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Sample records for class packing problem

  1. Heuristics for Multidimensional Packing Problems

    DEFF Research Database (Denmark)

    Egeblad, Jens

    In this thesis we consider solution methods for packing problems. Packing problems occur in many different situations both directly in the industry and as sub-problems of other problems. High-quality solutions for problems in the industrial sector may be able to reduce transportation and production...... costs significantly. For packing problems in general are given a set of items and one of more containers. The items must be placed within the container such that some objective is optimized and the items do not overlap. Items and container may be rectangular or irregular (e.g. polygons and polyhedra...... methods. Two important problem variants are the knapsack packing problem and the strip-packing problem. In the knapsack packing problem, each item is given a profit value, and the problem asks for the subset with maximal profit that can be placed within one container. The strip-packing problem asks...

  2. Heuristics for Multidimensional Packing Problems

    DEFF Research Database (Denmark)

    Egeblad, Jens

    In this thesis we consider solution methods for packing problems. Packing problems occur in many different situations both directly in the industry and as sub-problems of other problems. High-quality solutions for problems in the industrial sector may be able to reduce transportation and production...... costs significantly. For packing problems in general are given a set of items and one of more containers. The items must be placed within the container such that some objective is optimized and the items do not overlap. Items and container may be rectangular or irregular (e.g. polygons and polyhedra......) and may be defined in any number of dimensions. Solution methods are based on theory from both computational geometry and operations research. The scientific contributions of this thesis are presented in the form of six papers and a section which introduces the many problem types and recent solution...

  3. Generalized network improvement and packing problems

    CERN Document Server

    Holzhauser, Michael

    2016-01-01

    Michael Holzhauser discusses generalizations of well-known network flow and packing problems by additional or modified side constraints. By exploiting the inherent connection between the two problem classes, the author investigates the complexity and approximability of several novel network flow and packing problems and presents combinatorial solution and approximation algorithms. Contents Fractional Packing and Parametric Search Frameworks Budget-Constrained Minimum Cost Flows: The Continuous Case Budget-Constrained Minimum Cost Flows: The Discrete Case Generalized Processing Networks Convex Generalized Flows Target Groups Researchers and students in the fields of mathematics, computer science, and economics Practitioners in operations research and logistics The Author Dr. Michael Holzhauser studied computer science at the University of Kaiserslautern and is now a research fellow in the Optimization Research Group at the Department of Mathematics of the University of Kaiserslautern.

  4. The Maximum Resource Bin Packing Problem

    DEFF Research Database (Denmark)

    Boyar, J.; Epstein, L.; Favrholdt, L.M.

    2006-01-01

    Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used...... algorithms, First-Fit-Increasing and First-Fit-Decreasing for the maximum resource variant of classical bin packing. For the on-line variant, we define maximum resource variants of classical and dual bin packing. For dual bin packing, no on-line algorithm is competitive. For classical bin packing, we find...

  5. Modified strip packing heuristics for the rectangular variable-sized bin packing problem

    Directory of Open Access Journals (Sweden)

    FG Ortmann

    2010-06-01

    Full Text Available Two packing problems are considered in this paper, namely the well-known strip packing problem (SPP and the variable-sized bin packing problem (VSBPP. A total of 252 strip packing heuristics (and variations thereof from the literature, as well as novel heuristics proposed by the authors, are compared statistically by means of 1170 SPP benchmark instances in order to identify the best heuristics in various classes. A combination of new heuristics with a new sorting method yields the best results. These heuristics are combined with a previous heuristic for the VSBPP by the authors to find good feasible solutions to 1357 VSBPP benchmark instances. This is the largest statistical comparison of algorithms for the SPP and the VSBPP to the best knowledge of the authors.

  6. A Hybrid Algorithm for Strip Packing Problem with Rotation Constraint

    Directory of Open Access Journals (Sweden)

    Chen Huan

    2016-01-01

    Full Text Available Strip packing is a well-known NP-hard problem and it was widely applied in engineering fields. This paper considers a two-dimensional orthogonal strip packing problem. Until now some exact algorithm and mainly heuristics were proposed for two-dimensional orthogonal strip packing problem. While this paper proposes a two-stage hybrid algorithm for it. In the first stage, a heuristic algorithm based on layering idea is developed to construct a solution. In the second stage, a great deluge algorithm is used to further search a better solution. Computational results on several classes of benchmark problems have revealed that the hybrid algorithm improves the results of layer-heuristic, and can compete with other heuristics from the literature.

  7. On Approximating Four Covering and Packing Problems

    CERN Document Server

    Ashley, Mary; Berman, Piotr; Chaovalitwongse, Wanpracha; DasGupta, Bhaskar; Kao, Ming-Yang; 10.1016/j.jcss.2009.01.002

    2011-01-01

    In this paper, we consider approximability issues of the following four problems: triangle packing, full sibling reconstruction, maximum profit coverage and 2-coverage. All of them are generalized or specialized versions of set-cover and have applications in biology ranging from full-sibling reconstructions in wild populations to biomolecular clusterings; however, as this paper shows, their approximability properties differ considerably. Our inapproximability constant for the triangle packing problem improves upon the previous results; this is done by directly transforming the inapproximability gap of Haastad for the problem of maximizing the number of satisfied equations for a set of equations over GF(2) and is interesting in its own right. Our approximability results on the full siblings reconstruction problems answers questions originally posed by Berger-Wolf et al. and our results on the maximum profit coverage problem provides almost matching upper and lower bounds on the approximation ratio, answering a...

  8. Comparing Online Algorithms for Bin Packing Problems

    DEFF Research Database (Denmark)

    Epstein, Leah; Favrholdt, Lene Monrad; Kohrt, Jens Svalgaard

    2012-01-01

    The relative worst-order ratio is a measure of the quality of online algorithms. In contrast to the competitive ratio, this measure compares two online algorithms directly instead of using an intermediate comparison with an optimal offline algorithm. In this paper, we apply the relative worst-ord......-order ratio to online algorithms for several common variants of the bin packing problem. We mainly consider pairs of algorithms that are not distinguished by the competitive ratio and show that the relative worst-order ratio prefers the intuitively better algorithm of each pair....

  9. 49 CFR 173.141 - Class 9-Assignment of packing group.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Class 9-Assignment of packing group. 173.141...-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Definitions Classification, Packing Group Assignments... packing group. The packing group of a Class 9 material is as indicated in column 5 of the § 172.101 table....

  10. 49 CFR 173.125 - Class 4-Assignment of packing group.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Class 4-Assignment of packing group. 173.125...-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Definitions Classification, Packing Group Assignments... packing group. (a) The packing group of a Class 4 material is assigned in column (5) of the §...

  11. 49 CFR 173.121 - Class 3-Assignment of packing group.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Class 3-Assignment of packing group. 173.121...-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Definitions Classification, Packing Group Assignments... packing group. (a) The packing group of a Class 3 material is as assigned in column 5 of the §...

  12. 49 CFR 173.137 - Class 8-Assignment of packing group.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Class 8-Assignment of packing group. 173.137...-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Definitions Classification, Packing Group Assignments... packing group. The packing group of a Class 8 material is indicated in Column 5 of the § 172.101...

  13. Multi-dimensional Bin Packing Problems with Guillotine Constraints

    DEFF Research Database (Denmark)

    Amossen, Rasmus Resen; Pisinger, David

    2010-01-01

    The problem addressed in this paper is the decision problem of determining if a set of multi-dimensional rectangular boxes can be orthogonally packed into a rectangular bin while satisfying the requirement that the packing should be guillotine cuttable. That is, there should exist a series of face...... parallel straight cuts that can recursively cut the bin into pieces so that each piece contains a box and no box has been intersected by a cut. The unrestricted problem is known to be NP-hard. In this paper we present a generalization of a constructive algorithm for the multi-dimensional bin packing...

  14. The Planar Sandwich and Other 1D Planar Heat Flow Test Problems in ExactPack

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, Jr., Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-24

    This report documents the implementation of several related 1D heat flow problems in the verification package ExactPack [1]. In particular, the planar sandwich class defined in Ref. [2], as well as the classes PlanarSandwichHot, PlanarSandwichHalf, and other generalizations of the planar sandwich problem, are defined and documented here. A rather general treatment of 1D heat flow is presented, whose main results have been implemented in the class Rod1D. All planar sandwich classes are derived from the parent class Rod1D.

  15. Bin Completion Algorithms for Multicontainer Packing, Knapsack, and Covering Problems

    CERN Document Server

    Fukunaga, A S; 10.1613/jair.2106

    2011-01-01

    Many combinatorial optimization problems such as the bin packing and multiple knapsack problems involve assigning a set of discrete objects to multiple containers. These problems can be used to model task and resource allocation problems in multi-agent systems and distributed systms, and can also be found as subproblems of scheduling problems. We propose bin completion, a branch-and-bound strategy for one-dimensional, multicontainer packing problems. Bin completion combines a bin-oriented search space with a powerful dominance criterion that enables us to prune much of the space. The performance of the basic bin completion framework can be enhanced by using a number of extensions, including nogood-based pruning techniques that allow further exploitation of the dominance criterion. Bin completion is applied to four problems: multiple knapsack, bin covering, min-cost covering, and bin packing. We show that our bin completion algorithms yield new, state-of-the-art results for the multiple knapsack, bin covering,...

  16. 49 CFR 173.129 - Class 5, Division 5.2-Assignment of packing group.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Class 5, Division 5.2-Assignment of packing group... SHIPPERS-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Definitions Classification, Packing Group... 5.2—Assignment of packing group. All Division 5.2 materials are assigned to Packing Group II...

  17. A Personified Annealing Algorithm for Circles Packing Problem

    Institute of Scientific and Technical Information of China (English)

    ZHANGDe-Fu; LIXin

    2005-01-01

    Circles packing problem is an NP-hard problem and is difficult to solve. In this paper, a hybrid search strategy for circles packing problem is discussed. A way of generating new configuration is presented by simulating the moving of elastic objects, which can avoid the blindness of simulated annealing search and make iteration process converge fast. Inspired by the life experiences of people,an effective personified strategy to jump out of local minima is given. Based on the simulated annealing idea and personification strategy, an effective personified annealing algorithm for circles packing problem is developed. Numerical experiments on benchmark problem instances show that the proposed algorithm outperforms the best algorithm in the literature.

  18. An effective evolutionary algorithm for the multiple container packing problem

    Institute of Scientific and Technical Information of China (English)

    Sang-Moon Soak; Sang-Wook Lee; Gi-Tae Yeo; Moon-Gu Jeon

    2008-01-01

    This paper focuses on a new optimization problem, which is called "The Multiple Container Packing Problem (MCPP)" and proposes a new evolutionary approach for it. The proposed evolutionary approach uses "Adaptive Link Adjustment Evolutionary Algorithm (ALA-EA)" as a basic framework and it incorporates a heuristic local improvement approach into ALA-EA. The first step of the local search algorithm is to raise empty space through the exchange among the packed items and then to improve the fitness value through packing unpacked items into the raised empty space. The second step is to exchange the packed items and the unpacked items one another toward improving the fitness value. The proposed algorithm is compared to the previous evolutionary approaches at the benchmark instances (with the same container capacity) and the modified benchmark instances (with different container capacity) and that the algorithm is proved to be superior to the previous evolutionary approaches in the solution quality.

  19. Integrating packing and distribution problems and optimization through mathematical programming

    Directory of Open Access Journals (Sweden)

    Fabio Miguel

    2016-06-01

    Full Text Available This paper analyzes the integration of two combinatorial problems that frequently arise in production and distribution systems. One is the Bin Packing Problem (BPP problem, which involves finding an ordering of some objects of different volumes to be packed into the minimal number of containers of the same or different size. An optimal solution to this NP-Hard problem can be approximated by means of meta-heuristic methods. On the other hand, we consider the Capacitated Vehicle Routing Problem with Time Windows (CVRPTW, which is a variant of the Travelling Salesman Problem (again a NP-Hard problem with extra constraints. Here we model those two problems in a single framework and use an evolutionary meta-heuristics to solve them jointly. Furthermore, we use data from a real world company as a test-bed for the method introduced here.

  20. A Heuristic Algorithm for Solving Triangle Packing Problem

    Directory of Open Access Journals (Sweden)

    Ruimin Wang

    2013-01-01

    Full Text Available The research on the triangle packing problem has important theoretic significance, which has broad application prospects in material processing, network resource optimization, and so forth. Generally speaking, the orientation of the triangle should be limited in advance, since the triangle packing problem is NP-hard and has continuous properties. For example, the polygon is not allowed to rotate; then, the approximate solution can be obtained by optimization method. This paper studies the triangle packing problem by a new kind of method. Such concepts as angle region, corner-occupying action, corner-occupying strategy, and edge-conjoining strategy are presented in this paper. In addition, an edge-conjoining and corner-occupying algorithm is designed, which is to obtain an approximate solution. It is demonstrated that the proposed algorithm is highly efficient, and by the time complexity analysis and the analogue experiment result is found.

  1. The load-balanced multi-dimensional bin-packing problem

    DEFF Research Database (Denmark)

    Trivella, Alessio; Pisinger, David

    2016-01-01

    that the average center of mass of the loaded bins falls as close as possible to an ideal point, for instance, the center of the bin. We formally describe the problem using mixed-integer linear programming models, from the simple case where we want to optimally balance a set of items already assigned to a single...... bin, to the general balanced bin-packing problem. Given the difficulty for standard solvers to deal even with small size instances, a multi-level local search heuristic is presented. The algorithm takes advantage of the Fekete-Schepers representation of feasible packings in terms of particular classes...

  2. Statistical mechanics of the lattice sphere packing problem.

    Science.gov (United States)

    Kallus, Yoav

    2013-06-01

    We present an efficient Monte Carlo method for the lattice sphere packing problem in d dimensions. We use this method to numerically discover de novo the densest lattice sphere packing in dimensions 9 through 20. Our method goes beyond previous methods, not only in exploring higher dimensions but also in shedding light on the statistical mechanics underlying the problem in question. We observe evidence of a phase transition in the thermodynamic limit d→∞. In the dimensions explored in the present work, the results are consistent with a first-order crystallization transition but leave open the possibility that a glass transition is manifested in higher dimensions.

  3. A heuristic method for solving triangle packing problem

    Institute of Scientific and Technical Information of China (English)

    CHEN Chuan-bo; HE Da-hua

    2005-01-01

    Given a set of triangles and a rectangle container, the triangle packing problem is to determine ifthese triangles can be placed into the container without overlapping. Triangle packing problem is a special case of polygon packing problem and also NP-hard, so it is unlikely that an efficient and exact algorithm can be developed to solve this problem. In this paper, a new concept of rigid placement is proposed, based on which a discrete solution space called rigid solution space is constructed. Each solution in the rigid solution space can be built by continuously applying legal rigid placements one by one until all the triangles are placed into the rectangle container without overlapping. The proposed Least-Destruction-First (LDF) strategy determines which rigid placement has the privilege to go into the rectangle container. Based on this, a heuristic algorithm is proposed to solve the problem.Combining Least-Destruction-First strategy with backtracking, the corresponding backtracking algorithm is proposed. Computational results show that our proposed algorithms are efficient and robust. With slight modification, these techniques can be conveniently used for solving polygon packing problem.

  4. Solving non-standard packing problems by global optimization and heuristics

    CERN Document Server

    Fasano, Giorgio

    2014-01-01

    This book results from a long-term research effort aimed at tackling complex non-standard packing issues which arise in space engineering. The main research objective is to optimize cargo loading and arrangement, in compliance with a set of stringent rules. Complicated geometrical aspects are also taken into account, in addition to balancing conditions based on attitude control specifications. Chapter 1 introduces the class of non-standard packing problems studied. Chapter 2 gives a detailed explanation of a general model for the orthogonal packing of tetris-like items in a convex domain. A number of additional conditions are looked at in depth, including the prefixed orientation of subsets of items, the presence of unusable holes, separation planes and structural elements, relative distance bounds as well as static and dynamic balancing requirements. The relative feasibility sub-problem which is a special case that does not have an optimization criterion is discussed in Chapter 3. This setting can be exploit...

  5. Two personification strategies for solving circles packing problem

    Institute of Scientific and Technical Information of China (English)

    黄文奇[1; 许如初[2

    1999-01-01

    Two personification strategies are presented, which yield a highly efficient and practical algorithm for solving one of the NP hard problems——circles packing problem on the basis of the quasi-physical algorithm. A very clever polynomial time complexity degree approximate algorithm for solving this problem has been reported by Dorit S.Hochbaum and Wolfgang Maass in J. ACM. Their algorithm is extremely thorough-going and of great theoretical significance. But, just as they pointed out, their algorithm is feasible only in conception and even for examples frequently encountered in everyday life and of small scale, it is the case more often than not that up to a million years would be needed to perform calculations with this algorithm. It is suggested toward the end of their paper that a heuristic algorithm of higher practical effectiveness should be sought out. A direct response to their suggestion is intented to provide.

  6. Class and Home Problems: Optimization Problems

    Science.gov (United States)

    Anderson, Brian J.; Hissam, Robin S.; Shaeiwitz, Joseph A.; Turton, Richard

    2011-01-01

    Optimization problems suitable for all levels of chemical engineering students are available. These problems do not require advanced mathematical techniques, since they can be solved using typical software used by students and practitioners. The method used to solve these problems forces students to understand the trends for the different terms…

  7. A Novel Quantum Inspired Cuckoo Search Algorithm for Bin Packing Problem

    Directory of Open Access Journals (Sweden)

    Abdesslem Layeb

    2012-05-01

    Full Text Available The Bin Packing Problem (BPP is one of the most known combinatorial optimization problems. This problem consists to pack a set of items into a minimum number of bins. There are several variants of this problem; the most basic problem is the one-dimensional bin packing problem (1-BPP. In this paper, we present a new approach based on the quantum inspired cuckoo search algorithm to deal with the 1-BPP problem. The contribution consists in defining an appropriate quantum representation based on qubit representation to represent bin packing solutions. The second contribution is proposition of a new hybrid quantum measure operation which uses first fit heuristic to pack no filled objects by the standard measure operation. The obtained results are very encouraging and show the feasibility and effectiveness of the proposed approach.

  8. Hybrid next-fit algorithm for the two-dimensional rectangle bin-packing problem

    NARCIS (Netherlands)

    J.B.G. Frenk (Hans); G. Galambos

    1987-01-01

    textabstractWe present a new approximation algorithm for the two-dimensional bin-packing problem. The algorithm is based on two one-dimensional bin-packing algorithms. Since the algorithm is of next-fit type it can also be used for those cases where the output is required to be on-line (e. g. if we

  9. Nonconvex continuous models for combinatorial optimization problems with application to satisfiability and node packing problems

    NARCIS (Netherlands)

    Warners, J.P.

    1997-01-01

    We show how a large class of combinatorial optimization problems can be reformulated as a nonconvex minimization problem over the unit hyper cube with continuous variables. No additional constraints are required; all constraints are incorporated in the n onconvex objective function, which is a polyn

  10. Solving the non-oriented three-dimensional bin packing problem with stability and load bearing constraints

    DEFF Research Database (Denmark)

    Hansen, Jesper

    2003-01-01

    The three-dimensional bin packing problem is concerned with packing a given set of rectangular items into rectangular bins. We are interested in solving real-life problems where rotations of items are allowed and the packings must be packable and stable. Load bearing of items is taken into account...

  11. Packing, Scheduling and Covering Problems in a Game-Theoretic Perspective

    CERN Document Server

    Kleiman, Elena

    2011-01-01

    Many packing, scheduling and covering problems that were previously considered by computer science literature in the context of various transportation and production problems, appear also suitable for describing and modeling various fundamental aspects in networks optimization such as routing, resource allocation, congestion control, etc. Various combinatorial problems were already studied from the game theoretic standpoint, and we attempt to complement to this body of research. Specifically, we consider the bin packing problem both in the classic and parametric versions, the job scheduling problem and the machine covering problem in various machine models. We suggest new interpretations of such problems in the context of modern networks and study these problems from a game theoretic perspective by modeling them as games, and then concerning various game theoretic concepts in these games by combining tools from game theory and the traditional combinatorial optimization. In the framework of this research we in...

  12. Robust algorithm to generate a diverse class of dense disordered and ordered sphere packings via linear programming.

    Science.gov (United States)

    Torquato, S; Jiao, Y

    2010-12-01

    We have formulated the problem of generating dense packings of nonoverlapping, nontiling nonspherical particles within an adaptive fundamental cell subject to periodic boundary conditions as an optimization problem called the adaptive-shrinking cell (ASC) formulation [S. Torquato and Y. Jiao, Phys. Rev. E 80, 041104 (2009)]. Because the objective function and impenetrability constraints can be exactly linearized for sphere packings with a size distribution in d-dimensional Euclidean space R(d), it is most suitable and natural to solve the corresponding ASC optimization problem using sequential-linear-programming (SLP) techniques. We implement an SLP solution to produce robustly a wide spectrum of jammed sphere packings in R(d) for d=2, 3, 4, 5, and 6 with a diversity of disorder and densities up to the respective maximal densities. A novel feature of this deterministic algorithm is that it can produce a broad range of inherent structures (locally maximally dense and mechanically stable packings), besides the usual disordered ones (such as the maximally random jammed state), with very small computational cost compared to that of the best known packing algorithms by tuning the radius of the influence sphere. For example, in three dimensions, we show that it can produce with high probability a variety of strictly jammed packings with a packing density anywhere in the wide range [0.6, 0.7408...], where π/√18 = 0.7408... corresponds to the density of the densest packing. We also apply the algorithm to generate various disordered packings as well as the maximally dense packings for d=2, 4, 5, and 6. Our jammed sphere packings are characterized and compared to the corresponding packings generated by the well-known Lubachevsky-Stillinger (LS) molecular-dynamics packing algorithm. Compared to the LS procedure, our SLP protocol is able to ensure that the final packings are truly jammed, produces disordered jammed packings with anomalously low densities, and is appreciably

  13. Model and algorithm for container ship stowage planning based on bin-packing problem

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In a general case, container ship serves many different ports on each voyage. A stowage planning for container ship made at one port must take account of the influence on subsequent ports. So the complexity of stowage planning problem increases due to its multi-ports nature. This problem is NP-hard problem. In order to reduce the computational complexity, the problem is decomposed into two sub-problems in this paper. First, container ship stowage problem (CSSP) is regarded as "packing problem", ship-bays on the board of vessel are regarded as bins, the number of slots at each bay are taken as capacities of bins, and containers with different characteristics (homogeneous containers group) are treated as items packed. At this stage, there are two objective functions, one is to minimize the number of bays packed by containers and the other is to minimize the number of overstows. Secondly, containers assigned to each bays at first stage are allocate to special slot, the objective functions are to minimize the metacentric height, heel and overstows.The taboo search heuristics algorithm are used to solve the subproblem. The main focus of this paper is on the first subproblem. A case certifies the feasibility of the model and algorithm.

