bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of the Feedbacks and Regulation of Recruitment Dancing in Honey Bees
Authors: Anderson Carl
Published: October 2003

Honey bee nectar foragers returning to the hive experience a delay as they search for a receiver bee to whom they transfer their material. In this paper I describe the simulation of the "threshold rule" (Seeley, 1995) which relates the magnitude of this search delay to the probability of performing a recriutment dance — waggle dance, tremble dance, or no dance. Results show that this rule leads to self-organised near-optimal worker allocation in a fluctuating environment, is extremely robust, and operates over a wide range of parameter values. The reason for the robustness appears to be the particular sytem of feedbacks that operate within the system.
Definable relations and first-order query languages over strings
Authors: Benedikt Michael , Libkin Leonid , Schwentick Thomas , Segoufin Luc
Published: October 2003

We study analogs of classical relational calculus in the context of strings. We start by studying string logics. Taking a classical model-theoretic approach, we fix a set of string operations and look at the resulting collection of definable relations. These form an algebra---a class ofn-ary relations for everyn, closed under projection and Boolean operations. We show that by choosing the string vocabulary carefully, we get string logics that have desirable properties: computable evaluation and normal forms. We identify five distinct models and study the differences in their model-theory and complexity of evaluation. We identify a subset of these models that have additional attractive properties, such as finite VC dimension and quantifier elimination.Once you have a logic, the addition of free predicate symbols gives you a string query language. The resulting languages have attractive closure properties from a database point of view: while SQL does not allow the full composition of string pattern-matching expressions with relational operators, these logics yield compositional query languages that can capture common string-matching queries while remaining tractable. For each of the logics studied in the first part of the article, we study properties of the corresponding query languages. We give bounds on the data complexity of queries, extend the normal form results from logics to queries, and show that the languages have corresponding algebras expressing safe queries.
Fundamentals of spherical parameterization for 3D meshes
Authors: Gotsman Craig , Gu Xianfeng , Sheffer Alla
Published: October 2003

Parameterization of 3D mesh data is important for many graphics applications, in particular for texture mapping, remeshing and morphing. Closed manifold genus-0 meshes are topologically equivalent to a sphere, hence this is the natural parameter domain for them. Parameterizing a triangle mesh onto the sphere means assigning a 3D position on the unit sphere to each of the mesh vertices, such that the spherical triangles induced by the mesh connectivity are not too distorted and do not overlap. Satisfying the non-overlapping requirement is the most difficult and critical component of this process. We describe a generalization of the method of barycentric coordinates for planar parameterization which solves the spherical parameterization problem, prove its correctness by establishing a connection to spectral graph theory and show how to compute these parameterizations.
Evaluating the visual fidelity of physically based animations
Authors: O'Sullivan Carol , Dingliana John , Giang Thanh , Kaiser Mary K.
Published: October 2003

For many systems that produce physically based animations, plausibility rather than accuracy is acceptable. We consider the problem of evaluating the visual quality of animations in which physical parameters have been distorted or degraded, either unavoidably due to real-time frame-rate requirements, or intentionally for aesthetic reasons. To date, no generic means of evaluating or predicting the fidelity, either physical or visual, of the dynamic events occurring in an animation exists. As a first step towards providing such a metric, we present a set of psychophysical experiments that established some thresholds for human sensitivity to dynamic anomalies, including angular, momentum and spatio-temporal distortions applied to simple animations depicting the elastic collision of two rigid objects. In addition to finding significant acceptance thresholds for these distortions under varying conditions, we identified some interesting biases that indicate non-symmetric responses to these distortions (e.g., expansion of the angle between post-collision trajectories was preferred to contraction and increases in velocity were preferred to decreases). Based on these results, we derived a set of probability functions that can be used to evaluate the visual fidelity of a physically based simulation. To illustrate how our results could be used, two simple case studies of simulation levels of detail and constrained dynamics are presented.
Suggestive contours for conveying shape
Authors: DeCarlo Doug , Finkelstein Adam , Rusinkiewicz Szymon , Santella Anthony
Published: October 2003

In this paper, we describe a non-photorealistic rendering system that conveys shape using lines. We go beyond contours and creases by developing a new type of line to draw: the
suggestive contour
. Suggestive contours are lines drawn on clearly visible parts of the surface, where a true contour would first appear with a minimal change in viewpoint. We provide two methods for calculating suggestive contours, including an algorithm that finds the zero crossings of the radial curvature. We show that suggestive contours can be drawn consistently with true contours, because they anticipate and extend them. We present a variety of results, arguing that these images convey shape more effectively than contour alone.
The role of IT in successful knowledge management initiatives
Authors: Kankanhalli Atreyi , Tanudidjaja Fransiska , Sutanto Juliana , Tan Bernard C. Y.
Published: October 2003

Executives must confront the challenging task of deciding the type of IT to deploy in support of their knowledge management initiatives.
Concurrent-convergent strategy in IT consulting
Authors: Liao Ziqi , Cheung Michael Tow
Published: October 2003

