bluuebunny/crossref_metadata_2025 huggingface dataset:
Dioxin and diabetes mellitus: an analysis of the combined NIOSH and Ranch Hand data
Authors: Steenland K , Calvert G , Ketchum N , Michalek J
Published: July 2002

OBJECTIVES

To reanalyze in a similar manner the two principal studies of TCDD (tetrachlorodibenzo-p-dioxin) and diabetes in an attempt to reconcile disparate results.

METHODS

Data from 990 United States Air Force veterans (Ranch Hand) and 1275 referents were reanalyzed, and a NIOSH population of 267 chemical workers and 227 referents. The Ranch Hand veterans had lower concentrations of lipid adjusted serum TCDD (median 12 parts per trillion (ppt)) than the NIOSH workers (median 75 ppt) when examined in the late 1980s. An analysis was conducted of the combined data sets, adopting a uniform approach to outcome definition, data analysis, and covariate control.

RESULTS

The combined exposed groups did not differ markedly from the combined non-exposed groups for prevalence of diabetes (odds ratio (OR) 1.17, 95% confidence interval (95% CI) 0.92 to 1.48), with no evidence of heterogeneity of exposure effect between studies. Also virtually no difference was found between combined exposed and non-exposed groups in mean fasting serum glucose (difference in log serum glucose 0.002, 95% CI −0.006 to 0.010), and there was little evidence in either study of a dose-response trend for fasting serum glucose. An increasing trend was found (p=0.0001) in prevalence of diabetes with increased TCDD (at the time of examination or at time of last exposure) among the Ranch Hand population, with excess risk largely confined to the highest 8% of the exposed group (>78 ppt serum TCDD), which had an OR of 3.21 (95% CI 1.81 to 5.72) versus those with <10 ppt TCDD. However, no such positive dose-response was found in the NIOSH population.

CONCLUSIONS

There was little overall evidence that the exposed workers were at higher risk than the non-exposed workers of diabetes or abnormal fasting glucose. However, the Ranch Hand subjects showed a positive dose-response for diabetes, whereas the more highly exposed NIOSH subjects did not. The reason for the difference in diabetes dose-response trends between the two studies is unknown.
Eosinophilic fasciitis with pulmonary and pleural involvement
Authors: Killen J W W , Swift G L , White R J
Published: July 2002

We report a case of eosinophilic fasciitis, with the unusual features of pulmonary and pleural involvement. Similar cases which involve the lungs have been reported after exposure tol-tryptophan, but there is no relevant drug history in this case.
Withdrawing cardiovascular medications at a syncope clinic
Authors: Alsop K , Mac Mahon M
Published: July 2002

It is widely assumed in clinical practice that drug treatment associated with hypotension can result in falls and syncope, but there is actually very little evidence to support this. Therefore the data in all patients whose cardiovascular medications were stopped at a falls/syncope clinic were analysed to see if their symptoms were altered and if renewal of these medications was necessary at subsequent visits.

Of 338 consecutive referrals, cardiovascular medications had been stopped in 65 (19%). At follow up 78% reported improvement in their original presenting symptoms and renewal of medication was not necessary in 77% off antianginals, 69% off antihypertensives, and 36% off antiarrhythmics. It was concluded that adjusting cardiovascular medications could help in the management of falls and syncope and may obviate the need for other treatment. These medications can be stopped in select patients if there is regular monitoring and this should reduce unwanted side effects and costs of these drugs.
Intraoperative glove perforation—single versus double gloving in protection against skin contamination
Authors: Thomas S , Agarwal M , Mehta G
Published: July 2002

Surgeons have the highest risk of contact with patients' blood and body fluids, and breaches in gloving material may expose operating room staff to risk of infections. This prospective randomised study was done to assess the effectiveness of the practice of double gloving compared with single gloving in decreasing finger contamination during surgery.

In 66 consecutive surgical procedures studied, preoperative skin abrasions were detected on the hands of 17.4% of the surgeons. In the double gloving pattern, 32 glove perforations were observed, of which 22 were in the outer glove and 10 in the inner glove. Only four outer glove perforations had matching inner glove perforations, thus indicating that in 82% of cases when the outer glove is perforated the inner glove will protect the surgeon's hand from contamination. The presence of visible skin contamination was also higher in perforation with the single gloving pattern (42.1%) than with the double gloving pattern (22.7%).

An overwhelming majority of glove perforations (83.3%) went unnoticed. Double gloving was accepted by the majority of surgeons, especially with repeated use. It is recommended that double gloves are used routinely in all surgical procedures in view of the significantly higher protection it provides.
Acute hepatocellular and cholestatic injury in a patient taking celecoxib
Authors: Nachimuthu S , Volfinzon L , Gopal L
Published: July 2002

A case of acute hepatocellular and cholestatic liver injury that may have been associated with the use of celecoxib is described. This case was reported to US Food and Drug Administration and the manufacturer of celecoxib.
Comparison of diagenetic fluids in the Proterozoic Thelon and Athabasca Basins, Canada: implications for protracted fluid histories in stable intracratonic basins
Authors: Renac C , Kyser T K , Durocher K , Dreaver G , O'Connor T
Published: July 2002

