bluuebunny/crossref_metadata_2025 huggingface dataset:
Of Mice and Men: Natural Kinds of Emotions in the Mammalian Brain? A Response to Panksepp and Izard
Authors: Barrett Lisa Feldman , Lindquist Kristen A. , Bliss-Moreau Eliza , Duncan Seth , Gendron Maria , Mize Jennifer , Brennan Lauren
Published: September 2007

For almost 5 decades, the scientific study of emotion has been guided by the assumption that categories such as anger, sadness, and fear cut nature at its joints. Barrett (2006a) provided a comprehensive review of the empirical evidence from the study of emotion in humans and concluded that this assumption has outlived its usefulness. Panksepp and Izard have written lengthy papers (published in this issue) containing complementary but largely nonover lapping criticisms of Barrett (2006a) . In our response, we address three of their concerns. First, we discuss the value of correlational versus experimental studies for evaluating the natural-kind model of emotion and refute the claim that the evidence offered in Barrett (2006a) was merely correlational. Second, we take up the issue of whether or not there is evidence for “coherently organized neural circuits for natural kinds of emotions in the mammalian brain and counter the claim that Barrett (2006a) ignored crucial evidence for existence of discrete emotions as natural kinds. Third, we address Panksepp and Izard's misconceptions of an alternative view, the conceptual act model of emotion, that was briefly discussed in Barrett (2006a) . Finally, we end the article with some thoughts on how to move the scientific study of emotion beyond the debate over whether or not emotions are natural kinds.
Do Nutrients Limit Algal Periphyton in Small Blackwater Coastal Plain Streams?1
Authors: Carey Richard O. , Vellidis George , Lowrance Richard , Pringle Catherine M.
Published: September 2007

Abstract:  We examine the potential for nutrient limitation of algal periphyton biomass in blackwater streams draining the Georgia coastal plain. Previous studies have investigated nutrient limitation of planktonic algae in large blackwater rivers, but virtually no scientific information exists regarding how algal periphyton respond to nutrients under different light conditions in smaller, low‐flow streams. We used a modification of the Matlock periphytometer (nutrient‐diffusing substrata) to determine if algal growth was nutrient limited and/or light limited at nine sites spanning a range of human impacts from relatively undisturbed forested basins to highly disturbed agricultural sites. We employed four treatments in both shaded and sunny conditions at each site: (1) control, (2) N (NO3‐N), (3) P (PO4‐P), and (4) N + P (NO3‐N + PO4‐P). Chlorophyll a response was measured on 10 replicate substrates per treatment, after 15 days of in situ exposure. Chlorophyll a values did not approach what have been defined as nuisance levels (i.e., 100‐200 mg/m2), even in response to nutrient enrichment in sunny conditions. For Georgia coastal plain streams, algal periphyton growth appears to be primarily light limited and can be secondarily nutrient limited (most commonly by P or N + P combined) in light gaps and/or open areas receiving sunlight.
Nonparametric Monte Carlo Simulation for Flood Frequency Curve Derivation: An Application to a Korean Watershed1
Authors: Kwon Hyun‐Han , Moon Young‐Il , Khalil Abedalrazq F.
Published: September 2007

Abstract: A mix of causative mechanisms may be responsible for flood at a site. Floods may be caused because of extreme rainfall or rain on other rainfall events. The statistical attributes of these events differ according to the watershed characteristics and the causes. Traditional methods of flood frequency analysis are only adequate for specific situations. Also, to address the uncertainty of flood frequency estimates for hydraulic structures, a series of probabilistic analyses of rainfall‐runoff and flow routing models, and their associated inputs, are used. This is a complex problem in that the probability distributions of multiple independent and derived random variables need to be estimated to evaluate the probability of floods. Therefore, the objectives of this study were to develop a flood frequency curve derivation method driven by multiple random variables and to develop a tool that can consider the uncertainties of design floods. This study focuses on developing a flood frequency curve based on nonparametric statistical methods for the estimation of probabilities of rare floods that are more appropriate in Korea. To derive the frequency curve, rainfall generation using the nonparametric kernel density estimation approach is proposed. Many flood events are simulated by nonparametric Monte Carlo simulations coupled with the center Latin hypercube sampling method to estimate the associated uncertainty. This study applies the methods described to a Korean watershed. The results provide higher physical appropriateness and reasonable estimates of design flood.
A Monte Carlo model for out‐of‐field dose calculation from high‐energy photon therapy
Authors: Kry Stephen F. , Titt Uwe , Followill David , Pönisch Falk , Vassiliev Oleg N. , White R. Allen , Stovall Marilyn , Salehpour Mohammad
Published: September 2007