The concurrent-convergent strategy in IT consulting can be exploited to increase client efficiency, to draw conceptual and practical lessons for other information-based applications, and to develop synergy between IT consulting and business process reengineering.
Automatic generation of intelligent diagram editors
Authors: Chok Sitt Sen , Marriott Kim
Published: October 2003

The
intelligent diagram
is a recent metaphor for diagramming in which the underlying graphic editor parses the diagram as it is being constructed, performing error correction and collecting geometric constraints that capture the relationships between diagram components. During diagram manipulation a constraint solver uses these geometric constraints to maintain the diagram's semantics. We introduce the Penguins system. This automates the development of graphical editors that support the intelligent diagram metaphor. It takes a grammatical specification of a particular diagram language and generates an editor specialized for the creation, manipulation and parsing of diagrams in that visual language. We extend previous research in this area by allowing more expressive grammars, performing automatic error correction, and detailing how efficient incremental parsing has been achieved. We also provide an empirical evaluation of the system. This shows that the system can be used to generate customized editors for a wide variety of diagram languages, ranging from state transition diagrams to mathematical equations, with real-time incremental parsing and error correction.
Interaction between path and type constraints
Authors: Buneman Peter , Fan Wenfei , Weinstein Scott
Published: October 2003

Path constraints are capable of expressing inclusion and inverse relationships and have proved useful in modeling and querying semistructured data [Abiteboul and Vianu 1999; Buneman et al. 2000]. Types also constrain the structure of data and are commonly found in traditional databases. There has also been work on imposing structure or a type system on semistructured data for storing and querying semistructured data in a traditional database system [Alon et al. 2001; Deutsch et al. 1999a; Florescu and Kossmann 1999; Shanmugasundaram et al. 1999]. One wants to know whether complexity results for reasoning about path constraints established in the untyped (semistructured) context could carry over to traditional databases, and vice versa. It is therefore appropriate to understand the interaction between types and path constraints. In addition, XML [Bray et al. 1998], which may involve both an optional schema (e.g., DTDs or XML Schema [Thompson et al. 2001]) and integrity constraints, highlights the importance of the study of the interaction.This article investigates that interaction. In particular it studies constraint implication problems, which are important both in understanding the semantics of type/constraint systems and in query optimization. It shows that path constraints interact with types in a highly intricate way. For that purpose a number of results on path constraint implication are established in the presence and absence of type systems. These results demonstrate that adding a type system may in some cases simplify reasoning about path constraints and in other cases make it harder. For example, it is shown that there is a path constraint implication problem that is decidable in PTIME in the untyped context, but that becomes undecidable when a type system is added. On the other hand, there is an implication problem that is undecidable in the untyped context, but becomes not only decidable in cubic time but also finitely axiomatizable when a type system is imposed.
SCO's barroom brawl
Authors: Weiss Aaron
Published: October 2003

So you're sitting at home one Saturday night with nothing to do---the weekend's going nowhere fast. You call up your buddies and they come on over with a few 40s. Before long the room is spinning and you're ready to rumble. You and the boys stumble over to the corner tavern and raise a stink. You shove a few little guys around and work yourself into a frenzy. You smash your bottle against the counter and furiously wave and jab with the jagged stump, threatening everyone in the house unless they buy you a round. Does this sound like an effective way to get a free ride? It sure does if your name is the SCO Group and the bar is full of Linux distributors.
Term rewriting with traversal functions
Authors: van den Brand Mark G. J. , Klint Paul , Vinju Jurgen J.
Published: October 2003

Term rewriting is an appealing technique for performing program analysis and program transformation. Tree (term) traversal is frequently used but is not supported by standard term rewriting. We extend many-sorted, first-order term rewriting with
traversal functions
that automate tree traversal in a simple and type-safe way. Traversal functions can be bottom-up or top-down traversals and can either traverse all nodes in a tree or can stop the traversal at a certain depth as soon as a matching node is found. They can either define sort-preserving transformations or mappings to a fixed sort. We give small and somewhat larger examples of traversal functions and describe their operational semantics and implementation. An assessment of various applications and a discussion conclude the article.
BIST and production testing of ADCs using imprecise stimulus
Authors: Parthasarathy Kumar , Kuyel Turker , Price Dana , Jin Le , Chen Degang , Geiger Randall
Published: October 2003

A new approach for testing mixed-signal circuits based upon using imprecise stimuli is introduced. Unlike most existing Built-In Self-Test (BIST) and production test approaches that require excitation signals that are at least 3 bits or more linear than the Device-Under-Test (DUT), the proposed approach can work with stimuli that are several bits less linear than the DUT. This dramatically reduces the requirements on stimulus generation for BIST applications and offers potential for using inexpensive signal generators in production test, or for testing DUTs that have a linearity performance exceeding that of the available test equipment. As a proof of concept, a histogram-based algorithm for linearity testing for Analog-to-Digital Converters (ADCs) has been proposed. It can estimate the Integral Nonlinearity (INL) and Differential Nonlinearity (DNL) of an
n
-bit ADC by using a ramp signal of much less than
n
-bit linearity and a shifted version of the same nonlinear ramp as excitation. The performance of the algorithm is comparable to that of the traditional method which uses (
n
+ 3)-bits or a decade more linear input signals. Complete algorithm description, extensive simulation results and experimental results obtained from using a production tester on commercially available ICs are presented to validate the potential of this algorithm.
Watermark-based copyright protection system security
Authors: Kwok Sai Ho
Published: October 2003

