Showing papers on "Sorting published in 2002"

A fast and elitist multiobjective genetic algorithm: NSGA-II

Abstract: Multi-objective evolutionary algorithms (MOEAs) that use non-dominated sorting and sharing have been criticized mainly for: (1) their O(MN/sup 3/) computational complexity (where M is the number of objectives and N is the population size); (2) their non-elitism approach; and (3) the need to specify a sharing parameter. In this paper, we suggest a non-dominated sorting-based MOEA, called NSGA-II (Non-dominated Sorting Genetic Algorithm II), which alleviates all of the above three difficulties. Specifically, a fast non-dominated sorting approach with O(MN/sup 2/) computational complexity is presented. Also, a selection operator is presented that creates a mating pool by combining the parent and offspring populations and selecting the best N solutions (with respect to fitness and spread). Simulation results on difficult test problems show that NSGA-II is able, for most problems, to find a much better spread of solutions and better convergence near the true Pareto-optimal front compared to the Pareto-archived evolution strategy and the strength-Pareto evolutionary algorithm - two other elitist MOEAs that pay special attention to creating a diverse Pareto-optimal front. Moreover, we modify the definition of dominance in order to solve constrained multi-objective problems efficiently. Simulation results of the constrained NSGA-II on a number of test problems, including a five-objective, seven-constraint nonlinear problem, are compared with another constrained multi-objective optimizer, and the much better performance of NSGA-II is observed.

Receptor downregulation and multivesicular-body sorting

Abstract: The sorting of proteins into the inner vesicles of multivesicular bodies is required for many key cellular processes, which range from the downregulation of activated signalling receptors to the proper stimulation of the immune response. Recent advances in our understanding of the multivesicular-body sorting pathway have resulted from the identification of ubiquitin as a signal for the efficient sorting of proteins into this transport route, and from the discovery of components of the sorting and regulatory machinery that directs this complex process.

Extensive feature detection of N-terminal protein sorting signals.

Abstract: Motivation: The prediction of localization sites of various proteins is an important and challenging problem in the field of molecular biology. TargetP, by Emanuelsson et al. (J. Mol. Biol., 300, 1005‐1016, 2000) is a neural network based system which is currently the best predictor in the literature for N-terminal sorting signals. One drawback of neural networks, however, is that it is generally difficult to understand and interpret how and why they make such predictions. In this paper, we aim to generate simple and interpretable rules as predictors, and still achieve a practical prediction accuracy. We adopt an approach which consists of an extensive search for simple rules and various attributes which is partially guided by human intuition. Results: We have succeeded in finding rules whose prediction accuracies come close to that of TargetP, while still retaining a very simple and interpretable form. We also discuss and interpret the discovered rules. Availability: An (experimental) web service using rules obtained by our method is provided at http:

Fast two-dimensional phase-unwrapping algorithm based on sorting by reliability following a noncontinuous path.

Abstract: We describe what is to our knowledge a novel technique for phase unwrapping. Several algorithms based on unwrapping the most-reliable pixels first have been proposed. These were restricted to continuous paths and were subject to difficulties in defining a starting pixel. The technique described here uses a different type of reliability function and does not follow a continuous path to perform the unwrapping operation. The technique is explained in detail and illustrated with a number of examples.

Efficient C4.5 [classification algorithm]

Abstract: We present an analytic evaluation of the runtime behavior of the C4.5 algorithm which highlights some efficiency improvements. Based on the analytic evaluation, we have implemented a more efficient version of the algorithm, called EC4.5. It improves on C4.5 by adopting the best among three strategies for computing the information gain of continuous attributes. All the strategies adopt a binary search of the threshold in the whole training set starting from the local threshold computed at a node. The first strategy computes the local threshold using the algorithm of C4.5, which, in particular, sorts cases by means of the quicksort method. The second strategy also uses the algorithm of C4.5, but adopts a counting sort method. The third strategy calculates the local threshold using a main-memory version of the RainForest algorithm, which does not need sorting. Our implementation computes the same decision trees as C4.5 with a performance gain of up to five times.

Nondominated Sorting Genetic Algorithm for Optimal Phasor Maesurement Placement

Abstract: This paper considers a phasor measurement unit (PMU) placement problem requiring simultaneous optimization of two conflicting objectives, such as minimization of the number of PMUs and maximization of the measurement redundancy. The objectives are in conflict, for the improvement of one of them leads to deterioration of another. Consequently, instead of a unique optimal solution, there exists a set of the best trade-offs between competing objectives, the so-called Pareto-optimal solutions. A specially tailored nondominated sorting genetic algorithm (NSGA) for the PMU placement problem is proposed as a methodology to find these Pareto-optimal solutions. The algorithm is combined with the graph-theoretical procedure and a simple GA to reduce the initial number of the PMU candidate locations. The NSGA parameters are carefully set by performing a number of trial runs and evaluating the NSGA performances based on the number of distinct Pareto-optimal solutions found in the particular run and the distance of the obtained Pareto front from the optimal one. Illustrative results on the 39-bus and 118-bus IEEE systems are presented.