As cancer therapy becomes more efficacious and patients survive longer, the potential for late effects increases, including effects induced by radiation dose delivered away from the treatment site. This out‐of‐field radiation is of particular concern with high‐energy radiotherapy, as neutrons are produced in the accelerator head. We recently developed an accurate Monte Carlo model of a Varian 2100 accelerator using MCNPX for calculating the dose away from the treatment field resulting from low‐energy therapy. In this study, we expanded and validated our Monte Carlo model for high‐energy (18 MV) photon therapy, including both photons and neutrons. Simulated out‐of‐field photon doses were compared with measurements made with thermoluminescent dosimeters in an acrylic phantom up to 55 cm from the central axis. Simulated neutron fluences and energy spectra were compared with measurements using moderated gold foil activation in moderators and data from the literature. The average local difference between the calculated and measured photon dose was , including doses as low as of the central axis dose. The out‐of‐field photon dose varied substantially with field size and distance from the edge of the field but varied little with depth in the phantom, except at depths shallower than 3 cm, where the dose sharply increased. On average, the difference between the simulated and measured neutron fluences was and good agreement was observed with the neutron spectra. The neutron dose equivalent varied little with field size or distance from the central axis but decreased with depth in the phantom. Neutrons were the dominant component of the out‐of‐field dose equivalent for shallow depths and large distances from the edge of the treatment field. This Monte Carlo model is useful to both physicists and clinicians when evaluating out‐of‐field doses and associated potential risks.
Calibration model of a dual gain flat panel detector for 2D and 3D x‐ray imaging
Authors: Schmidgunst C. , Ritter D. , Lang E.
Published: September 2007

The continuing research and further development in flat panel detector technology have led to its integration into more and more medical x‐ray systems for two‐dimensional (2D) and three‐dimensional (3D) imaging, such as fixed or mobile arms. Besides the obvious advantages of flat panel detectors, like the slim design and the resulting optimum accessibility to the patient, their success is primarily a product of the image quality that can be achieved. The benefits in the physical and performance‐related features as opposed to conventional image intensifier systems, (e.g., distortion‐free reproduction of imaging information or almost linear signal response over a large dynamic range) can be fully exploited, however, only if the raw detector images are correctly calibrated and postprocessed. Previous procedures for processing raw data contain idealizations that, in the real world, lead to artifacts or losses in image quality. Thus, for example, temperature dependencies or changes in beam geometry, as can occur with mobile arm systems, have not been taken into account up to this time. Additionally, adverse characteristics such as image lag or aging effects have to be compensated to attain the best possible image quality. In this article a procedure is presented that takes into account the important dependencies of the individual pixel sensitivity of flat panel detectors used in 2D or 3D imaging and simultaneously minimizes the work required for an extensive recalibration. It is suitable for conventional detectors with only one gain mode as well as for the detectors specially developed for 3D imaging with dual gain read‐out technology.
Demonstration of scan path optimization in proton therapy
Authors: Kang Joanne H. , Wilkens Jan J. , Oelfke Uwe
Published: September 2007

A three‐dimensional (3D) intensity modulated proton therapy treatment plan to be delivered by magnetic scanning may comprise thousands of discrete beam positions. This research presents the minimization of the total scan path length by application of a fast simulated annealing (FSA) optimization algorithm. Treatment plans for clinical prostate and head and neck cases were sequenced for continuous raster scanning in two ways, and the resulting scan path lengths were compared: (1) A simple back‐and‐forth, top‐to‐bottom (zigzag) succession, and (2) an optimized path produced as a solution of the FSA algorithm. Using a first approximation of the scanning dynamics, the delivery times for the scan sequences before and after path optimization were calculated for comparison. In these clinical examples, the FSA optimization shortened the total scan path length for the 3D target volumes by approximately 13%–56%. The number of extraneous spilled particles was correspondingly reduced by about13%–54% due to the more efficient scanning maps that eliminated multiple crossings through regions of zero fluence. The relative decrease in delivery time due to path length minimization was estimated to be less than 1%, due to both a high scanning speed and time requirements that could not be altered by optimization (e.g., time required to change the beam energy). In a preliminary consideration of application to rescanning techniques, the decrease in delivery time was estimated to be 4%–20%.
Four‐dimensional cone beam CT with adaptive gantry rotation and adaptive data sampling
Authors: Lu Jun , Guerrero Thomas M. , Munro Peter , Jeung Andrew , Chi Pai‐Chun M. , Balter Peter , Zhu X. Ronald , Mohan Radhe , Pan Tinsu
Published: September 2007

We have developed a new four‐dimensional cone beam CT (4D‐CBCT) on a Varian image‐guided radiation therapy system, which has radiation therapy treatment and cone beam CT imaging capabilities. We adapted the speed of gantry rotation time of the CBCT to the average breath cycle of the patient to maintain the same level of image quality and adjusted the data sampling frequency to keep a similar level of radiation exposure to the patient. Our design utilized the real‐time positioning and monitoring system to record the respiratory signal of the patient during the acquisition of the CBCT data. We used the full‐fan bowtie filter during data acquisition, acquired the projection data over 200 deg of gantry rotation, and reconstructed the images with a half‐scan cone beam reconstruction. The scan time for a 200‐deg gantry rotation per patient ranged from 3.3 to 6.6 min for the average breath cycle of 3–6 s. The radiation dose of the 4D‐CBCT was about 1–2 times the radiation dose of the 4D‐CT on a multislice CT scanner. We evaluated the 4D‐CBCT in scanning, data processing and image quality with phantom studies. We demonstrated the clinical applicability of the 4D‐CBCT and compared the 4D‐CBCT and the 4D‐CT scans in four patient studies. The contrast‐to‐noise ratio of the 4D‐CT was 2.8–3.5 times of the contrast‐to‐noise ratio of the 4D‐CBCT in the four patient studies.
Waveform simulation based on 3D dose distribution for acoustic wave generated by proton beam irradiation
Authors: Terunuma Toshiyuki , Sakae Takeji , Hayakawa Yoshinori , Nohtomi Akihiro , Takada Yoshihisa , Yasuoka Kiyoshi , Maruhashi Akira
Published: September 2007