Both researchers and industry players are asking: Just how easy is it to break a watermark-based copyright management system?
Company character and the software business
Authors: Cusumano Michael
Published: October 2003

Consumers must evaluate a software producer's company character as well as its product offerings.
Transactions and Web services
Authors: Little Mark
Published: October 2003

Helping to realize the full potential of e-commerce.
Introduction
Authors: Dori Dov
Published: October 2003

How to evaluate and select the methods and tools for building conceptual models that faithfully represent the abstract concepts of a software system's architecture.
System function and architecture
Authors: Soderborg Nathan R. , Crawley Edward F. , Dori Dov
Published: October 2003

This framework for modeling and conceptually representing a system's specification identifies essential objects and processes while minimizing ambiguity in functional and architectural requirements.
Empirical evidence concerning AES
Authors: Hellekalek Peter , Wegenkittl Stefan
Published: October 2003

AES, the Advanced Encryption Standard, is one of the most important algorithms in modern cryptography. Certain randomness properties of AES are of vital importance for its security. At the same time, these properties make AES an interesting candidate for a fast nonlinear random number generator for stochastic simulation. In this article, we address both of these two aspects of AES. We study the performance of AES in a series of statistical tests that are related to cryptographic notions like confusion and diffusion. At the same time, these tests provide empirical evidence for the suitability of AES in stochastic simulation. A substantial part of this article is devoted to the strategy behind our tests and to their relation to other important test statistics like Maurer's Universal Test.
Nutrient Budgets, Dynamics and Storm Effects in a Eutrophic, Stratified Baltic Lake
Authors: Schernewski Gerald
Published: October 2003

Between 1989 and 1998 the small eutrophic stratified Lake Belau was investigated intensively and multidisciplinarily. This article is a short, comprehensive summary and re‐evaluation of the hydrochemistry of the lake, with focus on nitrogen and phosphorus. In several aspects the lake can be regarded as a typical example of the glacial north German lakes. The 1960's and 1970's are characterised by heavy nutrient inputs and fast eutrophication. During the last two decades the external nutrient load, especially the phosphorus load into Lake Belau was significantly reduced. But phosphorus‐rich sediments and large areas with summerly anoxic sediment surface conditions cause intensive release of phosphorus from older deeper sediment layers. Annual budgets reveal that despite an average sediment accumulation of 3 mm a−1 the lake has lost its function as net phosphorus sink and it is very likely that internal eutrophication by the sediments will keep the lake in its eutrophic state during the next decades. Despite that, monthly budgets of five vertical layers show that the main phosphorus supplier for the phosphorus depleted epilimnion during summer is the creek Alte Schwentine.

The annual nitrogen budget indicates groundwater and interflow water as well as atmospheric input as additional important nitrogen sources. 36% (98 μmol m −2 h−1 N) of all nitrogen input is lost to atmosphere mainly due to denitrification. The example of a heavy storm shows that about 10% of the annual nitrogen loss to the atmosphere can take place during a single day and in form of ammonia. The storm further made obvious that these unpredictable events can have strong impact on nutrient cycling and ecology in Lake Belau and the lake can become an unexpected nutrient source for downstream systems.
Aromaticity and Electron Affinity of Carbok‐[3]radialenes, k=0, 1, 2
Authors: Lepetit Christine , Brøndsted Nielsen Mogens , Diederich François , Chauvin Remi
Published: October 2003

Aromaticity enhancement is a possible driving force for the low reduction potentials of buta‐1,3‐diynediyl‐expanded [N]radialenes: this hypothesis is theoretically analyzed for the expanded [3]radialene prototype. This study is undertaken within a more general prospect, namely the evaluation of the variation of aromaticity with endocyclic and peripheral carbomeric expansion of [3]radialene and its mono‐ and dianions. The structures, denoted as [CH]6h[CC]3kcarbo‐[3]radialene(q) (h=0, 1; k=0, 1, 2; q=0, −1, −2), were optimized in relevant singlet, doublet, or triplet spin states at the B3PW91/6‐31G** level. They were found to be all planar. The structural aromaticity was measured through the average bond length dav over the [CC]3kcarbo‐[3]radialene core, and by the corresponding bond‐length equalization parameter σ(d), related to Krygowski's GEO. The magnetic aromaticity was measured by Schleyer's NICS values at the center of the rings. Regarding the relative variation of NICS and σ(d), two classes of species can be distinguished according to their endocyclic expansion level. The species with a nonexpanded (k=0) or doubly expanded (k=2) ring constitute the first class: they exhibit D3h symmetry and a strong correlation of NICS with σ(d). The species with a singly expanded ring (k=1) fall far from the correlation line, and constitute the second class. This class distinction is related to the degeneracy scheme of the frontier orbitals of the neutral representative. A finer appraisal of the electron (de)localization is brought by the ELF (Electron Localization Function) analysis of the electron density. It allows for a weighting of relevant resonance forms. Unsubstituted species are well described by the superimposition of two or three resonance forms. For (doublet spin state) monoanionic species, their respective weights are validated by comparison with AIM spin density. The weighted mean, n, of the formal numbers of paired πz electrons in the resonance forms was calculated and compared with the closest even integer of either forms 4m+2 or 4m. A density‐based continuous generalization of the orbital‐based discrete Hückel rule is then heuristically proposed through an analytical correlation of NICS versus σ(d), n, and S, the spin of the species. The frontier‐orbital‐degeneracy pattern of neutral species is discussed with respect to structural and magnetic aromaticity criteria. A decreasing HOMO–LUMO gap versus endocyclic expansion is obtained, but [CC]31carbo‐[3]radialene possesses the highest HOMO and LUMO energies. Vertical and adiabatic electron affinities of neutral and monoanionic species were also computed and compared with related experimental data.
Fluid flow and mass transfer in a sinusoidal wavy‐walled tube at moderate Reynolds numbers
Authors: Nishimura Tatsuo , Bian Yongning , Kunitsugu Koji , Morega Alexandru M.
Published: October 2003