The Paleoproterozoic Thelon Basin, located on the border between Nunavut and the Northwest Territories of Canada, is a contemporaneous analog of the uranium-rich Paleoproterozoic Athabasca Basin in Canada. Early diagenesis resulted in precipitation of extensive hematite on the surfaces of detrital quartz grains throughout the Thelon Formation and minor hydroxy-phosphate in veins locally. Continued diagenesis then resulted in syntaxial quartz cementation of detrital quartz at 130°C from fluids having ca. 17 wt.% equivalent NaCl, similar to the Athabasca Basin. Cementation of this type is most pronounced in fine-grained sequences in the Thelon Basin. A period of extensive desilicification during continued burial was followed by formation, at ca. 200°C, of peak-diagenetic illite having ArAr ages of ca. 14001690 Ma in the Thelon Formation. This illite was associated with fluids with δ18O and δD values of ca. 6 and 50, respectively, similar to those during peak diagenesis of the Athabasca Basin. Although the timing, salinity, and isotopic composition of the peak-diagenetic fluids in the Thelon and Athabasca Basins are similar, the peak-diagenetic mineral assemblage in the Athabasca Formation is dickite and illite, with minor dravite and goyasite rather than simply illite. Consequently, the fluids at peak diagenesis, which in the Athabasca Basin are synchronous with formation of world-class unconformity-type uranium deposits, had different compositions in each basin. Post-peak diagenesis in the Thelon Basin was quite distinct from that in the Athabasca Basin in that illite was replaced in the central portion of the basin by K-feldspar and then sudoite, which crystallized from saline brines at ca. 1000 Ma and 100°C. Evidence for later infiltration of these brines is absent in the Athabasca Basin, although uranium mobilization at ca. 900 Ma from fluids having the same characteristics as those at peak diagenesis was pronounced in the Athabasca Basin. Recent incursion of meteoric waters along reactivated structures into the Athabasca Basin has variably affected hydrous and uraniferous minerals, but evidence for this is lacking in the Thelon Basin. The Thelon Basin reflects less intensive fluidrock interaction in its early history than that recorded in the basal units of the Athabasca Basin.
Freshwater mussel abundance and species richness: GIS relationships with watershed land use and geology
Authors: Arbuckle Kelly E , Downing John A
Published: July 2002

We tested the hypotheses that mussel species richness and density are related to landscape features of watersheds. Measures of species richness and mussel density were estimated at 118 sites in 36 watersheds in the state of Iowa, U.S.A., a landscape characterized by >90% agricultural development. Geographical Information Systems (GIS) and regression analyses examined seven land use categories and nine geological descriptors, determining that both mean density and species richness were best correlated with mean watershed slope and the prevalence of alluvial deposits. Our analyses imply that agricultural watersheds with high slopes impact mussel abundance and richness through siltation and destabilization of stream substrate. Because alluvial deposits improve groundwater flux to streams, results suggest that relatively stable stream flows in alluvial watersheds improve mussel persistence. A second set of 82 observations on 38 independent watersheds corroborates the analyses, although historical and local impacts cause correlations between new observations and predictions to be weak.
Retrospective genetic testing ofPicea abiesunder controlled temperature and moisture regimes
Authors: Sonesson Johan , Jansson Gunnar , Eriksson Gösta
Published: July 2002

A retrospective early test of Picea abies (L.) Karst. was conducted under two temperature ("high" and "low") and two irrigation ("well-watered" and "drought") regimes. Height, dry mass, and phenological traits were assessed for seedlings from 36 open-pollinated families grown in a growth chamber for two growth periods. The attributes measured were compared with the growth traits of three 24-year-old field progeny trials propagated from the same parents. Heritabilities for biomass and height were mainly moderate to strong (0.10.8) in the well-watered treatments, while they were weaker in the drought treatments (0.00.5). Juvenile-mature (JM) genetic correlations for growth traits were generally weak. There were, on average, stronger JM correlations in the drought treatments than in the well-watered treatments. Similarly, there were stronger JM correlations in the high- than in the low-temperature treatment. The results suggest that genotype × environment (G×E) interaction between the juvenile and mature environment is one of the reasons for low JM correlations. This supports the hypothesis that higher JM correlations can be obtained by mimicking natural growth-limiting factors in the juveniles' growth chambers. We conclude that further development of more efficient early selection methods for P. abies should include periodic drought and the development of optimal temperature regimes.
Effects of building features on density and flock distribution of feral pigeons Columba livia var. domestica in an urban environment
Authors: Sacchi Roberto , Gentilli Augusto , Razzetti Edoardo , Barbieri Francesco
Published: July 2002

We censused feral pigeons (Columba livia) living in Milan, Italy (a 181-km2 area), between July 1999 and February 2000 by means of linear transects to examine population densities in different urban habitats and the relationships between population density and structural features of buildings. The pigeon population of Milan was 103 650 birds, with an average density of 570/km2. Population density increased significantly from farmland (434 birds/km2) to the suburbs (604 birds/km2) and from the suburbs to the centre of the city (2083 birds/km2). There was a positive relationship between both bird number and flock number and the abundance of buildings constructed before 1936. There were no significant associations between either bird number or flock number and the abundance of buildings when we did not consider date of construction. This indicated active selection of old buildings by feral pigeons.
AN EXPRESSIVE EXTENSION OF TLC
Authors: GULMANN HENRIKSEN JESPER
Published: July 2002