A pulsed proton beam is capable of generating an acoustic wave when it is absorbed by a medium. This phenomenon suggests that the acoustic waveform produced may well include information on the three‐dimensional (3D) dose distribution of the proton beam. We simulated acoustic waveforms by using a transmission model based on the Green function and the 3D dose distribution. There was reasonable agreement between the calculated and measured results. The results obtained confirm that the acoustic waveform includes information on the dose distribution.
Minimizing image noise in on‐board CT reconstruction using both kilovoltage and megavoltage beam projections
Authors: Zhang Junan , Yin Fang‐Fang
Published: September 2007

We studied a recently proposed aggregated CT reconstruction technique which combines the complementary advantages of kilovoltage (kV) and megavoltage (MV) x‐ray imaging. Various phantoms were imaged to study the effects of beam orientations and geometry of the imaging object on image quality of reconstructed CT. It was shown that the quality of aggregated CT was correlated with both kV and MV beam orientations and the degree of this correlation depended upon the geometry of the imaging object. The results indicated that the optimal orientations were those when kV beams pass through the thinner portion and MV beams pass through the thicker portion of the imaging object. A special preprocessing procedure was also developed to perform contrast conversions between kV and MV information prior to image reconstruction. The performance of two reconstruction methods, one filtered backprojection method and one iterative method, were compared. The effects of projection number, beam truncation, and contrast conversion on the CT image quality were investigated.
Model‐based crosstalk compensation for simultaneous dual‐isotope brain SPECT imaging
Authors: Du Yong , Tsui Benjamin M. W. , Frey Eric C.
Published: September 2007

In this work, we developed a model‐based method to estimate and compensate for the crosstalk contamination in simultaneous and dual isotope brain single photo emission computed tomography imaging. The model‐based crosstalk compensation (MBCC) includes detailed modeling of photon interactions inside both the object and the detector system. In the method, scatter in the object is modeled using the effective source scatter estimation technique, including contributions from all the photon emissions. The effects of the collimator‐detector response, including the penetration and scatter components due to high‐energy photons, are modeled using pre‐calculated tables of Monte Carlo simulated point‐source response functions obtained from sources in air at various distances from the face of the collimator. The model‐based crosstalk estimation method was combined with iterative reconstruction based compensation to reduce contamination due to crosstalk. The MBCC method was evaluated using Monte Carlo simulated and physical phantom experimentally acquired simultaneous dual‐isotope data. Results showed that, for both experimental and simulation studies, the model‐based method provided crosstalk estimates that were in good agreement with the true crosstalk. Compensation using MBCC improved image contrast and removed the artifacts for both Monte Carlo simulated and experimentally acquired data. The results were in good agreement with images acquired without any crosstalk contamination.
Investigating the low‐dose limits of multidetector CT in lung nodule surveillance
Authors: Paul N. S. , Siewerdsen J. H. , Patsios D. , Chung T.‐B.
Published: September 2007

The purpose of this study was to evaluate the factors limiting nodule detection in thoracic computed tomography (CT) and to determine whether prior knowledge of nodule size and attenuation, available from a baseline CT study, influences the minimum radiation dose at which nodule surveillance CT scans can be performed while maintaining current levels of nodule detectability. Multiple nodules varying in attenuation and diameter were layered in random and ordered sequences within 2 lung cylinders made of Rando® lung material and suspended within a custom‐built CT phantom. Multiple CT scans were performed at varying kVp (120, 100, and 80), mA (200, 150, 100, 50, 20, and 10), and beam collimation (5, 2.5, and ) on a four‐row multidetector scanner (Lightspeed, General Electric, Milwaukee, WI) using gantry rotation. The corresponding range of radiation dose over which images were acquired was . Nine observers independently performed three specific tasks, namely: (1) To detect a nodule of ; (2) To detect nodules of varying attenuation ; and (3) To detect nodules varying in size and attenuation . A two‐alternative forced‐choice test was used in order to determine the limits of nodule detection in terms of the proportion of correct responses (, related to the area under the ROC curve) as a summary metric of observer performance. The radiation dose levels for detection of 99% of nodules in each task were as follows: Task 1 ; Task 2 ; and Task 3 . The corresponding interobserver confidence limits were 1, 5, and for Tasks 1, 2, and 3, respectively. There was a fivefold increase in the radiation dose required for detection of lower‐density nodules (Tasks 1 to 2). Absence of prior knowledge of the nodule size and density (Task 3) corresponds to a significant increase in the minimum required radiation dose. Significant image degradation and reduction in observer performance for all tasks occur at a dose of . It is concluded that the size and attenuation of a nodule strongly influence the radiation dose required for confident evaluation with a minimum threshold value of (minimum dose CT). A prior knowledge of nodule size and attenuation is available from the baseline CT scan and is an important consideration in minimizing the radiation exposure required for nodule detection with surveillance CT.
Effects of hyperbaric exposures on cardiac pacemakers
Authors: Lafay V , Trigano J A , Gardette B , Micoli C , Carre F
Published: September 2007