Fluid flow and mass transfer characteristics in an axisymmetric sinusoidal wavy‐walled tube are experimentally investigated in the Reynolds number range of 50 to 1000. Attention is paid to the transitional flow, which is observed in the Reynolds number range of 160 to 200. In the laminar flow regime, wall shear stress and mass transfer rate increase with the slopes of 1 and 1/3, respectively, whereas in the turbulent flow regime they increase with the slopes of 3/2 and 3/5, respectively. In the transitional flow regime they increase dramatically, with a sharp slope. It is found that in this flow regime, laminar‐like motion and turbulent‐like motion alternatively take place at different time intervals. This is quite different from the flow instability for the wavy‐walled channel, where Tollmien‐Schlichting waves are observed. The flow instability in the wavy‐walled tube in the transitional flow regime is considered to be responsible for a significant increase in the wall shear stress and mass transfer rate. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(7): 650–661, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10121
Energy‐level alignment at metal–organic and organic–organic interfaces
Authors: Veenstra S. C. , Jonkman H. T.
Published: October 2003

This article reports on the electronic structure at interfaces found in organic semiconductor devices. The studied organic materials are C60 and poly (para‐phenylenevinylene) (PPV)‐like oligomers, and the metals are polycrystalline Au and Ag. To measure the energy levels at these interfaces, ultraviolet photoelectron spectroscopy has been used. It is shown how the energy levels at interfaces deviate from the bulk. Furthermore, it is demonstrated that the vacuum levels do not align at the studied interfaces. The misalignment is caused by an electric field at the interface. Several effects are presented that influence the energy alignment at interfaces, such as screening effects, dipole layer formation, charge transfer, and chemical interaction. The combination of interfaces investigated here is similar to interfaces found in polymer light‐emitting diodes and organic bulk heterojunction photovoltaic devices. The result, the misalignment of the vacuum levels, is expected to influence charge‐transfer processes across these interfaces, possibly affecting the electrical characteristics of organic semiconductor devices that contain similar interfaces. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2549–2560, 2003
Problem Solving Through Design
Authors: Nelson Wayne A.
Published: October 2003

To design is to solve problems. The author describes a model of problem solving through design that can be used to restructure courses, programs of study, or entire institutions.
Where the rubber meets the road: The importance of implementation
Authors: Barch Deanna M. , Braver Todd S.
Published: October 2003

Phillips & Silverstein argue that a range of cognitive disturbances in schizophrenia result from a deficit in cognitive coordination attributable to NMDA receptor dysfunction. We suggest that the viability of this hypothesis would be further supported by explicit implementation in a computational framework that can produce quantitative estimates of the behavior of both healthy individuals and individuals with schizophrenia.
Color and content
Authors: Jackson Frank
Published: October 2003

Those who identify colours with physical properties need to say how the content of colour experiences relate to their favoured identifications. This is because it is not plausible to hold that colour experiences represent things as having the physical properties in question. I sketch how physical realists about colour might tackle this item of unfinished business.
Synchronous dynamics for cognitive coordination: But how?
Authors: Tagamets M.-A. , Horwitz Barry
Published: October 2003

Although interesting, the hypotheses proposed by Phillips & Silverstein lack unifying structure both in specific mechanisms and in cited evidence. They provide little to support the notion that low-level sensory processing and high-level cognitive coordination share dynamic grouping by synchrony as a common processing mechanism. We suggest that more realistic large-scale modeling at multiple levels is needed to address these issues.
Beautiful red squares
Authors: Van Gulick Robert
Published: October 2003

The reflectance types that Byrne & Hilbert identify with colors count as types only in a way that is more dependent on, and more relative to color perceivers, than their account suggests. Their account of perceptual content may be overly focused on input conditions and distal causes.
A GENERALIZED CONVERGENCE RESULT FOR THE GRAPH-BASED ANT
SYSTEM METAHEURISTIC
Authors: Gutjahr Walter J.
Published: October 2003