  14. Optimisation of a Multi-Objective Two-Dimensional Strip Packing Problem based on Evolutionary Algorithms

    OpenAIRE

    De Armas, Jesica; Leon, Coromoto; Miranda, Gara; Segura, Carlos

    2010-01-01

    Abstract This paper considers a real-world Two-Dimensional Strip Packing Problem involving specific machinery constraints and actual cutting production industry requirements. To suit the problem to a wider range of machinery characteristics, the design objective contemplates the minimisation of material length and the total number of cuts for guillotinable-type patterns. The number of cuts required for the cutting process is crucial for the life of the industrial machines and...

  15. A CLASS OF GENERALIZED MULTIPROCESSOR SCHEDULING PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    YANG Xiaoguang

    2000-01-01

    The paper discusses a class of generalized multiprocessor scheduling problems which is to arrange some independent jobs on almost identical processors. Different from the classical multiprocessor scheduling, each job may only be processed by some processors,not all. In this paper, we first prove that the problems of minimization makespan and minimization total weighted completion time can be solved by the polynomial algorithms if all processing time are unit time. Then for arbitrary processing time, we try to analyze the worst performance of list schedule (LS) method and longest processing time(LPT) method when there are only two machines involved. We show that the bounds for LS and LPT are exactly two.

  16. HAPE3D-a new constructive algorithm for the 3D irregular packing problem

    Institute of Scientific and Technical Information of China (English)

    Xiao LIU; Jia-min LIU; An-xi CAO; Zhuang-le YAO

    2015-01-01

    We propose a new constructive algorithm, called HAPE3D, which is a heuristic algorithm based on the principle of minimum total potential energy for the 3D irregular packing problem, involving packing a set of irregularly shaped polyhedrons into a box-shaped container with fixed width and length but unconstrained height. The objective is to allocate all the polyhedrons in the container, and thus minimize the waste or maximize profit. HAPE3D can deal with arbitrarily shaped polyhedrons, which can be rotated around each coordinate axis at different angles. The most outstanding merit is that HAPE3D does not need to calculate no-fit polyhedron (NFP), which is a huge obstacle for the 3D packing problem. HAPE3D can also be hybridized with a meta-heuristic algorithm such as simulated annealing. Two groups of computational experiments demonstrate the good perfor-mance of HAPE3D and prove that it can be hybridized quite well with a meta-heuristic algorithm to further improve the packing quality.

  17. A branch-and-cut algorithm for the bandwidth packing problem

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.; Park, K.; Kang, S.

    1994-12-31

    We consider the bandwidth packing problem, that arises in the telecommunication network. The problem is to determine the set of calls and the assignment of them to the paths in an arc capacitated network to maximize profit. The problem is formulated by using path variables. To solve LP relaxation, an efficient column generation technique is proposed. Moreover, modified cover inequality is used to strengthen the formulation. The algorithm incorporates the column generation technique and the strong cutting plane approach into the branch-and-bound scheme. We test the proposed algorithm on several problem instances. The results show that the algorithm can be used to solve the problems to optimality within reasonably small time limits.

  18. A pure quasi-human algorithm for solving the cuboid packing problem

    Institute of Scientific and Technical Information of China (English)

    HUANG WenQi; HE Kun

    2009-01-01

    We excavate the wisdom from an old Chinese proverb "gold corner, silver side and strawy void", and further Improve it into "maximum value in diamond cave" for solving the NP-hard cuboid packing problem. We extract, Integrate and formalize the idea by west modern mathematical tools, and propose a pure quasi-human algorithm. The performance of the algorithm is evaluated on two sets of public benchmarks. For 100 strongly heterogeneous difficult benchmarks, experiments show an average packing utilization of 87.31%, which surpasses current best record reported in the literature by 1.83%. For 47 difficult benchmarks without orientation constraint, experiments show an average volume utilization of 92.05%, which improves current best record reported in the literature by 1.05%.

  19. Protein side-chain packing problem: a maximum edge-weight clique algorithmic approach.

    Science.gov (United States)

    Dukka Bahadur, K C; Tomita, Etsuji; Suzuki, Jun'ichi; Akutsu, Tatsuya

    2005-02-01

    "Protein Side-chain Packing" has an ever-increasing application in the field of bio-informatics, dating from the early methods of homology modeling to protein design and to the protein docking. However, this problem is computationally known to be NP-hard. In this regard, we have developed a novel approach to solve this problem using the notion of a maximum edge-weight clique. Our approach is based on efficient reduction of protein side-chain packing problem to a graph and then solving the reduced graph to find the maximum clique by applying an efficient clique finding algorithm developed by our co-authors. Since our approach is based on deterministic algorithms in contrast to the various existing algorithms based on heuristic approaches, our algorithm guarantees of finding an optimal solution. We have tested this approach to predict the side-chain conformations of a set of proteins and have compared the results with other existing methods. We have found that our results are favorably comparable or better than the results produced by the existing methods. As our test set contains a protein of 494 residues, we have obtained considerable improvement in terms of size of the proteins and in terms of the efficiency and the accuracy of prediction.

  20. Pattern formations and optimal packing.

    Science.gov (United States)

    Mityushev, Vladimir

    2016-04-01

    Patterns of different symmetries may arise after solution to reaction-diffusion equations. Hexagonal arrays, layers and their perturbations are observed in different models after numerical solution to the corresponding initial-boundary value problems. We demonstrate an intimate connection between pattern formations and optimal random packing on the plane. The main study is based on the following two points. First, the diffusive flux in reaction-diffusion systems is approximated by piecewise linear functions in the framework of structural approximations. This leads to a discrete network approximation of the considered continuous problem. Second, the discrete energy minimization yields optimal random packing of the domains (disks) in the representative cell. Therefore, the general problem of pattern formations based on the reaction-diffusion equations is reduced to the geometric problem of random packing. It is demonstrated that all random packings can be divided onto classes associated with classes of isomorphic graphs obtained from the Delaunay triangulation. The unique optimal solution is constructed in each class of the random packings. If the number of disks per representative cell is finite, the number of classes of isomorphic graphs, hence, the number of optimal packings is also finite.

  1. A new class of variational equation problems

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Applying an analysis method to a group of multivariable equations, a new class of variational equations are proved. This method is more concise and more direct than the others. This result can be applied to some stochastic control models.

  2. MNP:A Class of NP Optimization Problems

    Institute of Scientific and Technical Information of China (English)

    程歧; 朱洪

    1997-01-01

    A large class of NP optimization problems called MNP are studied.It is shown that Rmax(2)is in this class and some problems which are not likely in Rmax(2) are in this class.A new kind of reductions,SL-reductions,is defined to preserve approximability and nonapproximability,so it is a more general version of L-reductions and A-reductions.Then some complete problems of this class under SL-reductions are shown and it is proved that the max-clique problem is one of them.So all complete problems in this class are as difficult to approximate as the max-clique problem.

  3. SPECTRUM OF DIRECTED KIRKMAN PACKING DESIGNS

    Institute of Scientific and Technical Information of China (English)

    ZhangYan; DuBeiliang

    2003-01-01

    The problem studied in this article is the directed Kirkman packing, the resolvable directed packing which requires all blocks to be of size three except that ,each resolution class should contain either one block of size two(when v=2(mod 3)) or one block of size four (when v=l (mod 3)). A directed Kirkman packing design DKPD(v) is a resolvable directed packing of a v-set by the maximum possible number of resolution classes of this type. This article investigates the spectrum of DKPD(v) and it is found that it contains all positive integers v≥3 and v≠5,6.

  4. A non-classical class of variational problems

    CERN Document Server

    Cruz, Pedro A F; Zinober, Alan S I

    2009-01-01

    We study a new non-classical class of variational problems that is motivated by some recent research on the non-linear revenue problem in the field of economics. This class of problem can be set up as a maximising problem in the Calculus of Variations (CoV) or Optimal Control. However, the state value at the final fixed time, y(T), is a priori unknown and the integrand is a function of the unknown y(T). This is a non-standard CoV problem. In this paper we apply the new costate boundary conditions p(T) in the formulation of the CoV problem. We solve some sample examples in this problem class using the numerical shooting method to solve the resulting TPBVP, and incorporate the free y(T) as an additional unknown. Essentially the same results are obtained using symbolic algebra software.

  5. A dichotomous search-based heuristic for the three-dimensional sphere packing problem

    Directory of Open Access Journals (Sweden)

    Mhand Hifi

    2015-12-01

    Full Text Available In this paper, the three-dimensional sphere packing problem is solved by using a dichotomous search-based heuristic. An instance of the problem is defined by a set of $ n $ unequal spheres and an object of fixed width and height and, unlimited length. Each sphere is characterized by its radius and the aim of the problem is to optimize the length of the object containing all spheres without overlapping. The proposed method is based upon beam search, in which three complementary phases are combined: (i a greedy selection phase which determines a series of eligible search subspace, (ii a truncated tree search, using a width-beam search, that explores some promising paths, and (iii a dichotomous search that diversifies the search. The performance of the proposed method is evaluated on benchmark instances taken from the literature where its obtained results are compared to those reached by some recent methods of the literature. The proposed method is competitive and it yields promising results.

  6. Dynamic Multi-class Network Loading Problem

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The dynamic network loading problem (DNLP) consists in determining on a congested network, timedependent arc volumes, together with arc and path travel times, given the time varying path flow departure rates over a finite time horizon. The objective of this paper is to present the formulation of an analytical dynamic multiclass network loading model. The model does not require the assumption of the FIFO condition. The existence of a solution to the model is shown.

  7. Renormalization problem in a class of nonrenormalizable theories

    Energy Technology Data Exchange (ETDEWEB)

    Symanzik, K.

    1975-08-01

    A possible way to approach a certain class of nonrenormalizable theories is described. The simplest theory of this class with a probability of existence is chosen, the massless phi$sup 4$ theory in more than four space-time dimensions. The problem of extension to other nonrenormalizable theories in the class considered, and the conclusons reached thus far are compared with the corresponding ones for renormalizable theories. (JFP)

  8. SUBSPACE SEARCH METHOD FOR A CLASS OF LEAST SQUARES PROBLEM

    Institute of Scientific and Technical Information of China (English)

    Zi-Luan Wei

    2000-01-01

    A subspace search method for solving a class of least squares problem is pre sented in the paper. The original problem is divided into many independent sub problems, and a search direction is obtained by solving each of the subproblems, as well as a new iterative point is determined by choosing a suitable steplength such that the value of residual norm is decreasing. The convergence result is also given. The numerical test is also shown for a special problem,

  9. A class of ejecta transport test problems

    Energy Technology Data Exchange (ETDEWEB)

    Hammerberg, James E [Los Alamos National Laboratory; Buttler, William T [Los Alamos National Laboratory; Oro, David M [Los Alamos National Laboratory; Rousculp, Christopher L [Los Alamos National Laboratory; Morris, Christopher [Los Alamos National Laboratory; Mariam, Fesseha G [Los Alamos National Laboratory

    2011-01-31

    Hydro code implementations of ejecta dynamics at shocked interfaces presume a source distribution function ofparticulate masses and velocities, f{sub 0}(m, v;t). Some of the properties of this source distribution function have been determined from extensive Taylor and supported wave experiments on shock loaded Sn interfaces of varying surface and subsurface morphology. Such experiments measure the mass moment of f{sub o} under vacuum conditions assuming weak particle-particle interaction and, usually, fully inelastic capture by piezo-electric diagnostic probes. Recently, planar Sn experiments in He, Ar, and Kr gas atmospheres have been carried out to provide transport data both for machined surfaces and for coated surfaces. A hydro code model of ejecta transport usually specifies a criterion for the instantaneous temporal appearance of ejecta with source distribution f{sub 0}(m, v;t{sub 0}). Under the further assumption of separability, f{sub 0}(m,v;t{sub 0}) = f{sub 1}(m)f{sub 2}(v), the motion of particles under the influence of gas dynamic forces is calculated. For the situation of non-interacting particulates, interacting with a gas via drag forces, with the assumption of separability and simplified approximations to the Reynolds number dependence of the drag coefficient, the dynamical equation for the time evolution of the distribution function, f(r,v,m;t), can be resolved as a one-dimensional integral which can be compared to a direct hydro simulation as a test problem. Such solutions can also be used for preliminary analysis of experimental data. We report solutions for several shape dependent drag coefficients and analyze the results of recent planar dsh experiments in Ar and Xe.

  10. Characteristics, Problems and Needs of Multigrade Class Teachers in Burdur

    Directory of Open Access Journals (Sweden)

    Ramazan SAĞ

    2009-04-01

    Full Text Available This study aims at describing the characteristics, problems, and needs of primary teachers who carry out themultigrade class practices in Burdur. The study was conducted through the survey model and data wereobtained from teachers of multigrade classes through Schools with Multigrade Classes Questionnaire. A totalof 38 teachers participated to the research. Frequency and percentage statistics were used in the dataanalysis. In the study, a significant number of teachers of multigrade classes consisted of mid-age groupmales who reside in provinces and towns. More than half were graduates of class teacher education programsthough they had not taken any classes or courses related to multigrade classes and they perform theirteaching duties alongside school administration duties. It was found that the problems that teachers encounterconcentrate on school administration, instructional programs, instruction and assessment, and socioeconomicenvironment. Teachers of multigrade classes state that an in-service training program formultigrade class practices to be offered should include content addressing school administration,instructional programs, instructional conditions and assessment.

  11. The CM class number one problem for curves

    NARCIS (Netherlands)

    Kilicer, P.

    2016-01-01

    The main subject of this thesis is the CM class number one problem for curves of genus g, in the cases g=2 and g=3. The problem asks for which CM fields of degree 2g with a primitive CM type are the corresponding CM curves of genus g defined over the reflex field. Chapter 1 is an introduction to ab

  12. 49 CFR 173.127 - Class 5, Division 5.1-Definition and assignment of packing groups.

    Science.gov (United States)

    2010-10-01

    ...) Packing Group II, any material which exhibits a mean pressure rise time less than or equal to the pressure... Packing Group I are not met. (iii) Packing Group III, any material which exhibits a mean pressure rise... packing groups. 173.127 Section 173.127 Transportation Other Regulations Relating to...

  13. Pre-Service Class Teacher' Ability in Solving Mathematical Problems and Skills in Solving Daily Problems

    Science.gov (United States)

    Aljaberi, Nahil M.; Gheith, Eman

    2016-01-01

    This study aims to investigate the ability of pre-service class teacher at University of Petrain solving mathematical problems using Polya's Techniques, their level of problem solving skills in daily-life issues. The study also investigates the correlation between their ability to solve mathematical problems and their level of problem solving…

  14. A class of mechanically decidable problems beyond Tarski's model

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    By means of dimension-decreasing method and cell-decomposition,a practical algorithm is proposed to decide the positivity of a certain class of symmetric polynomials,the numbers of whose elements are variable.This is a class of mechanically decidable problems beyond Tarski model.To implement the algorithm,a program nprove written in maple is developed which can decide the positivity of these polynomials rapidly.

  15. Minimax theory for a class of nonlinear statistical inverse problems

    Science.gov (United States)

    Ray, Kolyan; Schmidt-Hieber, Johannes

    2016-06-01

    We study a class of statistical inverse problems with nonlinear pointwise operators motivated by concrete statistical applications. A two-step procedure is proposed, where the first step smoothes the data and inverts the nonlinearity. This reduces the initial nonlinear problem to a linear inverse problem with deterministic noise, which is then solved in a second step. The noise reduction step is based on wavelet thresholding and is shown to be minimax optimal (up to logarithmic factors) in a pointwise function-dependent sense. Our analysis is based on a modified notion of Hölder smoothness scales that are natural in this setting.

  16. Feature selection for multi-class problems by using pairwise-class and all-class techniques

    Science.gov (United States)

    You, Mingyu; Li, Guo-Zheng

    2011-05-01

    Feature selection has been a key technology in massive data processing, e.g. in microarray data analysis with few samples but high-dimensional genes. One common problem in multi-class microarray data analysis is the unbalanced recognition or prediction accuracies among classes, which usually leads to poor system performance. One of the main reasons is the unfair feature (gene) selection method. In this paper, a novel feature selection framework by using pairwise-class and all-class techniques (namely FrPA) is proposed to balance the performance among classes and improve the average accuracy. The feature (gene) rank list on all classes and the lists on each pair of classes are all taken into consideration during feature selection. The strategy of round-robin is embedded into the framework to select final features from the different rank lists. Experimental results on several microarray data sets show that FrPA helps to achieve higher classification accuracy and balance the performance among classes.

  17. The Monty Hall Problem as a Class Activity Using Clickers

    Science.gov (United States)

    Irons, Stephen H.

    2012-01-01

    Demonstrating probabilistic outcomes using real-time data is especially well-suited to larger lecture classes where one can generate large data sets easily. The difficulty comes in quickly collecting, analyzing, and displaying the information. With the advent of wireless polling technology (clickers), this difficulty is removed. In this paper we describe an activity developed in one of our physics classes to test one of the classic cases of probability in popular culture, The Monty Hall Problem. Using clickers, a paper handout, and stickers, one can easily probe the class opinion on the outcome and then vividly and definitively test it. At the end of the activity, the students have confronted through direct experience the often counterintuitive nature of probability.

  18. Output regulation problem for a class of regular hyperbolic systems

    Science.gov (United States)

    Xu, Xiaodong; Dubljevic, Stevan

    2016-01-01

    This paper investigates the output regulation problem for a class of regular first-order hyperbolic partial differential equation (PDE) systems. A state feedback and an error feedback regulator are considered to force the output of the hyperbolic PDE plant to track a periodic reference trajectory generated by a neutrally stable exosystem. A new explanation is given to extend the results in the literature to solve the regulation problem associated with the first-order hyperbolic PDE systems. Moreover, in order to provide the closed-loop stability condition for the solvability of the regulator problems, the design of stabilising feedback gain and its dual problem design of stabilising output injection gain are considered in this paper. This paper develops an easy method to obtain an adjustable stabilising feedback gain and stabilising output injection gain with the aid of the operator Riccati equation.

  19. Role-playing in the problem-based learning class.

    Science.gov (United States)

    Chan, Zenobia C Y

    2012-01-01

    Learning and teaching have been conceptualized and executed in many styles, such as self-learning, peer learning, and interaction between the learner and mentor. Today, openness to alternative ideas and embracing innovative approaches in nursing education are encouraged in order to meet students' learning interests and needs, and to address ever-changing healthcare requests. Problem-based learning has been widely adopted in nursing education, with various positive effects on students' learning, such as motivated learning, team work, problem-solving skills and critical thinking. Role-plays have been demonstrated as an effective learning strategy that includes an active and experiential feature that facilitates students' autonomy in their health-related learning. However, there is a lack of discussion of whether and how role-play can be used in problem-based learning (PBL). This paper shows the development of a classroom-based innovation using role-play in the PBL class for higher diploma year-one nurse students (a total of 20 students, five per group). This paper consists of five sections: a) the literature on PBL and nurse education, and role-plays as the innovation; b) the PBL case scenario with the illustration of the two role-play scripts, c) student evaluation on role-play in the PBL class; d) discussions on both achievements and limitations of this innovation, and e) the conclusion. It is hoped that this paper will be an example to other nurse educators who are keen on exploring interactive and student-driven learning and teaching strategies in the PBL class.

  20. The Problems and Solutions of Learning English Effectively in class

    Institute of Scientific and Technical Information of China (English)

    钟丽君

    2016-01-01

    English, as an international language, is becoming more and more important in our society. Its proficiency has become a major requirement for attaining the highest level of professional and economic success around the world. We, English learners mainly learn English in Classroom, so classroom is regarded as the most important place where we learn English language. This paper gives out an analysis of the problems which lead to the ineffective English learning and discusses the solutions of an effective English learning in class according to the author' s own experience in English teaching in secondary schools and colleges.

  1. A class of self-similar hydrodynamics test problems

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, Scott D [Los Alamos National Laboratory; Brown, Lowell S [Los Alamos National Laboratory; Nelson, Eric M [Los Alamos National Laboratory; Alme, Marv L [Los Alamos National Laboratory

    2010-12-08

    We consider self-similar solutions to the gas dynamics equations. One such solution - a spherical geometry Gaussian density profile - has been analyzed in the existing literature, and a connection between it, a linear velocity profile, and a uniform specific internal energy profile has been identified. In this work, we assume the linear velocity profile to construct an entire class of self-similar sol utions in both cylindrical and spherical geometry, of which the Gaussian form is one possible member. After completing the derivation, we present some results in the context of a test problem for compressible flow codes.

  2. How to Tackle the Problems in Large Classes

    Institute of Scientific and Technical Information of China (English)

    董艳海; 曹二玲

    2006-01-01

    This article mainly introduces three teaching methods of large classes through the analysis of teaching environment of large classes. These methods are the working experience of several years' teaching. With the combination of student and teacher interaction, creating environment of language learning and appropriate classroom management, it can improve the teaching effect of large classes. How to tackle the problems is of vital importance for achieving a successful transition from the traditional teaching style to a communicative model.%本文通过对大班英语教学环境的分析,介绍了三种大班英语授课的方法及具体措施.这些方法是多年英语教学经验的总结,主要通过师生互动、创设语言学习环境和教学管理相结合的模式,提高大班英语授课的教学效果.

  3. A Personified Annealing Algorithm for Circles Packing Problem%求解圆形packing问题的拟人退火算法

    Institute of Scientific and Technical Information of China (English)

    张德富; 李新

    2005-01-01

    Circles packing problem is an NP-hard problem and is difficult to solve. In this paper, a hybrid search strategy for circles packing problem is discussed. A way of generating new configuration is presented by simulating the moving of elastic objects, which can avoid the blindness of simulated annealing search and make iteration process converge fast. Inspired by the life experiences of people,an effective personified strategy to jump out of local minima is given. Based on the simulated annealing idea and personification strategy, an effective personified annealing algorithm for circles packing problem is developed. Numerical experiments on benchmark problem instances show that the proposed algorithm outperforms the best algorithm in the literature.

  4. [The immuno-endocrine system. A new endocrine theory: the problem of the packed transport].

    Science.gov (United States)

    Csaba, György

    2011-05-15

    Since the eighties of the last century hormone content was justified in immune cells (lymphocytes, granulocytes, monocytes, macrophages and mast cells), which produce, store and secrete these hormones. Although the amount of these materials in immune cells is relatively small, the mass of the producers (immune cells) is so large, that the phenomenon must be considered from endocrinological point of view, underlying the important differences between the "classical" and immuno-endocrine systems. Cells of the classic (built-in) endocrine system are mono-producers, while immune cells can synthesize many types of hormones (polyproducers). In addition, these cells can transport the whole hormone-producing machinery to the site of need, producing a local effect. This can be observed, for example, in the case of endorphin producing immune cells during inflammation and during early pregnancy around the chorionic villi. Hormone producing immune cells also have receptors for many hormones, so that they are poly-receivers. Via hormone producing and receiving capacity there is a bidirectional connection between the neuro-endocrine and immuno-endocrine systems. In addition, there is a network inside the immuno-endocrine system. The packed transport theory attempts to explain the mechanism and importance of the immuno-endocrine system.