A temporal logic of causality (TLC) was introduced by Alur, Penczek, and Peled in [1]. It is basically a linear time temporal logic interpreted over Mazurkiewicz traces which allows quantification over causal chains. Through this device one can directly formulate causality properties of distributed systems. In this paper we consider an extension of TLC by strengthening the chain quantification operators. We show that our logic TLC* adds to the expressive power of TLC. We doso by defining an Ehrenfeucht-Fraïssé game to capture the expressive power of TLC. We then exhibit a property and by means of this game prove that the chosen property is not definable in TLC. We then show that the same property is definable in TLC*. We prove in fact the stronger result that TLC* is expressively stronger than TLC exactly when the dependency relation associated with the underlying trace alphabet is not transitive. We then show that TLC* defines only regular trace languages by embedding it into the monadic second-order logic. Finally, the relative expressive power of TLC* and similar logics for traces is compared.
GLUING AND SHIFTING LATTICE CONSTRUCTIONS AND RATIONAL EQUIVALENCE
Authors: GANNON TERRY , LAM C. S.
Published: July 2002

This paper deals with the construction and classification of lattices. Two methods of constructing new lattices from old one — gluing and shifting — are discussed. A fairly exhaustive analysis of shifting is carried out, and its close relationships to gluing and to rational equivalence are investigated. This exploration enables rational equivalence to be seen in a more geometric light than has usually been the case. A related classification of lattices, called similarity, is introduced and studied. New geometric proofs of some old theorems are obtained, as well as a number of new results.
INTEGRABILITY AND BIHAMILTONIAN STRUCTURE OF THE EVEN ORDER SKDV HIERARCHIES
Authors: FIGUEROA-O'FARRILL JOSÉ M. , RAMOS EDUARDO , MAS JAVIER
Published: July 2002

We study reductions of the even order SKP hierarchy. We prove that these systems are integrable and bihamiltonian. We derive an infinite set of independent polynomial conservation laws, prove their nontriviality, and derive Lenard relations between them. A further reduction of the simplest such hierarchy is identified with the supersymmetric KdV hierarchy of Manin and Radul. We prove that it inherits all the bihamiltonian and integrability properties from the unreduced hierarchy.
INTEGRABLE DISCRETIZATIONS FOR LATTICE SYSTEM: LOCAL EQUATIONS OF MOTION AND THEIR HAMILTONIAN PROPERTIES
Authors: SURIS YURI B.
Published: July 2002

We develop the approach to the problem of integrable discretization based on the notion of r-matrix hierarchies. One of its basic features is the coincidence of Lax matrices of discretized systems with the Lax matrices of the underlying continuous time systems. A common feature of the discretizations obtained in this approach is non-locality. We demonstrate how to overcome this drawback. Namely, we introduce the notion of localizing changes of variables and construct such changes of variables for a large number of examples, including the Toda and the relativistic Toda lattices, the Volterra and the relativistic Volterra lattices, the second flows of the Toda and of the Volterra hierarchies, the modified Volterra lattice, the Belov–Chaltikian lattice, the Bogoyavlensky lattices, the Bruschi–Ragnisco lattice. We also introduce a novel class of constrained lattice KP systems, discretize all of them, and find the corresponding localizing change of variables. Pulling back the differential equations of motion under the localizing changes of variables, we find also (sometimes novel) integrable one-parameter deformations of integrable lattice systems. Poisson properties of the localizing changes of variables are also studied: they produce interesting one-parameter deformations of the known Poisson algebras.
IRREDUCIBLE UNITARY REPRESENTATIONS OF SUp,q II: THE CONTINUOUS SERIES
Authors: WILSON RAJ , TANNER ELIZABETH
Published: July 2002

A class of irreducible unitary representations belonging to the continuous series of SUp,q is explicitly determined in a space composed of the Kronecker product of three spaces of square integrable functions. The continuous series corresponds to a Cartan subgroup whose vector part has maximal dimension. These representations are distinguished by a parameter r = 1, 2, …, p for p ≤ q in SUp,q. For r = 0, one obtains the representations in the discrete series as in [5], and all representations in the continuous series, for r ≠ 0, are obtained explicitly.
THE QUANTUM QUARTER PLANE AND THE REAL QUANTUM PLANE
Authors: SCHMÜDGEN KONRAD
Published: July 2002

Suppose q≠±1 is a complex number of modulus one. Let [Formula: see text] be the *-algebra with two hermitean generators x and y satisfying the relation xy=qyx. Using Hilbert space representations of [Formula: see text] and the Weyl calculus of pseudodifferential operators we construct *-algebras of "functions" on the quantum quarter plane [Formula: see text] and on the real quantum plane [Formula: see text] which are left module *-algebras for the Hopf *-algebra [Formula: see text]. We define covariant positive linear functionals hk, k∈ℤ2, and study the actions of the *-algebras [Formula: see text] and [Formula: see text] on the associated Hilbert spaces. Quantum analogs of the partial Fourier transforms and the Fourier transform are found. A differential calculus on the "function" *-algebras is also developed and investigated.
A SIMPLE SOLID-ON-SOLID MODEL OF EPITAXIAL FILM GROWTH: SUBMONOLAYER SUBSTRATE COVERAGE
Authors: MALARZ K.
Published: July 2002

