Cavitation inception in the near field of turbulent shear layers occurs along secondary quasi-streamwise vortices developing between the primary spanwise vortices. To observe these incepting structures and understand the flow conditions under which they form, the present paper compares the flow statistics to results of high speed imaging performed in the shear layer behind a backward facing step. Simultaneous top and side imaging captures the location and spatial arrangement of the cavitating structures at varying cavitation indices. Two-dimensional PIV measurements characterize the mean velocity and Reynolds stress profiles, for Reynolds numbers in the separating boundary layer of Re τ = 807, 1504, 2345. Being concentrated within the quasi-streamwise strings, the cavitation events are preferentially located in the near field of the shear layer, where the unsteady flow is dominated by coherent structures, upstream of the peaks in turbulence level. They move more upstream with increasing Re and decreasing pressure. Furthermore, the probability of cavitation increases by 3-5 times when the velocity is increased from 10.5 to 16 m/s. These indicate that the pressure fluctuation peaks causing the cavitation do not follow the same trends as the Reynolds stresses which collapse when scaled by the freestream velocity.

Class variables are alternately called category, text, nominal, or string variables. They do not have numerical values. They are items or choices. For instance, “Which is better: a car, a motorcycle, or an airplane?” Here the DV is a method of transportation, and the assessment of best could be related to fuel and insurance cost, joy of travel, number of friends you can bring, operator training cost, speed of transportation, parking upon arrival, etc. The decision variable, the list of items, does not have a common, quantifiable metric (either continuum-valued or discretized) that defines the OF. In size, the airplane is largest and motorcycle smallest, but this aspect is not what defines the OF. The motorcycle might accelerate the fastest, and the car carries the most luggage per passenger, but, again, these are consequences of the DV.

Most engineering or science models provide a continuous-valued, deterministic response. These could either represent steady-state or transient phenomena. In contrast, models could predict a classification (nominal, class, text, or string variable) or a rank, but still a deterministic value. Alternately, Monte Carlo simulations predict a stochastic outcome, a range of possibilities, not a definitive value. There are diverse options to what you may be seeking to best fit, and you need to understand the application to choose the regression target.

The rod pump oil extraction is applied the most commonly machinery extraction method in the horizontal well. However, there is a big degree of tilt and the dog-leg, underground sucker rod string off-center wear accidents often occur, causes the sucker rod string to break away or the drill tubing breakage finally. This article based on the actual bore hole path establishment horizontal well sucker-rod string's three-dimensional model, carries on the transient state dynamics simulation analysis by using the ANSYS finite element software, and predict offcenter wear position of bar tube, through exerts the centralizer in the off-center wear region to optimize the pole combination, achieves the goal which reduce off-center wear of pole tube, Simultaneously established a set of numerical simulation method which is used for forecasting off-center wear position of the sucker rod and bar tube in horizontal well.

This Paper presents an integrated LED driver with boost converter designed with standard CMOS technology considering Lithium-Ion battery used to drive LED strings that provides overall maximum efficiency of 85% and current error accuracy of 0.0046%. The boost converter operates in PWM voltage mode at 600kHz with stable output voltage as a voltage source to LED driver. A dimmable LED driver with a dimming frequency up to 10MHz is implemented for the application of constant current driving capability for LED displays and LCD backlighting that is used in many portable devices with advanced video and image processing operating at low voltage. A current balance circuit is applied having two or three channels that act as a constant current source for the series connection of LED strings and also used to control the amount of driving current for regulating the constant light luminance of LEDs. The design is simulated with tsmc 0.351m process with an effective layout area of 2.279967 1 2.39105mm2 and a power consumption lower than 1W.

This research is mainly about detecting and preventing plagiarism among students. It provides the capability to detect similarities between documents submitted by students. The main focus of this research is to perform a study on how to detect textual plagiarism. Textual plagiarism is the most noticeable and serious form of plagiarism. This form of plagiarism can be categorized as a form of direct stealing without proper acknowledgment and consent of other's work. Rabin - Karp Algorithm which is a string searching algorithm that uses hashing to compare the strings will be use in detecting the similarities among the files. As a result, the developed application is able to make comparison in order to find for the similarities among them. The percentage of similarities will then be generated in a text format for reference.

The paper presents an improved algorithm based on suffix array for string matching. In paper, by utilizing a generalized algorithm, called DC3, that allows a space-efficient implementation and, moreover, supports the choice of a space-time tradeoff, we get the suffix array in linear time. Meanwhile, in order to reduce matching time, the new algorithm improves the search conditions in the process of accurate string matching and filters the suffix strings which do not meet the conditions to reduce the times of the character comparison. Comparing the improved algorithm with the original one, the experiment results show that the new algorithm saves query time and increases matching efficiency on the condition of increasing space complexity properly.

Given a collection of strings S = { s 1 , … , s n } over an alphabet Σ , a superstring s of S is a string containing each s i as a substring; that is, for each i , 1 < i < n , s contains a block of | s i | consecutive characters that match s i exactly. The shortest superstring problem is the problem of finding a superstring s of minimum length. This problem is NP- hard and has applications in computational biology and data compression. In this paper, we characterize the shortest superstring as a Hamiltonian path in a directed graph, and introduce an efficient (polynomial time) approach for it.

This study builds on previous work that classifies evolutionary computation problems via graph-based taxonomic techniques. A new collection of graphs that permit the measurement of small population effects are employed as well as a new distance measure that incorporates information on the variability of problem hardness into the taxonomic process. The new set of graphs and improved distance measure on problems are tested on a diverse set of string-based optimization problems including two new types of problems: fragmentation and K-max. The familiar SAW, one-max, and royal road problems are also included. It is found that problem difficulty, although explicitly removed from the information used to classify the problems, is nevertheless detected by the taxonomic technique. The problems appearing in earlier studies are shown to retain their diversity of behavior, confirming that the improvements to the problem classification system did not degrade a valuable feature of the earlier system.