bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Differences and Environments of Mussel Populations in the Maritime Provinces
Authors: Gartner-Kepkay K. E. , Dickie L. M. , Freeman K. R. , Zouros E.
Published: February 2009

Genetic differences among Mytilus edulis populations from four localities in Atlantic Canada were examined using electrophoretic techniques. On the basis of allele frequency distributions at four loci (LAP-1, PEPTIDASE-2, PGI, PGM), the localities fell into two pairs, paralleling a similar pairing on the basis of values of specific environmental parameters and their variability. Gene flow between environments could be eliminated as an explanation of gene frequency similarity in one of the pairs. The large heterozygote deficiencies appear not to be satisfactorily explained by the Wahlund effect, inbreeding, or "silent alleles," without the added influence of environmental selection. We conclude that the allele frequency patterns reflect differences in the average environmental characteristics among localities.Key words: isoenzymes, blue mussels, genetic differences, environmental selection, Mytilus edulis
A Salicylate–Hypochlorite Method for Determining Ammonia in Seawater
Authors: Bower Carol E. , Holm-Hansen Thomas
Published: February 2009

Total ammonia-nitrogen (NH4-N) in artificial seawater was determined spectrophotometrically by a method in which indophenol blue is produced by the reaction of ammonia with salicylate and hypochlorite, in the presence of sodium nitroprusside. Recoveries of 10 to 1000 μg NH4-N/L by the salicylate– and phenol–hypochlorite methods compared well (r = 0.99); the coefficient of variation for 25 μg NH4-N/L and above was less than 3% for the salicylate–hypochlorite method. The new method is safer than the phenol–hypochlorite method because phenol is not used, but it may not be suitable for field determinations because of photosensitivity. The characteristic colors produced by increasing concentrations of ammonia make the assay useful for the direct, visual estimation of ammonia in culture systems.Key words: ammonia, analytical methods, seawater analysis
Measurement of Whole Lake Sediment Accumulation and Phosphorus Retention Using Lead-210 Dating
Authors: Evans R. Douglas , Rigler Frank H.
Published: February 2009

Lead-210 dating was used to measure rates of sediment accumulation in 15 cores from Bob Lake, Ontario. The rate of accumulation was highly correlated with sample depth. This relation allowed the calculation of accumulation of sediments over the whole lake area. Phosphorus (P) retention was calculated from mean concentration of P in the sediments and the whole lake accumulation of sediment. Retention of P calculated in this way was similar to retention calculated from previously measured input and output of P.Key words: lead-210 dating, sediment accumulation, phosphorus retention
Relationships Between Metabolic Parameters and Stream Order in Oregon
Authors: Naiman Robert J. , Sedell James R.
Published: February 2009

The light regime, standing stock of chlorophyll, and five metabolic parameters were measured seasonally at four Oregon stream sites; Devils Club Creek (1st order), Mack Creek (3rd order), Lookout Creek (5th order), and the McKenzie River (7th order). Periphyton from pools and riffles, aquatic moss (Fontinalis), fine particulate organic matter (FPOM: 0.5 μm–1 cm), and coarse particulate organic matter (CPOM: > 1 cm) were examined separately for gross production (GP), net community production (NCP), diel respiration (R24), net daily metabolism (NDM), and the production to respiration (P:R) ratio. Total autotrophic production was found to increase in a downstream direction where more light is available; however, the efficiency of light utilization is greatest in heavily shaded Mack Creek. Detrital metabolism, per unit weight, is similar in all streams for each metabolic parameter. The standing stock of detritus though, is highest in headwater streams, decreasing as streams become larger. Therefore, the relative contribution of the detritus community to total metabolism decreases downstream. Mosses occur in significant quantities only in the McKenzie River and have an areal community respiration rate about twice that of periphyton; other metabolic parameters are nearly equal in this case. On an areal basis periphyton metabolism is much greater than detrital metabolism and, as a consequence, total stream metabolism and the P:R ratio increase downstream.Gross production rates measured for these sites are some of the lowest recorded (0.1–1.0 g O2∙m−2∙d−1). These rates are compared to those from other streams in the northwestern United States and western Canada, and the importance of photosynthesis to stream systems is demonstrated. The decomposition rate of the detrital standing stock is estimated to be 0.0029–0.0057%∙m−2∙d−1 and the turnover time is calculated to be 48–93 yr for particles < 10 cm in diameter.Key words: streams, rivers, metabolism, primary production, detritus, photosynthesis, chlorophyll, respiration, light, Oregon
Growth Rates of a New Cell Line from Channel Catfish Ovary and Channel Catfish Virus Replication at Different Temperatures
Authors: Bowser P. R. , Plumb J. A.
Published: February 2009

Growth rates of a new cell line from the channel catfish, Ictalurus punctatus, were determined at temperatures from 10 to 35 °C. Growth was more rapid at 35 °C with the cells having a population doubling time of 12 h, and cell numbers declined at 10 °C. The cells survived frozen storage at −70 °C for up to 6 mo. Replication of channel catfish virus occurred from 10 to 35 °C. Although it was most rapid at 35 °C, maximum replication occurred at 30 °C.Key words: fish viruses, channel catfish virus, herpesvirus, fish cell cultures, fish diseases, cell growth rates
Effects of Unconventional Size Limits on the Growth Rate of Trout
Authors: Favro L. D. , Kuo P. K. , McDonald J. F.
Published: February 2009