In this work, we investigate the influence of substrate temperature on the surface morphology for substrate coverage below one monolayer. The model of film growth is based on random deposition enriched by limited surface diffusion. Also, anisotropy in the growth is involved. We found from computer simulations for the simple cubic lattice and solid-on-solid model that the surface morphology changes with increasing temperature from isotropically distributed isolated small islands through anisotropic 1D stripes to larger 2D anisotropic islands and again randomly distributed single atoms. The transition is also marked in height–height correlation function dependence on temperature as directly seen by snapshots from simulations. The results are in good qualitative agreement with already published results of kinetic Monte Carlo simulations as well as with some experimental data.
SOLITONIC INVESTIGATION ON THE GENERAL FIFTH-ORDER SHALLOW WATER WAVE MODELS
Authors: GAO YI-TIAN , TIAN BO
Published: July 2002

For the general fifth-order shallow water wave models, we perform computerized symbolic computation to obtain two auto-Bäcklund transformations and four families of the bell-shaped solitonic solutions, which are exact analytic.
DEEP-SARSA: A REINFORCEMENT LEARNING ALGORITHM FOR AUTONOMOUS NAVIGATION
Authors: ANDRECUT M. , ALI M. K.
Published: July 2002

In this paper we discuss the application of reinforcement learning algorithms to the problem of autonomous robot navigation. We show that the autonomous navigation using the standard delayed reinforcement learning algorithms is an ill posed problem and we present a more efficient algorithm for which the convergence speed is greatly improved. The proposed algorithm (Deep-Sarsa) is based on a combination between the Depth-First Search (a graph searching algorithm) and Sarsa (a delayed reinforcement learning algorithm).
Does Deqi (Needle Sensation) Exist?
Authors: Park Hijoon , Park Jongbae , Lee Hyangsook , Lee Hyejung
Published: July 2002

The mechanism, by which acupuncture works is not yet clear, therefore there is no unequivocal consensus about styles and sensations of needling. To enhance the scientific base of acupuncture, needling somehow should be objectified. The term Deqi is understood to represent all or at least the main form of phenomena to acupuncture stimulation. The characteristics of Deqi, however, have always been based on a translation of original Chinese description. Hoping to find a clue to develop sham (placebo) method for subject blinding, we investigated which sensations are frequently expected and experienced, and whether or not these expectations and experiences of sensations are similar in naïve subjects. The acupuncture sensation scale developed by Vincent et al. (1989) was translated into Korean. Thirty-eight healthy acupuncture naïve female volunteers (mean age 29.1, range 25–39) were asked to complete the sensation scale of acupuncture according to what they expected needling to feel like before needling. Needling was done on left Hegu (LI4) point in the hand and consisted of insertion, stimulation for 30 seconds, and removal. Directly after needling, the subjects were asked to complete the same sensation scale according to what they experienced. The subjects expected to feel hurting, penetrating, sharp, tingling, pricking and stinging, and actually experienced aching, spreading, radiating, pricking and stinging more than 60% of the time. Comparison between expectation and experience, the subjects expected more penetrating, tingling, pricking and burning than they experienced, and on the contrary experienced more aching, pulling, heavy, dull, electric and throbbing than they expected. Traditionally described sensations of Deqi are something beyond just a general pain dimension in the Korean population. Further study involving acupuncture experienced subjects or subjects from other cultures need to confirm this finding. Moreover, sham acupuncture should be studied.
THE SIGNATURE TRIALITY OF MAJORANA–WEYL SPACE–TIMES
Authors: DE ANDRADE M. A. , ROJAS M. , TOPPAN F.
Published: July 2002

In this paper, a general property of field theories with Majorana–Weyl spinors (such as ten-dimensional SYM theories, superstrings, five-branes, etc.) is presented. It is shown that these theories, in a given dimension, admit different formulations in the allowed space–times signatures which are all interconnected by transformations which close the S3 permutation group (S3 duality). Explicit formulas to "translate" a theory from a given signature into another signature, are given. They are conveniently chosen to realize the S3 group.

The above construction applies for any dimension d which admit Majorana–Weyl spinors in more than one signature, that is for d ≥ 8. We prove that the S3 duality (valid for any even d ≥ 8) is in consequence of the famous triality property of the 8 dimensions, together with (for d > 8) the mod 8 property of Clifford Γ matrices.
COHERENT STATES AND GEOMETRIC PHASES IN THE CALOGERO–SUTHERLAND MODEL
Authors: SONG DAE-YUP , PARK JEONGHYEONG
Published: July 2002

Exact coherent states in the Calogero–Sutherland models (of time-dependent parameters) which describe identical harmonic oscillators interacting through inverse-square potentials are constructed, in terms of the classical solutions of a harmonic oscillator. For quasi-periodic coherent states of the time-periodic systems, geometric phases are evaluated. For the AN-1 Calogero–Sutherland model, the phase is calculated for a general coherent state. The phases for other models are also considered.
NEW FORM OF THE RENORMALIZATION COUNTERTERMS FOR A SCALAR FIELD
Authors: SUSHKOV SERGEY V.
Published: July 2002

We use the substitution m2 → M2(x) = m2 + ξR(x) to construct a new form of the proper-time expansion of the Feynman propagator and the corresponding form of the renormalization counterterms < ϕ2>DS and < Tμν > DS for the scalar field.
CORRELATIONS IN THE DIFFUSIVE MAPS WITH QUENCHED DISORDER
Authors: TSENG HSEN-CHE , CHEN HUNG-JUNG
Published: July 2002

