Pseudo Scale Research Articles

Species composition of coniferous plant pests in urban landscapes of the Krasnodar Territory

The results of the studies of conifers as a material for landscaping of settlements, and as an accent and dominant in decorative compositions or in mono-planting are presented. The expansion of coniferous plant assortment for landscape construction of southern Russia in the 2000s was noted due to the introduction of crops from other regions with different natural and climatic conditions. Newly planted crops are under stress, which has a negative effect on the immune status of the introduced plants. The results of the study of the species composition of sucking pests of coniferous plants in urban landscapes are presented. The world experience in the studies of urban landscapes shows the expansion of the species composition of pests from the order of homopterous insects (Homoptera). Phytosanitary monitoring of ornamental conifers in urban plantations and park areas in the Kuban zone of the central horticultural subzone of the Krasnodar Territory in 2012-2022 was conducted. As a result of these studies, the species diversity of sucking pests of coniferous plants in the region has been identified, their ranking by the type of feeding has been carried out, and a database is being compiled. It has been found that the dominant representatives of the superfamily Coccidae in the region are: European juniper scale insect (Carulaspis juniperi Bouché) and yew pseudo scale insect (Parthenolecanium pomeranicum Kawecki), and pine spindle scale insect (Anamaspis lowi Colvee). The regularities of food specialization of scales are of not only theoretical but also practical importance. Based on the research, the probable composition of pests on a newly introduced crop can be predicted. The resulting patterns are one of the theoretical foundations of pest control measures.

Curvature perturbation and domain wall formation with pseudo scaling scalar dynamics

Cosmological dynamics of scalar field with a monomial potential ϕn with a general background equation of state is revisited. It is known that if n is smaller than a critical value, the scalar field exhibits a coherent oscillation and if n is larger it obeys a scaling solution without oscillation. We study in detail the case where n is equal to the critical value, and find a peculiar scalar dynamics which is neither oscillating nor scaling solution, and we call it a pseudo scaling solution. We also discuss cosmological implications of a pseudo scaling scalar dynamics, such as the curvature perturbation and the domain wall problem.

A security constrained environmental/economic power dispatch technique using F-MSG algorithm for a power system area including limited energy supply thermal units

A security constrained non-convex environmental/economic power dispatch problem for a lossy electric power system area including limited energy supply thermal units is formulated. An iterative solution method based on modified subgradient algorithm operating on feasible values (F-MSG) and a common pseudo scaling factor for limited energy supply thermal units are used to solve it. In the proposed solution method, the F-MSG algorithm is used to solve the dispatch problem of each subinterval, while the common pseudo scaling factor is employed to adjust the amount of fuel spent by the limited energy supply thermal units during the considered operation period. We assume that limited energy supply thermal units are fueled under take-or-pay (T-O-P) agreement.The proposed dispatch technique is demonstrated on IEEE 30-bus power system with six thermal generating units having non-convex cost rate functions. Two of the generating units are selected as gas-fired limited energy supply thermal units. Pareto optimal solutions for the power system, where the constraint on the amount of fuel consumed by the limited energy supply thermal units is not considered, are calculated first. Later on, the same Pareto optimal solutions for the power system, where the fuel constraint is considered, are recalculated, and the obtained savings in the sum of optimal total fuel cost and total emission cost are presented. The dispatch problem of the first subinterval of the test system was solved previously by means of differential evolution (DE), and a hybrid method based on combination of DE and biogeography based optimization (BBO) for the best cost and the best emission cases in the literature. The results produced by these methods are compared with those of produced by the proposed method in terms of their total cost rate, emission rate and solution time values. It is demonstrated that the proposed method outperforms against the evolutionary methods mentioned in the above in terms of solution time values especially when the exact model of the test system is considered.

A Security-constrained Economic Power Dispatch Technique Using Modified Subgradient Algorithm Based on Feasible Values and Pseudo Scaling Factor for a Power System Area Including Limited Energy Supply Thermal Units

A security-constrained power dispatch problem with non-convex cost function for a lossy electric power system area including limited energy supply thermal units fueled under a take-or-pay agreement is formulated. Then, an iterative solution method based on a modified subgradient algorithm based on feasible values and common pseudo scaling factor for limited energy supply thermal units is proposed and used to solve the problem. In the iterative proposed solution method, a modified subgradient algorithm based on feasible values is used to solve the dispatch problem in each subinterval, while the common pseudo scaling factor for limited energy supply thermal units is employed to adjust the amount of fuel consumed by the limited energy supply units during the considered operation period. Since all equality and inequality constraints in the non-linear optimization model of a subinterval are functions of bus voltage magnitudes and phase angles (the off-nominal tap settings), they are taken as independent variables except for those belonging to the reference bus. Load flow equations are added to the model as equality constraints. The unit generation constraints, transmission line capacity constraints, bus voltage magnitude constraints, and off-nominal tap setting constraints are added into the optimization problem as inequality constraints. Since the modified subgradient algorithm based on feasible values requires that all inequality constraints should be expressed in equality constraint form, all inequality constraints are converted into equality constraints by the method given in this article before application of the modified subgradient algorithm based on feasible values to the optimization model. The proposed technique is tested on an IEEE 30-bus test system with a non-convex total cost rate curve. A portion of the dispatch problem considered in this article, where only a loading of the system in a subinterval is considered, was also solved by some other recently reported dispatch techniques. First, minimum total fuel cost rates and solution times obtained from the modified subgradient algorithm based on feasible values versus other techniques are compared, and the outperformance of the modified subgradient algorithm based on feasible values in terms of both total cost rate and solution time is demonstrated. After that, the optimal total fuel cost value and solution time of the system for the operation period for the cases where the fuel constraint is ignored and not ignored are presented, and it is shown that adding the fuel constraint into the dispatch problem further decreases the optimal total fuel cost for the considered dispatch problem. Finally, the modified subgradient algorithm based on feasible values was applied to the fuel constrained dispatch problem directly. It is demonstrated that the proposed solution method, where the modified subgradient algorithm based on feasible values is employed to solve an interval's dispatch problem, gives a solution time that is smaller than that obtained from the direct application of the modified subgradient algorithm based on feasible values to the dispatch problem.