A computer model was used to study the genetic effects on a trout population that was subjected to selective fishing with unconventional size limits; both a minimum and maximum size were specified. The model predicts that such window size limits will not have their intended effect, i.e. to increase the percentage of larger fish in the population.Key words: fish, trout, genetics, growth, size limit, window size limit, Salmo trutta
Polynomial correction function for half-power bandwidth (HPB) method of damping of glulam beams reinforced with e-glass reinforced epoxy polymer (GRP)
Authors: Naghipour M. , Mehrzadi M. , Taheri F. , Zou G. P.
Published: February 2009

Analytical and experimental investigation into dynamic properties of glued–laminated (glulam) beams reinforced with various lay ups of e-glass reinforced epoxy polymer (GRP) composites are discussed. Three unreinforced glulam (control) beams and 11 glulam beams reinforced with GRP on their bottom surface were clamped in a cantilever condition and tested using an instrumental hammer. The natural frequencies of all beams determined by the impact dynamic (hammer) method using power spectral density (PSD) were used to estimate damping ratio of all the beams through both time domain and frequency domain methods. In the time domain analysis, the method of logarithmic decrement analysis (LDA) and the Hilbert transform analysis (HTA) were considered; in the frequency domain analysis, both moving block analysis (MBA) and half-power bandwidth (HPB) were applied to the data and a new approach HPB method with a polynomial correction function was numerically established. A comparison between the results obtained from all the methods of analysis and a new approach shows that this method may improve the accuracy of the HPB method in evaluation of vibration damping properties of glulam reinforced composite beams because glulam beams have high level damping ratios and that this method should be modified especially when used with materials having high level damping ratios.
Equivalent uniform moment diagram factor for structural concrete columns
Authors: Tikka Timo K. , Mirza S. Ali
Published: February 2009

The equivalent uniform bending moment diagram factor (Cm) was introduced into design practice to eliminate the need for extensive calculations, based on the solution to a differential equation, to compute the effect of moment gradient, along the column height, caused by unequal column end moments. The expression currently in use in the Canadian Standards Association (CSA) A23.3 standard is a simplified equation based on the elastic behaviour of columns, and does not include the inelastic material behaviour of structural concrete. This study was conducted to investigate the influence of different variables on Cmof slender, tied, reinforced concrete columns, and composite steel–concrete columns in which steel sections are encased in concrete, and also to examine existing expressions for Cm. Approximately, 38 000 simulated columns, each with a different combination of specified values of variables, were used to generate the Cmdata. The columns studied were subjected to short-term ultimate loads and unequal end moments causing moment gradient in single curvature and double curvature bending. Two Cmdesign equations are proposed in this paper. One of the proposed equations is a modified version of the current CSA design equation for Cm.
A simplified approach to determine the optimum operating speed on high-speed railway lines
Authors: Öztürk Zübeyde , Öztürk Turgut
Published: February 2009

In this study, cost–speed relationship for high speed railways was examined and optimum economic speed was investigated. The Eskişehir–Ankara section of the İstanbul–Ankara railway line, which is still under construction, was taken as the sample. This section has been completed and test runs are being conducted. The new line is constructed parallel to the old railway line and the operation speeds and operation forms of the trains on this line are not yet finalized. It is not yet clear what the maximum operation speeds of the trains will be and whether the operation will be restricted to only high speed passenger trains or a combination of passenger and freight trains will be used. Therefore, cost changes associated with speed for both operations were examined in the study. The speed for the lowest cost was investigated for the benefit of the operating institute. The rail line is scheduled to begin operation in 2010, and as such demand estimation values for 2010 and unit cost values of Turkish State Railways (TCDD) were utilized. Only construction and operation costs were analyzed, societal costs were not included in the study. Several costs were formulated independent ofthe speed, whereas the majority of them were formulated and calculated based on speed. Finally, the contribution of each studied cost component, in the total cost, and variations in these costs and total cost for different speeds for both operation conditions were analyzed in this study. It was found that some cost components increased and some decreased as the speed increases. Total cost, which includes all the cost components studied, initially dropped off then rose up as the speed incrementally increases. Minimum cost occurred at 200 km/h in the case of operating with only passenger trains, while it occurred at the second speed level in combined operation (where passenger trains are at the speed of 200 km/h and freight trains are at the speed of 90 km/h).
Rate-dependent fracture modeling of asphalt concrete using the discrete element method
Authors: Kim Hyunwook , Wagoner Michael P. , Buttlar William G.
Published: February 2009

The discrete element method (DEM) represents a convenient and powerful tool for studying effects of material microstructure on fracture mechanisms in asphalt concrete. In this paper, the rate-dependency of asphalt concrete is investigated using a cohesive zone model with bulk viscoelastic properties combined with bilinear post-peak softening. Details of the constitutive models implemented in the DEM, with particular emphasis on the verification of viscoelastic models, are presented. Experimental test results based on a disk-shaped compact tension test are obtained under different loading rates and those are compared to numerical simulations with the help of the rate-dependent model. Homogeneous and heterogeneous model results are compared, where heterogeneous models are constructed to consider aggregate morphology for particles larger than 1.18 mm. The relative importance of time-dependence and the consideration of material heterogeneity in the simulation of monotonic Mode I fracture tests are demonstrated.
Co-composting of manure with fat, oil, and grease: Microbial fingerprinting and phytotoxicity evaluation
Authors: Al-Mutairi Nayef
Published: February 2009