Data on tolerance of cardiac pacemakers during diving are very scarce. The aim of this study was to test electronic and mechanical tolerances of pacemakers exposed to experimental reproductions of pressures encountered during diving. Two samples each of 20 different models of cardiac pacemakers were exposed to compression during continuous telemetric monitoring. The first sample of each model was exposed to a pressure of 60 metres of sea water (msw). Each second sample was first exposed to a pressure of 30 msw then to 60 msw hyperbaric testing, with a period of 1 month between the two tests. Electronic function and structural integrity of the cans were evaluated. No electronic dysfunction was noted. We merely observed in some devices a transient increase of the pacing rate during pressurisation. No significant deformation of the can (⩽0.2 mm) was observed after the 30 msw hyperbaric test. However, after the 60 msw test, more than half of the devices tested were significantly and definitively deformed. These results show that tested pacemakers preserved a normal electronic function up to 60 msw but most of the tested devices demonstrated significant deformations of the pacemaker can for the hyperbaric exposure observed deeper than 30 msw. Without prejudging diving aptitude for implanted pacemaker patients, it therefore seems prudent to advise them against diving beyond 30 msw because of the potential for electronic dysfunction beyond that depth.
THE ADVERSE INFLUENCE OF PHYTOTOXIC SUBSTANCES FROM DECOMPOSING PLANT RESIDUES ON RESISTANCE OF TOBACCO TO BLACK ROOT ROT
Authors: Patrick Z. A. , Koch L. W.
Published: September 2007

Exposure of tobacco plants to phytotoxic solutions obtained from decomposing rye and timothy residues increased their susceptibility to black root rot caused by Thielaviopsis basicola (Berk. & Br.) Ferraris. In greenhouse experiments 16 tobacco varieties, ranging from susceptible to highly resistant to black root rot in the field, were exposed to rye and timothy toxins and their relative resistance and severity of disease development were determined. Exposure to the toxins resulted in an apparent breakdown of resistance. There were no significant differences among the varieties and the disease was equally severe on roots of the resistant and the susceptible varieties after the toxin treatment. These results might explain in part, at least, the apparent breakdown of resistance that has at times been noted in the field with black root rot resistant varieties. The effect of the toxic compounds appears to be largely on the host rather than on the fungus. The precise biochemical and physiological changes which are induced in the root tissues by the toxins to make them more favorable for fungus invasion and colonization are at present not known. This study suggests, however, that phytotoxins may be important host-conditioning factors in the development of root diseases.
INFECTION OF BALSAM FIR, ABIES BALSAMEA (L.) MILL., BY STEREUM SANGUINOLENTUM (ALB. AND SCHW. EX FR.) FR.
Authors: Davidson A. G. , Etheridge D. E.
Published: September 2007

Studies in the Maritime Provinces and Quebec showed that Stereum sanguinolentum behaves as a primary invader of the heartwood of living balsam fir, becoming established in the trees only as a result of injuries to living stems and branches. These observations were largely confirmed by artificial inoculations. Other factors apparently influencing infection were the age of the wound, size of wounded part, and time of injury. The rate of decay was found to increase with increasing size of injury but was not influenced by the origin of the infection or the location of stands. Implications of the findings and the factors requiring additional study are discussed.
EFFECT OF BENZOIC ACID AND ITS DERIVATIVES ON PLANT METABOLISM: 6- EFFECT OF CHLOROBENZOIC ACID DERIVATIVES ON THE CARBOHYDRATE METABOLISM OF STARVED AND SUCROSE-FED ETIOLATED BARLEY LEAVES
Authors: Naguib M. I.
Published: September 2007

The effects of chlorobenzoic acids on respiration, sucrose absorption, and carbohydrate metabolism of etiolated barley leaves were studied. The results showed that respiration was retarded to the same extent irrespective of position of substitution, in the presence of these substances; inhibition was more pronounced at higher concentrations of chlorobenzoic acids. At low concentrations, o-chlorobenzoic acid enhanced sucrose uptake and p-chlorobenzoic inhibited uptake while at higher concentrations, both compounds inhibited sucrose uptake by etiolated barley leaves.Tissue analysis for carbohydrates showed a decrease in all carbohydrate fractions of treated leaves compared to the control samples. Even the sucrose-fed treated samples showed a carbohydrate content similar to that of the samples starving in distilled water in spite of the variable amounts of sugars absorbed by such samples.These observations, together with excretion of some copper-reducing substances that disappeared after clearing, support the previous suggestion (4) that the tissue carbohydrates were mostly transformed to non-sugar substances that might have been excreted as a result of increased permeability in the presence of the chlorobenzoic acids. This suggestion, together with the possibility of deactivation of the respiratory dehydrogenases, may explain the reduced rates of respiration of the treated samples.
ELECTRO-OSMOSIS, WITH SOME APPLICATIONS TO PLANT PHYSIOLOGY
Authors: Dainty J. , Croghan P. C. , Fensom D. S.
Published: September 2007