  5. Stability of Solutions to Classes of Traveling Salesman Problems.

    Science.gov (United States)

    Niendorf, Moritz; Kabamba, Pierre T; Girard, Anouck R

    2016-04-01

    By performing stability analysis on an optimal tour for problems belonging to classes of the traveling salesman problem (TSP), this paper derives margins of optimality for a solution with respect to disturbances in the problem data. Specifically, we consider the asymmetric sequence-dependent TSP, where the sequence dependence is driven by the dynamics of a stack. This is a generalization of the symmetric non sequence-dependent version of the TSP. Furthermore, we also consider the symmetric sequence-dependent variant and the asymmetric non sequence-dependent variant. Amongst others these problems have applications in logistics and unmanned aircraft mission planning. Changing external conditions such as traffic or weather may alter task costs, which can render an initially optimal itinerary suboptimal. Instead of optimizing the itinerary every time task costs change, stability criteria allow for fast evaluation of whether itineraries remain optimal. This paper develops a method to compute stability regions for the best tour in a set of tours for the symmetric TSP and extends the results to the asymmetric problem as well as their sequence-dependent counterparts. As the TSP is NP-hard, heuristic methods are frequently used to solve it. The presented approach is also applicable to analyze stability regions for a tour obtained through application of the k -opt heuristic with respect to the k -neighborhood. A dimensionless criticality metric for edges is proposed, such that a high criticality of an edge indicates that the optimal tour is more susceptible to cost changes in that edge. Multiple examples demonstrate the application of the developed stability computation method as well as the edge criticality measure that facilitates an intuitive assessment of instances of the TSP.

  6. New bounds for multi-dimensional packing

    NARCIS (Netherlands)

    Seiden, S.; Stee, R. van

    2001-01-01

    New upper and lower bounds are presented for a multi-dimensional generalization of bin packing called box packing. Several variants of this problem, including bounded space box packing, square packing, variable sized box packing and resource augmented box packing are also studied. The main results,

  7. Layout Optimization for the Dishes Installed on a Rotating Table——The Packing Problem With Equilibrium Behavioural Constraints

    Institute of Scientific and Technical Information of China (English)

    滕弘飞; 孙守林; 葛文海; 钟万勰

    1994-01-01

    The layout optimization for the dishes installed on a rotating table is investigated. This is a packing problem with equilibrium behavioural constraints. To deal with its layout topo-models and initial layout, a mathematical model and heuristic approaches, including the method of model-changing iteration (MCI) and the method of main objects topo-models (MOT), are proposed, with a series of intuitive algorithms embedded in, such as the technique for the search under the initial guess and the strategies for remission of "combinatorial explosion" . The validity and reliability of the proposed algorithms are verified by numerical examples and engineering applications, which could be used in satellite module, multiple spindle box, rotating structure and so on.

  8. First IDA Submittal for Transducer Element Design for Loosely Packed Planar Array Common Problem 1.1

    Science.gov (United States)

    1966-05-11

    FIRST IDA SUBMITTAL FOR TRANSDUCER ELEMENT DESIGN FOR LOOSELY PACKED PLANAR ARRAY CID COMMON PROBLEM 1. 1 Submitted to Conformal/Planar Array Project...R4JEN2’ TRACOR, INC. MID BAND 6..I ~JUUliL-UnLU i C.P. 1 5 INCH CIRCULRR HERD MIO BRINO LPz.3777 QP=E +iD L1oooo -i00 F -WFC 4q(TI’ ERT R-EC c-AE O ALPPE...8217 LcO [a x I. Cr l Z2) D zS x) q." L)I I Iu T~ xj Co4 C3= 1-L Z (nw x V O vV 5% C3 CD .* * -3x U l 1C .) uw wU -A CID .4 i I--I- U- 49 (1’)W uri J m LAJ 0

  9. An off-line dual maximum resource bin packing model for solving the maintenance problem in the aviation industry

    Directory of Open Access Journals (Sweden)

    George Cristian Gruia

    2013-05-01

    Full Text Available In the aviation industry, propeller motor engines have a lifecycle of several thousand hours of flight and the maintenance is an important part of their lifecycle. The present article considers a multi-resource, priority-based case scheduling problem, which is applied in a Romanian manufacturing company, that repairs and maintains helicopter and airplane engines at a certain quality level imposed by the aviation standards. Given a reduced budget constraint, the management’s goal is to maximize the utilization of their resources (financial, material, space, workers, by maintaining a prior known priority rule. An Off-Line Dual Maximum Resource Bin Packing model, based on a Mixed Integer Programming model is thus presented. The obtained results show an increase with approx. 25% of the Just in Time shipping of the engines to the customers and approx. 12,5% increase in the utilization of the working area.

  10. New bounds for multi-dimensional packing

    OpenAIRE

    Seiden, S.; Stee, van, Rob

    2001-01-01

    New upper and lower bounds are presented for a multi-dimensional generalization of bin packing called box packing. Several variants of this problem, including bounded space box packing, square packing, variable sized box packing and resource augmented box packing are also studied. The main results, stated for d=2, are as follows: A new upper bound of 2.66013 for online box packing, a new $14/9 + varepsilon$ polynomial time offline approximation algorithm for square packing, a new upper bound ...

  11. Emotional Psychological and Related Problems among Truant Youths: An Exploratory Latent Class Analysis

    Science.gov (United States)

    Dembo, Richard; Briones-Robinson, Rhissa; Ungaro, Rocio Aracelis; Gulledge, Laura M.; Karas, Lora M.; Winters, Ken C.; Belenko, Steven; Greenbaum, Paul E.

    2012-01-01

    Intervention Project. Results identified two classes of youths: Class 1(n=9) - youths with low levels of delinquency, mental health and substance abuse issues; and Class 2(n=37) - youths with high levels of these problems. Comparison of these two classes on their urine analysis test results and parent/guardian reports of traumatic events found…

  12. Rack 'em, pack 'em and stack 'em: challenges and opportunities in teaching large classes in higher education.

    Science.gov (United States)

    Kumar, Saravana

    2013-01-01

    The higher education sector is undergoing tremendous change, driven by complex driving forces including financial, administrative, and organisational and stakeholder expectations. It is in this challenging environment, educators are required to maintain and improve the quality of teaching and learning outcomes while contending with increasing class sizes. Despite mixed evidence on the effectiveness of large classes on student outcomes, large classes continue to play an important part in higher education. While large classes pose numerous challenges, they also provide opportunities for innovative solutions. This paper provides an overview of these challenges and highlights opportunities for innovative solutions.

  13. QUANTUM COMPLEXITY OF THE INTEGRATION PROBLEM FOR ANISOTROPIC CLASSES

    Institute of Scientific and Technical Information of China (English)

    Xiao-fei Hu; Pei-xin Ye

    2005-01-01

    We obtain the optimal order of high-dimensional integration complexity in the quantum computation model in anisotropic Sobolev classes Wr∞ ([0, 1]d) and Holder Nikolskii classes Hr∞([0, 1]d). It is proved that for these classes of functions there is a speed-up of quantum algorithms over deterministic classical algorithms due to factor n-1 and over randomized classical methods due to factor n-1/2. Moreover, we give an estimation for optimal query complexity in the class H∧∞ (D) whose smoothness index is the boundary of some complete set in Zd+.

  14. Integral Transforms and a Class of Singular S-Hermitian Eigenvalue Problems

    NARCIS (Netherlands)

    Dijksma, A.; Snoo, H.S.V. de

    1973-01-01

    For a class of singular S-hermitian eigenvalue problems we show that the corresponding integral transforms are surjective. This class was discussed by us earlier and is more restricted than the one, which has been considered by others.

  15. SPECTRUM OF DIRECTED KIRKMAN PACKING DESIGNS%有向Kirkman填充设计的谱

    Institute of Scientific and Technical Information of China (English)

    张彦; 杜北梁

    2003-01-01

    The problem studied in this article is the directed Kirkman packing,the resolvable directed packing which requires all blocks to be of size three except that,each resolution class should contain either one block of size two(when v≡2(mod 3)) or one block of size four (when v≡1 (mod 3)). A directed Kirkman packing design DKPD(v) is a resolvable directed packing of a v-set by the maximum possible number of resolution classes of this type. This article investigates the spectrum of DKPD(v) and it is found that it contains all positive integers v≥3 and v≠ 5,6.

  16. Existence for a class of discrete hyperbolic problems

    Directory of Open Access Journals (Sweden)

    Luca Rodica

    2006-01-01

    Full Text Available We investigate the existence and uniqueness of solutions to a class of discrete hyperbolic systems with some nonlinear extreme conditions and initial data, in a real Hilbert space.

  17. THE CAUCHY PROBLEM FOR A CLASS OF DOUBLY DEGENERATE NONLINEAR PARABOLIC EQUATION

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This article studies the Cauchy problem for a class of doubly nonlinear deauthor considers its regularized problem and establishes some estimates. On the basis of the estimates, the existence and uniqueness of the generalized solutions in BV space are proved.

  18. A Heuristic Algorithm for 3D Bin-packing Problem%三维装箱问题的启发式算法

    Institute of Scientific and Technical Information of China (English)

    罗建军; 吴东辉; 罗细飞

    2012-01-01

    The 3D bin-packing problem is a classic NP-hard combinatorial optimization problem. On the basis of ID and 2D bin-packing problems, this paper develops a heuristic algorithm to overcome the over-reliance on "experience" of the general heuristic algorithm. This algorithm is structurally simple and has high convergence speed as is demonstrated in an experimental study.%三维装箱问题是一类典型的NP-hard组合优化问题.在一维、二维装箱问题基础上,设计了一种启发式算法,借以克服一般启发式算法依赖“经验”的不足,该算法结构简单,实验表明算法收敛速度快.

  19. The vehicle routing problem with two classes of vehicles and a limit on the number of vehicles in each class

    Energy Technology Data Exchange (ETDEWEB)

    Martins, P.; Gouveia, L.

    1994-12-31

    In this talk we discuss several linear integer programming formulations for a particular case of the Vehicle Routing Problem, where several classes of vehicles are considered and a fixed number of vehicles is imposed in each class. We also present a set of valid inequalities which lead to significant improvements on the lower bounds. Some heuristics are also discussed. We present computational results taken from a set of tests with the number of clients ranging from 13 to 75.

  20. Optimized packings with applications

    CERN Document Server

    Pintér, János

    2015-01-01

    This volume presents a selection of case studies that address a substantial range of optimized object packings (OOP) and their applications. The contributing authors are well-recognized researchers and practitioners. The mathematical modelling and numerical solution aspects of each application case study are presented in sufficient detail. A broad range of OOP problems are discussed: these include various specific and non-standard container loading and object packing problems, as well as the stowing of hazardous and other materials on container ships, data centre resource management, automotive engineering design, space station logistic support, cutting and packing problems with placement constraints, the optimal design of LED street lighting, robust sensor deployment strategies, spatial scheduling problems, and graph coloring models and metaheuristics for packing applications. Novel points of view related to model development and to computational nonlinear, global, mixed integer optimization and heuristic st...

  1. Minimizers of a Class of Constrained Vectorial Variational Problems: Part I

    KAUST Repository

    Hajaiej, Hichem

    2014-04-18

    In this paper, we prove the existence of minimizers of a class of multiconstrained variational problems. We consider systems involving a nonlinearity that does not satisfy compactness, monotonicity, neither symmetry properties. Our approach hinges on the concentration-compactness approach. In the second part, we will treat orthogonal constrained problems for another class of integrands using density matrices method. © 2014 Springer Basel.

  2. Multisplitting Iteration Schemes for Solving a Class of Nonlinear Complementarity Problems

    Institute of Scientific and Technical Information of China (English)

    Chen-liang Li; Jin-ping Zeng

    2007-01-01

    We consider several synchronous and asynchronous multisplitting iteration schemes for solving a class of nonlinear complementarity problems with the system matrix being an H-matrix. We establish the convergence theorems for the schemes. The numerical experiments show that the schemes are efficient for solving the class of nonlinear complementarity problems.

  3. Global Optimization of a Class of Nonconvex Quadratically Constrained Quadratic Programming Problems

    Institute of Scientific and Technical Information of China (English)

    Yong XIA

    2011-01-01

    In this paper we study a class of nonconvex quadratically constrained quadratic programming problems generalized from relaxations of quadratic assignment problems.We show that each problem is polynomially solved.Strong duality holds if a redundant constraint is introduced.As an application,a new lower bound is proposed for the quadratic assignment problem.

  4. On a class of inverse electrostatic and elasticity problems

    OpenAIRE

    Artemev, Andrei; Parnovski, Leonid; Polterovich, Iosif

    2012-01-01

    We study the inverse electrostatic and elasticity problems associated with Poisson and Navier equations. The uniqueness of solutions of these problems is proved for piecewise constant electric charge and internal stress distributions having a checkered structure: they are constant on rectangular blocks. Such distributions appear naturally in practical applications. We also discuss computational challenges arising in the numerical implementation of our method.

  5. On stochastic approximation algorithms for classes of PAC learning problems

    Energy Technology Data Exchange (ETDEWEB)

    Rao, N.S.V.; Uppuluri, V.R.R.; Oblow, E.M.

    1994-03-01

    The classical stochastic approximation methods are shown to yield algorithms to solve several formulations of the PAC learning problem defined on the domain [o,1]{sup d}. Under some assumptions on different ability of the probability measure functions, simple algorithms to solve some PAC learning problems are proposed based on networks of non-polynomial units (e.g. artificial neural networks). Conditions on the sizes of these samples required to ensure the error bounds are derived using martingale inequalities.

  6. Lithuanian Education System Problems: Senior Class Students' Position

    Directory of Open Access Journals (Sweden)

    V. Lamanauskas

    2010-11-01

    Full Text Available Various changes are taking place in Lithuanian comprehensive schools in recent years. Not all of them can be considered positive and making the system’s work effective. The changes taking place encourage natural interest in them. It is necessary not only to fix the current state, but to search for the ways how to optimize the changes taking place and to control them. Education is a complex, manifold phenomenon, the researches of which are complicated and complex as well. In this article Lithuanian comprehensive school senior class pupils’ position on current education questions is analysed: preparation and teaching/learning process evaluation, the identification of advantages and disadvantages of education system and other. It is revealed how Lithuanian comprehensive school pupils value current education system, teacher provided knowledge quality and ability to prepare students for further studies at universities and other higher schools.

  7. The relationship between heart problems and mortality in different social classes.

    Science.gov (United States)

    Kåreholt, I

    2001-05-01

    The aim of this study is to analyze how relative mortality risk varies between persons with and without heart problems in different social classes. Cox proportional hazards regression was used to analyze relative mortality risk for the period 1968-1996 for a Swedish nationally representative sample of 4585 persons born between 1892 and 1942, and interviewed 1968. Survivors from the original sample were also interviewed in 1974, 1981 and 1991 or 1992. "Heart problems" is defined as the presence of three mild or one severe symptom associated with circulatory problems. Social class is based on occupation. The relative mortality risk varied significantly between social classes and between persons with and without heart problems, among both men and women. These differences were smaller among women than among men. The main results are that there are significant additive interactions between social class and heart problems among men. Men from lower social classes have a more elevated mortality risk than men from higher social classes when they have a heart problem. Among white-collar workers the coefficient of the difference between men with and without heart problems was 0.53. The corresponding difference was significantly larger among workers (1.59, P = 0.01), thus demonstrating an additive interaction. The difference was even greater (1.86) among "unclassifiable" men--those who could not report an occupation that could be coded into a social class, mainly because they were long-term unemployed or on early-retirement pensions. Among women, the mortality difference between white-collar workers with and without heart problems was 0.85. None of the mortality differences between those with and without heart problems in other social classes differed significantly from those of white-collar workers. The mortality difference between women with and without heart problems was, however, large (2.34) among the "unclassifiable". This difference is even larger than the corresponding

  8. Class Differences in Family Problem Solving: The Effects of Verbal Ability, Hierarchical Structure, and Role Expectations

    Science.gov (United States)

    Tallman, Irving; Miller, Gary

    1974-01-01

    Reports on a study which used propositions drawn from small group problem-solving research, combined and modified, to explain social class differences in family problem solving with externally generated, rule-bound, conjunctive, puzzle-like problems. (Author/SF)

  9. An active learning based classification strategy for the minority class problem: application to histopathology annotation

    Directory of Open Access Journals (Sweden)

    Doyle Scott

    2011-10-01

    Full Text Available Abstract Background Supervised classifiers for digital pathology can improve the ability of physicians to detect and diagnose diseases such as cancer. Generating training data for classifiers is problematic, since only domain experts (e.g. pathologists can correctly label ground truth data. Additionally, digital pathology datasets suffer from the "minority class problem", an issue where the number of exemplars from the non-target class outnumber target class exemplars which can bias the classifier and reduce accuracy. In this paper, we develop a training strategy combining active learning (AL with class-balancing. AL identifies unlabeled samples that are "informative" (i.e. likely to increase classifier performance for annotation, avoiding non-informative samples. This yields high accuracy with a smaller training set size compared with random learning (RL. Previous AL methods have not explicitly accounted for the minority class problem in biomedical images. Pre-specifying a target class ratio mitigates the problem of training bias. Finally, we develop a mathematical model to predict the number of annotations (cost required to achieve balanced training classes. In addition to predicting training cost, the model reveals the theoretical properties of AL in the context of the minority class problem. Results Using this class-balanced AL training strategy (CBAL, we build a classifier to distinguish cancer from non-cancer regions on digitized prostate histopathology. Our dataset consists of 12,000 image regions sampled from 100 biopsies (58 prostate cancer patients. We compare CBAL against: (1 unbalanced AL (UBAL, which uses AL but ignores class ratio; (2 class-balanced RL (CBRL, which uses RL with a specific class ratio; and (3 unbalanced RL (UBRL. The CBAL-trained classifier yields 2% greater accuracy and 3% higher area under the receiver operating characteristic curve (AUC than alternatively-trained classifiers. Our cost model accurately predicts

  10. Some new analysis results for a class of interface problems.

    Science.gov (United States)

    Li, Zhilin; Wang, Li; Aspinwall, Eric; Cooper, Racheal; Kuberry, Paul; Sanders, Ashley; Zeng, Ke

    2015-12-01

    Interface problems modeled by differential equations have many applications in mathematical biology, fluid mechanics, material sciences, and many other areas. Typically, interface problems are characterized by discontinuities in the coefficients and/or the Dirac delta function singularities in the source term. Due to these irregularities, solutions to the differential equations are not smooth or discontinuous. In this paper, some new results on the jump conditions of the solution across the interface are derived using the distribution theory and the theory of weak solutions. Some theoretical results on the boundary singularity in which the singular delta function is at the boundary are obtained. Finally, the proof of the convergency of the Immersed Boundary method is presented. The IB method is shown to be first order convergent in L(∞) norm.

  11. A new class of problems in the calculus of variations

    Science.gov (United States)

    Ekeland, Ivar; Long, Yiming; Zhou, Qinglong

    2013-11-01

    This paper investigates an infinite-horizon problem in the one-dimensional calculus of variations, arising from the Ramsey model of endogeneous economic growth. Following Chichilnisky, we introduce an additional term, which models concern for the well-being of future generations. We show that there are no optimal solutions, but that there are equilibrium strateges, i.e. Nash equilibria of the leader-follower game between successive generations. To solve the problem, we approximate the Chichilnisky criterion by a biexponential criterion, we characterize its equilibria by a pair of coupled differential equations of HJB type, and we go to the limit. We find all the equilibrium strategies for the Chichilnisky criterion. The mathematical analysis is difficult because one has to solve an implicit differential equation in the sense of Thom. Our analysis extends earlier work by Ekeland and Lazrak.

  12. 条形装箱问题的优化模型和增广Lagrange算法%An Optimization Model for the Strip-packing Problem and Its Augmented Lagrangian Method

    Institute of Scientific and Technical Information of China (English)

    于洪霞; 张宏伟; 张立卫

    2006-01-01

    This paper formulates a two-dimensional strip packing problem as a nonlinear programming (NLP) problem and establishes the first-order optimality conditions for the NLP problem. A numerical algorithm for solving this NLP problem is given to find exact solutions to strip-packing problems involving up to 10 items.Approximate solutions can be found for big-sized problems by decomposing the set of items into small-sized blocks of which each block adopts the proposed numerical algorithm. Numerical results show that the approximate solutions to big-sized problems obtained by this method are superior to those by NFDH, FFDH and BFDH approaches.

  13. Optimal Packed String Matching

    DEFF Research Database (Denmark)

    Ben-Kiki, Oren; Bille, Philip; Breslauer, Dany

    2011-01-01

    In the packed string matching problem, each machine word accommodates – characters, thus an n-character text occupies n/– memory words. We extend the Crochemore-Perrin constantspace O(n)-time string matching algorithm to run in optimal O(n/–) time and even in real-time, achieving a factor – speedup...... over traditional algorithms that examine each character individually. Our solution can be efficiently implemented, unlike prior theoretical packed string matching work. We adapt the standard RAM model and only use its AC0 instructions (i.e., no multiplication) plus two specialized AC0 packed string...

  14. New Fuzzy Support Vector Machine for the Class Imbalance Problem in Medical Datasets Classification

    Directory of Open Access Journals (Sweden)

    Xiaoqing Gu

    2014-01-01

    Full Text Available In medical datasets classification, support vector machine (SVM is considered to be one of the most successful methods. However, most of the real-world medical datasets usually contain some outliers/noise and data often have class imbalance problems. In this paper, a fuzzy support machine (FSVM for the class imbalance problem (called FSVM-CIP is presented, which can be seen as a modified class of FSVM by extending manifold regularization and assigning two misclassification costs for two classes. The proposed FSVM-CIP can be used to handle the class imbalance problem in the presence of outliers/noise, and enhance the locality maximum margin. Five real-world medical datasets, breast, heart, hepatitis, BUPA liver, and pima diabetes, from the UCI medical database are employed to illustrate the method presented in this paper. Experimental results on these datasets show the outperformed or comparable effectiveness of FSVM-CIP.

  15. A local search algorithm based on chromatic classes for university course timetabling problem

    Directory of Open Access Journals (Sweden)

    Velin Kralev

    2016-12-01

    Full Text Available This paper presents a study for a local search algorithm based on chromatic classes for the university course timetabling problem. Several models and approaches to resolving the problem are discussed. The main idea of the approach is through a heuristic algorithm to specify the chromatic classes of a graph in which the events of the timetable correspond to the graph vertices and the set of the edges represents the possible conflicts between events. Then the chromatic classes should be sorted according to specific sort criteria (a total weight or a total count of events in each class, and finally the local search algorithm starts. The aim of the experiments is to determine the best criterion to sort chromatic classes. The results showed that the algorithm generates better solutions when the chromatic classes are sorted in a total weight criterion.