Sole carbon source utilization profiles to characterize compost maturity were evaluated in reference to several other physicochemical and biological maturity indices. The results suggested that the addition of fat, oil, and grease (FOG) had a significant effect on the biological processes in the sample piles when compared to the control pile. Additionally, principal components analysis of the patterns and the levels of microbial activity indicate that microbial communities differentiate in response to FOG additions from 1 to 20 L/m3. However, between 10 and 20 L/m3, no recognizable differences were found between the control and the FOG amendment communities. Biolog data indicates a shift in the structure and function of the microbial community in compost with high FOG additions, which may be a useful indicator of high functional diversity and evenness during composting processes. Finally, the germination index (GI) of lettuce increased from 9% in the control to 100% in the FOG amended compost. However, the addition of high amounts of FOG might in turn inhibit seed germination and root growth because of the high pH and electrical conductivity (EC), and the volatilization of NH3. From the present results, 10 L/m3 was found to be the optimum FOG amendment rate for manure compost. These amendment rates are empirical and may be regarded as potential guidelines to agricultural practitioners.
Delay analysis in resource-constrained schedules
Authors: Kim Kyunghwan
Published: February 2009

The schedule for construction delay analysis should consider resources because it is acknowledged that a schedule without resources is not realistic. However, the conventional resource-constrained scheduling (RCS) technique is not properly operated for the widely accepted delay analysis techniques such as the contemporaneous period analysis (CPA) and the “but-for” method. The “CPM + RCS” method for rescheduling to analyze delay impacts may cause unexpected activity sequence changes and the “RCS-only” method does not reflect the time impact of the duration reduction of an activity and may cause substantial project completion delay by a minor change in the activity duration. This study analyzes the problems that arise when CPA and the “but-for” method are performed on the basis of the conventional RCS technique and shows how the resource-constrained critical path method can be utilized in those delay analyses that have advantages as compared with the RCS technique.
Decision-making support model for reusable construction materials in multiple project management
Authors: Han Juyeoun , Kim Kyungrai , Chin Sangyoon , Shin Dongwoo
Published: February 2009

Although reusable materials in a construction project need to be specifically managed by the head office of the construction company for proper retrieval and reuse, they are not efficiently managed. In many cases, construction companies treat reusable materials no differently from non-reusable materials. To manage reusable materials for effective and efficient procurement, the current procurement system needs to be improved based on the records of usage from multiple projects monitored and managed by the head office of the construction company. The objective of this paper is to discern and analyze the problems of the procurement process of reusable materials for current multiple projects by following case studies of three construction companies against this background. Based on the analysis, this paper emphasizes the need to implement systems for reusable materials procurement requests, outgoing materials quantity forecasts, and economic analysis for vehicle distribution, as well as the need to expand applicable uses of a resource pool. A model is also proposed to support the decision-making process in the procurement of reusable materials.
Regression models for the prediction of water quality in the stormwater of urban arid catchmentsA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Nouh M. , Al-Noman N.
Published: February 2009

Data from five residential urban arid catchments were used to develop regression equations for predicting mean concentrations of selected heavy metals in the stormwater runoff from duststorm and stormwater flow properties. The selected metals are copper (Cu), lead (Pb), nickel (Ni), zinc (Zn), and iron (Fe). The concentrations of the selected metals were predicted through two groups of equations. The first group of equations relates concentrations of suspended sediment with duststorm and stormwater parameters, whereas the second group relates the concentrations of the suspended sediment with those of heavy metals in the stormwater runoff. The results of the predictions encouraged recommendations on the use of the equations in the investigated catchments and identified the relative importance of the stormwater runoff and duststorms on the accumulation and transportation of heavy metals in the stormwater runoff. Based on the obtained results, recommendations concerning water quality control in arid areas are made.
Membrane-based treatment for tanning wastewatersA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Catarino Justina , Mendonça Elsa , Picado Ana , Lança Ana , Silva Luis , Norberta de Pinho Maria
Published: February 2009

Tanning wastewater was subjected to different unit operations to select the best treatment sequences. Textile membrane filtration (TMF), microfiltration (MF), and ultrafiltration (UF) were complemented by screening, flocculation or flotation operations. The general chemical characterization determined that the wastewater had a high organic load. The ecotoxicological study classified the wastewater as highly ecotoxic. The sequence of screening–TMF–UF was found to be the optimal treatment for wastewaters of the first and second soaking stages, while the sequence of screening–TMF–flotation–UF proved to be adequate for the liming wastewater concerning productivity and water quality. Larger pore sizes MF membrane or higher molecular weight cut off (MWCO) UF membranes with higher permeability to pure water showed lower permeation fluxes for tanning wastewater. After membrane treatments, a decrease in the ecotoxicity was measured. The use of membrane treatment technology showed to be promising in removing organic pollutants and allowing the reuse of water and chemicals in the process.
NEW EXTENSIONS OF PAIRING-BASED SIGNATURES INTO UNIVERSAL (MULTI) DESIGNATED VERIFIER SIGNATURES
Authors: VERGNAUD DAMIEN
Published: February 2009

