic 2-D projected image of a 3-D object.
A Large Memory Storage and Retrieval Neural Network for Adaptive Retrieval and Diagnosis
Authors: Graupe D. , Kordylewski H.
Published: August 2003

The neural network discussed in this paper is a self trained network for LArge Memory STorage And Retrieval (LAMSTAR) of information. It employs features such as forgetting, interpolation, extrapolation and filtering, to enhance processing and memory efficiency and to allow zooming in and out of memories. The network is based on modified SOM (Self-Organizing-Map) modules and on arrays of link-weight vectors to channel information vertically and horizontally throughout the network. Direct feedback and up/down counting serve to set these link weights as a higher-hierarchy performance evaluator element which also provides high level interrupts. Pseudo random modulation of the link weights prevents dogmatic network behavior. The input word is a coded vector of several sub-words (sub-vectors). These features facilitate very rapid intelligent retrieval and diagnosis of very large memories, that have properties of a self-adaptive expert system with continuously adjustable weights. The authors have applied the network to a simple medical diagnosis and fault detection problems.
An Active Multimedia Information System for Information Retrieval, Discovery and Fusion
Authors: Chang Shi-Kuo , Graupe Daniel , Hasegawa Keiko , Kordylewski Hubert
Published: August 2003

To accomplish the retrieval, discovery and fusion of multimedia information from diverse sources, an active multimedia information system capable of retrieving, processing and filtering multimedia information, checking for consistency, and structuring the relevant information for distribution is needed. We describe a framework for the human- and system-directed retrieval, discovery and fusion of multimedia information, which is based upon the observation that a significant event often manifests itself in different media over time and space. Therefore if we can index such manifestations and dynamically link them, then we can check for consistency and discover important and relevant multimedia information. This dynamic indexing technique is based upon the theory of active index. For the discovery of significant events, a powerful newly developed artificial neural network is used to serve as the decision network subsystem of the proposed information system. An experimental system is implemented for further empirical research.
Metrics for Concept-Oriented Knowledge Bases
Authors: Lethbridge Timothy C.
Published: August 2003

Metrics are widely researched and used in software engineering; however there is little analogous work in the field of knowledge engineering. In other words, there are no widely-known metrics that the developers of knowledge bases can use to monitor and improve their work. In this paper we adapt the GQM (Goals-Questions-Metrics) methodology that is used to select and develop software metrics. We use the methodology to develop a series of metrics that measure the size and complexity of concept-oriented knowledge bases. Two of the metrics measure raw size; seven measure various aspects of complexity on scales of 0 to 1, and are shown to be largely independent of each other. The remaining three are compound metrics that combine aspects of the other nine in an attempt to measure the overall 'difficulty' or 'complexity' of a knowledge base. The metrics have been implemented and tested in the context of a knowledge management system called CODE4.
Deriving Identity from Extensionality
Authors: Hofstede A. H. M. ter , van der Weide Th. P.
Published: August 2003

In recent years, a number of proposals have been made to extend conventional conceptual data modeling techniques with concepts for modeling complex object structures. Among the most prominent proposed concepts is the concept of collection type. A collection type is an object type of which the instances are sets of instances of another object type. A drawback of the introduction of such a new concept is that the formal definition of the technique involved becomes considerably more complex. In this paper a new kind of constraint, the extensional uniqueness constraint, is introduced, providing an alternative treatment of complex object types. The formal definition of this constraint type is presented, the advantages of its introduction are discussed, and its consequences for, among others, identification schemes are elaborated.
Task Analysis and Design Plans in Formal Specification Design
Authors: Alexander Perry
Published: August 2003

This paper presents BENTON, a prototype system demonstrating task analysis and multi-agent reasoning applied to formal specification synthesis. BENTON transforms specifications written as attribute-value pairs into Larch Modula-3 interface language and Larch Shared Language specifications. BENTON decomposes the software specification design task into synthesis, analysis and evaluation subtasks. Each subtask is assigned a specific design method based on problem and domain characteristics. This task analysis is achieved using blackboard knowledge sources and multi-agent reasoning employing design plans to implement different problem solving methods. Knowledge sources representing different problem solving methodologies monitor blackboard spaces and activate when they are applicable. When executed, Design plans send subtasks to agents that select from available problem solving methodologies. BENTON agents and knowledge sources use case-based reasoning, schemata-based reasoning and procedure execution as their fundamental reasoning methods. This paper presents an overview of the BENTON design model, its agent architecture and plan execution capabilities, and two annotated examples of BENTON problem solving activities.
A Formal Definition of FRSM and Applications
Authors: Liu Shaoying
Published: August 2003

FRSM (Formal Requirements Specification Method) is a structured formal language and method for requirements analysis and specification construction based on data flow analysis. It uses a formalized DeMarco data flow diagram to describe the overall structure of systems and a VDM-SL like formal notation to describe precisely the functionality of components in the diagrams. This paper first describes the formal syntax and semantics of FRSM and then presents an example of using the axiom and inference rules given in the definition of the formal semantics for checking consistency of specifications. A case study of applying FRSM to a practical example is described to demonstrate the principle of constructing requirements specifications and to uncover the benefits and deficiencies of FRSM.
A Formal Methodology for Analyzing Tradeoffs of Imprecise Requirements
Authors: Yen John , Tiao W. Amos
Published: August 2003

Conflict identification and resolution are inevitable parts of the requirement analysis process. Over the past few years, the need to deal with conflicting system requirements has become increasingly important. These requirements are often elastic in that they can be satisfied to a degree. The overall goal of this research is to develop a formal methodology that facilitates the identification and tradeoff analysis of conflicting requirements by explicitly capturing their elasticity. In order to capture the elasticity of imprecise requirements, we represent imprecise requirements using fuzzy logic. Based on the representation, we build a formal foundation to facilitate the identification of conflicting requirements. Once the conflicting requirements are identified, we describe a systematic approach for analyzing the tradeoff between conflicting requirements using the techniques in decision science. The systematic tradeoff analyses are used for three important tasks in the requirement engineering process:

(1) for validating the structure used in aggregating prioritized requirements,

(2) for assisting requirement engineers in identifying the structures and the parameters of the underlying representation of imprecise requirements and in eliciting them from the customer, and

(3) for assessing the priorities of conflicting requirements.

We illustrate the usage of these techniques using the requirements of a conference room scheduling system.