It was shown by G. Radons1 that, for a large class of one-dimensional maps, diffusion is suppressed by the presence of quenched disorder. Focusing on simple diffusive maps with discrete disorder, we investigate the behavior of the correlation functions χ1 (τ; t) and χ01 (τ; t), which arise naturally from the random walks induced by disorder of the system. Our numerical simulations show that both χ1 (τ; t) and χ01 (τ; t) decay with τ more slowly than the exponential decay, and both scale linearly with t; i.e. χ1 (τ; t) = tϕ1 (τ) and χ01 (τ; t) = tϕ01 (τ). Interestingly, we have also found that both [Formula: see text] and [Formula: see text] are mainly independent of the disorder configurations of the system.
CORRELATION BAGS, VIBRONS, AND STRONG CORRELATION FLUCTUATIONS IN THE COPPER OXIDES
Authors: GOODENOUGH J. B. , ZHOU J.-S.
Published: July 2002

Two equilibrium Cu-O bond lengths coexist in the superconductive CuO 2 sheets of the high T c copper oxides because of a discontinuous change in the volume of localized and delocalized electrons at a cross-over from localized to itinerant electronic behavior. Cooperative bond-length segregation and a progressive ordering of the two bond lengths with decreasing temperature result. Transformation from local fluctuations to long- range order in a traveling charge- density wave occurs at a critical point T crit ≈ T c for a hole concentration x ≈ 1/6 per Cu atom in the superconductive CuO 2 sheets. Extensive experimental evidence for the model is cited.
TEMPERATURE DEPENDENCE OF SECONDARY RELAXATION IN A SUPERCOOLED LIQUID
Authors: SRIVASTAVA SUDHA , DAS SHANKAR P.
Published: July 2002

The dynamics of Lennard–Jones fluid is studied through extended mode coupling theory (MCT) with the inclusion of the slow mode of defect density. Inclusion of defect density facilitates the liquid like state for temperatures much lower than predicted from ideal MCT. In the present paper we consider the secondary relaxation over time scales long compared to microscopic time scales but shorter than the final relaxation. Particularly we study the temperature dependence and wave number dependence of the relaxation process.
THE ROLES OF AMBIENT OXYGEN AND SUBSTRATE TEMPERATURE ON GROWTH OF DIAMOND THIN FILMS BY PULSED LASER DEPOSITION
Authors: YOSHITAKE TSUYOSHI , NISHIYAMA TAKASHI , HARA TAKESHI , NAGAYAMA KUNIHITO
Published: July 2002

Diamond thin films were grown on diamond (100) substrates in oxygen atmospheres by pulsed laser deposition (PLD) using an ArF excimer laser. The suitable oxygen atmosphere of 5 × 10-2 Torr can etch the sp2 bonding fractions preferentially. At substrate temperatures between 550°C and 650°C, single-phase diamond films consisting of diamond crystal with diameters of 1 - 5 μm could be grown. The results demonstrated that the diamond thin films can be grown homoepitaxially using PLD by controlling the deposition parameters, such as the oxygen pressure and the substrate temperature.
Optimization of Multilayered Bi-2223/Ag-Au Conductors for Current Lead Applications
Authors: Martini L. , Barberis F. , Berti R. , Bigoni L. , Curcio F. , Volpini G.
Published: July 2002

Multilayered Bi-2223 composite conductors fabricated by means of the "Accordion folding" method appear to be suitable for applications as current leads (CL). In this work, we report on the results of electrical characterization of silver-gold alloy sheathed Bi-2223 conductors up to 400 mm long, having a DC overall critical current density J c eng exceeding 3000 A/cm2 at 77 K. The I c evolution from the first to the third thermal treatment as well as the uniformity along the specimen lenght has been monitored. Lastly, calculations of the magnetic field profile across stacked multilayered Bi-2223 conductors are reported and discussed.
Visualization Study on Chain Structure in Electro-Rheological Fluids
Authors: Tomiuga Takeshi , Okamoto Koji , Madarame Haruki
Published: July 2002

The electrorheological (ER) effect is known as a phenomenon that shows reversible increase of apparent viscosity by applied electric field. The electric field induces the particle polarization, resulting in the chains between the electrodes.

In this study, the ER fluids in the channel with two parallel electrodes were visualized under the pressure flow. The laser light sheet and transparent electrodes were used in the experimental apparatus to visualize the particles under 10wt% concentration. The particle chain structure in the channel was clearly visualized. Under higher voltage condition, particle layers were formed at the neighbor of the electrodes. Processing the visualized images, the effects of the chain structure and the layer on the flow resistance were investigated.
SUPERPOSITIONS OF SQUEEZED COHERENT STATES: PROPERTIES AND GENERATION
Authors: OBADA A.-S. F. , AL-KADER G. M. ABD
Published: July 2002

The s-parameterized charactristic function for the superposition of squeezed coherent states (SCS's) is given. The s-parameterized distribution functions for the superposition of SCS's are investigated. Various moments are calculated by using this charactristic function. The Glauber second-order coherence function is calculated. The photon number distribution of the superposition of SCS's studied. Analytical and numerical results for the quadrature component distributions for the superposition of a pair of SCS's are presented. The phase distribution calculated from the integration of s-parameterized distribution function over the phase space. A generation scheme is discussed.
CRITICAL SCALING BEHAVIOR IN COUPLED MAGNETIC OSCILLATORS
Authors: KIM SANG-YOON
Published: July 2002