It is shown that on fairly weak conditions, the current solutions
of a metaheuristic following the ant colony optimization paradigm,
the graph-based ant system, converge with a probability that
can be made arbitrarily close to unity to one element of the
set of optimal solutions. The result generalizes a previous
result by removing the very restrictive condition that both
the optimal solution and its encoding are unique (this
generalization makes the proof distinctly more difficult) and
by allowing a wide class of implementation variants in the first
phase of the algorithm. In this way, the range of application
of the convergence result is considerably extended.
Needs, supply and demand for health care by elderly people in
the NHS
Authors: Vetter NJ
Published: October 2003

It is often said that the demand for health care is growing
inexorably in the UK, so that the NHS is constantly struggling to keep up. The
dilemma was most famously put by Enoch Powell, who said that any health service
faces the problem of infinite demand meeting finite resources. This was an
economist's view, which suggests that anything that is free will be
demanded infinitely.
The Elusive Bose Metal
Authors: Phillips Philip , Dalidovich Denis
Published: October 2003

The conventional theory of metals is in crisis. In the past 15 years, there has been an unexpected sprouting of metallic states in low-dimensional systems, directly contradicting conventional wisdom. For example, bosons are thought to exist in one of two ground states: condensed in a superconductor or localized in an insulator. However, several experiments on thin metal-alloy films have observed that a metallic phase disrupts the direct transition between the superconductor and the insulator. We analyze the experiments on the insulator-superconductor transition and argue that the intervening metallic phase is bosonic. All relevant theoretical proposals for the Bose metal are discussed, particularly the recent idea that the metallic phase is glassy. The implications for the putative vortex-glass state in the copper oxide superconductors are examined.
Stability of Quantum Computing in the Presence of Imperfections
Authors: Benenti G. , Casati G. , Montangero S.
Published: October 2003

We model an isolated quantum computer as a two-dimensional lattice of qubits (spin halves) with fluctuations in individual qubit energies and residual short-range inter-qubit couplings. We show that above a critical inter-qubit coupling strength, quantum chaos sets in and this results in the interaction induced dynamical thermalization and occupation numbers well described by the Fermi–Dirac distribution. This thermalization destroys the noninteracting qubit structure and sets serious requirements for the quantum computer operability. We then construct a quantum algorithm which uses qubits in an optimal way and efficiently simulates a physical model with rich and complex dynamics. The numerical study of the effect of static imperfections in the quantum computer hardware shows that the main elements of the phase space structures are accurately reproduced up to a time scale which is polynomial in the number of qubits. The errors generated by these imperfections are more significant than the errors of random noise in gate operations.
Noise, Synchronization and Coherence in Chaotic Oscillators
Authors: Kurths Jürgen , Zhou Changsong
Published: October 2003

We study effects of noise in two types of chaotic oscillators. The first one, represented by the Rössler system, has very coherent phase dynamics while the amplitude fluctuates strongly. The other type, homoclinic chaos characterized by chaotic spiking behavior, has regular orbits in the phase space while the interspike time intervals vary enormously. We demonstrate that in both classes of systems, noise may play a constructive role to enhance synchronization and generate the most coherent behavior in the collective oscillation of coupled phase coherent oscillators or in the spike sequences of homoclinic chaos.
New Frontiers in Controlling the Motion of Matter with Light: From Single Atoms to Neurons
Authors: Raizen Mark G.
Published: October 2003

In this talk I will discuss recent experiments in my group on the interactions and control of matter with light. At the atomic level we have been studying the interface between quantum mechanics and nonlinear dynamics. I will describe some recent experiments on atomic motion in "optical billiards", a new system that we developed, and indicate some future directions for quantum dynamics and control in many-body systems. In the past year we have also extended our work to the realm of biophysics in collaboration with the group of Josef Kas. We have shown experimentally that we can use weak light forces to precisely guide the direction of neuron growth, which opens many exciting directions for the future.
Slow Switching and Broken Cluster State in a Population of Neuronal Oscillators
Authors: Kori Hiroshi
Published: October 2003

We discuss a novel class of cluster states in globally coupled neuronal oscillators. It is well known that steady cluster states such as perfect synchrony and multi-cluster states arise in globally coupled oscillators. However, little has been discussed on unsteady cluster states which often arise in populations of neuronal oscillators. We show three types of unsteady cluster states, i.e. a pair of clusters involving slow switching, three clusters involving slow switching, and a broken single cluster. These states result from saddle connections between different cluster states, and typically arise near a bifurcation point where perfect synchrony loses its stability.
A Time-Dependent Bifurcation Model with Control and Pulsing Oscillations
Authors: Lu Qishao , Hua Cuncai
Published: October 2003

A time-dependent bifurcation model and its control problem are studied. Firstly, the delayed bifurcating transition with memory effects due to time-dependent parameters are analysed. Secondly, a control problem with time-dependent parametric feedback in this bifurcation model is investigated. Finally, an important mechanism for pulsing oscillation is found as the result of the delayed bifurcation transition occurring when the bifurcation parameter varies periodically across the steady bifurcation value.
Controlling Hyper Chaos with Feedback of Dynamical Variables
Authors: Luo Xiao-Shu , Wang Bing-Hong
Published: October 2003