General expressions for electrokinetic phenomena of relevance in biology are derived using the methods of irreversible thermodynamics and Onsager coefficients, not only for a Helmholtz-Smoluchowski model but also for a factional model and the model of Schmid. These last two models would seem to be more appropriate for biological cell membranes.Some applications of these expressions to plant physiology include the following: the pressure contribution of electro-osmosis to the turgor of Nitella or Chara cells is found to be negligible; the power used by an electro-osmotic pump can never be less than that used by a pressure mechanism; electro-osmosis may account for the present discrepancies between calculations of membrane conductance using tracer ions fluxes and those using applied potential differences; the streaming potentials developed by pressures across biological membranes would be too small to detect, but in large pores such as xylem or phloem vessels or in cell walls small pressures would result in easily measured potentials.
TARGET CHARACTERIZATION USING TIME-REVERSAL SYMMETRY OF WAVE PROPAGATION
Authors: CHAMBERS D. H.
Published: September 2007

Over the last 15 years, there has been rapid growth in applications of time-reversal symmetry of wave propagation to enhance communications and imaging through highly scattering media. These techniques exploit both temporal and spatial reciprocity to mitigate signal distortion created from the large number of independent propagation paths between a transmitter and receiver. The time-reversal process is often described by the time-reversal operator (TRO), or equivalently by the multistatic response matrix (MRM), defined by the transmit and receive system. A singular value decomposition of this operator (or MRM) is the starting point for many of the time-reversal imaging techniques. In addition to imaging, this decomposition can also be used to extract information about objects embedded within the propagation medium, i.e., target characterization. In this paper, we review the development of target characterization in time-reversal, with an emphasis on extracting information from small targets. We will analyze the MRM for both acoustic and electromagnetic scattering and show how the symmetry of the target is reflected in the properties of the singular value spectrum. Finally, we discuss several open problems and potential applications.
SEQUENCES OF CYCLES AND TRANSITIONS TO CHAOS IN A MODIFIED GOODWIN'S GROWTH CYCLE MODEL
Authors: COLACCHIO GIORGIO , SPARRO MARCO , TEBALDI CLAUDIO
Published: September 2007

The model introduced by Goodwin [1967] in "A Growth Cycle" represents a milestone in the nonlinear modeling of economic dynamics. On the basis of a few simple assumptions, the Goodwin Model (GM) is formulated exactly as the well-known Lotka–Volterra system, in terms of the two variables "wage share" and "employment rate". A number of extensions have been proposed with the aim to make the model more robust, in particular, to obtain structural stability, lacking in GM original formulation. We propose a new extension that: (a) removes the limiting hypothesis of "Harrod-neutral" technical progress: (b) on the line of Lotka–Volterra models with adaptation, introduces the concept of "memory", which plays a relevant role in the dynamics of economic systems. As a consequence, an additional equation appears, the validity of the model is substantially extended and a rich phenomenology is obtained, in particular, transition to chaotic behavior via period-doubling bifurcations.
HOW MUCH INFORMATION CAN THERE BE IN A REAL NUMBER?
Authors: CHAITIN GREGORY
Published: September 2007

This note gives some information about the magical number Ω and why it is of interest. Our purpose is to explain the significance of recent work by Calude and Dinneen attempting to compute Ω. Furthermore, we propose measuring human intellectual progress (not scientific progress) via the number of bits of Ω that can be determined at any given moment in time using the current mathematical theories.
FAULT TOLERANCE AND DETECTION IN CHAOTIC COMPUTERS
Authors: JAHED-MOTLAGH MOHAMMAD R. , KIA BEHNAM , DITTO WILLIAM L. , SINHA SUDESHNA
Published: September 2007

We introduce a structural testing method for a dynamics based computing device. Our scheme detects different physical defects, manifesting themselves as parameter variations in the chaotic system at the core of the logic blocks. Since this testing method exploits the dynamical properties of chaotic systems to detect damaged logic blocks, the damaged elements can be detected by very few testing inputs, leading to very low testing time. Further the method does not entail dedicated or extra hardware for testing. Specifically, we demonstrate the method on one-dimensional unimodal chaotic maps. Some ideas for testing higher dimensional maps and flows are also presented.
RESONANCES OF PERIODIC ORBITS IN RÖSSLER SYSTEM IN PRESENCE OF A TRIPLE-ZERO BIFURCATION
Authors: ALGABA ANTONIO , FREIRE EMILIO , GAMERO ESTANISLAO , RODRÍGUEZ-LUIS ALEJANDRO J.
Published: September 2007

This paper focuses on resonance phenomena that occur in a vicinity of a linear degeneracy corresponding to a triple-zero eigenvalue of an equilibrium point in an autonomous tridimensional system. Namely, by means of blow-up techniques that relate the triple-zero bifurcation to the Kuramoto–Sivashinsky system, we characterize the resonances that appear near the triple-zero bifurcation.