The concept of universal designated verifier signatures was introduced by Steinfeld, Bull, Wang and Pieprzyk at Asiacrypt 2003. These signatures can be used as standard publicly verifiable digital signatures but have an additional functionality which allows any holder of a signature to designate the signature to any desired verifier. This designated verifier can check that the message was indeed signed, but is unable to convince anyone else of this fact. We propose new efficient constructions for pairing-based short signatures. Our first scheme is based on Boneh-Boyen signatures and its security can be analyzed in the standard security model. We prove its resistance to forgery assuming the hardness of the so-called strong Diffie-Hellman problem, under the knowledge-of-exponent assumption. The second scheme is compatible with the Boneh-Lynn-Shacham signatures and is proven unforgeable, in the random oracle model, under the assumption that the computational bilinear Diffie-Hellman problem is untractable. Both schemes are designed for devices with constrained computation capabilities since the signing and the designation procedure are pairing-free. Finally, we present extensions of these schemes in the multi-user setting proposed by Desmedt in 2003.
ON PARIKH MATRICES, AMBIGUITY, AND PRINTS
Authors: ŞERBĂNUŢĂ VIRGIL NICOLAE
Published: February 2009

In the algebraic study of words and languages it is often convenient to analyze words as numerical quantities. One such now-famous example is the study of words by using their attached Parikh mapping (or vector). However, the Parikh vector abstracts away too much of the structure of the word. Parikh matrices were introduced as a means to obtain more than just the number of occurrences of single letters. When studying properties of words, an important property is that a word is uniquely determined by the number of occurrences of certain predetermined subwords. In the context of Parikh matrices, the problem is translated in finding which words are completely characterized by their associated Parikh matrix. This paper links this problem with that of the print of a word, i.e. the word obtained by considering consecutive occurrences of the same letter as only one letter. We obtain results regarding finiteness and context-freeness of such classes of words.
ON DETERMINISTIC CD-SYSTEMS OF RESTARTING AUTOMATA
Authors: MESSERSCHMIDT HARTMUT , OTTO FRIEDRICH
Published: February 2009

Three variants of determinism are introduced for CD-systems of restarting automata, called strict determinism, global determinism, and local determinism. In mode = 1 globally deterministic CD-systems of restarting automata are of the same expressive power as nonforgetting deterministic restarting automata of the same type, which corresponds to the situation for nondeterministic CD-systems. On the other hand, for the various types of restarting automata without auxiliary symbols, strictly deterministic CD-systems of restarting automata are strictly less expressive than the corresponding deterministic types of nonforgetting restarting automata. Further, globally deterministic CD-systems of restarting automata can be simulated by locally deterministic CD-systems of restarting automata of the same type. In fact, we conjecture that, for all types of restarting automata without auxiliary symbols, the latter are strictly more expressive than the former, but they are strictly less expressive than the corresponding nondeterministic CD-systems of restarting automata.
DISCRETE REPAIR-COST LIMIT REPLACEMENT POLICIES WITH/WITHOUT IMPERFECT REPAIR
Authors: IWAMOTO KAZUKI , DOHI TADASHI , KAIO NAOTO
Published: February 2009

This paper addresses statistical estimation problems of the optimal repair-cost limits minimizing the long-run average costs per unit time in discrete seting. Two discrete repair-cost limit replacement models with/without imperfect repair are considered. We derive the optimal repair-cost limits analytically and develop the statistical non-parametric procedures to estimate them from the complete sample of repair cost. Then the discrete total time on test (DTTT) concept is introduced and applied to propose the resulting estimators. Numerical experiments through Monte Carlo simulation are provided to show their asymptotic convergence properties as the number of repair-cost data increases. A comprehensive bibliography in this research topic is also provided.
ECONOMIC PRODUCTION RUN LENGTH AND WARRANTY PERIOD FOR PRODUCT WITH WEIBULL LIFETIME
Authors: CHEN CHUNG-HO
Published: February 2009

Traditional economic manufacturing quantity (EMQ) model addressed the perfect production for product. However, there possibly exists the defective product in the production process. In this paper, we present a modified EMQ model with shortage based on considering the product revenue and the inventory cost. The economic production run length, the maximum shortage level, and the optimal warranty period are simultaneously determined for obtaining the maximum expected total profit per year. The numerical example and the sensitivity analysis are further provided for illustration.
MONITORING AUTOCORRELATED PROCESS MEAN AND VARIANCE USING A GWMA CHART BASED ON RESIDUALS
Authors: SHEU SHEY-HUEI , LU SHIN-LI
Published: February 2009

This investigation elucidates the feasibility of monitoring a process for which observational data are largely autocorrelated. Special causes typically affect not only the process mean but also the process variance. The EWMA control chart has recently been developed and adopted to detect small shifts in the process mean and/or variance. This work extends the EWMA control chart, called the generally weighted moving average (GWMA) control chart, to monitor a process in which the observations can be regarded as a first-order autoregressive process with a random error. The EWMA and GWMA control charts of residuals used to monitor process variability and to monitor simultaneously the process mean and variance are considered to evaluate how average run lengths (ARLs) differ in each case.
A MAINTENANCE MODEL FOR MANUFACTURING LEAD TIME IN A PRODUCTION SYSTEM WITH BMAP INPUT AND BILEVEL SETUP CONTROL
Authors: LEE HO WOO , PARK NO IK
Published: February 2009