We study the critical scaling behaviors of period doublings in N (N=2,3,4,…) coupled magnetic oscillators by varying the driving amplitude A and the coupling strength c. It is found that the critical scaling behaviors depend on the range of coupling. For the extreme long-range case of global coupling, the critical set (set of critical points) is composed of the zero-coupling critical point with c=0 and an infinity of critical line segments in the A-c plane, independently of N. Three kinds of critical scaling behaviors are found on the critical set. However, for any other nonglobal-coupling cases of shorter-range couplings, the structure of the critical set becomes different from that for the global-coupling case, because of a significant change in the stability diagram. We also note that the structure of the critical set and the critical scaling behaviors for both cases of the global and nonglobal couplings are the same as those in the abstract system of the coupled one-dimensional maps.
STUDY OF PMN-PT THICK FILMS FABRICATED BY SPIN-COATING
Authors: WANG J. T. , TANG F. , BROWN W. D. , FAN J. D. , LIAN K.
Published: July 2002

Having high dielectric constants and large mechanical strain, relaxor materials are attractive to the application of actuators in electromechanical systems and elements for large and bright display of optical image where the lower operation voltage and larger deformation are required. In this paper, we study the dielectric properties of 0.9PMN-0.1PT thick films fabricated by a spin coating method. The thick film is prepared for the application of large and bright display elements of an optical-image. In this application a layer of PMN-PT is filled in a mold. The thickness of the layer in the device should be in tens or hundreds of micrometers. Therefore, we used spin-coading technique to make PMN-PT thick films. The thickness of the films fabricated with this method ranges from 70mm to 100mm which are suitable to this application. The samples were electroded with silver print and characterized by dielectric constant and loss measurements. The experimental results show that the dielectric loss is less than 2 percent and the dielectric constant is greater than 10 at the room temperature in the frequency ranging from 100Hz to 1.0 MHz. A comparison of the results with those of PZT thick films manufactured with the same method is also presented.
FLUX DYNAMICS IN YBCO THIN FILMS
Authors: HASANAIN S. K. , KHALIQUE UZMA
Published: July 2002

Magnetic measurements are reported on YBCO thin films (d<500 nm ) in the perpendicular geometry, H‖c. By analyzing the sweep rate dependence of the magnetization for temperatures 35 ≤ T ≤ 77 K and H≤10 kOe , we find that the moment has a power law dependence on the sweep rate. This dependence is indicative of power law E(J) characteristics for these thin films and from this a logarithmic current dependence of the activation potential U(J) is inferred. We find that our magnetic relaxation measurements are also consistent with the logarithmic U(J) dependence obtained from the sweep rate measurements. Activation barriers for flux creep are determined for various temperatures and their field dependence is discussed.
ACTIVATION ENERGY OF Bi2Sr2Ca(Cu1-xFex)2O8+d THIN FILMS
Authors: ILONCA G. , POP A. V. , STIUFIUC G. , LUNG C. , STIUFIUC R.
Published: July 2002

The scaling behavior of the effective activation energy U(T,H) of epitaxial c-axis oriented Bi 2 Sr 2 Ca ( Cu 1-x Fe x)2 O 8+d thin films with 0 ≤ x ≤ 0.02 has been studied as a function of temperature and magnetic field. It has been found that the activation energy scales as U(H,T) = U0(1 - t)mHn with exponent m = 1.15 ± 0.03 and n = -1/2. The field and temperature dependence of the activation energy, as well as its overall magnitude is consistent with a model in which U(T,H) arises from plastic deformations of viscous flux liquid above the vortex-glass transition temperature.
STRUCTURE AND DEBYE TEMPERATURE OF WURTZITE GaN
Authors: CHEN X. L. , LIANG J. K. , XU Y. P. , XU T. , JIANG P. Z. , YU Y. D. , LU K. Q.
Published: July 2002

High Pure Wurtzite structure GaN has been synthesized by gas reaction method. Its structure was determined by powder X-ray diffraction using the Rietveld technique. The positions in the unit cell for Ga and N were refined to be (0, 0, 0) and (0, 0, 0.3814). The Debye temperature was determined as 586 K from the refined temperature factor by using the Debye approximation.
FROZEN FLUX SUPERCONDUCTORS
Authors: LYUKSYUTOV I. F. , NAUGLE D. G.
Published: July 2002

We propose a new class of composite superconductors with embedded magnetic nanoparticles/nanorods. These nanomagnets can create a thermodynamically stable, frozen, dense flux line network. We discuss the methods of fabrication of these novel materials. We show that due to the frozen flux created by magnetic nanorods, the critical current in this composite superconductor can be higher than in the superconductor with a comparable density of columnar defects.
QUASI-MODULAR SYMMETRY AND QUASI-HYPERGEOMETRIC FUNCTIONS IN QUANTUM STATISTICAL MECHANICS OF FRACTIONAL EXCLUSION STATISTICS
Authors: IGUCHI KAZUMOTO , AOMOTO KAZUHIKO
Published: July 2002

We investigate a novel symmetry in dualities of Wu's equation: wg(1+w)1-g=eβ(ε-μ) for a degenerate g-on gas with fractional exclusion statistics of g, where β=1/k B T, ∊ the energy, and μ the chemical potential of the system. We find that the particle–hole duality between g and 1/g and the supersymmetric duality between g and 1-g form a novel quasi-modular group of order six for Wu's equation. And we show that many physical quantities in quantum systems with the fractional exclusion statistics can be represented in terms of quasi-hypergeometric functions and that the quasi-modular symmetry acts on these functions.
AUTOMATED 3D–2D PROJECTIVE REGISTRATION OF HUMAN FACIAL IMAGES USING EDGE FEATURES
Authors: HAIDER ALI MD. , KANEKO TOYOHISA
Published: July 2002