Using numerical tools, the results are applied to the Rössler equation, showing a number of interesting bifurcation behaviors associated to these resonance phenomena. In particular, the merging of the periodic orbits appeared in resonances, the existence of two types of Takens–Bogdanov bifurcations of periodic orbits and the presence of Feigenbaum cascades of these bifurcations, joined by invariant tori curves, are pointed out.
DYNAMICAL SYSTEMS ON THREE MANIFOLDS PART I: KNOTS, LINKS AND CHAOS
Authors: SONG YI , BANKS STEPHEN P. , DIAZ DAVID
Published: September 2007

In this paper, we give an explicit construction of dynamical systems (defined within a solid torus) containing any knot (or link) and arbitrarily knotted chaos. The first is achieved by expressing the knots in terms of braids, defining a system containing the braids and extending periodically to obtain a system naturally defined on a torus and which contains the given knotted trajectories. To get explicit differential equations for dynamical systems containing the braids, we will use a certain function to define a tube neighborhood of the braid. The second one, generating chaotic systems, is realized by modeling the Smale horseshoe.
DYNAMICAL SYSTEMS ON THREE MANIFOLDS PART II: THREE-MANIFOLDS, HEEGAARD SPLITTINGS AND THREE-DIMENSIONAL SYSTEMS
Authors: SONG YI , BANKS STEPHEN P.
Published: September 2007

The global behavior of nonlinear systems is extremely important in control and systems theory since the usual local theories will only provide information about a system in some neighborhood of an operating point. Away from that point, the system may have totally different behavior and so the theory developed for the local system will be useless for the global one.

In this paper we shall consider the analytical and topological structure of systems on two- and three-manifolds and show that it is possible to obtain systems with "arbitrarily strange" behavior, i.e. arbitrary numbers of chaotic regimes which are knotted and linked in arbitrary ways. We shall do this by considering Heegaard Splittings of these manifolds and the resulting systems defined on the boundaries.
LABYRINTH CHAOS
Authors: SPROTT J. C. , CHLOUVERAKIS KONSTANTINOS E.
Published: September 2007

A particularly simple and mathematically elegant example of chaos in a three-dimensional flow is examined in detail. It has the property of cyclic symmetry with respect to interchange of the three orthogonal axes, a single bifurcation parameter that governs the damping and the attractor dimension over most of the range 2 to 3 (as well as 0 and 1) and whose limiting value b = 0 gives Hamiltonian chaos, three-dimensional deterministic fractional Brownian motion, and an interesting symbolic dynamic.
SYNCHRONIZATION OF CHAOTIC SYSTEMS USING NEURAL-NETWORK-BASED CONTROLLER
Authors: LAM H. K. , SENEVIRATNE L. D.
Published: September 2007

This paper presents the synchronization of chaotic systems. A feed-forward neural network will be employed to form the proposed neural-network-based controller to perform chaotic synchronization. Stability conditions will be derived to guarantee the system stability. The system performance will be ensured and the parameters of the neural networks can be obtained by solving the solution to the generalized eigenvalue minimization problem. A simulation example will be given to illustrate the effectiveness of the proposed approach.
HOPF BIFURCATION ANALYSIS IN A MACKEY–GLASS SYSTEM
Authors: WEI JUNJIE , FAN DEJUN
Published: September 2007

The dynamics of a Mackey–Glass equation with delay are investigated. We prove that a sequence of Hopf bifurcations occur at the positive equilibrium as the delay increases. Explicit algorithm for determining the direction of the Hopf bifurcations and the stability of the bifurcating periodic solutions are derived, using the theory of normal form and center manifold. Global existence of periodic solutions are established using a global Hopf bifurcation result due to Wu [1998] and a Bendixson criterion for higher dimensional ordinary differential equations due to Li and Muldowney [1994].
POST-ANALYSIS OF KNOWLEDGE-CREATION PROCESSES IN SMALL RESEARCH PROJECTS
Authors: SUGIYAMA KOZO
Published: September 2007

This paper proposes a work guide (or framework) for analyzing organizational knowledge creation processes of small research projects, integrating basic concepts (or primitives) from several existing knowledge-creation theories. This guide has been developed during the evaluation of projects. We present results of the process analysis of research projects that have been completed recently. We indicate evidence of the concepts through our own experience and remark on differences among processes of different projects.
A KNOWLEDGE MANAGEMENT SYSTEM FOR DYNAMIC ORGANIZATIONAL KNOWLEDGE CIRCULATION
Authors: HIRAI CHIAKI , UCHIDA YOSHINOBU , FUJINAMI TSUTOMU
Published: September 2007

The demand for knowledge management is increasing because knowledge is an important and essential resource for sustaining competitiveness. We report a system to support knowledge asset reuse. Incorporating work breakdown structure-based project management, workflow management, and a document database, the system guides workers to efficiently store and reuse knowledge assets. To dynamically circulate knowledge throughout an organization, the system supports the concept of knowledge flow, through which knowledge is transferred from one project to another. A distinctive feature of our approach is that after collecting relevant knowledge, the system sends it to the members of a project and prompts them to have a meeting to discuss whether they accept the knowledge. The purpose of this meeting is to have members internalize knowledge assets and share their tacit knowledge through discussion. We developed a prototype system and evaluated it using our experience with it.
B3LYP-SVM METHOD FOR THE ESTIMATION OF MOLECULAR ENTHALPIES OF FORMATION
Authors: YAN GUI-KAI , LI JUN-JIE , LI BING-RUI , HU JIA , GUO WEN-PING
Published: September 2007