In this paper, the manufacturing lead time in a production system with maintenance period, non-renewal BMAP (Batch Markovian Arrival process) input and bilevel threshold control is analyzed. The factorization principle is used to derive the distribution of the manufacturing lead time and the mean value. A numerical example is provided to see the effect of the non-renewal input on the system performance.
SERVICE LEVEL ANALYSIS OF (S - 1, S) INVENTORY POLICY FOR NEGATIVE BINOMIAL DISTRIBUTED FAILURES
Authors: AHN SUNEUNG , KIM WOOHYUN
Published: February 2009

This paper deals with the analysis of uncertain parameters in the (S - 1, S) inventory control policy. In order to determine the number of spare parts under the policy, parameters in a probability model for the number of failures during a replenishment lead time should be interpreted first. In case of the negative binomial distributed failures, the presented interpretation facilitates the incorporation of experts' opinions into the estimation of uncertain parameters. Determination of parameters via their interpretation is useful for deciding a service level in the area of reliability-based inventory control.
GRAPHICAL SOLUTION OF THE ISING MODEL ON HONEYCOMB LATTICE
Authors: JAFARI S. AKBAR
Published: February 2009

In this work, we present a detailed graphical solution for the Ising model on the honeycomb lattice. In view of the mapping between the calculation of the partition function for generalizations of the Ising model and the calculus of resonating valence bond (RVB) states at zero temperature, our calculation may be of relevance to the RVB physics on the honeycomb lattice.
EFFECT OF Ba SUBSTITUTION ON ELECTRICAL TRANSPORT AND MAGNETORESISTANCE OF La1.2Sr1.8Mn2O7
Authors: REDDY Y. S. , KISTAIAH P. , VISHNUVARDHAN REDDY C.
Published: February 2009

Polycrystalline samples of double layered (DL) manganite system La 1.2( Sr 1-x Ba x)1.8 Mn 2 O 7(0.0≤×≤0.4) were prepared by the sol-gel method. The anisotropic lattice expansion is observed with the substitution of Ba 2+ into Sr 2+ sites. The electrical resistivity and magnetoresistance (MR) measurements were carried out over the temperature range 4.2 K–300 K. The substitution of Ba results in the suppression of T IM , insulator-to-metal transition temperature. A low temperature upturn of resistivity is seen in all the samples of the system, which is attributed to the spin-glass-like transition. The conduction mechanism above T IM is explained by Mott variable range hopping (VRH) mechanism. The variation of MR with temperature and applied magnetic field is discussed. From the temperature dependent MR curves, it is observed that the large MR values are present over a wide temperature range and the maximum MR values occur at [Formula: see text]. The x=0.4 sample exhibits ~31% of MR with the application of a mere 0.4 T field at 5 K, which accounts for ~35% enhancement of MR of parent compound (~23% of MR% at 0.4 T at 5 K). The MR — H data is fitted to the power law ρ = ρ0-αHn, and it is found that the low temperature MR varies as square root of the applied magnetic field, as expected in conventional metals.
He's ENERGY BALANCE AND He's VARIATIONAL METHODS FOR NONLINEAR OSCILLATIONS IN ENGINEERING
Authors: GANJI S. S. , GANJI D. D. , KARIMPOUR S.
Published: February 2009

In this work, two powerful analytical methods, called Energy Balance Method (EBM) and Variational Approach Solution are applied to various nonlinear oscillators. To assess the accuracy of the solutions, we compare the results with the Exact or other analytical approximation solutions, revealing that both methods are capable of solving effectively a large number of nonlinear differential equations with high accuracy.
APPLICATION OF He's VARIATIONAL ITERATION METHOD AND ADOMIAN'S DECOMPOSITION METHOD TO PROCHHAMMER–CHREE EQUATION
Authors: GANJI D. D. , MIRMOHAMMADSADEGHI S. E. , SAFARI M.
Published: February 2009

In this paper, the He's variational iteration method and Adomian's decomposition method are employed to solve the Prochhammer–Chree equation which include various models. Results derived from the two methods are compared graphically. Figures illustrate that results obtained from both methods are in excellent agreement and show powerful reliability and efficiency of these methods.
ON THE FLUCTUATIONS OF WATER WAVES GOVERNED BY THE CAMASSA–HOLM AND KdV EQUATIONS IN (1+1)-DIMENSION
Authors: MASOUDI A. A. , VASHEGHANI FARAHANI S. , AZADI SAM
Published: February 2009

In this paper, we are planning to consider the fluctuations of two nonlinear equations which govern the dynamics of water waves named Camassa–Holm and KdV. We consider the total number of positive slopes [Formula: see text] produced when the fluctuations of the wave velocity u(x) of a surface wave of a fluid, for example water, is crossed by the level [Formula: see text] in the Camassa–Holm and KdV equations. Here, we just concentrate on the high Reynolds number limit and do the level crossing analysis where υ → 0. In our desired limit, the dissipative term becomes absent or very weak compared to the nonlinear term which is responsible for increasing the amplitude and creating wave steepening, which results in the appearance of shocks. Thus, our analysis works at the times before the appearance of shocks. Our aim in this paper is to show how the quantity, [Formula: see text], counts the fluctuations of the wave velocity in the surface water wave fluctuations which are governed by the KdV and Camassa–Holm (CH) equations.
DEFORMED QUANTUM STATISTICS IN TWO DIMENSIONS
Authors: LAVAGNO A. , NARAYANA SWAMY P.
Published: February 2009