  16. Effectiveness of decomposition algorithms for multi-class classification problems

    OpenAIRE

    Wołyński, Waldemar

    2010-01-01

    Problem predykcji etykiety klasy (grupy, populacji) na podstawie obserwacji wektora cech jest nazywany klasyfikacją, analizą dyskryminacyjną lub uczeniem się pod nadzorem. Zbiór etykiet składa się z K > 2 elementów w przypadku zagadnień wieloklasowych oraz z K = 2 elementów w przypadku zagadnień dwuklasowych (binarnych). Ponieważ zagadnienia dwuklaso- we są z reguły o wiele prostsze od zagadnień wieloklasowych (co więcej, niektóre algorytmy ...

  17. A CLASS OF SINGULARLY PERTURBED INITIAL BOUNDARY PROBLEM FOR REACTION DIFFUSION EQUATION

    Institute of Scientific and Technical Information of China (English)

    Xie Feng

    2003-01-01

    The singularly perturbed initial boundary value problem for a class of reaction diffusion equation isconsidered. Under appropriate conditions, the existence-uniqueness and the asymptotic behavior of the solu-tion are showed by using the fixed-point theorem.

  18. Minimization and error estimates for a class of the nonlinear Schrodinger eigenvalue problems

    Institute of Scientific and Technical Information of China (English)

    MurongJIANG; JiachangSUN

    2000-01-01

    It is shown that the nonlinear eigenvaiue problem can be transformed into a constrained functional problem. The corresponding minimal function is a weak solution of this nonlinear problem. In this paper, one type of the energy functional for a class of the nonlinear SchrSdinger eigenvalue problems is proposed, the existence of the minimizing solution is proved and the error estimate is given out.

  19. Packing Products: Polystyrene vs. Cornstarch

    Science.gov (United States)

    Starr, Suzanne

    2009-01-01

    Packing materials such as polystyrene take thousands of years to decompose, whereas packing peanuts made from cornstarch, which some companies are now using, can serve the same purpose, but dissolve in water. The author illustrates this point to her class one rainy day using the sculptures students made from polystyrene and with the cornstarch…

  20. ADOPTING THE PROBLEM BASED LEARNING APPROACH IN A GIS PROJECT MANAGEMENT CLASS

    Science.gov (United States)

    Problem Based Learning (PBL) is a process that emphasizes the need for developing problem solving skills through hands-on project formulation and management. A class adopting the PBL method provides students with an environment to acquire necessary knowledge to encounter, unders...

  1. ASYMPTOTIC ESTIMATION FOR SOLUTION OF A CLASS OF SEMI-LINEAR ROBIN PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Cheng Ouyang

    2005-01-01

    A class of semi-linear Robin problem is considered. Under appropriate assumptions, the existence and asymptotic behavior of its solution are studied more carefully. Using stretched variables, the formal asymptotic expansion of solution for the problem is constructed and the uniform validity of the solution is obtained by using the method of upper and lower solution.

  2. Dynamic and stochastic planning problems with online decision making : a novel class of models

    NARCIS (Netherlands)

    Cremers, M.L.A.G.

    2009-01-01

    In this thesis we study planning problems in the area of routing and scheduling by means of mathematical models and (numerical) optimization. Characteristic for this class of problems is that here-and-now decisions have to be made while only probabilistic information is available on the relevant pla

  3. An Analysis on the Problem of Students’ Engagement in English Class

    Institute of Scientific and Technical Information of China (English)

    陈瑜

    2015-01-01

    Students’ engagement in English class is a common problem facing by English teachers.This study analyzes the factors which influence students’ classroom engagement, tries to find out possible solutions to solve this problem from the perspective of SLA theory and teaching approaches and gives implications for future teaching.

  4. Free boundary value problems for a class of generalized diffusion equation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The transport behavior of free boundary value problems for a class of generalized diffusion equations was studied. Suitable similarity transformations were used to convert the problems into a class of singular nonlinear two-point boundary value problems and similarity solutions were numerical presented for different representations of heat conduction function, convection function, heat flux function, and power law parameters by utilizing the shooting technique. The results revealed the flux transfer mechanism and the character as well as the effects of parameters on the solutions.

  5. Some Problems and Solutions of Applying TBLT in a Chinese Large-sized Class

    Institute of Scientific and Technical Information of China (English)

    周尧

    2014-01-01

    This paper mainly looks into the problems of applying Task-based Language Teaching(TBLT) and possible solutions to them.TBLT is now also widely used in Chinese classrooms.It can also be called as "the Age of Task"(Johnson,2001: P.194).However,there are still some problems when TBLT is applied in China.Most of the problems are caused by the large class size and examination-oriented education in China.

  6. A NEW CLASS OF BILEVEL GENERALIZED MIXED EQUILIBRIUM PROBLEMS IN BANACH SPACES

    Institute of Scientific and Technical Information of China (English)

    Ding Xieping

    2012-01-01

    A new class of bilevel generalized mixed equilibrium problems involving setvalued mappings is introduced and studied in a real Banach space.By using the auxiliary principle technique,new iterative algorithms for solving the generalized mixed equilibrium problems and bilevel generalized mixed equilibrium problems involving set-valued mappings are suggested and analyzed.Existence of solutions and strong convergence of the iterative sequences generated by the algorithms are proved under quite mild conditions.The behavior of the solution set of the generalized mixed equilibrium problems and bilevel generalized mixed equilibrium problems is also discussed.These results are new and generalize some recent results in this field.

  7. Prediction-correction alternating direction method for a class of constrained rain-max problems

    Institute of Scientific and Technical Information of China (English)

    LI Min; HE Bingsheng

    2007-01-01

    The problems concerned in this paper are a class of constrained min-max problems. By introducing the Lagrange multipliers to the linearconstraints, such problems can be solved by some projection type prediction-correction methods. However, to obtain components of the predictor one by one, we use an alternating direction method. And then the new iterate is generated by a minor correction. Global convergence of the proposed method is proved. Finally, numerical results for a constrained single-facility location problem are provided to verify that the new method is effective for some practical problems.

  8. Problems that Class Teachers Faced in the Classroom Related to Undesired Behaviors and Their Solutions

    Directory of Open Access Journals (Sweden)

    Barış ÇETİN

    2013-04-01

    Full Text Available The aim this study is to determine the undesired behaviors of students that class teachers faced in the classroom and their solutions. The sample of the study consists of 37 class teachers working in the provinces of Gumushane, Canakkale, Erzurum, Istanbul, Tekirdag, Kocaeli, Kutahya, Bursa, Samsun, Eskisehir, and Mus in Turkey in the fall term of 2011-2012 academic year. As a result, the undesired behaviors of students that teachers faced in the classroom have been determined as not obeying the class rules, swearing, talking without permission, shyness, hyperactivity and lack of attention, and problems caused by watching violent TV programs (such as threatening. Solutions to these problems have been stated as: punishments and awards, warning, ignoring, behaving more sincerely towards students, including students by means of activities, guidance service, giving assignment, making students sit in front of the class, and playing games.

  9. A rectangle bin packing optimization approach to the signal scheduling problem in the FlexRay static segment

    Institute of Scientific and Technical Information of China (English)

    Rui ZHAO; Gui-he QIN; Jia-qiao LIU

    2016-01-01

    As FlexRay communication protocol is extensively used in distributed real-time applications on vehicles, signal scheduling in FlexRay network becomes a critical issue to ensure the safe and efficient operation of time-critical applications. In this study, we propose a rectangle bin packing optimization approach to schedule communication signals with timing constraints into the FlexRay static segment at minimum bandwidth cost. The proposed approach, which is based on integer linear program-ming (ILP), supports both the slot assignment mechanisms provided by the latest version of the FlexRay specification, namely, the single sender slot multiplexing, and multiple sender slot multiplexing mechanisms. Extensive experiments on a synthetic and an automotive X-by-wire system case study demonstrate that the proposed approach has a well optimized performance.

  10. On the initial value problem for a class of discrete velocity models.

    Science.gov (United States)

    Bellandi, Davide

    2017-02-01

    In this paper we investigate the initial value problem for a class of hyperbolic systems relating the mathematical modeling of a class of complex phenomena, with emphasis on vehicular traffic flow. Existence and uniqueness for large times of solutions, a basic requisite both for models building and for their numerical implementation, are obtained under weak hypotheses on the terms modeling the interaction among agents. The results are then compared with the existing literature on the subject.

  11. The Cauchy problem for a class of pseudodifferential equations over p-adic field

    Science.gov (United States)

    Chuong, Nguyen Minh; Co, Nguyen Van

    2008-04-01

    In this paper, some classes much more general than the one in [N.M. Chuong, Yu.V. Egorov, A. Khrennikov, Y. Meyer, D. Mumford (Eds.), Harmonic, Wavelet and p-Adic Analysis, World Scientific, Singapore, 2007] of Cauchy problems for an interesting class of pseudodifferential equations over p-adic fields are studied. The used functions belong to mixed classes of real and p-adic functions. Even for p-adic partial differential equations such problems in such function spaces have not been discussed yet. The established mathematical foundation requires very complicated and very difficult proofs. Days after days, these equations occur increasingly in mathematical physics, quantum mechanics. Explicit solutions of such problems are very needed for specialists on applied mathematics, physics, and engineering.

  12. Method for dense packing discovery.

    Science.gov (United States)

    Kallus, Yoav; Elser, Veit; Gravel, Simon

    2010-11-01

    The problem of packing a system of particles as densely as possible is foundational in the field of discrete geometry and is a powerful model in the material and biological sciences. As packing problems retreat from the reach of solution by analytic constructions, the importance of an efficient numerical method for conducting de novo (from-scratch) searches for dense packings becomes crucial. In this paper, we use the divide and concur framework to develop a general search method for the solution of periodic constraint problems, and we apply it to the discovery of dense periodic packings. An important feature of the method is the integration of the unit-cell parameters with the other packing variables in the definition of the configuration space. The method we present led to previously reported improvements in the densest-known tetrahedron packing. Here, we use the method to reproduce the densest-known lattice sphere packings and the best-known lattice kissing arrangements in up to 14 and 11 dimensions, respectively, providing numerical evidence for their optimality. For nonspherical particles, we report a dense packing of regular four-dimensional simplices with density ϕ=128/219≈0.5845 and with a similar structure to the densest-known tetrahedron packing.

  13. A recurrent neural network for solving a class of generalized convex optimization problems.

    Science.gov (United States)

    Hosseini, Alireza; Wang, Jun; Hosseini, S Mohammad

    2013-08-01

    In this paper, we propose a penalty-based recurrent neural network for solving a class of constrained optimization problems with generalized convex objective functions. The model has a simple structure described by using a differential inclusion. It is also applicable for any nonsmooth optimization problem with affine equality and convex inequality constraints, provided that the objective function is regular and pseudoconvex on feasible region of the problem. It is proven herein that the state vector of the proposed neural network globally converges to and stays thereafter in the feasible region in finite time, and converges to the optimal solution set of the problem.

  14. Packing Smart

    Centers for Disease Control (CDC) Podcasts

    2011-08-22

    In this podcast for kids, the Kidtastics talk about packing a lunch that's not boring and is full of the power and energy kids need to make it through the day.  Created: 8/22/2011 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 8/22/2011.

  15. Power Packing

    Centers for Disease Control (CDC) Podcasts

    2011-08-16

    In this podcast for kids, the Kidtastics talk about how to pack a lunch safely, to help keep you from getting sick.  Created: 8/16/2011 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 8/16/2011.

  16. An Efficient Approach to a Class of Non-smooth Optimization Problems

    Institute of Scientific and Technical Information of China (English)

    李兴斯

    1994-01-01

    This paper presents an entropy-based smoothing technique for solving a class of non-smooth optimization problems that are in some way related to the maximum function.Basic ideas concerning this approach are that we replace the non-smooth maximum function by a smooth one,called aggregate function,which is derived by employing the maximum entropy principle and its useful properties are proved.Wilh this smoothing technique,both unconstrained and constrained mimma.x problems are transformed into unconstrained optimization problems of smooth functions such that this class of non-smooth optimization problems can be solved by some existing unconstrained optimization softwares for smooth functions The present approach can be very easily implemented on computers with very fast and -.Inhie convergence.

  17. Initial value problem for a class of fourth-order nonlinear wave equations

    Institute of Scientific and Technical Information of China (English)

    Guo-wang CHEN; Chang-shun HOU

    2009-01-01

    In this paper, existence and uniqueness of the generalized global solution and the classical global solution to the initial value problem for a class of fourth-order nonlinear wave equations are studied in the fractional order Sobolev space using the contraction mapping principle and the extension theorem. The sufficient conditions for the blow up of the solution to the initial value problem are given.

  18. BRINGING CULTURAL CONTENT AND AUTHENTIC MATERIALS TO ENHANCE PROBLEM-BASED LEARNING IN EFL CLASSES

    OpenAIRE

    2012-01-01

    In a class where elements and filters of Problem-Based Learning are used, students are engaged in language learning through organied and purposeful activities with authentic materials and collaborative learning models. Research has shown that this approach is effective in raising student’s motivation, enhancing their problem solving and critical thinking skills, and deepening their understanding of the subject contents. This paper aims to answer the questions of when and how authentic materia...

  19. THE NONLINEAR BOUNDARY VALUE PROBLEM FOR A CLASS OF INTEGRO-DIFFERENTIAL SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Rongrong Tang

    2006-01-01

    In this paper, using the theory of differential inequalities, we study the nonlinear boundary value problem for a class of integro-differential system. Under appropriate assumptions, the existence of solution is proved and the uniformly valid asymptotic expansions for arbitrary n-th order approximation and the estimation of remainder term are obtained simply and conveniently.

  20. Initial-boundary value problems for a class of nonlinear thermoelastic plate equations

    Institute of Scientific and Technical Information of China (English)

    Zhang Jian-Wen; Rong Xiao-Liang; Wu Run-Heng

    2009-01-01

    This paper studies initial-boundary value problems for a class of nonlinear thermoelastic plate equations. Under some certain initial data and boundary conditions,it obtains an existence and uniqueness theorem of global weak solutions of the nonlinear thermoelstic plate equations,by means of the Galerkin method. Moreover,it also proves the existence of strong and classical solutions.

  1. Hydrostatic Pressure Project: Linked-Class Problem-Based Learning in Engineering

    Science.gov (United States)

    Davis, Freddie J.; Lockwood-Cooke, Pamela; Hunt, Emily M.

    2011-01-01

    Over the last few years, WTAMU Mathematics, Engineering and Science faculty has used interdisciplinary projects as the basis for implementation of a linked-class approach to Problem-Based Learning (PBL). A project that has significant relevance to engineering statics, fluid mechanics, and calculus is the Hydrostatic Pressure Project. This project…

  2. Behaviour problems of young motor disabled children at home and in the therapeutic toddler class

    NARCIS (Netherlands)

    Hendriks, A.H.C.; Moor, J.M.H. de; Oud, J.H.L.; Franken, W.M.; Savelberg, M.M.H.W.

    2001-01-01

    Behaviour problems of young motor disabled children at home and in the therapeutic toddler class were examined and possible determinants and parents' need for and received help were assessed. The study is based on a representative sample of 81 motor disabled children with central nervous system rela

  3. EXISTENCE OF SOLUTIONS TO A CLASS OF NONLINEAR n-DIMENSIONAL DISCRETE BOUNDARY VALUE PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    In this paper,using the critical point theory,we obtain a new result on the existence of the solutions to a class of n-dimensional discrete boundary value problems.Results obtained extend or improve the existing ones.

  4. Solvability for a Class of Abstract Two-Point Boundary Value Problems Derived from Optimal Control

    Directory of Open Access Journals (Sweden)

    Wang Lianwen

    2007-01-01

    Full Text Available The solvability for a class of abstract two-point boundary value problems derived from optimal control is discussed. By homotopy technique existence and uniqueness results are established under some monotonic conditions. Several examples are given to illustrate the application of the obtained results.

  5. Solvability for a Class of Abstract Two-Point Boundary Value Problems Derived from Optimal Control

    Directory of Open Access Journals (Sweden)

    Lianwen Wang

    2008-01-01

    Full Text Available The solvability for a class of abstract two-point boundary value problems derived from optimal control is discussed. By homotopy technique existence and uniqueness results are established under some monotonic conditions. Several examples are given to illustrate the application of the obtained results.

  6. SOLVING A CLASS OF INVERSE QP PROBLEMS BY A SMOOTHING NEWTON METHOD

    Institute of Scientific and Technical Information of China (English)

    Xiantao Xiao; Liwei Zhang

    2009-01-01

    We consider an inverse quadratic programming (IQP) problem in which the parameters in the objective function of a given quadratic programming (QP) problem are adjusted as little as possible so that a known feasible solution becomes the optimal one. This problem can be formulated as a minimization problem with a positive semidefinite cone constraint and its dual (denoted IQD(A, b)) is a semismoothly differentiable (SC~1) convex program-ming problem with fewer variables than the original one. In this paper a smoothing New-ton method is used for getting a Karush-Kuhn-Tucker point of IQD(A, b). The proposed method needs to solve only one linear system per iteration and achieves quadratic conver-gence. Numerical experiments are reported to show that the smoothing Newton method is effective for solving this class of inverse quadratic programming problems.

  7. L1-norm packings from function fields

    Institute of Scientific and Technical Information of China (English)

    LI Hongli

    2005-01-01

    In this paper, we study some packings in a cube, namely, how to pack n points in a cube so as to maximize the minimal distance. The distance is induced by the L1-norm which is analogous to the Hamming distance in coding theory. Two constructions with reasonable parameters are obtained, by using some results from a function field including divisor class group, narrow ray class group, and so on. We also present some asymptotic results of the two packings.

  8. Solving the coincidence problem in a large class of running vacuum cosmologies

    CERN Document Server

    Zilioti, G J M; Lima, J A S

    2015-01-01

    Decaying vacuum cosmological models evolving smoothly between two extreme (very early and late time) de Sitter phases are capable to solve naturally several cosmic problems, among them: (i) the singularity, (ii) the horizon, (iii) the graceful-exit from inflation. Here we discuss a solution the coincidence problem based on a large class of running vacuum cosmologies evolving from de Sitter to de Sitter recently proposed. It is argued that even the cosmological constant problem can be solved provided that the characteristic scales of the limiting de Sitter manifolds are predicted from first principles.

  9. Asymptotic solution for a class of weakly nonlinear singularly perturbed reaction diffusion problem

    Institute of Scientific and Technical Information of China (English)

    TANG Rong-rong

    2009-01-01

    Under appropriate conditions, with the perturbation method and the theory of differential inequalities, a class of weakly nonlinear singularly perturbed reaction diffusion problem is considered. The existence of solution of the original problem is proved by constructing the auxiliary functions. The uniformly valid asymptotic expansions of the solution for arbitrary mth order approximation are obtained through constructing the formal solutions of the original problem, expanding the nonlinear terms to the power in small parameter e and comparing the coefficient for the same powers of ε. Finally, an example is provided, resulting in the error of O(ε2).

  10. Lie and Conditional Symmetries of a Class of Nonlinear (1 + 2-Dimensional Boundary Value Problems

    Directory of Open Access Journals (Sweden)

    Roman Cherniha

    2015-08-01

    Full Text Available A new definition of conditional invariance for boundary value problems involving a wide range of boundary conditions (including initial value problems as a special case is proposed. It is shown that other definitions worked out in order to find Lie symmetries of boundary value problems with standard boundary conditions, followed as particular cases from our definition. Simple examples of direct applicability to the nonlinear problems arising in applications are demonstrated. Moreover, the successful application of the definition for the Lie and conditional symmetry classification of a class of (1 + 2-dimensional nonlinear boundary value problems governed by the nonlinear diffusion equation in a semi-infinite domain is realised. In particular, it is proven that there is a special exponent, k ≠ —2, for the power diffusivity uk when the problem in question with non-vanishing flux on the boundary admits additional Lie symmetry operators compared to the case k ≠ —2. In order to demonstrate the applicability of the symmetries derived, they are used for reducing the nonlinear problems with power diffusivity uk and a constant non-zero flux on the boundary (such problems are common in applications and describing a wide range of phenomena to (1 + 1-dimensional problems. The structure and properties of the problems obtained are briefly analysed. Finally, some results demonstrating how Lie invariance of the boundary value problem in question depends on the geometry of the domain are presented.

  11. Hybrid Method for a Class of Stochastic Bi-criteria Optimization Problems

    Directory of Open Access Journals (Sweden)

    Wan Zhong

    2010-01-01

    Full Text Available We study a class of stochastic bi-criteria optimization problems with one quadratic and one linear objective functions and some linear inequality constraints. A hybrid method of chance-constrained programming (CCP combined with variance expectation (VE is proposed to find the optimal solution of the original problem. By introducing the expectation level, the bi-criteria problem is converted into a single-objective problem. By introducing the confidence level and the preference level of decision maker, we obtain a relaxed robust deterministic formulation of the stochastic problem. Then, an interactive algorithm is developed to solve the obtained deterministic model with three parameters, reflecting the preferences of decision maker. Numerical experiments show that the proposed method is superior to the existing methods. The optimal solution obtained by our method has less violation of the constraints and reflects the satisfaction degree of decision-maker.

  12. Orthosurgical management of an asymmetric case with class III malocclusion and transversal problem in the maxilla

    Directory of Open Access Journals (Sweden)

    Juan Carlos Perez Varela

    2016-01-01

    Full Text Available Class III malocclusions are considered to be one of the most difficult problems to treat. For us, the complex of these cases is the esthetic of the face and the smile because the treatment of the malocclusions without surgery produces a more retrusive face. We present a case report of an adult male patient with skeletal Class III malocclusion with compression in the maxilla and mandibular asymmetry, who has treated the orthosurgical approach. The result is acceptable in terms of occlusion-function, esthetic of the smile, and facial esthetics.

  13. Valve Packing

    Science.gov (United States)

    1992-01-01

    "S Glass" yarn was originally developed by NASA for high temperature space and aeronautical applications. When John Crane, Inc. required material that would withstand temperatures higher than 1,200 degrees Fahrenheit, they contacted Owens-Corning, which had developed a number of applications for the material. John Crane combines the yarn with other components to make Style 287-I packing. The product can be used in chemical processing operations, nuclear power stations, petroleum products, etc. Advantages include increased service life and reduced maintenance costs.