Support vector machine (SVM) is used to predict the enthalpies of formation at 298 K [Formula: see text] for 261 molecules based on B3LYP/6-311g (3df,2p) results. With data randomly separated into two parts: 195 for training set and 66 for test set, the resulting mean absolute deviation (MAD) and maximum deviation (MD) for training set are 1.51 kcal/mol and 9.23 kcal/mol (correlation coefficient R = 0.9995), and for test set they become to 1.78 kcal/mol and 7.31 kcal/mol (R = 0.9990). The result is improved according to G2 method.
THEORETICAL VIBRATIONAL SPECTRA STUDIES: THE EFFECT OF RING SIZE ON THE CARBONYL VIBRATIONAL FREQUENCIES
Authors: HOOSHYAR H. , RAHEMI H. , DILMAGANI K. A. , TAYYARI S. F.
Published: September 2007

In this paper, molecular structures and vibrational frequencies of cycloketone, cyclopropanone, cyclobutanone, cyclopentanone, and cyclohexanone have been investigated by density functional theory (DFT) and the second order Møller and Plesset (MP2) levels of theory, using 6-311G, 6-311G**, 6-311++G, and 6-311++G** basis sets.

The calculations predict a planar structure for cyclopropanone. The cyclobutanone ring is puckered and according to the calculations at B3LYP/6-311++G** and MP2/6-311++G** levels of theory, it deviates from planarity by 5.0° and 15.7°, respectively. The calculated barrier height between puckered and planar conformer, at MP2/6-311G** level of theory, is 196.7 cm-1. The puckering frequency at B3LYP/6-311G** and MP2/6-311G** levels are 47.5 cm-1 and 121.2 cm-1. Cyclopentanone has twisted conformations ( C 2 symmetry) in which carbons C1 and C2 are out-of-plane with a torsional angle of 11.5° (MP2/6-311G**) and the molecule goes from one conformation to the other via an envelope transition conformation ( C s symmetry). or planar hilltop conformation ( C 2v symmetry). The most stable conformation of the cyclohexanone is C s chair, which has no ring strain, is used as land mark.
THE ORIGIN OF THE ROTATIONAL BARRIER IN DIMETHYL ETHER AND DIMETHYL SULFIDE: A THEORETICAL STUDY
Authors: JÍMENEZ-FABIAN  , JALBOUT A. F.
Published: September 2007

The torsional potential function for methyl rotation in dimethyl ether (DME) and dimethyl sulfide (DMS) has been determined by utilizing ab initio (Hartree–Fock and MP2) and density functional theory (B3LYP, B3P86, and B3PW91) methods along with several basis sets. Natural bond orbital (NBO) analysis was also applied to investigate the origin of the rotational barrier.
THEORETICAL STUDY ON PARTIAL POTENTIAL SURFACE AND SCATTERING RESONANCE STATE OF THE ASYMMETRICAL H EXCHANGINGX+H2O→XH+OH(X=Cl, F, H) REACTIVE SYSTEM
Authors: LU XI , WANG HUAYANG , CAI ZHENGTING , FENG DACHENG
Published: September 2007

In the course of an extensive investigation aimed at understanding the detailed mechanism of a prototypical polyatomic reaction, several remarkable observations were uncovered. To interpret these findings, we surmise the existence of a reactive resonance in this polyatomic reaction. The system of concern is X + H2O → XH + OH ( X = Cl, F, H ), and it belongs to a type of asymmetrical H exchanging reaction. Because the concerned electronic number is quite small, it is usually regarded as a template constructed the model of theory or experiment. In this paper, compared with the symmetrical systems, we constructed the partial potential surfaces of asymmetrical systems in order to research their resonance states. All results are in good agreement with previous theoretical and experimental works.
FORECASTING TIME SERIES USING WAVELETS
Authors: AMINGHAFARI MINA , POGGI JEAN-MICHEL
Published: September 2007

This paper deals with wavelets in time series, focusing on statistical forecasting purposes. Recent approaches involve wavelet decompositions in order to handle non-stationary time series in such context. A method, proposed by Renaud et al.,11 estimates directly the prediction equation by direct regression of the process on the Haar non-decimated wavelet coefficients depending on its past values. In this paper, this method is studied and extended in various directions. The new variants are used first for stationary data and after for stationary data contaminated by a deterministic trend.
MULTISELECTIVE PYRAMIDAL DECOMPOSITION OF IMAGES: WAVELETS WITH ADAPTIVE ANGULAR SELECTIVITY
Authors: JACQUES LAURENT , ANTOINE JEAN-PIERRE
Published: September 2007

Many techniques have been devised these last ten years to add an appropriate directionality concept in decompositions of images from the specific transformations of a small set of atomic functions. Let us mention, for instance, works on directional wavelets, steerable filters, dual-tree wavelet transform, curvelets, wave atoms, ridgelet packets, etc. In general, features that are best represented are straight lines or smooth curves as those defining contours of objects (e.g. in curvelets processing) or oriented textures (e.g. wave atoms, ridgelet packets). However, real images present also a set of details less oriented and more isotropic, like corners, spots, texture components, etc. This paper develops an adaptive representation for all these image elements, ranging from highly directional ones to fully isotropic ones. This new tool can indeed be tuned relatively to these image features by decomposing them into a Littlewood–Paley frame of directional wavelets with variable angular selectivity. Within such a decomposition, 2D wavelets inherit some particularities of the biorthogonal circular multiresolution framework in their angular behavior. Our method can therefore be seen as an angular multiselectivity analysis of images. Two applications of the proposed method are given at the end of the paper, namely, in the fields of image denoising and N-term nonlinear approximation.
INTERPOLATORY CURL-FREE WAVELETS AND APPLICATIONS
Authors: JIANG YINGCHUN , LIU YOUMING
Published: September 2007