It is known from the early work of May in 1964 that ideal Bose gas do not exhibit condensation phenomenon in two dimensions. On the other hand, it is also known that the thermostatistics arising from q-deformed oscillator algebra has no connection with the spatial dimensions of the system. Our recent work concerns the study of important thermodynamic functions such as the entropy, occupation number, internal energy and specific heat in ordinary three spatial dimensions, where we established that such thermostatistics is developed by consistently replacing the ordinary thermodynamic derivatives by the Jackson derivatives. The thermostatistics of q-deformed bosons and fermions in two spatial dimensions is an unresolved question that is the subject of this investigation. We study the principal thermodynamic functions of both bosons and fermions in the two-dimensional q-deformed formalism and we find that, different from the standard case, the specific heat of q-boson and q-fermion ideal gas, at fixed temperature and number of particles, are no longer identical.
ANALYTICAL APPROACHES FOR SYSTEM OF NONLINEAR EQUATIONS ARISING IN MELTING OF A FINITE SLAB
Authors: VAREDI S. M. , GANJI D. D. , RAJABI M.
Published: February 2009

Most engineering problems, especially heat transfer equations are mostly nonlinear. Variational iteration method (VIM) and homotopy perturbation method (HPM) are useful numerical and analytical methods for solving nonlinear heat transfer equations. Perturbation methods depend on a small parameter, which is difficult to be found for real-life nonlinear problems. To overcome this shortcoming, two newly powerful analytical methods are introduced to solve nonlinear heat transfer problems in our work; one is the VIM and the other one is the HPM. The VIM is to construct correction functionals using general Lagrange multipliers identified optimally via the variational theory, and the initial approximations can be freely chosen with unknown constants. The HPM makes a difficult problem much easier to be evaluated. In this research, these methods are used to solve nonlinear ordinary differential system for melting of a finite slab.
TEMPERATURE AND FIELD DEPENDENT MÖSSBAUER STUDY OF CeSn3andCeSn3.1 CRYSTALS
Authors: SINGHAL R. K. , SÁNCHEZ D. R. , SAITOVITCH ELISA , GAUR S. K. , GARG K. B.
Published: February 2009

Mössbauer spectroscopic measurements have been carried out for CeSn 3 and CeSn 3.1 single crystals in the temperature range 1.5 K to 300 K under applied magnetic field, with an aim to look into the local surroundings of the Sn site and the possibility of magnetization at low temperatures. The spectra indicate a paramagnetic ground state throughout the temperature range with two different doublets associated with two sites S1 and S2. This indicates two crystallographic sites of Sn with the presence of a distortion in the cubic crystal. However, the contribution of S2 site is very small (only 3% for the CeSn 3 but slightly higher, i.e., 4.3% for the CeSn 3.1) at room temperature. Upon cooling (below 4 K), the S2 contribution disappears for the stoichiometric sample ( CeSn 3) but continues to stay for the slightly nonstoichiometric compound ( CeSn 3.1). The isomer shift reveals a Sn 2+ valence state throughout. A weak hyperfine field has been observed only at low temperatures (4.2 and 1.5 K spectra) for both the compounds, but not for the 300 K spectra. This is indicative of some magnetization, i.e., an increase in magnetic moments of Ce atoms, that is felt by the neighbor Sn atoms through RKKY interactions. However, upon cooling the samples from 4.2 K to 1.5 K, no further enhancement in magnetization is observed. The magnetic field was also applied for the CeSn 3 sample at low temperatures to check if there is any enhancement in the magnetic properties that yielded negative results, i.e., the applied field is equal to the hyperfine field, indicating no enhancement of magnetic moment.
YANG–LEE AND FISHER ZEROS GENERALIZED ON SOME FAR-FROM-EQUILIBRIUM SYSTEMS
Authors: SARGSYAN K. G.
Published: February 2009

A generalization of the Yang–Lee and Fisher zeros on far-from-equilibrium systems coupled with two thermal baths is proposed. The Yang–Lee zeros were obtained for minimal models which exhibit complicated behavior in the context of the partition function zeros and provide an analitycal treatment. This type of model may be considered as a simplest one and analogous to Ising model for equilibrium. The obtained distributions of generalized Yang–Lee zeros show nontrivial behavior for these simple models.
ATOMIC POPULATION OSCILLATIONS FOR A BOSE–EINSTEIN CONDENSATE IN A SYMMETRIC THREE-WELL POTENTIAL
Authors: WANG FENGJIAO , YAN XIAOHONG , WANG DENGLONG
Published: February 2009

By developing a three-mode approximation, we derive dynamical equations governing a condensate in a symmetric three-well potential. Based on the dynamical equations, we numerically simulate the dynamical properties of a Bose–Einstein condensate in a symmetric three-well potential. It is shown that, for the zero-phase mode, atomic population in each well oscillates periodically with the amplitude dependent on the initial conditions, and there may exist a critical initial distribution. However, for the π-phase mode, it is possible for the system to exhibit a set of behaviors directly dependent on the ratio between the nonlinearity induced by the atom-atom interactions and the coupling of neighboring wells.
COUPLED NONLINEAR SCHRÖDINGER EQUATIONS FOR SOLITARY-WAVE AND KINK SIGNALS PROPAGATING IN DISCRETE NONLINEAR DISPERSIVE TRANSMISSION LINES
Authors: KENGNE E. , VAILLANCOUR R. , MALOMED B. A.
Published: February 2009