  14. A new class of symmetric periodic solutions of the spatial elliptic restricted three-body problem

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    We show that there exists a new class of symmetric periodic solutions of the spatial elliptic restricted three-body problem. In such a solution, the infinitesimal body is confined to the vicinity of a primary and moves on a nearly circular orbit. This orbit is almost perpendicular to the orbital plane of the primaries, where the line of symmetry of the orbit lies. The existence is shown by applying a corollary of Arenstorf’s fixed point theorem to a periodicity equation system of the problem. And this existence doesn’t require any restriction on the mass ratio of the primaries, nor on the eccentricity of their relative elliptic orbit. Potential relevance of this new class of periodic solutions to real celestial body systems and the follow-up studies in this respect are also discussed.

  15. A new class of symmetric periodic solutions of the spatial elliptic restricted three-body problem

    Institute of Scientific and Technical Information of China (English)

    XU XingBo; FU YanNing

    2009-01-01

    We show that there exists a new class of symmetric periodic solutions of the spatial elliptic restricted three-body problem.In such a solution,the infinitesimal body is confined to the vicinity of a primary and moves on a nearly circular orbit.This orbit is almost perpendicular to the orbital plane of the pri-maries,where the line of symmetry of the orbit lies.The existence is shown by applying a corollary of Arenstorf's fixed point theorem to s periodicity equation system of the problem.And this existence doesn't require any restriction on the mass ratio of the primaries,nor on the eccentricity of their rela-tive elliptic orbit.Potential relevance of this new class of periodic solutions to real celestial body sys-tems and the follow-up studies in this respect are also discussed.

  16. A New Class of Complementarity Function and the Boundedness of Its Merit Function for Symmetric Cone Complementarity Problem

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun-sheng

    2014-01-01

    In this paper, we introduce a new class of two-parametric penalized function, which includes the penalized minimum function and the penalized Fischer-Burmeister func-tion over symmetric cone complementarity problems. We propose that this class of function is a class of complementarity functions(C-function). Moreover, its merit function has bounded level set under a weak condition.

  17. INTERVAL ADJUSTABLE ENTROPY ALGORITHM FOR A CLASS OF UNCONSTRAINED DISCRETE MINIMAX PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    LiSubei; CaoDexin; WangHaijun; DengKazhong

    2004-01-01

    In this paper,a class of unconstrained discrete minimax problems is described,in which the objective functions are in C1. The paper deals with this problem by means of taking the place of maximum-entropy function with adjustable entropy function. By constructing an interval extension of adjustable entropy function and some region deletion test rules, a new interval algorithm is presented. The relevant properties are proven, The minimax value and the localization of the minimax points of the problem can be obtained by this method. This method can overcome the flow problem in the maximum-entropy algorithm. Both theoretical and numerical results show that the method is reliable and efficient.

  18. A New Global Optimization Algorithm for Solving a Class of Nonconvex Programming Problems

    Directory of Open Access Journals (Sweden)

    Xue-Gang Zhou

    2014-01-01

    Full Text Available A new two-part parametric linearization technique is proposed globally to a class of nonconvex programming problems (NPP. Firstly, a two-part parametric linearization method is adopted to construct the underestimator of objective and constraint functions, by utilizing a transformation and a parametric linear upper bounding function (LUBF and a linear lower bounding function (LLBF of a natural logarithm function and an exponential function with e as the base, respectively. Then, a sequence of relaxation lower linear programming problems, which are embedded in a branch-and-bound algorithm, are derived in an initial nonconvex programming problem. The proposed algorithm is converged to global optimal solution by means of a subsequent solution to a series of linear programming problems. Finally, some examples are given to illustrate the feasibility of the presented algorithm.

  19. Existence results for a class of nonlocal problems involving p-Laplacian

    OpenAIRE

    Zhang Jihui; Yang Yang

    2011-01-01

    Abstract This paper is concerned with the existence of solutions to a class of p-Kirchhoff type equations with Neumann boundary data as follows: - M ∫ Ω ∇ u p d x p - 1 Δ p u = f ( x , u ) , in Ω ; ∂ u ∂ υ = 0 , on ∂ Ω . By means of a direct variational approach, we establish conditions ensuring the existence and multiplicity of solutions for the problem.

  20. Existence results for a class of nonlocal problems involving p-Laplacian

    Directory of Open Access Journals (Sweden)

    Zhang Jihui

    2011-01-01

    Full Text Available Abstract This paper is concerned with the existence of solutions to a class of p-Kirchhoff type equations with Neumann boundary data as follows: - M ∫ Ω ∇ u p d x p - 1 Δ p u = f ( x , u , in Ω ; ∂ u ∂ υ = 0 , on ∂ Ω . By means of a direct variational approach, we establish conditions ensuring the existence and multiplicity of solutions for the problem.

  1. An Efficient Pseudospectral Method for Solving a Class of Nonlinear Optimal Control Problems

    OpenAIRE

    Emran Tohidi; Atena Pasban; Kilicman, A.; S. Lotfi Noghabi

    2013-01-01

    This paper gives a robust pseudospectral scheme for solving a class of nonlinear optimal control problems (OCPs) governed by differential inclusions. The basic idea includes two major stages. At the first stage, we linearize the nonlinear dynamical system by an interesting technique which is called linear combination property of intervals. After this stage, the linearized dynamical system is transformed into a multi domain dynamical system via computational interval partitioning. Moreover,...

  2. A New Neural Network for Solving a Class of Constrained Least Square Problems

    Institute of Scientific and Technical Information of China (English)

    YE Dazhen; XIA Youshen; WU Xinyu

    2001-01-01

    A new neural network for solvinga class of constrained least square problems is pre-sented. The network is shown to be completely stableand globally convergent to the exact solutions to theconstrained least square problem. In contrast to theneural network proposed in the Ref.[1], our new neu-ral network has the following advantages in two ma-jor aspects. First, the convergent region of this newnetwork is the whole space Rn. Second, in hardwareimplementations this new network does not need theexpensive analogue multiplier for variables.

  3. Symmetry Reduction and Cauchy Problems for a Class of Fourth-Order Evolution Equations

    Institute of Scientific and Technical Information of China (English)

    LI Ji-Na; ZHANG Shun-Li

    2008-01-01

    We exploit higher-order conditional symmetry to reduce initial-value problems for evolution equations to Cauehy problems for systems of ordinary differential equations (ODEs).We classify a class of fourth-order evolution equations which admit certain higher-order generalized conditional symmetries (GCSs) and give some examples to show the main reduction procedure.These reductions cannot be derived within the framework of the standard Lie approach,which hints that the technique presented here is something essential for the dimensional reduction of evolution equations.

  4. Improving classification of mature microRNA by solving class imbalance problem

    Science.gov (United States)

    Wang, Ying; Li, Xiaoye; Tao, Bairui

    2016-05-01

    MicroRNAs (miRNAs) are ~20–25 nucleotides non-coding RNAs, which regulated gene expression in the post-transcriptional level. The accurate rate of identifying the start sit of mature miRNA from a given pre-miRNA remains lower. It is noting that the mature miRNA prediction is a class-imbalanced problem which also leads to the unsatisfactory performance of these methods. We improved the prediction accuracy of classifier using balanced datasets and presented MatFind which is used for identifying 5‧ mature miRNAs candidates from their pre-miRNA based on ensemble SVM classifiers with idea of adaboost. Firstly, the balanced-dataset was extract based on K-nearest neighbor algorithm. Secondly, the multiple SVM classifiers were trained in orderly using the balance datasets base on represented features. At last, all SVM classifiers were combined together to form the ensemble classifier. Our results on independent testing dataset show that the proposed method is more efficient than one without treating class imbalance problem. Moreover, MatFind achieves much higher classification accuracy than other three approaches. The ensemble SVM classifiers and balanced-datasets can solve the class-imbalanced problem, as well as improve performance of classifier for mature miRNA identification. MatFind is an accurate and fast method for 5‧ mature miRNA identification.

  5. Improved Online Square-into-Square Packing

    OpenAIRE

    Brubach, Brian

    2014-01-01

    In this paper, we show an improved bound and new algorithm for the online square-into-square packing problem. This two-dimensional packing problem involves packing an online sequence of squares into a unit square container without any two squares overlapping. The goal is to find the largest area $\\alpha$ such that any set of squares with total area $\\alpha$ can be packed. We show an algorithm that can pack any set of squares with total area $\\alpha \\leq 3/8$ into a unit square in an online se...

  6. Circle Packing for Origami Design Is Hard

    CERN Document Server

    Demaine, Erik D; Lang, Robert J

    2010-01-01

    We show that deciding whether a given set of circles can be packed into a rectangle, an equilateral triangle, or a unit square are NP-hard problems, settling the complexity of these natural packing problems. On the positive side, we show that any set of circles of total area 1 can be packed into a square of size 8/pi=2.546... These results are motivated by problems arising in the context of origami design.

  7. Enhancing Higher Order Thinking Skills In A Marine Biology Class Through Problem-Based Learning

    Directory of Open Access Journals (Sweden)

    Richard M. Magsino

    2014-10-01

    Full Text Available The purpose of this research was to examine students' perspectives of their learning in marine biology in the collaborative group context of Problem-based Learning (PBL. Students’ higher order thinking skills (HOTS using PBL involves the development of their logical thinking and reasoning abilities which stimulates their curiosity and associative thinking. This study aimed to investigate how critical thinking skills, particularly analysis, synthesis and evaluation were enhanced in a marine biology class through PBL. Qualitative research approach was used to examine student responses in a questionnaire involving 10 open-ended questions that target students’ HOTS on a problem presented in a marine biology class for BS Biology students. Using axial coding as a qualitative data analysis technique by which grounded theory can be performed, the study was able to determine how students manifest their higher reasoning abilities when confronted with a marine biology situation. Results show student responses yielding affirmative remarks on the 10 questions intended to know their level of analysis (e.g., analyzing, classifying, inferring, discriminating and relating or connecting, synthesis (e.g., synthesizing and collaborating, and evaluation (e.g., comparing, criticizing, and convincing of information from the presented marine biology problem. Consequently, students were able to effectively design experiments to address the presented issue through problem-based learning. Results of the study show that PBL is an efficient instructional strategy embedded within a conventional curriculum used to develop or enhance critical thinking in marine biology.

  8. The pursuit of perfect packing

    CERN Document Server

    Weaire, Denis

    2008-01-01

    Coauthored by one of the creators of the most efficient space packing solution, the Weaire-Phelan structure, The Pursuit of Perfect Packing, Second Edition explores a problem of importance in physics, mathematics, chemistry, biology, and engineering: the packing of structures. Maintaining its mathematical core, this edition continues and revises some of the stories from its predecessor while adding several new examples and applications. The book focuses on both scientific and everyday problems ranging from atoms to honeycombs. It describes packing models, such as the Kepler conjecture, Voronoï decomposition, and Delaunay decomposition, as well as actual structure models, such as the Kelvin cell and the Weaire-Phelan structure. The authors discuss numerous historical aspects and provide biographical details on influential contributors to the field, including emails from Thomas Hales and Ken Brakke. With examples from physics, crystallography, engineering, and biology, this accessible and whimsical bo...

  9. Optimality conditions and duality for a class of nondifferentiable multiobjective generalized fractional programming problems

    Institute of Scientific and Technical Information of China (English)

    GAO Ying; RONG Wei-dong

    2008-01-01

    This paper studies a class of multiobjective generalized fractional programming problems, where the numerators of objective functions are the sum of differentiable function and convex function, while the denominators are the difference of differentiable function and convex function. Under the assumption of Calmness Constraint Qualification the Kuhn-Tucker type necessary conditions for efficient solution are given, and the Kuhn-Tucker type sufficient conditions for efficient solution are presented under the assumptions of (F, α, ρ, d)-V-convexity.Subsequently, the optimality conditions for two kinds of duality models are formulated and duality theorems are proved.

  10. Research on the Optimal Parallel Algorithms of Broadcast—Class Problems

    Institute of Scientific and Technical Information of China (English)

    李晓峰; 寿标; 等

    1998-01-01

    Speedup is considered as the criterion of determining whether a parallel algorithm is optimal.But broadcast-class problems,existing only on parallel computer system,have no sequential algorithms at all.Speedup standard becomes invalid here.Through this research on broadcast algorithms under several typical prallel computation models,a model-independent evaluation standard min C2 is developed,which can be not only used to determine an optimal broadcasting algorithm,but also normalized to apply to any parallel algorithm.As a new idea,min C2 will lead to a new way in this field.

  11. A multiplicity result for a class of quasilinear elliptic and parabolic problems

    Directory of Open Access Journals (Sweden)

    M. R. Grossinho

    1997-04-01

    Full Text Available We prove the existence of infinitely many solutions for a class of quasilinear elliptic and parabolic equations, subject respectively to Dirichlet and Dirichlet-periodic boundary conditions. We assume that the primitive of the nonlinearity at the right-hand side oscillates at infinity. The proof is based on the construction of upper and lower solutions, which are obtained as solutions of suitable comparison equations. This method allows the introduction of conditions on the potential for the study of parabolic problems, as well as to treat simultaneously the singular and the degenerate case.

  12. Application of a hybrid generation/utility assessment heuristic to a class of scheduling problems

    Science.gov (United States)

    Heyward, Ann O.

    1989-01-01

    A two-stage heuristic solution approach for a class of multiobjective, n-job, 1-machine scheduling problems is described. Minimization of job-to-job interference for n jobs is sought. The first stage generates alternative schedule sequences by interchanging pairs of schedule elements. The set of alternative sequences can represent nodes of a decision tree; each node is reached via decision to interchange job elements. The second stage selects the parent node for the next generation of alternative sequences through automated paired comparison of objective performance for all current nodes. An application of the heuristic approach to communications satellite systems planning is presented.

  13. NEUMANN PROBLEMS OF A CLASS OF ELLIPTIC EQUATIONS WITH DOUBLY CRITICAL SOBOLEV EXPONENTS

    Institute of Scientific and Technical Information of China (English)

    韩丕功

    2004-01-01

    This paper deals with the Neumann problem for a class of semilinear elliptic equations -△u + u =|u|2*- 2u + μ|u|q- 2u in Ω, u/r=|u|s*- 2u on Ω, where 2* = 2N/N- 2,s*=2(N- 1)/N-2, 1 < q < 2, N ≥ 3, μ> 0,γ denotes the unit outward normal to boundaryΩ. By variational method and dual fountain theorem, the existence of infinitely many solutions with negative energy is proved.

  14. Damped Arrow-Hurwicz algorithm for sphere packing

    Science.gov (United States)

    Degond, Pierre; Ferreira, Marina A.; Motsch, Sebastien

    2017-03-01

    We consider algorithms that, from an arbitrarily sampling of N spheres (possibly overlapping), find a close packed configuration without overlapping. These problems can be formulated as minimization problems with non-convex constraints. For such packing problems, we observe that the classical iterative Arrow-Hurwicz algorithm does not converge. We derive a novel algorithm from a multi-step variant of the Arrow-Hurwicz scheme with damping. We compare this algorithm with classical algorithms belonging to the class of linearly constrained Lagrangian methods and show that it performs better. We provide an analysis of the convergence of these algorithms in the simple case of two spheres in one spatial dimension. Finally, we investigate the behaviour of our algorithm when the number of spheres is large in two and three spatial dimensions.

  15. A class of singular Ro-matrices and extensions to semidefinite linear complementarity problems

    Directory of Open Access Journals (Sweden)

    Sivakumar K.C.

    2013-01-01

    Full Text Available For ARnxn and qRn, the linear complementarity problem LCP(A, q is to determine if there is xRn such that x ≥ 0; y = Ax + q ≥ 0 and xT y = 0. Such an x is called a solution of LCP(A,q. A is called an Ro-matrix if LCP(A,0 has zero as the only solution. In this article, the class of R0-matrices is extended to include typically singular matrices, by requiring in addition that the solution x above belongs to a subspace of Rn. This idea is then extended to semidefinite linear complementarity problems, where a characterization is presented for the multplicative transformation.

  16. Reflective discourse techniques: From in-class discussions to out-of-classroom problem solving

    Science.gov (United States)

    Wampler, Wendi; Demaree, Dedra; Gilbert, Dennis

    2013-01-01

    Instructors often give prompts that encourage students to articulate their beliefs and conceptions, as well as encourage students to understand the thoughts of their peers. This reflective discourse is used in a calculus-based introductory physics class at Lane Community College, where the instructor explicitly has discourse goals integrated into his course structure. We investigate whether students utilize this discourse when solving problems outside of the classroom context. We interviewed groups of students after the end of spring term, 2012. The students were asked to solve open-ended problems, with analysis focused on whether students applied this reflective discourse. Students were asked a series of follow-up questions to reflect upon their experiences in the course.

  17. A Selective Dynamic Sampling Back-Propagation Approach for Handling the Two-Class Imbalance Problem

    Directory of Open Access Journals (Sweden)

    Roberto Alejo

    2016-07-01

    Full Text Available In this work, we developed a Selective Dynamic Sampling Approach (SDSA to deal with the class imbalance problem. It is based on the idea of using only the most appropriate samples during the neural network training stage. The “average samples”are the best to train the neural network, they are neither hard, nor easy to learn, and they could improve the classifier performance. The experimental results show that the proposed method is a successful method to deal with the two-class imbalance problem. It is very competitive with respect to well-known over-sampling approaches and dynamic sampling approaches, even often outperforming the under-sampling and standard back-propagation methods. SDSA is a very simple method for automatically selecting the most appropriate samples (average samples during the training of the back-propagation, and it is very efficient. In the training stage, SDSA uses significantly fewer samples than the popular over-sampling approaches and even than the standard back-propagation trained with the original dataset.

  18. An Efficient Cost-Sensitive Feature Selection Using Chaos Genetic Algorithm for Class Imbalance Problem

    Directory of Open Access Journals (Sweden)

    Jing Bian

    2016-01-01

    Full Text Available In the era of big data, feature selection is an essential process in machine learning. Although the class imbalance problem has recently attracted a great deal of attention, little effort has been undertaken to develop feature selection techniques. In addition, most applications involving feature selection focus on classification accuracy but not cost, although costs are important. To cope with imbalance problems, we developed a cost-sensitive feature selection algorithm that adds the cost-based evaluation function of a filter feature selection using a chaos genetic algorithm, referred to as CSFSG. The evaluation function considers both feature-acquiring costs (test costs and misclassification costs in the field of network security, thereby weakening the influence of many instances from the majority of classes in large-scale datasets. The CSFSG algorithm reduces the total cost of feature selection and trades off both factors. The behavior of the CSFSG algorithm is tested on a large-scale dataset of network security, using two kinds of classifiers: C4.5 and k-nearest neighbor (KNN. The results of the experimental research show that the approach is efficient and able to effectively improve classification accuracy and to decrease classification time. In addition, the results of our method are more promising than the results of other cost-sensitive feature selection algorithms.

  19. Infeasible-interior-point algorithm for a class of nonmonotone complementarity problems and its computational complexity

    Institute of Scientific and Technical Information of China (English)

    HE; Shanglu

    2001-01-01

    [1]Andersen, E. D., Ye, Y., On homogeneous algorithm for the monotone complementarity problem, Mathematical Programming, 1999, 84(2): 375.[2]Wright, S., Ralph, D., A supperlinear infeasible-interior-point algorithm for monotone complementarity problems, Mathematics of Operations Research, 1996, 24(4): 815.[3]Kojima, M., Noma, T., Yoshise, A., Global convergence in infeasible-interior-point algorithms, Mathematical Programming, 1994, 65(1): 43.[4]Kojima, M., Megiddo, N., Noma, T., A new continuation method for complementarity problems with uniform p-functions, Mathematical Programming, 1989, 43(1): 107.[5]Kojima, M., Megiddo, N., Mizuno, S., A general framework of continuation method for complementarity problems, Mathematics of Operations Research, 1993, 18(4): 945.[6]More, J., Rheinboldt, W., On P- and S-functions and related classes of n-dimensional nonlinear mappings, Linear Algebra and Its Applications, 1973, 6(1): 45.

  20. Personality types in childhood: relations to latent trajectory classes of problem behavior and overreactive parenting across the transition into adolescence

    NARCIS (Netherlands)

    van den Akker, A.L.; Deković, M.; Asscher, J.J.; Shiner, R.L.; Prinzie, P.

    2013-01-01

    This study investigated relations among children's personality types, trajectories of internalizing and externalizing problems, and overreactive parenting across 6 years. Latent Class Analysis of the Big 5 personality dimensions (modeled as latent factors, based on mother, father and teacher reports

  1. The pursuit of perfect packing

    CERN Document Server

    Weaire, Denis

    2000-01-01

    In 1998 Thomas Hales dramatically announced the solution of a problem that has long teased eminent mathematicians: what is the densest possible arrangement of identical spheres? The Pursuit of Perfect Packing recounts the story of this problem and many others that have to do with packing things together. The examples are taken from mathematics, physics, biology, and engineering, including the arrangement of soap bubbles in foam, atoms in a crystal, the architecture of the bee''s honeycomb, and the structure of the Giant''s Causeway. Using an informal style and with key references, the book also includes brief accounts of the lives of many of the scientists who devoted themselves to problems of packing over many centuries, together with wry comments on their efforts. It is an entertaining introduction to the field for both specialists and the more general public.

  2. 求解0-1背包问题的二进制狼群算法%A binary wolf pack algorithm for solving 0-1 knapsack problem

    Institute of Scientific and Technical Information of China (English)

    吴虎胜; 张凤鸣; 战仁军; 汪送; 张超

    2014-01-01

    狼群算法(wolf pack algorithm,WPA)源于狼群在捕食及其猎物分配中所体现的群体智能,已被成功应用于复杂函数求解。在此基础上,通过定义运动算子,对人工狼位置、步长和智能行为重新进行二进制编码设计,提出了一种解决离散空间组合优化问题的二进制狼群算法(binary wolf pack algorithm,BWPA)。该算法保留了狼群算法基于职责分工的协作式搜索特性,选取离散空间的经典问题---0-1背包问题进行仿真实验,具体通过10组经典的背包问题算例和 BWPA 算法与经典的二进制粒子群算法、贪婪遗传算法、量子遗传算法在求解3组高维背包问题时的对比计算,例证了算法具有相对更好的稳定性和全局寻优能力。%The wolf pack algorithm (WPA),inspired by swarm intelligence of wolf pack in their prey hun-ting behaviors and distribution mode,has been proposed and successfully applied in complex function optimiza-tion problems.Based on the designing of the move operator,the artificial wolves’position,step-length and in-telligent behaviors are redesigned by binary coding,and a binary wolf pack algorithm (BWPA)is proposed to solve combinatorial optimization problems in discrete spaces.BWPA preserves the feature of cooperative search-ing based on job distribution of the wolf pack and is applied to 10 classic 0-1 knapsack problems.Moreover,the 3 high-dimensional 0-1 knapsack problems are tested.All results show that BWPA has better global convergence and computational robustness and outperforms the binary particle swarm optimization algorithm,the greedy genetic al-gorithm and the quantum genetic algorithm,especially for high-dimensional knapsack problems.