We propose a method for controlling chaos and hyper-chaos by applying continuous proportional feedback to the system variables and their derivatives. The method has been applied successfully in six-order coupled Chua's hyper-chaotic circuit system. The theoretical analysis and numerical simulation results show that unstable fixed points embedded in hyper-chaotic attractors can be stabilized and Hopf bifurcation can be observed for the controlled system.
Localized Coherent Soliton Structures in a Generalized (2+1)-Dimensional Nonlinear Schrödinger System
Authors: Zheng Chun-Long , Sheng Zheng-Mao
Published: October 2003

A variable separation approach is used to obtain localized coherent structures in a generalized (2+1)-dimensional nonlinear Schrödinger system. Applying a special Bäcklund transformation and introducing arbitrary functions of the seed solutions, the abundance of the localized structures of this system are derived. By selecting the arbitrary functions appropriately, some special types of localized excitations such as dromions, dromion lattice, peakons, breathers and instantons are constructed.
Bone Mineral Density in Normal Chinese Men and Women in Singapore
Authors: Lee Soon Tai , Goh James Cho Hong , Low Siew Leng , Bose Kamal
Published: October 2003

169 men and 267 women aged 20 to 69 years had bone mineral density measured in the lumbar spine and femoral neck by dual energy X-ray absorptiometry (DXA). The male subjects were significantly taller and heavier than the female subjects. However, there was no significant difference in body mass indexes of males and females. In males, the regression of age on lumbar spine and femoral neck BMD was linear, with peak BMD attained in the 20–29 age group. In females, peak BMD occurred in the age group 30–39 years. The regression of BMD with age in females was best fit by a cubic regression curve. There was no difference in peak spine BMD (1.176 ± 0.121 g/cm2 for males versus 1.221 ± 0.129 g/cm2 for females; p < 0.01). However, males were found to have significantly higher peak BMD in the femoral neck (1.052 ± 0.119 g/cm2 for males versus 0.949 ± 0.108 g/cm2 for females; p < 0.01). When our data was compared to the reference database from the American and Japanese populations, it was found that Chinese women in Singapore and American women had similar BMD values and both groups had significantly higher BMD than the Japanese in both the lumbar spine and femoral neck.
Motion Analysis Evaluation of Knee Braces During Level Walking
Authors: Su F. C. , Lin C. H.
Published: October 2003

The purpose of this study is to evaluate the influence of two currently available rehabilitative knee braces on knee motion and their ability to protect against the knee displacement. Using the Eulerian angle, finite helical axis and three-dimensional motion analysis system, we measured all six degrees of freedom (DOF) of knee motion during level walking. The experimental group consisted of seven left anterior cruciate ligament deficient patients. Six normal subjects comprised the control group. Four test conditions were investigated: 1) injured limb; 2) injured limb with a range of motion (ROM) splint; 3) injured limb with 4-Point brace; and 4) control limb. Among the three knee joint angles, the maximal change induced by the brace occurred in flexion/extension, whereas the minimum occurred in abduction / adduction. Among the three translations, the maximal change appeared in the anterior / posterior displacement, whereas the minimum appeared in the medial / lateral displacement. Both knee braces were shown to significantly reduce three rotations and three translations of knee motion. The ROM splint restricted more knee motion than 4-Point brace, but no noticeable changes in the kinematic patterns, walking speed, and the percentage of left or right stance phase in the gait cycle could be demonstrated between two designs. In vivo measurements of translation of knee joint gave important information in the study of cruciate ligament injury problems or knee brace design.
Radiologic Evaluation of Bone Incorporation of Strut Allografting in Bone Defects After Curettage of Benign Bone Tumors
Authors: Shih H.-N. , Chen Y.-J. , Hsu K.-Y. , Huang T.-J. , Tan C.-F. , Hsu R. W.-W.
Published: October 2003

Large osseous defects have long been a challenge to the reconstructive surgeon. In a series of 104 patients (average age of 26 years; range, 11–60 years) with space occupying lesions of the long bone, we implanted deep-frozen (-70° C) cortical strut allografts into the defects after intralesional curettage. Because of the relatively few published reports on the radiographic appearance of the postoperative course of bone grafting healing, this study was done to investigate the course of radiographic change. This series included 36 fibrous dysplasias, 29 unicameral bone cysts, 22 giant cell tumors, 12 aneurysmal bone cysts, 3 benign fibrous histiocytomas and 2 ossifying fibromas. Fifty-six patients had pathologic fractures. The mean volume of the defect after curettage was 210 ml (range, 56–460 ml). All the patients were followed up for an average of 4 years (range, 2–6 years). At follow-up, good or excellent functional results were found in 97% of the patients (101/104). The radiographs demonstrated complete incorporation of the allogeneic implant and new bone formation in the cavity in 83% of the patients (86/104) (using a semiquantitative method). All pathologic fractures healed. There was no local recurrence or fracture of the cortical graft. There were no other serious complications except for one avascular necrosis of the femoral head. The process of allograft incorporation was similar to that of fresh autograft, though remodeling was rather delayed.
Electrodynamical Model of Quasi-Efficient Financial Markets
Authors: Ilinski Kirill N. , Stepanenko Alexander S.
Published: October 2003