Development of a microfluidic device for fluorescence activated cell sorting

Abstract: This paper describes the development towards a miniaturized analytical system that can perform the major key functions of a flow cytometer. The development aims at diagnostic applications for cell counting and sorting with the ultimate goal of a low-cost portable instrument for point of care diagnosis. The present systems configuration consists of a disposable microfluidic device, that enables injection, single file cell flow through a miniaturized laser induced fluorescence detection system as well as sorting of identified samples. The microfluidic devices were fabricated by means of rapid prototyping technologies based on thick film photo-polymers. This paper reports various approaches on cell sorting and demonstrates sorting of single cells by means of an off-chip valve switching technique. The miniaturized fluorescence detection system employs active and passive micro-optical components, including semiconductor laser and ultra bright LED sources, highly sensitive avalanche photodiodes as well as micro-prism, holographic diffraction gratings and fibre optics for transmission and collection of light. Furthermore we demonstrate the feasibility of integrating solid-state components as part of an on-chip detection system.

Method, apparatus and article for verifying card games, such as playing card distribution

Abstract: One or more actual hands of playing cards are verified against respective expected hands of playing cards, to determine whether the playing cards actually dealt correspond to the playing cards that should have been dealt based on a starting sequence of playing card values. The starting sequence of playing card values can be computationally pseudo-randomly generated, where playing cards will be ordered, for example by printing or sorting, according to the sequence for distribution to the player and/or dealer. The starting sequence of playing card values can be determined by reading identifiers from a number of playing cards prior to dealing.

Improved Ant-Based Clustering and Sorting in a Document Retrieval Interface

Abstract: Sorting and clustering methods inspired by the behavior of real ants are among the earliest methods in ant-based meta-heuristics. We revisit these methods in the context of a concrete application and introduce some modifications that yield significant improvements in terms of both quality and efficiency. Firstly, we re-examine their capability to simultaneously perform a combination of clustering and multi-dimensional scaling. In contrast to the assumptions made in earlier literature, our results suggest that these algorithms perform scaling only to a very limited degree. We show how to improve on this by some modifications of the algorithm and a hybridization with a simple pre-processing phase. Secondly, we discuss how the time-complexity of these algorithms can be improved. The improved algorithms are used as the core mechanism in a visual document retrieval system for world-wide web searches.

Q-sorting and MIS Research: A Primer

Abstract: Q-sort offers a powerful, theoretically grounded, and quantitative tool for examining opinions and attitudes. This article provides clear guidelines in an effort to facilitate successful understanding and application of Q-sort. Following a description of the steps of Q-sorting, an example Q-sort of MIS professors on the topic of PhD preparation is presented. The example includes details of Web-based data collection and data analysis using freeware tools. The use of Q-sorting in MIS research and issues surrounding the use of Q-sort are discussed.

1.375-Approximation Algorithm for Sorting by Reversals

Abstract: Analysis of genomes evolving by inversions leads to a general combinatorial problem of Sorting by Reversals, MIN-SBR, the problem of sorting a permutation by a minimum number of reversals. Following a series of preliminary results, Hannenhalli and Pevzner developed the first exact polynomial time algorithm for the problem of sorting signed permutations by reversals, and a polynomial time algorithm for a special case of unsigned permutations. The best known approximation algorithm for MIN-SBR, due to Christie, gives a performance ratio of 1.5. In this paper, by exploiting the polynomial time algorithm for sorting signed permutations and by developing a new approximation algorithm for maximum cycle decomposition of breakpoint graphs, we design a new 1.375-algorithm for the MIN-SBR problem.

Vortex tracking in scale-space

Abstract: Scale-space techniques have become popular in computer vision for their capability to access the multiscale information inherently contained in images. We show that the field of flow visualization can benefit from these techniques, too, yielding more coherent features and sorting out numerical artifacts as well as irrelevant large-scale features. We describe an implementation of scale-space computation using finite elements and show that performance is sufficient for computing a scale-space of time-dependent CFD data. Feature tracking, if available, allows to process the information provided by scale-space not just visually but also algorithmically. We present a technique for extending a class of feature extraction schemes by an additional dimension, resulting in an efficient solution of the tracking problem.

BP-80 as a vacuolar sorting receptor.