Multifractality in TCP/IP traffic: the case against

The discovery of long-range dependence (a kind of asymptotic fractal scaling) in packet data from LANs and WANs, was followed by further work detailing evidence for multifractal behaviour in TCP/IP traffic in WANs. In terms of networking however, physical mechanisms for such behaviour have never been convincingly demonstrated, leaving open the question of whether multifractal traffic models are of black box type, or alternatively if there is anything ‘real’ behind them. In this paper we review the evidence for multifractal behaviour of aggregate TCP traffic, and show that in many ways it is weak. Our study includes classic traces and very recent ones. We point out misunderstandings in the literature concerning the scales over which multifractality has been claimed. We explain other pitfalls which have led to the multifractal case being overstated, in particular the possibility of ‘pseudo scaling’ being confused with true scaling, due to shortcomings in the statistical tools. We argue for an alternative point process model with strong physical meaning. It reproduces the higher order statistics of the data well, despite not being calibrated for them, yet is not multifractal. From its standpoint, the empirical multifractal behaviour is seen as a misinterpretation due to a lack of power in the statistical methodology.

Pseudo-scaling and multifractality

Random systems with stretched (and fluctuating) exponential form of probability density functions (PDFs), such as turbulence (distribution of velocity differences) and percolation (visiting frequency in percolative diffusion), are studied. Dimensionless moments are defined as F np ( r) = ƒ p / ƒ n p/ n , where ƒ p ( r) is the standard moments of order p ( p > n). Pseudo-scaling (PS) is defined as existence of power relationships F np ∼ F nq ρ , where exponent ρ npq depends on p, q and n. It is shown that for large enough n, p, q, the PS takes place even if the ordinary scaling is broken. It is shown that there are two kinds of the asymptotical pseudo-scaling: with ρ npq = ( p− n)/( q− n) and with ρ npq = ( p/ q) [ln( p/ n)/(ln( q/ n)]. If ordinary scaling also takes place in the systems then these two kinds of the pseudo-scaling lead to two kinds of corresponding ordinary scaling laws. A speculation concerning genesis of the stretched exponential PDFs is briefly discussed. Phase transition from random fractal structures to homogeneity is studied in the framework of the pseudo-scaling approach and it is shown that multifractality of passive scalar concentration has the pseudo-scaling form of the second kind near the transition (whereas for systems far from the transition the multifractality has the pseudo-scaling form of the first kind). The condition of compatibility of the pseudo-scaling and of the generalized dimension approaches is also investigated. Agreement between the theoretical results and experimental data of different authors is established both for the situations where ordinary scaling takes place and for situations where ordinary scaling does not take place.

Pseudo-scaling in laboratory and in numerical simulations of turbulence

Stochastic systems with a stretched exponential form of probability density function (turbulence etc) are studied. A dimensionless moments is defined as , where is the standard moment of order p (p > n). Pseudo-scaling (PS) is defined as the existence of power relationships , where exponent depends on p,q and n. The scaling is purely due to the way the given quantities are constructed and to the existence of the stretched exponential decay of the probability density functions. It is shown that for large enough n,p,q the pseudo-scaling takes place even if the ordinary scaling is broken. It is shown that there are two kinds of asymptotic pseudo-scaling: with and with . If ordinary scaling also takes place in the system, then these two kinds of pseudo-scaling lead to two kinds of corresponding ordinary scaling laws. Agreement between the theoretical approach and experimental results of different authors is established for turbulent systems (laboratory and numerical simulations), both for situations where ordinary scaling takes place and for situations where ordinary scaling does not take place.

Nickel Oxide Scales and Sodium Sulfate-Induced Hot Corrosion of Nickel

Abstract The protection that a nickel oxide scale gives nickel metal against sodium sulfate induced hot corrosion is investigated in this research. The failure of a scale to protect the metal is attributed to infiltration, rather than dissolution, of the by molten salt along cracks and pores. The addition of chromium, chromium sesquioxide, or chromate ions to the sodium sulfate could not be shown to inhibit corrosion in spite of the fact that the chromium content of nickel base alloys is known to enhance their hot corrosion resistance. These results are consistent with a pseudo scale model of sodium sulfate induced hot corrosion for nickel base alloys rather than an acid base model. The addition of molybdenum, tungsten, or their oxidation products to sodium sulfate was found to increase the rate of corrosion. This increase is ascribed to an increase in the rate of infiltration of the scale by the molten salt as the result of an increase in the size or number of defects, which is also consistent with the p...