In this paper, we describe a method of automatic 3D–2D projective registration between the 3D (i.e. polygonal face surface derived from CT or MRI data) and the 2D faces of the same individual in the photographs. Our task is to make a realistic 3D model face for post-surgical simulation by pasting color textures accurately on the face surface. We utilize edge features such as external edge (facial outline) and internal edges like eye, nose and mouth edges from both the 3D face and photographs for matching. We define 3D edge as a set of 3D surface points which is 2D edge on the projected space. We choose 3D edges within the specific regions alone by automatically categorizing the 3D face into eye, nose, mouth and ear regions using a knowledge-based technique. Experimentally we have shown that for human face matching selected region-based edge yields better matching accuracy than that of the usual edge. Moreover, we average the root mean square (RMS) measures of the selected facial regions rather than computing a single RMS measure to obtain matching uniformity over the entire region.
KNOWLEDGE-BASED FINGERPRINT POST-PROCESSING
Authors: BIAN ZHAOQI , ZHANG DAVID , SHU WEI
Published: July 2002

True minutiae extraction in fingerprint image is critical to the performance of an automated identification system. Generally, a set of endings and bifurcations (both called feature points) can be obtained by the thinning image from which the true minutiae of the fingerprint are extracted by using the rules based on the structure of ridges. However, considering some false and true minutiae have similar ridge structures in the thinning image, in a lot of cases, we have to explore their difference in the binary image or the original gray image. In this paper, we first define the different types of feature points and analyze the properties of their ridge structures in both thinning and binary images for the purpose of distinguishing the true and false minutiae. Based on the knowledge of these properties, a fingerprint post-processing approach is developed to eliminate the false minutiae and at the same time improve the thinning image for further application. Many experiments are performed and the results have shown the great effectiveness of the approach.
MULTIPLE-PERSON TRACKING SYSTEM FOR CONTENT ANALYSIS
Authors: HSIEH JUN-WEI , HUANG YEA-SHUAN
Published: July 2002

This paper presents a framework to track multiple persons in real-time. First, a method with real-time and adaptable capability is proposed to extract face-like regions based on skin, motion and silhouette features. Then, an adaptable skin model is used for each detected face to overcome the changes of the observed environment. After that, a two-stage face verification algorithm is proposed to quickly eliminate false faces based on face geometries and the SVM (Support Vector Machine) approach. In order to overcome the effect of lighting changes, during verification, a method of color constancy compensation is proposed. Then, a robust tracking scheme is applied to identify multiple persons based on a face-status table. With the table, the proposed system has powerful capabilities to track different persons at different statuses, which is quite important in face-related applications. Experimental results show that the proposed method is more robust and powerful than other traditional methods, which utilize only color, motion information, and the correlation technique.
QUANTIFYING LOCAL INSTABILITY AND PREDICTABILITY OF CHAOTIC DYNAMICAL SYSTEMS BY MEANS OF LOCAL METRIC ENTROPY
Authors: WEI MOZHENG
Published: July 2002

A local metric entropy (LME) is introduced and used as a measure of local instability of chaotic dynamical systems. The predictability time scale of a dynamical system during a given period of time can also be estimated with high accuracy by using the LME. It is shown that LME, at any time during the evolution of a dynamical system, can be calculated as the sum of all the positive local Lyapunov exponents (LEs). This conclusion implies that the positive local LEs represent the rates of local information changes along the directions of their respective Lyapunov vectors. LME does not depend upon the amplitudes nor the configurations of initial perturbations; it depends on the positive local LEs which are intrinsic properties of dynamical systems. In addition, the sum of all the local LEs is proven to be equal to the divergence of phase space. Thus for a general chaotic system at any time, the sum of all the local LEs is equal to the sum of all the local growth rates of either instantaneous optimal modes or normal modes.

In analyzing local instability, the performance of LME is evaluated by comparing an instability index with LME, the first local LE, locally largest LE, local growth rates of the dominant instantaneous optimal mode and normal mode. When LME is used to estimate the predictability time scales of systems over specified time periods, it is found that the time scales defined by LME are generally closer to the standard predictability times than the Lyapunov times and Kolmogorov–Sinai times for most cases in the two dynamical systems we have tested. Both the instability index and standard predictability time are defined and calculated through a large number of random errors.
A CIRCLE MAP FOR A PHYTOPLANKTONIC LIFE CYCLE
Authors: GRIST ERIC P. M.
Published: July 2002

I focus on the temporal dynamics generated by a life cycle consisting of two contiguous stages developing under the influence of a stimulus which pulsates between on and off. I ask: under what general conditions does a population held in exposure to this kind of periodic stimulus achieve life cycle synchrony? The situation is represented by a dynamical system consisting of a nondecreasing circle map whose plot is made up of 45° and horizontal piecewise-linear sections. These features permit the iterative dynamics (itineraries) followed by successive generations to be derived and algebraic conditions for high-ordered synchronization to be derived. Using development data obtained for the phytoplankton Thalassiorira pseudonana and mean daily irradiation intensities recorded over different months at the latitude of Oban (west coast of Scotland), I apply the model to investigate how seasonal change in daily irradiance may directly influence the synchronous dynamics of such populations.
QUANTUM CHAOS FOR THE VIBRATING RECTANGULAR BILLIARD
Authors: PORTER MASON A. , LIBOFF RICHARD L.
Published: July 2002