Abstract: In eucaryotic cells, soluble proteins are selected via multiple sorting processes from their site of synthesis to their proper destination. The general idea that sorting or targeting signals dictate the dynamics of transport within a plant cell is well established. Signalmediated transport, as opposed to transport by a default process, has been extensively reviewed (Mellman and Warren, 2000). In the latter case, a soluble protein lacking any signal will remain at its site of synthesis, the cytoplasm. In contrast, soluble proteins with a signal peptide enter the secretory pathway at the level of the endoplasmic reticulum. From there, a protein with no additional sorting information is transported downstream the pathway by a ‘bulk flow’ process and is finally secreted out of the cell. Retention or sorting signals are therefore required for soluble proteins to be diverted from secretion. The corresponding signals described so far in plants are peptidic in nature and the best studied examples are located to either protein extremity. The objective of this paper is to detail an example of signal-mediated transport in plant cells that leads soluble proteins to the vacuolar system. More precisely, the recognition step of a vacuolar-sorting signal from aleurain by a specific receptor, BP-80 for binding protein of 80 kDa, will be discussed. BP-80 is a type I membrane pea protein involved in sorting and targeting aleurain from the trans-Golgi to the lytic type of vacuoles in plants (Paris et al., 1997; Humair et al., 2001). It is clear that the recognition by the receptor of the vacuolar signal carried by a soluble protein is critical for vacuolar transport. The approaches to investigate this key protein-protein interaction will be described and compared. Finally, BP-80 belongs to a large family of proteins with functions so far unclear. The latest accessible data on these variants will be summarized in order to draw an update on the knowledge in vacuolar targeting.

Interactive light-driven and parallel manipulation of inhomogeneous particles

Abstract: A light-driven micromanipulation system with real-time userfeedback control is used to simultaneously trap colloidal suspensions enabling a unique interactive sorting capability and arbitrary patterning of microscopic particles The technique is based on a straightforward phase-tointensity conversion generating multiple beam patterns for manipulation of particles in the observation plane of a microscope Encoding of phase patterns in a spatial light modulator, which is directly controlled by a computer, allows for dynamic reconfiguration of the trapping patterns, where independent control of the position, size, shape and intensity of each beam is possible Efficient sorting of microsphere mixtures of distinct sizes and colors using multiple optical traps is demonstrated

Discrete event simulator

Abstract: A system and method for the simulation of discrete events. Events can be defined or mapped from Boolean logic, finite equations, lookup tables, emulation of processors, or may be algebraic in nature. An event-based simulation scheme with single-memory word representation of event models and timing is described. Event models are instantiated in parallel simulator engines (logic, behavioral, soft-emulation, memory, processor, interconnection, and/or any combination of these). A central scheduler minimizes computation time traditionally spent on sorting chronology and sequence of events as the events propagate through models and interconnections or links, with the scheduler interfaced to each engine via dedicated pipelined communications channels. The scheduler simultaneously serves pending events to simulation engines for evaluation and retrieves future events from these engines for sorting and resubmitting for further simulation. The simulator scheduler addresses simulator cycle time management, sub-cycle event handling (new pending events), and the recording of results. The capacity of simulator preferably exceeds multi-millions of models and the computational speed approaches multi-millions of events per second.

Navigation method and system for extracting, sorting and displaying POI information

Abstract: A navigation method and system for extracting point of interest (POI) data from a map data source and sorting the POIs by distance from a current user position to display the same at high speed without requiring a large memory. The navigation system aligns the cells each having specified POI in an cell array and classifies the cells into a plurality of different levels based on[, for example, a] distance (first sorting operation) from the current user position, or positions of the cells in the cell array relative to the cell closest to the user position. The navigation system extracts the POIs from the cells in the specified level, sorts the POIs by distance (second sorting operation), and displays the POIs. During each process, the navigation system retrieves and processes only a small amount of POIs sufficient for the current display screen and immediate scrolls of few pages.

Efficient evaluation of continuous range queries on moving objects

Abstract: In this paper we evaluate several in-memory algorithms for efficient and scalable processing of continuous range queries over collections of moving objects. Constant updates to the index are avoided by query indexing. No constraints are imposed on the speed or path of moving objects. We present a detailed analysis of a grid approach which shows the best results for both skewed and uniform data. A sorting based optimization is developed for significantly improving the cache hit ratio. Experimental evaluation establishes that indexing queries using the Grid index yields orders of magnitude better performance than other index structures such as R*-trees.

Method for sorting integrated circuit devices

Abstract: A method for sorting integrated circuit (IC) devices of the type having a substantially unique identification (ID) code, such as a fuse ID, including automatically reading the ID code of each of the IC devices and sorting the IC devices in accordance with their automatically read ID codes, is disclosed.