A system of coupled nonlinear Schrödinger (CNLS) equations is derived, starting with a model for an electric LC transmission line, in which nonlinear capacitance C is approximated, as a function of voltage V, by a general truncated expansion, C(V) = C0(1 - αV + βV2 + ⋯). Within the framework of the CNLS equations, we obtain exact solutions for solitary-wave and kink-anti-kink complexes, at specific relations between the XPM and SPM coefficients. The modulational stability of uniform states with constant amplitudes in the framework of the pair of CNLS equations is analyzed too.
IMITATION OF VISUAL ILLUSIONS VIA OPENCV AND CNN
Authors: ITOH MAKOTO , CHUA LEON O.
Published: February 2009

Visual illusion is the fallacious perception of reality or some actually existing object. In this paper, we imitate the mechanism of Ehrenstein illusion, neon color spreading illusion, watercolor illusion, Kanizsa illusion, shifted edges illusion, and hybrid image illusion using the Open Source Computer Vision Library (OpenCV). We also imitate these illusions using Cellular Neural Networks (CNNs). These imitations suggest that some illusions are processed by high-level brain functions. We next apply the morphological gradient operation to anomalous motion illusions. The processed images are classified into two kinds of images, which correspond to the central drift illusion and the peripheral drift illusion, respectively. It demonstrates that the contrast of the colors plays an important role in the anomalous motion illusion. We also imitate the anomalous motion illusions using both OpenCV and CNN. These imitations suggest that some visual illusions may be processed by the illusory movement of animations.
GENERALIZED CELLULAR NEURAL NETWORKS (GCNNs) CONSTRUCTED USING PARTICLE SWARM OPTIMIZATION FOR SPATIO-TEMPORAL EVOLUTIONARY PATTERN IDENTIFICATION
Authors: WEI H. L. , BILLINGS S. A.
Published: February 2009

Particle swarm optimization (PSO) is introduced to implement a new constructive learning algorithm for training generalized cellular neural networks (GCNNs) for the identification of spatio-temporal evolutionary (STE) systems. The basic idea of the new PSO-based learning algorithm is to successively approximate the desired signal by progressively pursuing relevant orthogonal projections. This new algorithm will thus be referred to as the orthogonal projection pursuit (OPP) algorithm, which is in mechanism similar to the conventional projection pursuit approach. A novel two-stage hybrid training scheme is proposed for constructing a parsimonious GCNN model. In the first stage, the orthogonal projection pursuit algorithm is applied to adaptively and successively augment the network, where adjustable parameters of the associated units are optimized using a particle swarm optimizer. The resultant network model produced at the first stage may be redundant. In the second stage, a forward orthogonal regression (FOR) algorithm, aided by mutual information estimation, is applied to refine and improve the initially trained network. The effectiveness and performance of the proposed method is validated by applying the new modeling framework to a spatio-temporal evolutionary system identification problem.
UNCONVENTIONAL INVERTIBLE BEHAVIORS IN REVERSIBLE ONE-DIMENSIONAL CELLULAR AUTOMATA
Authors: MORA JUAN CARLOS SECK TUOH , HERNÁNDEZ MANUEL GONZÁLEZ , MARTÍNEZ GENARO JUÁREZ , VERGARA SERGIO V. CHAPA , McINTOSH HAROLD V.
Published: February 2009

Reversible cellular automata are discrete invertible dynamical systems determined by local interactions among their components. For the one-dimensional case, there are classical references providing a complete characterization based on combinatorial properties. Using these results and the simulation of every automaton by another with neighborhood size 2, this paper describes other types of invertible behaviors embedded in these systems different from the classical one observed in the temporal evolution. In particular, spatial reversibility and diagonal surjectivity are studied, and the generation of macrocells in the evolution space is analyzed.
BISTABILITY AND HYSTERESIS IN SYMMETRIC 3D PIECEWISE LINEAR OSCILLATORS WITH THREE ZONES
Authors: FREIRE EMILIO , PONCE ENRIQUE , ROS JAVIER
Published: February 2009

A degeneration in a two-parameter setting for the focus-center-limit cycle bifurcation of symmetric 3D piecewise linear systems with three zones is studied. The analysis gives a rigorous mathematical explanation for the appearance in piecewise linear oscillators of up to two limit cycles along with a related hysteresis phenomenon.

A piecewise linear oscillator, which is a member of the generic Chua's circuit family, is shown to exhibit bistability, that is, coexistence of stable oscillations with a stable steady state. Also, the corresponding hysteresis in the appearance of periodic oscillations is explained. The analytical results included in the paper predict accurately the observed behavior.
AUTOMATA ON FRACTAL SETS OBSERVED IN HYBRID DYNAMICAL SYSTEMS
Authors: NISHIKAWA JUN , GOHARA KAZUTOSHI
Published: February 2009

We studied a hybrid dynamical system composed of a higher module with discrete dynamics and a lower module with continuous dynamics. Two typical examples of this system were investigated from the viewpoint of dynamical systems. One example is a nonfeedback system whose higher module stochastically switches inputs to the lower module. The dynamics was characterized by attractive and invariant fractal sets with hierarchical clusters addressed by input sequences. The other example is a feedback system whose higher module switches in response to the states of the lower module at regular intervals. This system converged into various switching attractors that correspond to infinite switching manifolds, which define each feedback control rule at the switching point. We showed that the switching attractors in the feedback system are subsets of the fractal sets in the nonfeedback system. The feedback system can be considered an automaton that generates various sequences from the fractal set by choosing the typical switching manifold. We can control this system by adjusting the switching interval to determine the fractal set as a constraint and by adjusting the switching manifold to select the automaton from the fractal set. This mechanism might be the key to developing information processing that is neither too soft nor too rigid.
EFFECTS OF TREND AND PERIODICITY ON THE CORRELATION DIMENSION AND THE LYAPUNOV EXPONENTS
Authors: CECEN AYDIN A. , ERKAL CAHIT
Published: February 2009