Divergence-free and curl-free vector wavelets have many applications for the analysis and numerical simulation of incompressible flows and certain electromagnetic phenomena. Because special domains are required in those applications, Bittner and Urban constructed interpolating divergence-free multi-wavelets based on cubic Hermite splines in 2005. In this paper, we construct interpolating curl-free multi-wavelets and give two wavelet estimates for a class of vector Besov spaces.
The geology and slopes of the Bristol region
Authors: Hawkins Alfred Brian
Published: September 2007

The geology of the Bristol region and its influence on slope development is described. Emphasis is placed on the main lithological variations and their importance to the engineering geologist. Movements in the Carboniferous Limestone, Quartzitic Sandstone Group, Coal Measures, Keuper Marl and Lias Clay Formations are described.
Non-diastrophic structures at Bredon Hill, Worcestershire
Authors: Whittaker A.
Published: September 2007

B
redon
H
ill
is an outlier of the Cotswold Hills situated in the southern part of the Vale of Evesham. Essentially the hill is composed of argillaceous Lias sediments capped by Inferior Oolite limestones. A detailed six-inch geological survey in 1966–7, aided by the sinking of two cored boreholes and by photogeological studies, has enabled the effects of superficial mass movements to be assessed.

Erosion of a thick, incompetent sequence of mudstones overlain by massive, competent limestones has led to the development of landslips, cambers and gulls. Several types of mass movement can be recognized, including slumping, mudflow and composite slip. Cambering is virtually restricted to the Inferior Oolite limestones which cap the hill and includes down-dip extension of the competent beds over the underlying mudstones. A type of hinged camber is also present. Gulls are well developed on the limestone dip-slope surface and have contributed considerably towards the down-dip extension of the beds. Wherever observed, the Inferior Oolite limestones are in a disturbed state, a feature which is attributed to the development of superficial structures under periglacial conditions.

The Inferior Oolite surface presents a large catchment area for meteoric waters, and copious springs and water seepages break out at the limestone-mudstone junction in the south part of the hill. There is evidence for considerable sub-Inferior Oolite erosion, a process which would facilitate superficial mass movements. Evidence from gravels, which flank the hill, strongly suggests that many of the non-diastrophic structures were well developed by River Avon No. 2 Terrace times (38 000 ± 700), although later phases of instability are indicated by clayflow features which in places obscure older landslip and solifluxion deposits. There is much evidence that landslip movements have also taken place throughout historic times; eyewitness accounts are available over the last one hundred years or so.
Soil and rock slope instrumentation
Authors: Savage R. J.
Published: September 2007

1. Introduction

T
he purpose of this paper
is to describe two out of several unconventional instrumentation schemes which are useful for detecting the onset and monitoring the progression of slope instabilities. The devices concerned are the strip gauge and the long span displacement gauge and both were originally conceived for use in nuclear weapons testing programmes, to measure the gross dynamic soil and rock motions associated with such tests.

Both gauges are equally suitable for measuring the quasi-static creep motion of slopes which characteristically precede soil and rock slides, the initial parts of the actual slide motion itself and, if subsequently arrested, the time history of slope settlement and stabilisation.

Both gauges can be made to substantial lengths so that it becomes feasible to monitor the displacement trends of any medium along a line of expected motion in three mutually orthogonal axes. By arranging the gauges in a matrix, the motion of a large surface or plane can be monitored and, although not yet attempted, it is now possible to monitor the strains and motions of large volumes of suspect soil and rock. By comparison it would be prohibitively expensive to attempt the same measurement with individual, or discrete transducers.

The strip gauge was first used to measure the horizontal displacement occurring at various depths in a soil mass due to a large magnitude surface detonation. The blast effect produced a crater and several unexpected subterranean motions during its formation. These were recorded via the strain gauges on the strip
Two simple devices for monitoring movements in rock slopes
Authors: Boyd J. M. , Hinds D. V. , Moy D. , Rogers C.
Published: September 2007

Experience in monitoring movement across tension cracks in a slate quarry in Cornwall suggested a need for two types of instrument. One would be sufficiently sensitive for the measurement of daily variations used to predict failure on the basis of acceleration. The other would provide enough detail for the calculation of the direction and magnitude of movements across the crack.

The two instruments are an Invar bar extensometer developed by the Cement and Concrete Association and a large vernier caliper fitted with a clinometer and modified for measurements between steel pegs topped with phosphor bronze balls.

Performance figures are given along with some of the design considerations. A statistical evaluation of precision and an analysis of the errors inherent in ball-in-cone measurements form appendices to the paper.
Design considerations for excavated mine slopes in hard rock
Authors: Ross-Brown Dermot Macaragh
Published: September 2007

There are important differences in the approach to the design of rock slopes in Mining and in Civil Engineering due to different economic, operational and political factors. These factors have to be considered in a discussion of mining slope failures and the geotechnical approach to the design of pit slopes. Emphasis, in the paper, is also placed upon the importance of geological structure and the influence of the excavation technique.