Monitoring and control of droplet sorting

Abstract: Methods, systems and apparatus are provided for sorting particles in a stream of a sample in a flow cytometer by producing from a stable sort having desirable sort characteristics multiple images of a portion of the stream; generating from the multiple images an averaged numerical reference standard representative of the stable sort; continuously collecting during the sorting multiple running images of the portion of the stream; generating from the multiple running images at least one numerical sample average representative of the sample sort of each collection of the multiple running images; and comparing each numerical sample average to the numerical reference standard and determining whether a sample average exhibits a deviation from the reference standard that requires an adjustment of the sort. The sort may then be adjusted to eliminate or reduce the deviation and maintain the stable sort of the reference histogram. A novel imaging apparatus may be employed in a flow cytometer performing this method.

Fitness Landscapes Based on Sorting and Shortest Paths Problems

Abstract: The analysis of evolutionary algorithms is up to now limited to special classes of functions and fitness landscapes. It is not possible to describe those subproblems of NP-hard optimization problems where certain evolutionary algorithms work in polynomial time. Therefore, fitness landscapes based on important computer science problems as sorting and shortest paths problems are investigated here. Although it cannot be expected that evolutionary algorithms outperform the well-known problem specific algorithms on these simple problems, it is interesting to analyze how evolutionary algorithms work on these fitness landscapes which are based on practical problems. The following results are obtained: - Sorting is the maximization of "sortedness" which is measured by one of several well-known measures of presortedness. The different measures of presortedness lead to fitness landscapes of quite different difficulty for EAs. - Shortest paths problems are hard for all types of EA, if they are considered as single-objective optimization problems, while they are easy as multi-objective optimization problems.

Efficient Evaluation of Continuous Range Queries on Moving Objects

Abstract: In this paper we evaluate several in-memory algorithms for efficient and scalable processing of continuous range queries over collections of moving objects. Constant updates to the index are avoided by query indexing. No constraints are imposed on the speed or path of moving objects. We present a detailed analysis of a grid approach which shows the best results for both skewed and uniform data. A sorting based optimization is developed for significantly improving the cache hit ratio. Experimental evaluation establishes that indexing queries using the Grid index yields orders of magnitude better performance than other index structures such as R*-trees.

Cache Oblivious Distribution Sweeping

Abstract: We adapt the distribution sweepingmetho d to the cache oblivious model. Distribution sweepingis the name used for a general approach for divide-and-conquer algorithms where the combination of solved subproblems can be viewed as a merging process of streams. We demonstrate by a series of algorithms for specific problems the feasibility of the method in a cache oblivious setting. The problems all come from computational geometry, and are: orthogonal line segment intersection reporting, the all nearest neighbors problem, the 3D maxima problem, computingthe measure of a set of axis-parallel rectangles, computingthe visibility of a set of line segments from a point, batched orthogonal range queries, and reportingpairwise intersections of axis-parallel rectangles. Our basic buildingblo ck is a simplified version of the cache oblivious sorting algorithm Funnelsort of Frigo et al., which is of independent interest.

Multiobjective Optimization of Industrial FCC Units Using Elitist Nondominated Sorting Genetic Algorithm

Abstract: This study provides insights into the optimal operation of the fluidized-bed catalytic cracking unit (FCCU). A five-lump model is used to characterize the feed and the products. The model is tuned using industrial data. The elitist nondominated sorting genetic algorithm (NSGA-II) is used to solve a three-objective function optimization problem. The objective functions used are maximization of the gasoline yield, minimization of the air flow rate, and minimization of the percent CO in the flue gas using a fixed feed (gas oil) flow rate. The decision variables and several important state variables corresponding to the optimal conditions of operation are obtained. The optimal solutions correspond to the unstable, saddle-kind, middle steady states. The procedure used is quite general and can be applied to other industrial FCCUs. The optimal results obtained here provide physical insights that can help one in obtaining and interpreting such solutions.

Synchronous semi-automatic parallel sorting

Abstract: The present invention reveals a sorting system for use in manual sorting, which presents a detached ephemeral display moving in a manner corresponding to the movement of the article, by which an article to be sorted can be quickly and easily identified. To accomplish its purpose, the device comprises: feed conveyors; a switching unit; optical readers positioned to capture destination indicia affixed to each article; a detached moving display which remains close to the article to be sorted and presents information representative of the article's destination location; a destination location which signals when a related article is approaching; and a controller capable of assigning destination locations and controlling display devices.

Image generation method and device used therefor

Abstract: The present invention ensures that object images to be subjected to a predetermined image processing are subjected to such image processing depending on predetermined coefficients of semi-transparency, and that a portion of the object images closest to a virtual viewpoint is processed last. This successfully provides an image based on a first image processing (α-blending, for example) depending on coefficients of semi-transparency in a natural and unfailing manner without using a technique such as Z sorting.