  3. Packing ellipsoids with overlap

    CERN Document Server

    Uhler, Caroline

    2012-01-01

    The problem of packing ellipsoids of different sizes and shapes into an ellipsoidal container so as to minimize a measure of overlap between ellipsoids is considered. A bilevel optimization formulation is given, together with an algorithm for the general case and a simpler algorithm for the special case in which all ellipsoids are in fact spheres. Convergence results are proved and computational experience is described and illustrated. The motivating application - chromosome organization in the human cell nucleus - is discussed briefly, and some illustrative results are presented.

  4. ExactPack Documentation

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, Jr., Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Israel, Daniel M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Doebling, Scott William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Woods, Charles Nathan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kaul, Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Walter, Jr., John William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rogers, Michael Lloyd [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-09

    For code verification, one compares the code output against known exact solutions. There are many standard test problems used in this capacity, such as the Noh and Sedov problems. ExactPack is a utility that integrates many of these exact solution codes into a common API (application program interface), and can be used as a stand-alone code or as a python package. ExactPack consists of python driver scripts that access a library of exact solutions written in Fortran or Python. The spatial profiles of the relevant physical quantities, such as the density, fluid velocity, sound speed, or internal energy, are returned at a time specified by the user. The solution profiles can be viewed and examined by a command line interface or a graphical user interface, and a number of analysis tools and unit tests are also provided. We have documented the physics of each problem in the solution library, and provided complete documentation on how to extend the library to include additional exact solutions. ExactPack’s code architecture makes it easy to extend the solution-code library to include additional exact solutions in a robust, reliable, and maintainable manner.

  5. [Research progress on standards of commodity classes of Chinese materia medica and discussion on several key problems].

    Science.gov (United States)

    Yang, Guang; Zeng, Yan; Guo, Lan-Ping; Huang, Lu-Qi; Jin, Yan; Zheng, Yu-Guang; Wang, Yong-Yan

    2014-05-01

    Standards of commodity classes of Chinese materia medica is an important way to solve the "Lemons Problem" of traditional Chinese medicine market. Standards of commodity classes are also helpful to rebuild market mechanisms for "high price for good quality". The previous edition of commodity classes standards of Chinese materia medica was made 30 years ago. It is no longer adapted to the market demand. This article researched progress on standards of commodity classes of Chinese materia medica. It considered that biological activity is a better choice than chemical constituents for standards of commodity classes of Chinese materia medica. It is also considered that the key point to set standards of commodity classes is finding the influencing factors between "good quality" and "bad quality". The article also discussed the range of commodity classes of Chinese materia medica, and how to coordinate standards of pharmacopoeia and commodity classes. According to different demands, diversiform standards can be used in commodity classes of Chinese materia medica, but efficacy is considered the most important index of commodity standard. Decoction pieces can be included in standards of commodity classes of Chinese materia medica. The authors also formulated the standards of commodity classes of Notoginseng Radix as an example, and hope this study can make a positive and promotion effect on traditional Chinese medicine market related research.

  6. Towards optimal packed string matching

    DEFF Research Database (Denmark)

    Ben-Kiki, Oren; Bille, Philip; Breslauer, Dany;

    2014-01-01

    -size string-matching instruction wssm is available in contemporary commodity processors. The other word-size maximum-suffix instruction wslm is only required during the pattern pre-processing. Benchmarks show that our solution can be efficiently implemented, unlike some prior theoretical packed string......In the packed string matching problem, it is assumed that each machine word can accommodate up to α characters, thus an n-character string occupies n/α memory words.(a) We extend the Crochemore–Perrin constant-space O(n)-time string-matching algorithm to run in optimal O(n/α) time and even in real...... matching work.(b) We also consider the complexity of the packed string matching problem in the classical word-RAM model in the absence of the specialized micro-level instructions wssm and wslm. We propose micro-level algorithms for the theoretically efficient emulation using parallel algorithms techniques...

  7. Student collaboration, investigation problems, and technology use in an innovative university mechanics class

    Science.gov (United States)

    Kuech, Robert K.

    This study investigated the learning of a selected group of students within a calculus based, university physics course organized to incorporate strategies of effective learning and instruction including: collaborative grouping, authentic investigations, and easy access to technology tools. More than half the students' class time was spent engaged in the investigations with less than one-quarter of the time in lecture. A complementary study has shown that students had high conceptual gains during the course and this study reports similar gains for students in the selected group. This research examined student interactions during group investigations and the roles that may have been played by the problem types, the computer tools, and the behaviors of other students and instructors on conceptual learning. Data were collected from video tapes throughout all sessions of the class while the students worked together on the investigations. Field notes, pre and post-test data, and investigation reports provided contextual and assessment information. A detailed descriptive study was conducted and grounded theory guided the research methodology throughout the study. The research analyses focused especially on student-student student instructor; student-technology and student-problem interactions. Within these interactions the students in the group were observed to engage in important cognitive processes including: recall of previous knowledge that promoted familiarity, reflection on data and hypotheses that promoted intersubjectivity, and elaboration that promoted questioning. These processes appeared to be linked to modifications in the students' conceptual understanding. The instructors generally intended to act as facilitators and helped to guide the students through the investigations. Technology may have provided a means for the students to critically reflect on data collected or test and retest hypotheses, either by ``real time'' plotting of data or the rapid

  8. Polarizable protein packing

    KAUST Repository

    Ng, Albert H.

    2011-01-24

    To incorporate protein polarization effects within a protein combinatorial optimization framework, we decompose the polarizable force field AMOEBA into low order terms. Including terms up to the third-order provides a fair approximation to the full energy while maintaining tractability. We represent the polarizable packing problem for protein G as a hypergraph and solve for optimal rotamers with the FASTER combinatorial optimization algorithm. These approximate energy models can be improved to high accuracy [root mean square deviation (rmsd) < 1 kJ mol -1] via ridge regression. The resulting trained approximations are used to efficiently identify new, low-energy solutions. The approach is general and should allow combinatorial optimization of other many-body problems. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011 Copyright © 2011 Wiley Periodicals, Inc.

  9. Treatment engagement in adolescents with severe psychiatric problems: a latent class analysis.

    Science.gov (United States)

    Roedelof, A J M; Bongers, Ilja L; van Nieuwenhuizen, Chijs

    2013-08-01

    Motivation is considered a pivotal factor in treatment, but a better understanding of this topic is needed. Drieschner et al. (Clin Psychol Rev 23:1115-1137, 2004) proposed to distinguish treatment motivation and treatment engagement. This study aimed to discover whether it is possible to identify classes of adolescents with severe psychiatric problems having comparable profiles of treatment engagement. To this end, professionals filled out the Treatment Engagement Rating Scale 5 times for 49 adolescents (mean age 18.3 years; SD = 1.6) during the first year of case management treatment. Using a longitudinal latent class analysis, the number of profiles of treatment engagement was investigated and described. Results identified three profiles: high (19 clients, 39%), medium (20 clients, 41%) and low (10 clients, 20%). Adolescents with a high engagement profile were at first equally, and later on more engaged in treatment than clients with a medium engagement profile. Adolescents with a low engagement profile made the least effort to engage, except after 30 weeks. Adolescents with a low engagement profile were often substance-dependent males with the lowest scores on the Global Assessment of Functioning Scale after a year. Only adolescents with a high engagement profile improved on global functioning. In conclusion, it is possible to identify different treatment engagement profiles by asking one question about level of global treatment engagement. Frequent assessment of engagement of the individual client as well as including a behavioural component into assessment and treatment may help to improve case management treatment for adolescents with medium and low engagement profiles.

  10. Random close packing of polydisperse jammed emulsions

    Science.gov (United States)

    Brujic, Jasna

    2010-03-01

    Packing problems are everywhere, ranging from oil extraction through porous rocks to grain storage in silos and the compaction of pharmaceutical powders into tablets. At a given density, particulate systems pack into a mechanically stable and amorphous jammed state. Theoretical frameworks have proposed a connection between this jammed state and the glass transition, a thermodynamics of jamming, as well as geometric modeling of random packings. Nevertheless, a simple underlying mechanism for the random assembly of athermal particles, analogous to crystalline ordering, remains unknown. Here we use 3D measurements of polydisperse packings of emulsion droplets to build a simple statistical model in which the complexity of the global packing is distilled into a local stochastic process. From the perspective of a single particle the packing problem is reduced to the random formation of nearest neighbors, followed by a choice of contacts among them. The two key parameters in the model, the available space around a particle and the ratio of contacts to neighbors, are directly obtained from experiments. Remarkably, we demonstrate that this ``granocentric'' view captures the properties of the polydisperse emulsion packing, ranging from the microscopic distributions of nearest neighbors and contacts to local density fluctuations and all the way to the global packing density. Further applications to monodisperse and bidisperse systems quantitatively agree with previously measured trends in global density. This model therefore reveals a general principle of organization for random packing and lays the foundations for a theory of jammed matter.

  11. Accuracy and cut-off point selection in three-class classification problems using a generalization of the Youden index.

    Science.gov (United States)

    Nakas, Christos T; Alonzo, Todd A; Yiannoutsos, Constantin T

    2010-12-10

    We study properties of the index J(3), defined as the accuracy, or the maximum correct classification, for a given three-class classification problem. Specifically, using J(3) one can assess the discrimination between the three distributions and obtain an optimal pair of cut-off points c(1)sum of the correct classification proportions will be maximized. It also serves as the generalization of the Youden index in three-class problems. Parametric and non-parametric approaches for estimation and testing are considered and methods are applied to data from an MRS study on human immunodeficiency virus (HIV) patients.

  12. Dynamic heat transfer problems in a thermal storage unit with packed bed of encapsulated PCM. Analysis in the case of fusible alloy

    Energy Technology Data Exchange (ETDEWEB)

    Asahina, Tadashi; Kosaka, Mineo (Government Industrial Research Inst., Nagoya (Japan))

    1989-06-10

    It is important to know the dynamical properties of a heat storage unit for effective use of energy at low temperature for air conditioning and hot water supply. In the present study, in order to clarify a dynamical heat transfer characteristic of encapsulated heat storage unit in which a fusible alloy was packed as a phase change type heat storage material, temperature changes of the heat storage material and the heat transfer media injecting hot or cold air were measured and were compared with calculated results. Sn-Pb-Bi based molten Rose's alloy metal was poured into the cylindrical aluminum capsules of 20 mm in outside diameter, 1 mm in thickness and 20 mm in height. The packed bed was composed of 4430 capsules stacked in ten steps. Measured values of temperature change of the heat storage unit in the process of heat storage and radiation conformed sufficiently with calculated values, and thus showed that an assumed simple models in calculation were adequate. This heat storage unit with packed bed of encapsulated phase change material has comparatively sufficient characteristic of heat trantsient response and has a wider range of application as a higher efficient heat storage unit with constant temperature thermal output. 13 refs., 9 figs.

  13. Linear Matrix Inequality Method for a Quadratic Performance Index Minimization Problem with a class of Bilinear Matrix Inequality Conditions

    Science.gov (United States)

    Tanemura, M.; Chida, Y.

    2016-09-01

    There are a lot of design problems of control system which are expressed as a performance index minimization under BMI conditions. However, a minimization problem expressed as LMIs can be easily solved because of the convex property of LMIs. Therefore, many researchers have been studying transforming a variety of control design problems into convex minimization problems expressed as LMIs. This paper proposes an LMI method for a quadratic performance index minimization problem with a class of BMI conditions. The minimization problem treated in this paper includes design problems of state-feedback gain for switched system and so on. The effectiveness of the proposed method is verified through a state-feedback gain design for switched systems and a numerical simulation using the designed feedback gains.

  14. Poly-cross-linked PEI through aromatically conjugated imine linkages as a new class of pH-responsive nucleic acids packing cationic polymers

    Directory of Open Access Journals (Sweden)

    Shun eChen

    2016-02-01

    Full Text Available Cationic polyimines polymerized through aromatically conjugated bis-imine linkages and intra-molecular cross-linking were found to be a new class of effective transfection materials for their flexibility in structural optimization, responsiveness to intracellular environment, the ability to facilitate endosome escape and cytosol release of the nucleic acids, as well as self-metabolism. When three phthalaldehydes of different substitution positions were used to polymerize highly branched low molecular weight polyethylenimine (PEI-1.8K, the product through ortho-phthalimines (named PPOP showed significantly higher transfection activity than its two tere- and iso-analogues (named PPTP and PPIP. Physicochemical characterization confirmed the similarity of three polyimines in pH-responded degradability, buffer capacity, as well as the size and Zeta potential of the polyplexes formed from the polymers. A mechanistic speculation may be that the ortho-positioned bis-imine linkage of PPOP may only lead to the straight trans-configuration due to steric hindrance, resulting in larger loops of intra-polymer cross-linking and more flexible backbone.

  15. Hard sphere packings within cylinders.

    Science.gov (United States)

    Fu, Lin; Steinhardt, William; Zhao, Hao; Socolar, Joshua E S; Charbonneau, Patrick

    2016-03-07

    Arrangements of identical hard spheres confined to a cylinder with hard walls have been used to model experimental systems, such as fullerenes in nanotubes and colloidal wire assembly. Finding the densest configurations, called close packings, of hard spheres of diameter σ in a cylinder of diameter D is a purely geometric problem that grows increasingly complex as D/σ increases, and little is thus known about the regime for D > 2.873σ. In this work, we extend the identification of close packings up to D = 4.00σ by adapting Torquato-Jiao's adaptive-shrinking-cell formulation and sequential-linear-programming (SLP) technique. We identify 17 new structures, almost all of them chiral. Beyond D ≈ 2.85σ, most of the structures consist of an outer shell and an inner core that compete for being close packed. In some cases, the shell adopts its own maximum density configuration, and the stacking of core spheres within it is quasiperiodic. In other cases, an interplay between the two components is observed, which may result in simple periodic structures. In yet other cases, the very distinction between the core and shell vanishes, resulting in more exotic packing geometries, including some that are three-dimensional extensions of structures obtained from packing hard disks in a circle.

  16. Effect of Problem Based Learning Scenario on Knowledge of Third Class Students About Childhood Poisoning

    Directory of Open Access Journals (Sweden)

    Nazan Karaoğlu

    2011-08-01

    Full Text Available Introduction: It is stated that students cannot carry their knowledge on basic medical sciences that they gained with classical education to clinical classes and clinical practice and problem based learning (PBL can compensate this drawback. It was aimed to evaluate the effect of PBL scenario written on this topic on level of knowledge about childhood poisoning of third class students who completed the most of theoretical pharmacology education.Materials and Method: A questionnaire form prepared by researchers was applied to randomly chosen PBL groups without writing names and on the basis of voluntariness before and after a case of childhood poisoning which was applied as the second PBL scenario in the second midterm of 2009-2010 academic years. Numbers, percentages, chi-square and student’s t-test were used for evaluation of the questionnaire form comprised of demographic data, open-closed ended questions for measuring attitudes and level of knowledge against case of poisoning and statements as making a priority ranking.Results: In the study group, 89 students took part in pre-test and 96 students took part in post-test. In the answers to the list including the substances that are the most common causes of admission according to data of Refik Saydam National Poison Center (e.g. lotion, bath foam, cosmetics, water color and calamine lotions, the substances that the students stated to be toxic in pre-test were answered correctly in the post-test (p<0.05. Number of correct answers increased significantly for knowledge about commonly used drugs in clinical practice like anti-depressants, calcium canal blockers, oral antidiabetics that were marked as non-toxic by the students although they are toxic (p<0.05. While mean knowledge score for these 40 items was 17.52±5.82 in pre-test, it increased to 27.89±8.79 in post-test (p<0.001.Conclusion: Results of this study indicate that PBL scenario applied to the students who learned pharmacology

  17. SOLUTION WITH SHOCK-BOUNDARY LAYER AND SHOCK-INTERIOR LAYER TO A CLASS OF NONLINEAR PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    In this paper,the shock behaviors of solution to a class of nonlinear singularly perturbed problems are considered.Under some appropriate conditions,the outer and interior solutions to the original problem are constructed.Using the special limit and matching theory,the expressions of solutions with the shock behavior near the boundary and some interior points are given and the domain for boundary values is obtained.

  18. Existence of a Renormalised Solutions for a Class of Nonlinear Degenerated Parabolic Problems with L1 Data

    Institute of Scientific and Technical Information of China (English)

    AKDIM Y; BENNOUNA J; MEKKOUR M; REDWANE H

    2013-01-01

    We study the existence of renormalized solutions for a class of nonlinear degenerated parabolic problem.The Carathéodory function satisfying the coercivity condition,the growth condition and only the large monotonicity.The data belongs to L1(Q).

  19. Challenges of Conducting Problem-Based Learning in a Large Class: A Study at Shantou University Medical College in China

    Science.gov (United States)

    Long, Ting; Qin, Danian

    2014-01-01

    One major challenge of developing problem-based learning (PBL) curricula in medical schools in China is to meet the requirements of sufficient qualified PBL tutors. Since 2011, we have developed a modified group teaching approach where an experienced faculty tutor facilitates several small PBL student groups in a large class. Although our study…

  20. POSITIVE SOLUTIONS TO A CLASS OF SECOND-ORDER SINGULAR SEMIPOSITIVE NEUMANN BOUNDARY VALUE PROBLEM WITH GENERAL FORM

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    By constructing an explicit Green function and using the fixed point index theory on a cone, we present some existence results of positive solutions to a class of second-order singular semipositive Neumann boundary value problem, where the nonlinear term is allowed to be nonnegative and unbounded.

  1. "Hoffman v. Monsanto": Courts, Class Actions, and Perceptions of the Problem of GM Drift

    Science.gov (United States)

    McLeod-Kilmurray, Heather

    2007-01-01

    "Hoffman v. Monsanto" raises questions about the civil litigation system. Are courts appropriate institutions, and are class actions the appropriate procedure, for resolving disputes about genetically modified organisms (GMOs)? After addressing the institutional question, this article focuses on procedure. Although class actions are designed to…

  2. "Hoffman v. Monsanto": Courts, Class Actions, and Perceptions of the Problem of GM Drift

    Science.gov (United States)

    McLeod-Kilmurray, Heather

    2007-01-01

    "Hoffman v. Monsanto" raises questions about the civil litigation system. Are courts appropriate institutions, and are class actions the appropriate procedure, for resolving disputes about genetically modified organisms (GMOs)? After addressing the institutional question, this article focuses on procedure. Although class actions are…

  3. Maximum principles for a class of nonlinear second-order elliptic boundary value problems in divergence form

    Directory of Open Access Journals (Sweden)

    Cristian Enache

    2006-06-01

    Full Text Available For a class of nonlinear elliptic boundary value problems in divergence form, we construct some general elliptic inequalities for appropriate combinations of u(x and |∇u|2, where u(x are the solutions of our problems. From these inequalities, we derive, using Hopf's maximum principles, some maximum principles for the appropriate combinations of u(x and |∇u|2, and we list a few examples of problems to which these maximum principles may be applied.

  4. Right-angled Artin groups and a generalized isomorphism problem for finitely generated subgroups of mapping class groups

    CERN Document Server

    Koberda, Thomas

    2010-01-01

    Consider the mapping class group $\\Mod_{g,n}$ of a surface of finite type and a finite collection $F$ of mapping classes. In this paper we prove that there are positive exponents such that after replacing the elements of $F$ by the corresponding powers, they generate a right-angled Artin group. Under some further suitable hypotheses, these mapping classes are the vertex generators of the underlying graph, or form a right-angled Artin system in the terminology which we shall develop. We prove an analogous result for a finite volume real and complex hyperbolic $n$-manifolds, thus establishing the primary result as a rank one type phenomenon for the mapping class group. We also show the unsolvability of the isomorphism problem for finitely generated subgroups of $\\Mod_{g,n}$, and prove a homological rigidity result for right-angled Artin groups which implies a solution to the isomorphism problem for right-angled Artin groups. We thus solve a generalized isomorphism problem for finitely generated subgroups of $\\M...

  5. Priority classes and weighted constrained equal awards rules for the claims problem

    DEFF Research Database (Denmark)

    Szwagrzak, Karol

    2015-01-01

    . They are priority-augmented versions of the standard weighted constrained equal awards rules, also known as weighted gains methods (Moulin, 2000): individuals are sorted into priority classes; the resource is distributed among the individuals in the first priority class using a weighted constrained equal awards...... rule; if some of the resource is left over, then it is distributed among the individuals in the second priority class, again using a weighted constrained equal awards rule; the distribution carries on in this way until the resource is exhausted. Our characterization extends to a generalized version...

  6. A method for dense packing discovery

    CERN Document Server

    Kallus, Yoav; Gravel, Simon

    2010-01-01

    The problem of packing a system of particles as densely as possible is foundational in the field of discrete geometry and is a powerful model in the material and biological sciences. As packing problems retreat from the reach of solution by analytic constructions, the importance of an efficient numerical method for conducting de novo (from-scratch) searches for dense packings becomes crucial. In this paper, we use the divide and concur framework to develop a general search method for the solution of periodic constraint problems, and we apply it to the discovery of dense periodic packings. An important feature of the method is the integration of the unit cell parameters with the other packing variables in the definition of the configuration space. The method we present led to improvements in the densest-known tetrahedron packing which are reported in [arXiv:0910.5226]. Here, we use the method to reproduce the densest known lattice sphere packings and the best known lattice kissing arrangements in up to 14 and ...

  7. Class and Home Problems. The Lambert W Function in Ultrafiltration and Diafiltration

    Science.gov (United States)

    Foley, Greg

    2016-01-01

    Novel analytical solutions based on the Lambert W function for two problems in ultrafiltration and diafiltration are described. Example problems, suitable for incorporation into an introductory module in unit operations, membrane processing, or numerical methods are provided in each case.

  8. A CLASS OF SINGULARLY PERTURBED ROBIN BOUNDARY VALUE PROBLEMS FOR SEMILINEAR ELLIPTIC EQUATION

    Institute of Scientific and Technical Information of China (English)

    MoJiaqi

    2001-01-01

    The singularly perturbed Robin boundary value problems for the semilinear elliptic equation are considered. Under suitable conditions and by using the fixed point theorem the existence ,uniqueness and asymptotic behavior of solution for the boundary value problems are studied.

  9. A Class of Single Machine Scheduling Problems with Variable Processing Time

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, single machine scheduling problems with variableprocessing time are raised. The criterions of the problem considered are minimizing scheduling length of all jobs, flow time and number of tardy jobs and so on. The complexity of the problem is determined.

  10. Electronically configured battery pack

    Energy Technology Data Exchange (ETDEWEB)

    Kemper, D.