We consider oscillations of the length and width in rectangular quantum billiards, a two "degree-of-vibration" configuration. We consider several superpositon states and discuss the effects of symmetry (in terms of the relative values of the quantum numbers of the superposed states) on the resulting evolution equations and derive necessary conditions for quantum chaos for both separable and inseparable potentials. We extend this analysis to n-dimensional rectangular parallelepipeds with two degrees-of-vibration. We produce several sets of Poincaré maps corresponding to different projections and potentials in the two-dimensional case. Several of these display chaotic behavior. We distinguish between four types of behavior in the present system corresponding to the separability of the potential and the symmetry of the superposition states. In particular, we contrast harmonic and anharmonic potentials. We note that vibrating rectangular quantum billiards may be used as a model for quantum-well nanostructures of the stated geometry, and we observe chaotic behavior without passing to the semiclassical (ℏ → 0) or high quantum-number limits.
CHAOS BEHAVIOR IN THE DISCRETE BVP OSCILLATOR
Authors: JING ZHUJUN , JIA ZHIYUAN , WANG RUIQI
Published: July 2002

The discrete BVP oscillator obtained through the Euler method is investigated, and also first proved that there exist chaotic phenomena in the sense of Marotto's definition of chaos and two-period cycles. And numerical simulations not only show the consistence with the theoretical analysis but also exhibit the complex dynamical behaviors, including the ten-periodic orbit, a cascade of period-doubling bifurcation, quasiperiodic orbits and the chaotic orbits in Marotto's chaos and intermitten's chaos. The computations of Lyapunov exponents confirm the existence of dynamical behaviors.
ON IMPULSIVE CONTROL AND ITS APPLICATION TO CHEN'S CHAOTIC SYSTEM
Authors: GUAN ZHI-HONG , LIAO RUI-QUAN , ZHOU FENG , WANG HUA O.
Published: July 2002

In this paper, impulsive control of nonlinear systems and its application to Chen's chaotic system are considered. A new impulsive control method for chaos suppression, using Chen's system as an example, is developed. Some new general criteria for exponential stability and asymptotical stability of nonlinear impulsive systems are established and, particularly, some simple conditions sufficient for driving the chaotic state of Chen's system to its zero equilibrium are presented.
BIFURCATION PHENOMENA IN FLOWS OF A NEMATIC LIQUID CRYSTAL
Authors: PEACOCK T. , MULLIN T. , BINKS D. J.
Published: July 2002

Results are presented of an experimental investigation of cellular flows in a nematic liquid crystal cell with physical dimensions comparable to the thickness of a human hair. Finite geometry effects have been exploited to investigate detailed bifurcation events which combine to give complicated flows in some parameter regimes. Initially observed flows consist of either six or eight convection cells which possess maximum symmetry consistent with the boundary conditions. These states undergo symmetry-breaking and Hopf bifurcations as the control parameter is continuously changed and interactions of the critical events are found to generate Silnikov dynamics. At stronger forcing it is possible to obtain both ordered fluid motion, consisting of square convection cells, and microturbulence.
THE EFFECT OF NONLINEAR DAMPING ON THE UNIVERSAL ESCAPE OSCILLATOR
Authors: SANJUÁN MIGUEL A. F.
Published: July 2002

This paper analyzes the role of nonlinear dissipation on the universal escape oscillator. Nonlinear damping terms proportional to the power of the velocity are assumed and an investigation on its effects on the dynamics of the oscillator, such as the threshold of period-doubling bifurcation, fractal basin boundaries and how the basins of attraction are destroyed, is carried out. The results suggest that increasing the power of the nonlinear damping, has similar effects as of decreasing the damping coefficient for a linearly damped case, showing the very importance of the level or amount of energy dissipation.
SYNCHRONIZATION OF HIGH-DIMENSIONAL CHAOS GENERATORS BY OBSERVER DESIGN
Authors: GRASSI GIUSEPPE , MASCOLO SAVERIO
Published: July 2002

In this Letter a method for synchronizing hyperchaotic systems described by ordinary differential equations (ODEs) as well as functional differential equations (FDEs) is illustrated. The technique, which exploits the concept of observer from system theory, is at first applied for synchronizing an example of high-order circuit. A remarkable feature is that hyperchaos synchronization is achieved via a scalar signal. Successively, the tool is applied for synchronizing an example of high-dimensional chaos generator, represented by a cell equation in Cellular Neural Networks with delay. Finally, the advantages of the proposed approach are discussed in detail.
BIFURCATION STRUCTURES GENERATED BY THE NONAUTONOMOUS DUFFING EQUATION
Authors: MIRA C. , TOUZANI-QRIOUET M. , KAWAKAMI H.
Published: July 2002

This paper deals with some properties of bifurcation structures in the parameter space related to the Duffing equation in the presence of an external periodical excitation B + B0 cos t. So global qualitative modifications of structures in the parameter plane (B, B0) are considered, when a third parameter ε (the damping term of the equation) varies. Complex sets of bifurcation curves are defined. They are based on the global bifurcation structure: crossroad area, saddle area, spring area, lip, quasi-lip, identified in the past with their "foliated representation", and their qualitative changes. For the Duffing model, special associations of the above areas, giving typical patterns called islands, are described with their qualitative modifications.