The modelling of financial markets presents a problem which is both theoretically challenging and practically important. The theoretical aspects concern the issue of market efficiency which may even have political implications (Cuthbertson, 1996), whilst the practical side of the problem has clear relevance to portfolio management (Elton and Gruber, 1995) and derivative pricing (Hull, 1997). Up till now all market models contain "smart money" traders and "noise" traders whose joint activity constitutes the market (De Long et al., 1990; Bak et al., 1997). On a short time scale this traditional separation does not seem to be realistic, and is hardly acceptable since all high-frequency market participants are professional traders and cannot be separated into "smart" and "noise". In this paper we present a "microscopic" model with homogenuous quasi-rational behaviour of traders, aiming to describe short time market behaviour. To construct the model we use an analogy between "screening" in quantum electrodynamics and an equilibration process in a market with temporal mispricing (Ilinski, 1997; Dunbar, 1998). As a result, we obtain the time-dependent distribution function of the returns which is in quantitative agreement with real market data and obeys the anomalous scaling relations recently reported for both high-frequency exchange rates (Ghashghaie et al., 1996, S&P500 (Mantegna and Stanley, 1994) and other stock market indices (Bouchaud and Sornette, 1994; Matacz, 1997).
Abstract state machines capture parallel algorithms
Authors: Blass Andreas , Gurevich Yuri
Published: October 2003

We give an axiomatic description of parallel, synchronous algorithms. Our main result is that every such algorithm can be simulated, step for step, by an abstract state machine with a background that provides for multisets.
The Plurality of Chinese Modernity
Authors: Ip Hung-Yok , Hon Tze-Ki , Lee Chiu-Chun
Published: October 2003

In recent years, some scholars in Chinese studies in the United States have begun to look beyond those historical processes that had once been viewed as pivotal for twentieth-century China's modernization. In this review article, the authors examine four works representative of the pioneering effort to decenter the May Fourth Movement: David Der-wei Wang's Fin-de-Siècle Splendor , Lydia Liu's Translingual Practice , Leo Lee's Shanghai Modern , and Yeh Wenhsin's edited volume, Becoming Chinese . They analyze how the authors of these works move beyond existing scholarship's interpretation of the movement and its historical implications. In addition, they also compare U.S. and P.R.C. approaches to the decentering of the May Fourth Movement. The authors conclude by pointing out the weakness of the four American publications, contending that they cling to assumptions about the May Fourth Movement, Chinese modernity, or both that undercut their search for the multiplicity of the Chinese modern.
Alopecia Areata
Authors: Gaurav Ahana , Eang Brynner , Mostaghimi Arash
Published: January 2024

This Patient Page describes the symptoms, diagnosis, and treatment of alopecia areata.
Retrospective Case Series of Cocaine-Associated Plasma Cell Orificial Mucositis
Authors: Viedma-Martinez Myriam , Gallo-Pineda Gonzalo , Recio-Monescillo Miguel , Jimenez-Gallo David , Lopez-Sanz Pablo , Drake-Monfort Marta , Urigoitia-Ugalde Peru , Martínez-Signes Vicenta , Llorca-Juan David , Fuertes-Vega Laura , Ríos-Viñuela Elisa , Escario-Travesedo Eduardo , Ríos-Martín Juan José , Requena-Caballero Luis , Linares-Barrios Mario
Published: January 2024

Importance

Plasma cell orificial mucositis (PCOM) associated with cocaine use is an emerging, rare condition that has become a concern in Spain in recent years. Limited knowledge exists regarding this novel condition.

Objectives

To delineate the clinicopathologic characteristics of this emerging entity and establish a novel approach in the differential diagnosis of cocaine-associated lesions.

Design, Setting, and Participants

A descriptive, retrospective, multicenter case series of 10 patients diagnosed with cocaine-associated PCOM was conducted in Spain from April 2020 to March 2023.

Main Outcomes and Measures

Patient demographic, clinical, histopathologic, and treatment data were collected.

Results

A total of 10 patients (6 [60%] male; median [range] age, 45.5 [36-66] years) presenting with exudative ulcerated plaques were identified for this study. The lesions had raised and erythematous edges over the nostril and a median (range) evolution time of 9 (2-24) months. Septal or palate perforations were observed in 4 (40%) of the patients. Biopsies revealed a dense inflammatory infiltrate of plasma cells in the dermis without atypia and with eosinophils. All patients reported recent cocaine use. Three urine tests detected cocaine but found no presence of amphetamines or opiates. Six patients improved with corticosteroid therapy. Up to 60% of patients were lost to follow-up.