    1997-03-01

    Battery packs for portable equipment must sometimes accommodate conflicting requirements to meet application needs. An electronically configurable battery pack was developed to support two highly different operating modes, one requiring very low power consumption at a low voltage and the other requiring high power consumption at a higher voltage. The configurable battery pack optimizes the lifetime and performance of the system by making the best use of all available energy thus enabling the system to meet its goals of operation, volume, and lifetime. This paper describes the cell chemistry chosen, the battery pack electronics, and tradeoffs made during the evolution of its design.

  11. Development of an effective valve packing program

    Energy Technology Data Exchange (ETDEWEB)

    Hart, K.A.

    1996-12-01

    Current data now shows that graphite valve packing installed within the guidance of a controlled program produces not only reliable stem sealing but predictable running loads. By utilizing recent technological developments in valve performance monitoring for both MOV`s and AOV`s, valve packing performance can be enhanced while reducing maintenance costs. Once known, values are established for acceptable valve packing loads, the measurement of actual valve running loads via the current MOV/AOV diagnostic techniques can provide indication of future valve stem sealing problems, improper valve packing installation or identify the opportunity for valve packing program improvements. At times the full benefit of these advances in material and predictive technology remain under utilized due to simple past misconceptions associated with valve packing. This paper will explore the basis for these misconceptions, provide general insight into the current understanding of valve packing and demonstrate how with this new understanding and current valve diagnostic equipment the key aspects required to develop an effective, quality valve packing program fit together. The cost and operational benefits provided by this approach can be significant impact by the: elimination of periodic valve repacking, reduction of maintenance costs, benefits of leak-free valve operation, justification for reduced Post Maintenance Test Requirements, reduced radiation exposure, improved plant appearance.

  12. COMPUTER COMPUTATION OF THE METHOD OF MULTIPLE SCALES-DIRICHLET PROBLEM FOR A CLASS OF SYSTEM OF NONLINEAR DIFFERENTIAL EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    谢腊兵; 江福汝

    2003-01-01

    The method of boundary layer with multiple scales and computer algebra were applied to study the asymptotic behavior of solution of boundary value problems for a class of system of nonlinear differential equations. The asymptotic expansions of solution were constructed. The remainders were estimated. And an example was analysed. It provides a new foreground for the application of the method of boundary layer with multiple scales.

  13. On The Fekete-Szegö Problem for Generalized Class Mα,γ(β Defined By Differential Operator

    Directory of Open Access Journals (Sweden)

    Fethiye Müge SAKAR

    2016-11-01

    Full Text Available In this study the classical Fekete-Szegö problem was investigated. Given f(z=z+a2z2+a3z3+...  to be an analytic standartly normalized function in the open unit disk U={z ∈ C : |z|<1}. For |a3-μa22|, a sharp maximum value is provided through the classes of S*α,γ(β order β and type α under the condition of μ≥1.

  14. On the coupled NBEM and FEM for a class of nonlinear exterior Dirichlet problem in R2

    Institute of Scientific and Technical Information of China (English)

    WU; Zhengpeng; KANG; Tong; YU; Dehao

    2004-01-01

    In this paper, based on the natural boundary reduction advanced by Feng and Yu, we couple the finite elementapproach with the natural boundary element method to study theweak solvability and Galerkin approximation of a class ofnonlinear exterior boundary value problems. The analysis is mainlybased on the variational formulation with constraints.We provethe error estimate of the finite element solution and obtain theasymptotic rate of convergence. Finally, we also give anumerical example.

  15. A global solution curve for a class of periodic problems, including the pendulum equation

    Science.gov (United States)

    Korman, Philip

    2007-09-01

    Using continuation methods and bifurcation theory, we study the exact multiplicity of periodic solutions, and the global solution structure, for a class of periodically forced pendulum-like equations. Our results apply also to the first order equations. We also show that by choosing a forcing term, one can produce periodic solutions with any number of Fourier coefficients arbitrarily prescribed.

  16. THE CAUCHY PROBLEM FOR A CLASS OF COUPLED SYSTEMS CONTAINING A CONVOLUTION OPERATOR

    Institute of Scientific and Technical Information of China (English)

    杨成荣; 伍卓群

    2003-01-01

    Some results on the invariant regions ,existence and uniqueness of solutions to a class of integrodifferential systems are established. Applying these results to integrodifferential systems with a small parameter e > 0, we obtain,in particular, some estimates of solutions uniform in ε> 0.

  17. Mixed Messages: The Problem of Class in Mary Norton's "Borrowers" Series

    Science.gov (United States)

    Travis, Madelyn

    2007-01-01

    Scholars have posited various theories as to which sector of society Mary Norton's Borrowers most closely reflect, from exploitative aristocrats to helpless victims. Through social and literary contextualization, this article highlights the ways in which Norton represents social class in the series and explores the competing ideologies embedded in…

  18. 一类半无穷优化问题的求解方法%THE METHOD FOR SOLVING A CLASS OF SEMI-INFINITE PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    孟香惠; 李木桂; 胡新生; 周济; 施保昌

    2001-01-01

    In this paper we present a class of nondifferentiable optimization problems:seim-infinite minimax problems which arise from engineering design. Two algorithms for solving the problems are constructed by combining the idea of discretion with the method for solving minimax problems, and the convergence of the algorithms is proved under weaker conditions. Numerical tests show that the algorithms are practical and effective.

  19. TLC Pack Unpacked

    Science.gov (United States)

    Oberhofer, Margret; Colpaert, Jozef

    2015-01-01

    TLC Pack stands for Teaching Languages to Caregivers and is a course designed to support migrants working or hoping to work in the caregiving sector. The TLC Pack resources range from A2 to B2 level of the Common European Framework of Reference for Languages (CEFR), and will be made available online in the six project languages: Dutch, English,…

  20. A Greedy Algorithm for a Special Class of Geometric Set Covering Problems

    DEFF Research Database (Denmark)

    Stolpe, Mathias; Bechmann, Andreas

    We consider the problem of covering a set of given points in the plane by the smallest number of axis aligned squares of a given fixed size. This problem is of importance for computational fluid dynamics simulations of both onshore and offshore wind turbine parks. For this special case...

  1. On Quadratic Scalarization of One Class of Vector Optimization Problems in Banach Spaces

    Directory of Open Access Journals (Sweden)

    V. M. Bogomaz

    2012-01-01

    Full Text Available We study vector optimization problems in partially ordered Banach Spaces. We sup­pose that the objective mapping possesses a weakened property of lower semicontinuity and make no assumptions on the interior of the ordering cone. We discuss the ”clas­sical” scalarization of vector optimization problems in the form of weighted sum and also we propose other type of scalarization for vector optimization problem, the socalled adaptive scalarization, which inherits some ideas of Pascoletti-Serafini approach. As a result, we show that the scalar nonlinear optimization problems can byturn approxi­mated by the quadratic minimization problems. The advantage of such regularization is especially interesting from a numerical point of view because it gives a possibility to apply rather simple computational methods for the approximation of the whole set of efficient solutions.

  2. The class actions in italy: problems and perspectives in comparative analysis Le class actions in italia: problemi e prospettive in chiave comparata

    Directory of Open Access Journals (Sweden)

    Gianluca Sgueo

    2008-01-01

    Full Text Available The Italian financial laws for 2008 introduce, in Article 2, item 445, the first organic discipline of class actions in the Italian order. The decision made by the Italian legislator is, therefore, meaningful in relation not only to the effects produced in the legal system but also to the possible repercussions in contractual relations between citizens, companies and local and national public authorities. The article, ideally structured in three parts, puts together a historical reconstruction of the facts before the approval of the law with a detailed analysis of its contents in the light of the most relevant jurisprudential cases. The core of this brief research consists of the analysis of the perspectives as well as their problems, since the analysis of the concrete data tries to discover (possible solutions for such problems.La legge finanziaria italiana per il 2008 introduce, all’articolo 2, comma 445, la prima disciplina organica dell’azione di classe nell’ordinamento italiano. La scelta compiuta dal Legislatore italiano è comunque significativa, sia quanto agli effetti prodotti sul sistema giuridico, sia quanto alle possibili ripercussioni nei rapporti contrattuali tra cittadini, imprese e autorità pubbliche, locali e nazionali. L’articolo, idealmente strutturato in tre parti, combina una ricostruzione storica degli avvenimenti antecedenti all’approvazione della norma di legge in commento con un’analisi più approfondita di quella, alla luce della casistica giurisprudenziale più significativa. È proprio l’analisi delle prospettive e dei problemi Che costituisce il cardine di questa breve ricerca, poiché dall’analisi dei dati concreti tenta di rinvenir e le (possibili soluzioni agli stessi.

  3. An Optimal Algorithm for a Class of Parallel Machines Scheduling Problem

    Institute of Scientific and Technical Information of China (English)

    常俊林; 邵惠鹤

    2004-01-01

    This paper considers the parallel machines scheduling problem where jobs are subject to different release times. A constructive heuristic is first proposed to solve the problem in a modest amount of computer time. In general, the quality of the solutions provided by heuristics degrades with the increase of the probiem's scale. Combined the global search ability of genetic algorithm, this paper proposed a hybrid heuristic to improve the quality of solutions further. The computational results show that the hybrid heuristic combines the advantages of heuristic and genetic algorithm effectively and can provide very good solutions to some large problems in a reasonable amount of computer time.

  4. Development of Generic Field Classes for Finite Element and Finite Difference Problems

    Directory of Open Access Journals (Sweden)

    Diane A. Verner

    1993-01-01

    Full Text Available This article considers the development of a reusable object-oriented array library, as well as the use of this library in the construction of finite difference and finite element codes. The classes in this array library are also generic enough to be used to construct other classes specific to finite difference and finite element methods. We demonstrate the usefulness of this library by inserting it into two existing object-oriented scientific codes developed at Sandia National Laboratories. One of these codes is based on finite difference methods, whereas the other is based on finite element methods. Previously, these codes were separately maintained across a variety of sequential and parallel computing platforms. The use of object-oriented programming allows both codes to make use of common base classes. This offers a number of advantages related to optimization and portability. Optimization efforts, particularly important in large scientific codes, can be focused on a single library. Furthermore, by encapsulating machine dependencies within this library, the optimization of both codes on different architec-tures will only involve modification to a single library.

  5. Random Walks, Electric Networks and The Transience Class problem of Sandpiles

    CERN Document Server

    Choure, Ayush

    2011-01-01

    The Abelian Sandpile Model is a discrete diffusion process defined on graphs (Dhar \\cite{DD90}, Dhar et al. \\cite{DD95}) which serves as the standard model of \\textit{self-organized criticality}. The transience class of a sandpile is defined as the maximum number of particles that can be added without making the system recurrent (\\cite{BT05}). We develop the theory of discrete diffusions in contrast to continuous harmonic functions on graphs and establish deep connections between standard results in the study of random walks on graphs and sandpiles on graphs. Using this connection and building other necessary machinery we improve the main result of Babai and Gorodezky (SODA 2007,\\cite{LB07}) of the bound on the transience class of an $n \\times n$ grid, from $O(n^{30})$ to $O(n^{7})$. Proving that the transience class is small validates the general notion that for most natural phenomenon, the time during which the system is transient is small. In addition, we use the machinery developed to prove a number of au...

  6. Diagnosis of class using swarm intelligence applied to problem of identification of nuclear transient

    Energy Technology Data Exchange (ETDEWEB)

    Villas Boas Junior, Manoel; Strauss, Edilberto, E-mail: junior@lmp.ufrj.b [Instituto Federal de Educacao, Ciencia e Tecnologia do Ceara/ Universidade do Estado do Ceara, Itaperi, CE (Brazil). Mestrado Integrado em Computacao Aplicada; Nicolau, Andressa dos Santos; Schirru, Roberto, E-mail: andressa@lmp.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Mello, Flavio Luis de [Universidade Federal do Rio de Janeiro (POLI/UFRJ), RJ (Brazil). Escola Politecnica. Dept. de Engenharia Eletronica e Computacao

    2011-07-01

    This article presents a computational model of the diagnostic system of transient. The model makes use of segmentation techniques applied to support decision making, based on identification of classes and optimized by Particle Swarm Optimization algorithm (PSO). The method proposed aims to classify an anomalous event in the signatures of three classes of the design basis transients postulated for the Angra 2 nuclear plant, where the PSO algorithm is used as a method of separation of classes, being responsible for finding the best centroid prototype vector of each accident/transient, ie equivalent to Voronoi vector that maximizes the number of correct classifications. To make the calculation of similarity between the set of the variables anomalous event in a given time t, and the prototype vector of variables of accident/transients, the metrics of Manhattan, Euclidean and Minkowski were used. The results obtained by the method proposed were compatible with others methods reported in the literature, allowing a solution that approximates the ideal solution, ie the Voronoi vectors. (author)

  7. Scaled first-order methods for a class of large-scale constrained least square problems

    Science.gov (United States)

    Coli, Vanna Lisa; Ruggiero, Valeria; Zanni, Luca

    2016-10-01

    Typical applications in signal and image processing often require the numerical solution of large-scale linear least squares problems with simple constraints, related to an m × n nonnegative matrix A, m « n. When the size of A is such that the matrix is not available in memory and only the operators of the matrix-vector products involving A and AT can be computed, forward-backward methods combined with suitable accelerating techniques are very effective; in particular, the gradient projection methods can be improved by suitable step-length rules or by an extrapolation/inertial step. In this work, we propose a further acceleration technique for both schemes, based on the use of variable metrics tailored for the considered problems. The numerical effectiveness of the proposed approach is evaluated on randomly generated test problems and real data arising from a problem of fibre orientation estimation in diffusion MRI.

  8. The Expansion of Dynamic Solving Process About a Class of Non-linear Programming Problems

    Institute of Scientific and Technical Information of China (English)

    ZANG Zhen-chun

    2001-01-01

    In this paper, we research non-linear programming problems which have a given specialstructure, some simple forms of this kind structure have been solved in some papers, here we focus on othercomplex ones.

  9. Infeasible-interior-point algorithm for a class of nonmonotone complementarity problems and its computational complexity

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents an infeasible-interior-point algorithm for aclass of nonmonotone complementarity problems, and analyses its convergence and computational complexity. The results indicate that the proposed algorithm is a polynomial-time one.

  10. On the Inclusion of Difference Equation Problems and Z Transform Methods in Sophomore Differential Equation Classes

    Science.gov (United States)

    Savoye, Philippe

    2009-01-01

    In recent years, I started covering difference equations and z transform methods in my introductory differential equations course. This allowed my students to extend the "classical" methods for (ordinary differential equation) ODE's to discrete time problems arising in many applications.

  11. WEAK REGULARIZATION FOR A CLASS OF ILL-POSED CAUCHY PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This article is concerned with the ill-posed Cauchy problem associated with a densely defined linear operator A in a Banach space. A family of weak regularizing operators is introduced. If the spectrum of A is contained in a sector of right-half complex plane and its resolvent is polynomially bounded, the weak regularization for such ill-posed Cauchy problem can be shown by using the quasi-reversibility method and regularized semigroups. Finally, an example is given.

  12. Mathematical programming based approaches for classes of complex network problems : economical and sociological applications

    OpenAIRE

    Nasini, Stefano

    2015-01-01

    The thesis deals with the theoretical and practical study of mathematical programming methodologies to the analysis complex networks and their application in economic and social problems. More specifically, it applies models and methods for solving linear and integer programming problems to network models exploiting the matrix structure of such models, resulting in efficient computational procedures and small processing time. As a consequence, it allows the study of larger and more complex n...

  13. A Special Class of Univalent Functions in Hele-Shaw Flow Problems

    Directory of Open Access Journals (Sweden)

    Paula Curt

    2011-01-01

    Full Text Available We study the time evolution of the free boundary of a viscous fluid for planar flows in Hele-Shaw cells under injection. Applying methods from the theory of univalent functions, we prove the invariance in time of Φ-likeness property (a geometric property which includes starlikeness and spiral-likeness for two basic cases: the inner problem and the outer problem. We study both zero and nonzero surface tension models. Certain particular cases are also presented.

  14. A CLASS OF ASYNCHRONOUS PARALLEL MULTISPLITTING RELAXATION METHODS FOR LARGE SPARSE LINEAR COMPLEMENTARITY PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Zhong-zhi Bai; Yu-guang Huang

    2003-01-01

    Asynchronous parallel multisplitting relaxation methods for solving large sparse linear complementarity problems are presented, and their convergence is proved when the system matrices are H-matrices having positive diagonal elements. Moreover, block and multi-parameter variants of the new methods, together with their convergence properties,are investigated in detail. Numerical results show that these new methods can achieve high parallel efficiency for solving the large sparse linear complementarity problems on multiprocessor systems.

  15. Solvability of a class of second-order quasilinear boundary value problems

    Institute of Scientific and Technical Information of China (English)

    Qing-liu YAO

    2009-01-01

    The second-order quasilinear boundary value problems are considered when the nonlinear term is singular and the limit growth function at the infinite exists. With the introduction of the height function of the nonlinear term on a bounded set and the consideration of the integration of the height function, the existence of the solution is proven. The existence theorem shows that the problem has a solution ff the integration of the limit growth function has an appropriate value.

  16. A Hybrid Simulated Annealing Algorithm for the Three-Dimensional Packing Problem%求解三维装箱问题的混合模拟退火算法

    Institute of Scientific and Technical Information of China (English)

    张德富; 彭煜; 朱文兴; 陈火旺

    2009-01-01

    This paper presents an efficient hybrid simulated annealing algorithm for three dimen-sional container loading problem (3D-CLP). The 3D-CLP is the problem of loading a subset of a given set of rectangular boxes into a rectangular container so that the stowed volume is maxi-mized. The algorithm introduced in this paper is based on three important algorithms. First, complex block generating, complex block can contain any number boxes of different types, which differs from the traditional algorithm. Second, basic heuristic, which is a new construction heu-ristic algorithm used to generate a feasible packing solution from a packing sequence. Third, sim-ulated annealing algorithm, based on the complex block and basic heuristic, it encodes a feasible packing solution as a packing sequence, and searches in the encoding space to find an approxima-ted optimal solution. 1500 benchmark instances with weakly and strongly heterogeneous boxes are considered in this paper. The computational results show that the volume utilization of hybrid algorithm outperforms current excellent algorithms for the considered problem.%提出了一个高效求解三维装箱问题(Three Dimensional Container Loading Problem 3D-CLP)的混合模拟退火算法.三维装箱问题要求装载给定箱子集合的一个子集到容器中,使得被装载的箱子总体积最大.文中介绍的混合模拟退火算法基于三个重要算法:(1)复合块生成算法,与传统算法不同的是文中提出的复合块不只包含单一种类的箱子,而是可以在一定的限制条件下包含任意种类的箱子.(2)基础启发式算法,该算法基于块装载,可以按照指定装载序列生成放置方案.(3)模拟退火算法,以复合块生成和基础启发式算法为基础,将装载序列作为可行放置方案的编码,在编码空间中采用模拟退火算法进行搜索以寻找问题的近似最优解.文中采用1500个弱异构和强异构的装箱问题数据对算法进行测试.

  17. Some Results Connected with the Class Number Problem in Real Quadratic Fields

    Institute of Scientific and Technical Information of China (English)

    Aleksander GRYTCZUK; Jaroslaw GRYTCZUK

    2005-01-01

    We investigate arithmetic properties of certain subsets of square-free positive integers and obtain in this way some results concerning the class number h(d) of the real quadratic field Q(√d). In particular, we give a new proof of the result of Hasse, asserting that in this case h(d) = 1 is possible only if d is of the form p, 2q or qr, where p, q, r are primes and q ≡ r ≡ 3(mod4).

  18. A non-penalty recurrent neural network for solving a class of constrained optimization problems.

    Science.gov (United States)

    Hosseini, Alireza

    2016-01-01

    In this paper, we explain a methodology to analyze convergence of some differential inclusion-based neural networks for solving nonsmooth optimization problems. For a general differential inclusion, we show that if its right hand-side set valued map satisfies some conditions, then solution trajectory of the differential inclusion converges to optimal solution set of its corresponding in optimization problem. Based on the obtained methodology, we introduce a new recurrent neural network for solving nonsmooth optimization problems. Objective function does not need to be convex on R(n) nor does the new neural network model require any penalty parameter. We compare our new method with some penalty-based and non-penalty based models. Moreover for differentiable cases, we implement circuit diagram of the new neural network.

  19. Improved lower bound for online strip packing

    NARCIS (Netherlands)

    Harren, Rolf; Kern, Walter

    2015-01-01

    We study the online strip packing problem and derive an improved lower bound of ρ ≥ 2.589... for the competitive ratio of this problem. The construction is based on modified “Brown-Baker-Katseff sequences” (Brown et al. in Acta Inform. 18:207–225, 1982) using only two types of rectangles. In additio

  20. Strongly polynomial algorithm for a class of minimum-cost flow problems with separable convex objectives

    OpenAIRE

    Vegh, Laszlo A.

    2011-01-01

    A well-studied nonlinear extension of the minimum-cost flow problem is to minimize the objective $\\sum_{ij\\in E} C_{ij}(f_{ij})$ over feasible flows $f$, where on every arc $ij$ of the network, $C_{ij}$ is a convex function. We give a strongly polynomial algorithm for the case when all $C_{ij}$'s are convex quadratic functions, settling an open problem raised e.g. by Hochbaum [1994]. We also give strongly polynomial algorithms for computing market equilibria in Fisher markets with linear util...

  1. Efficacious End User Measures—Part 1: Relative Class Size and End User Problem Domains

    Directory of Open Access Journals (Sweden)

    E. Earl Eiland

    2013-01-01

    errors can cause significant losses, even loss of life. Hence, end users are best served when they have performance information relevant to their needs, this paper’s focus. Relative class size (rCS is commonly recognized as a confounding factor in CPD evaluation. Unfortunately, rCS-invariant measures are not easily mapped to end user conditions. We determine a cause of rCS invariance, joint probability table (JPT normalization. JPT normalization means that more end user efficacious measures can be used without sacrificing invariance. An important revelation is that without data normalization, the Matthews correlation coefficient (MCC and information coefficient (IC are not relative class size invariants; this is a potential source of confusion, as we found not all reports using MCC or IC normalize their data. We derive MCC rCS-invariant expression. JPT normalization can be extended to allow JPT rCS to be set to any desired value (JPT tuning. This makes sensitivity analysis feasible, a benefit to both applied researchers and practitioners (end users. We apply our findings to two published CPD studies to illustrate how end users benefit.

  2. Linear one-dimensional cutting-packing problems: numerical experiments with the sequential value correction method (SVC and a modified branch-and-bound method (MBB

    Directory of Open Access Journals (Sweden)

    Mukhacheva E.A.

    2000-01-01

    Full Text Available Two algorithms for the one-dimensional cutting problem, namely, a modified branch-and-bound method (exact method and a heuristic sequential value correction method are suggested. In order to obtain a reliable assessment of the efficiency of the algorithms, hard instances of the problem were considered and from the computational experiment it seems that the efficiency of the heuristic method appears to be superior to that of the exact one, taking into account the computing time of the latter. A detailed description of the two methods is given along with suggestions for their improvements.