We present a critical remark on the pitfalls of calculating the correlation dimension and the largest Lyapunov exponent from time series data when trend and periodicity exist. We consider a special case where a time series Zican be expressed as the sum of two subsystems so that Zi= Xi+ Yiand at least one of the subsystems is deterministic. We show that if the trend and periodicity are not properly removed, correlation dimension and Lyapunov exponent estimations yield misleading results, which can severely compromise the results of diagnostic tests and model identification. We also establish an analytic relationship between the largest Lyapunov exponents of the subsystems and that of the whole system. In addition, the impact of a periodic parameter perturbation on the Lyapunov exponent for the logistic map and the Lorenz system is discussed.
CODIMENSION 3 HETEROCLINIC BIFURCATIONS WITH ORBIT AND INCLINATION FLIPS IN REVERSIBLE SYSTEMS
Authors: XU YANCONG , ZHU DEMING , GENG FENGJIE
Published: February 2009

Heteroclinic bifurcations with orbit-flips and inclination-flips are investigated in a four-dimensional reversible system by using the method originally established in [Zhu, 1998; Zhu & Xia, 1998]. The existence and coexistence of R-symmetric homoclinic orbit and R-symmetric heteroclinic orbit, R-symmetric homoclinic orbit and R-symmetric periodic orbit are obtained. The double R-symmetric homoclinic bifurcation is found, and the continuum of R-symmetric periodic orbits accumulating into a homoclinic orbit is also demonstrated. Moreover, the bifurcation surfaces and the existence regions are given, and the corresponding bifurcation diagrams are drawn.
GLOBAL CHAOS SYNCHRONIZATION OF NONAUTONOMOUS GYROSTAT SYSTEMS VIA VARIABLE SUBSTITUTION CONTROL
Authors: CHEN YUN , WU XIAOFENG
Published: February 2009

This paper suggests a master-slave nonautonomous synchronization scheme with variable substitution control. According to the scheme, some sufficient algebraic criteria for global chaos synchronization of the master and slave nonautonomous gyrostat systems via various single-variable coupling are derived. The effectiveness of the obtained criteria is numerically verified by some examples.
SYNCHRONIZATION OF UNCERTAIN HYPERCHAOTIC AND CHAOTIC SYSTEMS BY ADAPTIVE CONTROL
Authors: LIU ZHI-YU , LIU CHIA-JU , HO MING-CHUNG , HUNG YAO-CHEN , HSU TZU-FANG , JIANG I-MIN
Published: February 2009

This paper presents the synchronization between uncertain hyperchaotic and chaotic systems. Based on Lyapunov stability theory, an adaptive controller is derived to achieve synchronization of hyperchaotic and chaotic systems, including the case of unknown parameters in these two systems. The T.N.Č. hyperchaotic oscillator is used as the master system, and the Rössler system is used as the slave system. Numerical simulations verify these results. Additionally, the effect of noise is investigated by measuring the mean squared error (MSE) of two systems.
BIFURCATION AND STABILITY OF MARTENSITIC TRANSFORMATION DYNAMICS
Authors: JIN LIHUA , HUO YONGZHONG
Published: February 2009

In this paper, we have studied the mathematical properties and their physical implications of a system of nonlinear ordinary differential equations with two variables and six parameters, which was proposed to model the martensitic transformation of shape memory alloys. While the system could not have limit cycles, bifurcation to hysteresis was found in load and/or temperature controlled processes with large enough interfacial energies. This agrees qualitatively quite well with the experimental observation and theoretical understandings of the stress-strain-temperature hysteresis of the alloys. A three-dimensional bifurcation diagram was identified. Nonhyperbolic equilibrium points were found as saddle nodes and high order node points. The local behavior was studied and the phase portrait of the system was obtained for the load and temperature parameters. Accordingly, a stable node represents the stable martensitic or austenitic phase, a saddle stands for the unstable phase mixture, and a saddle node corresponds to the beginning or the end of the transformation. Therefore, for a thermal-mechanical loading path, the martensitic transformation process accords with the qualitative changes of the equilibrium points.
LYAPUNOV SPECTRA OF COUPLED CHAOTIC MAPS
Authors: LI XIAOWEN , XUE YU , SHI PENGLIANG , HU GANG
Published: February 2009

Largest Lyapunov exponents and Lyapunov spectra of desynchronous coupled chaotic maps with finite coupling strength are investigated by considering different map functions. For sufficiently large system size there exists a parameter region where the largest Lyapunov exponents are independent of system size and coupling strength. This parameter region is called the scaling region. Some scaling exponent and scaling function in the distribution of Lyapunov spectra are found. These scaling behaviors are model independent. All the above numerical observations are explained, based on heuristic physical understanding of the competition of intensity of chaoticity, and strength of coupling, and on an analogy of the discrete coupled maps with continuous extended systems.