Conclusions and Relevance

This case series describes the clinicopathologic characteristics of PCOM, an emerging entity associated with cocaine use in Spain, and demonstrates a novel approach in the differential diagnosis of cocaine-associated lesions. To date, cocaine-associated skin lesions have been reported as neutrophilic dermatoses and vasculitis. The appearance of a plasma cell infiltrate changes what has been described in the medical literature so far. PCOM is a benign condition of unknown cause characterized by a proliferative polyclonal plasma cell infiltrate. A comprehensive differential diagnosis workup is required to reach this exclusionary diagnosis. Several irritants have been documented in cases of PCOM, and a hypersensitivity mechanism has been proposed. Since the initial report of cocaine-associated PCOM in Spain, its incidence has experienced a surge in the country. The cause of this phenomenon may be attributed to newly unidentified adulterants. The administration of corticosteroids and discontinuation of cocaine use are the sole treatments that have demonstrated efficacy. Clinicians should be vigilant regarding this emerging condition and conduct inquiries into cocaine use. Additional research is required to clarify the pathophysiology of this emerging condition.
Fracture Risk Among Living Kidney Donors 25 Years After Donation
Authors: Maradit Kremers Hilal , Grossardt Brandon R. , Miller Adam R. , Kasiske Bertram L. , Matas Arthur J. , Khosla Sundeep , Kremers Walter K. , Amer Hatem , Kumar Rajiv
Published: January 2024

Importance

Living kidney donors may have an increased risk of fractures due to reductions in kidney mass, lower concentrations of serum 1,25-dihydroxyvitamin D, and secondary increases in serum parathyroid hormone.

Objective

To compare the overall and site-specific risk of fractures among living kidney donors with strictly matched controls from the general population who would have been eligible to donate a kidney but did not do so.

Design, Setting, and Participants

This survey study was conducted between December 1, 2021, and July 31, 2023. A total of 5065 living kidney donors from 3 large transplant centers in Minnesota were invited to complete a survey about their bone health and history of fractures, and 16 156 population-based nondonor controls without a history of comorbidities that would have precluded kidney donation were identified from the Rochester Epidemiology Project and completed the same survey. A total of 2132 living kidney donors and 2014 nondonor controls responded to the survey. Statistical analyses were performed from May to August 2023.

Exposure

Living kidney donation.

Main Outcomes and Measures

The rates of overall and site-specific fractures were compared between living kidney donors and controls using standardized incidence ratios (SIRs).

Results

At the time of survey, the 2132 living kidney donors had a mean (SD) age of 67.1 (8.9) years and included 1245 women (58.4%), and the 2014 controls had a mean (SD) age of 68.6 (7.9) years and included 1140 women (56.6%). The mean (SD) time between donation or index date and survey date was 24.2 (10.4) years for donors and 27.6 (10.7) years for controls. The overall rate of fractures among living kidney donors was significantly lower than among controls (SIR, 0.89; 95% CI, 0.81-0.97). However, there were significantly more vertebral fractures among living kidney donors than among controls (SIR, 1.42; 95% CI, 1.05-1.83).

Conclusions and Relevance

This survey study found a reduced rate of overall fractures but an excess of vertebral fractures among living kidney donors compared with controls after a mean follow-up of 25 years. Treatment of excess vertebral fractures with dietary supplements such as vitamin D3 may reduce the numbers of vertebral fractures and patient morbidity.
Managerial and Organizational Challenges in the Age of AI
Authors: Obradovich Nick , Johnson Tim , Paulus Martin P.
Published: January 2024

This Viewpoint discusses the managerial and organizational challenges that could result from the use of artificial intelligence systems in psychiatric research and care.
Enhanced Air Stability and Li Metal Compatibility of Li‐Argyrodite Electrolytes Triggered by In2O3 Co‐Doping for All‐Solid‐State Li Metal Batteries
Authors: Wang Chengdeng , Hao Jiamao , Wu Jun , Shi Haofeng , Fan Liubing , Wang Jiashuai , Wang Zhaokun , Wang Zhi , Yang Lu , Gao Yan , Yan Xiaoqin , Gu Yousong
Published: January 2024

Sulfide solid electrolytes (SSEs) have become an ideal candidate material for all‐solid‐state Li metal batteries (ASSLMBs) because of their high ionic conductivity. However, the vile Li incompatibility and poor air stability of SSEs barriers their commercial application. Herein, novel Li6+2xP1−xInxS5−1.5xO1.5xCl (0 ≤ x ≤ 0.1) SSEs are synthesized via In and O co‐doped Li6PS5Cl. By regulating the substitution concentration, the prepared Li6.12P0.92In0.08S4.88O0.12Cl exhibits considerable ionic conductivity (2.67 × 10−3 S cm−1) and enhanced air stability. Based on the first‐principles density functional theory (DFT) calculation, it is predicted that In3+ replaces P5+ to form InS45− tetrahedron and O2− replaces S2− to form PS3O4− group. The mechanism of enhancing air stability by In, O co‐substituting Li6PS5Cl is clarified. More remarkably, the formation of Li‐In alloys induced by Li6.16P0.92In0.08S4.88O0.12Cl electrolyte at the anode interface is beneficial to reducing the migration barrier of Li‐ions, promoting their remote migration, and enhancing the stability of the Li/SSEs interface. The optimized electrolyte shows superior critical current density (1.4 mA cm−2) and satisfactory Li dendrite inhibition (stable cycle at 0.1 mA cm−2 over 3000 h). The ASSLMBs with Li6.16P0.92In0.08S4.88O0.12Cl electrolyte reveal considerable cycle stability. This work emphasizes In, O co‐doping to address redox issues of sulfide electrolytes.