  3. Online Variable-Sized Bin Packing with Conflicts

    DEFF Research Database (Denmark)

    Epstein, Leah; Favrholdt, Lene Monrad; Levin, Asaf

    2011-01-01

    We study a new kind of on-line bin packing with conflicts, motivated by a problem arising when scheduling jobs on the Grid. In this bin packing problem, the set of items is given at the beginning, together with a set of conflicts on pairs of items. A conflict on a pair of items implies...

  4. Singular Initial Value Problem for Certain Classes of Systems of Ordinary Differential Equations

    Directory of Open Access Journals (Sweden)

    Josef Diblík

    2013-01-01

    dimension of the set of initial data generating such solutions is estimated. An asymptotic behavior of solutions is determined as well and relevant asymptotic formulas are derived. The method of functions defined implicitly and the topological method (Ważewski's method are used in the proofs. The results generalize some previous ones on singular initial value problems for differential equations.

  5. A TWO-STEP EXPLICIT METHOD FOR A CLASS OF LINEAR PERIODIC INITIAL VALUE PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    李庆宏; 罗亮生; 吴新元

    2003-01-01

    This paper presents a two-step explicit method of order four for solving aclass of linear periodic initial value problems. At each computational step, only tworight function evaluations and one derivative evaluation are employed. Basing on aspecial vector operation, the method can be extended to the vector-applicable in multi-dimensional space.

  6. A Class of Constrained Inverse Eigenproblem and Associated Approximation Problem for Symmetric Reflexive Matrices

    Institute of Scientific and Technical Information of China (English)

    Xiaoping Pan; Xiyan Hu; Lei Zhang

    2006-01-01

    Let S ∈ Rn×n be a symmetric and nontrival involution matrix. We say that A ∈ Rn×n is a symmetric reflexive matrix if AT = A and SAS = A. Let SRrn×n(S)={A|A =AT, A = SAS, A ∈ Rn×n}. This paper discusses the following two problems. The first one is as follows.Given Z∈Rn×m (m<n),∧=diag(λ1…,λm)∈Rm×m,and α,β∈R with α<β. Find a subset ψ(Z,A,α,β) of SRrn×n(S) such that AZ = ZA holds for any A∈ ψ(Z,∧,α, β)and the remaining eigenvalues λm+1,…λn of A are located in the interval [α, β]. Moreover, for a given B ∈ Rn×n, the second problem is to find AB ∈ψ(Z, A, α,β)such that ||B-AB||= min A∈ψ(A,∧,α,β) ||B - A||,where ||.|| is the Frobenius norm. Using the properties of symmetric reflexive matrices,the two problems are essentially decomposed into the samekind of subproblems for two real symmetric matrices with smaller dimensions, and then the expressions of the general solution for the two problems are derived.

  7. An Inverse Robust Optimisation Approach for a Class of Vehicle Routing Problems under Uncertainty

    Directory of Open Access Journals (Sweden)

    Liang Sun

    2016-01-01

    Full Text Available There is a trade-off between the total penalty paid to customers (TPC and the total transportation cost (TTC in depot for vehicle routing problems under uncertainty (VRPU. The trade-off refers to the fact that the TTC in depot inevitably increases when the TPC decreases and vice versa. With respect to this issue, the vehicle routing problem (VRP with uncertain customer demand and travel time was studied to optimise the TPC and the TTC in depot. In addition, an inverse robust optimisation approach was proposed to solve this kind of VRPU by combining the ideas of inverse optimisation and robust optimisation so as to improve both the TPC and the TTC in depot. The method aimed to improve the corresponding TTC of the robust optimisation solution under the minimum TPC through minimising the adjustment of benchmark road transportation cost. According to the characteristics of the inverse robust optimisation model, a genetic algorithm (GA and column generation algorithm are combined to solve the problem. Moreover, 39 test problems are solved by using an inverse robust optimisation approach: the results show that both the TPC and TTC obtained by using the inverse robust optimisation approach are less than those calculated using a robust optimisation approach.

  8. Interpreting Students' and Teachers' Discourse in Science Classes: An Underestimated Problem?

    Science.gov (United States)

    Klaassen, C. W. J. M.; Lijnse, P. L.

    1996-01-01

    Deals with the problem of the proper interpretation of discourse between students and teachers in classrooms. Presents several interpretations of a concrete classroom protocol in terms of misconceptions. Draws on Davidson's principle of charity and distinguishes between belief and meaning to present an analysis that interprets the discourse…

  9. Problem-Based Learning in an Eleventh Grade Chemistry Class: "Factors Affecting Cell Potential"

    Science.gov (United States)

    Tarhan, Leman; Acar, Burcin

    2007-01-01

    The purpose of this research study was to examine the effectiveness of problem-based learning (PBL) on eleventh grade students' understanding of "The effects of temperature, concentration and pressure on cell potential" and also their social skills. Stratified randomly selected control and experimental groups with 20 students each were used in…

  10. New Class of Solutions for Water Infiltration Problems in Unsaturated Soils

    DEFF Research Database (Denmark)

    Barari, Amin; Omidvar, M; Momeni, M;

    2010-01-01

    This paper presents the results of approximate analytical solutions to Richards’ equation, which governs the problem of unsaturated flow in porous media. The existing methods generally fall within the category of numerical and analytical methods, often having many restrictions for practical situa...

  11. Problem-Based Learning in 9th Grade Chemistry Class: "Intermolecular Forces"

    Science.gov (United States)

    Tarhan, Leman; Ayar-Kayali, Hulya; Urek, Raziye Ozturk; Acar, Burcin

    2008-01-01

    This research study aims to examine the effectiveness of a problem-based learning (PBL) on 9th grade students' understanding of intermolecular forces (dipole-dipole forces, London dispersion forces and hydrogen bonding). The student's alternate conceptions about intermolecular bonding and their beliefs about PBL were also measured. Seventy-eight…

  12. Class and Home Problems. Modeling an Explosion: The Devil Is in the Details

    Science.gov (United States)

    Hart, Peter W.; Rudie, Alan W.

    2011-01-01

    Within the past 15 years, three North American pulp mills experienced catastrophic equipment failures while using 50 wt% hydrogen peroxide. In two cases, explosions occurred when normal pulp flow was interrupted due to other process problems. To understand the accidents, a kinetic model of alkali-catalyzed decomposition of peroxide was developed.…

  13. Extended Kalman Filter with a Fuzzy Method for Accurate Battery Pack State of Charge Estimation

    Directory of Open Access Journals (Sweden)

    Saeed Sepasi

    2015-06-01

    Full Text Available As the world moves toward greenhouse gas reduction, there is increasingly active work around Li-ion chemistry-based batteries as an energy source for electric vehicles (EVs, hybrid electric vehicles (HEVs and smart grids. In these applications, the battery management system (BMS requires an accurate online estimation of the state of charge (SOC in a battery pack. This estimation is difficult, especially after substantial battery aging. In order to address this problem, this paper utilizes SOC estimation of Li-ion battery packs using a fuzzy-improved extended Kalman filter (fuzzy-IEKF for Li-ion cells, regardless of their age. The proposed approach introduces a fuzzy method with a new class and associated membership function that determines an approximate initial value applied to SOC estimation. Subsequently, the EKF method is used by considering the single unit model for the battery pack to estimate the SOC for following periods of battery use. This approach uses an adaptive model algorithm to update the model for each single cell in the battery pack. To verify the accuracy of the estimation method, tests are done on a LiFePO4 aged battery pack consisting of 120 cells connected in series with a nominal voltage of 432 V.

  14. Nasal packing and stenting

    Directory of Open Access Journals (Sweden)

    Weber, Rainer K.

    2009-01-01

    Full Text Available Nasal packs are indispensable in ENT practice. This study reviews current indications, effectiveness and risks of nasal packs and stents. In endoscopic surgery, nasal packs should always have smooth surfaces to minimize mucosal damage, improve wound healing and increase patient comfort. Functional endoscopic endonasal sinus surgery allows the use of modern nasal packs, since pressure is no longer required. So called hemostatic/resorbable materials are a first step in this direction. However, they may lead to adhesions and foreign body reactions in mucosal membranes. Simple occlusion is an effective method for creating a moist milieu for improved wound healing and avoiding dryness. Stenting of the frontal sinus is recommended if surgery fails to produce a wide, physiologically shaped drainage path that is sufficiently covered by intact tissue.

  15. Mathematical methods for a class of mixed boundary-value problems of planar pentagonal quasicrystal and some solutions

    Institute of Scientific and Technical Information of China (English)

    范天佑; 郭玉翠

    1997-01-01

    The mathematical theory of elasticity for planar pentagonal quasicrystals is developed and some analytic solutions for a class of mixed boundary-value problems (corresponding to a Griffith crack) of the theory are offered.An alternate procedure and a direct integral approach are proposed.Some analytical solutions are constructed and the stress and displacement fields of a Griffith crack in the quasicrystals are determined.A basis for further studying the mechanical behavior of the material related to planar defects is provided.

  16. Layered circle packings

    Directory of Open Access Journals (Sweden)

    David Dennis

    2005-01-01

    Full Text Available Given a bounded sequence of integers {d0,d1,d2,…}, 6≤dn≤M, there is an associated abstract triangulation created by building up layers of vertices so that vertices on the nth layer have degree dn. This triangulation can be realized via a circle packing which fills either the Euclidean or the hyperbolic plane. We give necessary and sufficient conditions to determine the type of the packing given the defining sequence {dn}.

  17. 消毒供应室无纺布包装湿包问题的改进效果%Improvement in the wet bag problem of the no-woven packing in the central sterile supply

    Institute of Scientific and Technical Information of China (English)

    靳寸朵; 赵小丽; 王苗; 贾桂香; 麻雷

    2013-01-01

    Objective To explore the method of reducing the phenomenon of wet bag in the no-woven packing after sterilization in the central sterile supply .Methods The phenomenon of wet bag in the no-woven operation packing after sterilization was due to the bad absorption of water molecules in the non -woven packaging, movement the non-woven packaging without the given time and poor temperature and humidity in the storage.The improvements were carried out according to the above problems , and the effective method of reducing the phenomenon of wet bagwas summarized .The no-woven packing in the experimental group was packed by no-woven, and filled up a piece of the crepe paper between the instruments and the non-woven and laid the single deck cotton cloth over the sterilization frame in the packaging process .Results The incidence rate of wet bag was decreased from 7.64%to 1.04%three months after improvement.Conclusions Filling up a piece of the crepe paper between the instruments and the non-woven and laying the single deck cotton cloth over the sterilization frame in the packaging process can effectivelyprevent the phenomenon of wet bag in the no -woven operation packing after sterilization .%目的:探讨减少消毒供应室无纺布包装在灭菌完成后湿包现象发生的方法。方法无纺布包装水分子吸收性差、工作中未在规定时间内移动无纺布包及无菌物品存放区温湿度欠佳等原因造成无纺布包装湿包现象。针对以上问题进行改进,总结减少无纺布包装湿包现象发生的有效方法。结果经过3个多月的改进,在器械包打包过程中,将皱纹纸垫于器械与无纺布之间,且铺一层棉布在灭菌架上,湿包率由原来的7.64%降低至1.04%。结论在器械包打包过程中,将皱纹纸垫于器械与无纺布之间,且铺一层棉布在灭菌架上,能有效预防无纺布包装手术包灭菌后湿包现象的发生。

  18. Dynamics of a Dirac oscillator coupled to an external field: a new class of solvable problems

    Energy Technology Data Exchange (ETDEWEB)

    SadurnI, E; Torres, J M; Seligman, T H, E-mail: sadurni@fis.unam.m, E-mail: mau@fis.unam.m, E-mail: seligman@fis.unam.m [Instituto de Ciencias FIsicas, Universidad Nacional Autonoma de Mexico, Cuernavaca, Morelos (Mexico)

    2010-07-16

    The Dirac oscillator coupled to an external two-component field can retain its solvability, if couplings are appropriately chosen. This provides a new class of integrable systems. A simplified way of a solution is given by recasting the known solution of the Dirac oscillator into matrix form; there one notes that a block-diagonal form arises in a Hamiltonian formulation. The blocks are two dimensional. Choosing couplings that do not affect the block structure, these blow up the 2 x 2 matrices to 4 x 4 matrices, thus conserving solvability. The result can be cast again in covariant form. By way of an example we apply this exact solution to calculate the evolution of entanglement.

  19. Dynamics of a Dirac oscillator coupled to an external field: a new class of solvable problems

    Science.gov (United States)

    Sadurní, E.; Torres, J. M.; Seligman, T. H.

    2010-07-01

    The Dirac oscillator coupled to an external two-component field can retain its solvability, if couplings are appropriately chosen. This provides a new class of integrable systems. A simplified way of a solution is given by recasting the known solution of the Dirac oscillator into matrix form; there one notes that a block-diagonal form arises in a Hamiltonian formulation. The blocks are two dimensional. Choosing couplings that do not affect the block structure, these blow up the 2 × 2 matrices to 4 × 4 matrices, thus conserving solvability. The result can be cast again in covariant form. By way of an example we apply this exact solution to calculate the evolution of entanglement.

  20. On existence and uniqueness of positive solutions to a class of fractional boundary value problems

    Directory of Open Access Journals (Sweden)

    Caballero J

    2011-01-01

    Full Text Available Abstract The purpose of this paper is to investigate the existence and uniqueness of positive solutions for the following fractional boundary value problem D 0 + α u ( t + f ( t , u ( t = 0 , 0 < t < 1 , u ( 0 = u ( 1 = u ′ ( 0 = 0 , where 2 < α ≤ 3 and D 0 + α is the Riemann-Liouville fractional derivative. Our analysis relies on a fixed-point theorem in partially ordered metric spaces. The autonomous case of this problem was studied in the paper [Zhao et al., Abs. Appl. Anal., to appear], but in Zhao et al. (to appear, the question of uniqueness of the solution is not treated. We also present some examples where we compare our results with the ones obtained in Zhao et al. (to appear. 2010 Mathematics Subject Classification: 34B15

  1. Obstacle problem for a class of parabolic equations of generalized p-Laplacian type

    Science.gov (United States)

    Lindfors, Casimir

    2016-11-01

    We study nonlinear parabolic PDEs with Orlicz-type growth conditions. The main result gives the existence of a unique solution to the obstacle problem related to these equations. To achieve this we show the boundedness of weak solutions and that a uniformly bounded sequence of weak supersolutions converges to a weak supersolution. Moreover, we prove that if the obstacle is continuous, so is the solution.

  2. SIMPLY OPTIMAL - BEYOND EOQ FOR A POPULAR CLASS OF INVENTORY PROBLEMS

    Directory of Open Access Journals (Sweden)

    W. Van Wijck

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: True optimal solution s to real life problems are normally only achievable at the expense of great complexity. Every now and then however, one is almost stunned by the simplicity of a good solution to a practical problem. This paper discusses a relatively simple method for determining the joint optimum order quantity and reorder point for the case where service level is specified as a desired fraction of demand to be satisfied directly from stock. Separate solutions were derived for complete backorders and lost sales, and the method is equally applicable to fixed order quantity and periodic review inventory problems . Demand during the lead time is assumed to be normally distributed . The intent of the paper is to focus on the findings and the application of the method, rather than the mathematical derivation of the formulae itself.

    AFRIKAANSE OPSOMMING: Ware optimale oplossings vir werklike praktiese probleme is gewoonlik net bereikbaar ten koste van groot kompleksiteit. Elke nou en dan staan 'n mens egter bykans verstom omtrerit die eenvoud van 'n voortreflike oplossing vir 'n bepaalde probleem. Hierdie artikel bespreek 'n relatief eenvoudige metode om die gesamentlike optimale bestel-grootte en veiligheidsvoorraad te bepaal, vir die geval waar dienspeil uitgedruk word as die proporsie van voorraad-items wat op eerste aanvraag direk uit voorraad op hande voorsien word. Aparte oplossings is gevind vir die gevalle van volledige agterstallige bestellings en volledige verlore verkope , en die metode is ewe toepaslik vir vaste bestel-hoeveelheid- en periodieke hersiening-voorraad-stelsels. Die normaal-verdeling is as die statistiese verdeling van aanvraag gedurende die leityd aanvaar, Die artikel fokus op toepassing en bevindings eerder as op die wiskundige afleiding van die formules.

  3. A programme for a problem-free cosmology within the framework of a rich class of scalar-tensor theories

    CERN Document Server

    Lohiya, D; Lohiya, Daksh; Sethi, Meetu

    1999-01-01

    A search for a problem free cosmology within the framework of a finite range theory of gravitation is suggested. We profile a toy model that uses a multicomponent non-minimally coupled scalar tensor theory to achieve this objective. In an SO(2) invariant theory for example, we outline a program that can accommodate a coasting Milne universe with a distribution of non - topological soliton solutions [NTS's]. The interior of these solutions would be domains where effective gravitational effects would be indistinguishable from those expected in standard Einstein theory. For a large class of non - minimal coupling terms and the scalar effective potential, the effective cosmological constant identically vanishes in the region exterior to the NTS's and dynamically approaches a small value in the interior region. We describe features of a problem free cosmology that follows.

  4. Child feeding practices in families of working and nonworking mothers of Indonesian middle class urban families: what are the problems?

    Science.gov (United States)

    Roshita, Airin; Schubert, Elizabeth; Whittaker, Maxine

    2013-01-01

    This study aims to explore the feeding practices in families of working and nonworking mothers with children (aged 12-36 months) of different nutritional status and types of domestic caregiver in Indonesian urban middle class families. It was designed as a qualitative multiple case study. Mothers and caregivers from 26 families were interviewed in depth, and caregivers were categorized as family and domestic-paid caregivers. The result suggested that offering formula milk to young children was a common practice, and there was a high recognition and familiarity toward a range of formula milk brands. Mothers reported challenges in encouraging their children to eat, and in some cases they appeared to lack knowledge on overcoming their child's feeding problem. The findings suggested the need to address the child feeding problems experienced by mothers in order to overcome the double burden of child nutrition in Indonesia.

  5. Numerical Simulation of Random Close Packing with Tetrahedra

    Institute of Scientific and Technical Information of China (English)

    LI Shui-Xiang; ZHAO Jian; ZHOU Xuan

    2008-01-01

    The densest packing of tetrahedra is still an unsolved problem.Numerical simulations of random close packing of tetrahedra are carried out with a sphere assembly model and improved relaxation algorithm. The packing density and average contact number obtained for random close packing of regular tetrahedra is 0.6817 and 7.21respectively,while the values of spheres are 0.6435 and 5.95.The simulation demonstrates that tetrahedra can be randomly packed denser than spheres.Random close packings of tetrahedra with a range of height are simulated as well.We find that the regular tetrahedron might be the optimal shape which gives the highest packing density of tetrahedra.

  6. On existence of weak solutions to a Cauchy problem for one class of conservation laws

    Directory of Open Access Journals (Sweden)

    P. I. Kogut

    2015-02-01

    Full Text Available We discuss the existence of weak solutions to the Cauchy problem for one classof hyperbolic conservation laws that models a highly re-entrant production system.The output of the factory is described as a function of the work in progress and theposition of the so-called push-pull point (PPP where we separate the beginning ofthe factory employing a push policy from the end of the factory, which uses a pullpolicy. The main question we discuss in this paper is about the optimal choice ofthe input in-ux, push and pull constituents, and the position of PPP.

  7. An interactive approach based on a discrete differential evolution algorithm for a class of integer bilevel programming problems

    Science.gov (United States)

    Li, Hong; Zhang, Li; Jiao, Yong-Chang

    2016-07-01

    This paper presents an interactive approach based on a discrete differential evolution algorithm to solve a class of integer bilevel programming problems, in which integer decision variables are controlled by an upper-level decision maker and real-value or continuous decision variables are controlled by a lower-level decision maker. Using the Karush--Kuhn-Tucker optimality conditions in the lower-level programming, the original discrete bilevel formulation can be converted into a discrete single-level nonlinear programming problem with the complementarity constraints, and then the smoothing technique is applied to deal with the complementarity constraints. Finally, a discrete single-level nonlinear programming problem is obtained, and solved by an interactive approach. In each iteration, for each given upper-level discrete variable, a system of nonlinear equations including the lower-level variables and Lagrange multipliers is solved first, and then a discrete nonlinear programming problem only with inequality constraints is handled by using a discrete differential evolution algorithm. Simulation results show the effectiveness of the proposed approach.

  8. Identification and well-posedness in a class of nonparametric problems

    CERN Document Server

    Zinde-Walsh, Victoria

    2010-01-01

    This is a companion note to Zinde-Walsh (2010), arXiv:1009.4217v1[MATH.ST], to clarify and extend results on identification in a number of problems that lead to a system of convolution equations. Examples include identification of the distribution of mismeasured variables, of a nonparametric regression function under Berkson type measurement error, some nonparametric panel data models, etc. The reason that identification in different problems can be considered in one approach is that they lead to the same system of convolution equations; moreover the solution can be given under more general assumptions than those usually considered, by examining these equations in spaces of generalized functions. An important issue that did not receive sufficient attention is that of well-posedness. This note gives conditions under which well-posedness obtains, an example that demonstrates that when well-posedness does not hold functions that are far apart can give rise to observable arbitrarily close functions and discusses ...

  9. Student Perceptions about Group Based Problem Solving Process in Online and In-Class Settings

    Directory of Open Access Journals (Sweden)

    Salih Birişçi

    2013-12-01

    Full Text Available The aim of this study, through qualitative measures, was to systematically examine the perspectives and meanings formed by the teachers about teaching and learning. This study took place in the spring semester of the 2010-2011 academic year of Artvin Çoruh University. The sample size was 27. The participants were divided in two groups – Group 1 with group work taking place in an online test (D1, N=12; Group 2 with group work taking place in a classroom experiment (D2, N=12. After six weeks implementation, semi-structured interviews were conducted in order to determine students’ thoughts on problem solving and group work with success on attitudes towards mathematics. Positive change in students’ attitudes towards mathematics occurred in both the D1 and D2 groups. According to the application, the students stated that they developed increased interest towards mathematics and it turned into enjoyable.Key Words:    Problem solving, group study, online learning, student views

  10. The Solution of Two-Point Boundary Value Problem of a Class of Duffing-Type Systems with Non-C1 Perturbation Term

    Directory of Open Access Journals (Sweden)

    Jiang Zhengxian

    2009-01-01

    Full Text Available This paper deals with a two-point boundary value problem of a class of Duffing-type systems with non-C1 perturbation term. Several existence and uniqueness theorems were presented.

  11. Problems and Countermeasures of Colloquial English Large Size Class Teach-ing of Higher Vocational Public English under the Constructivism Theory

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-ping

    2014-01-01

    Based on the theory of constructivism, this article analyzes the open problems colloquial English large size class teach-ing of higher vocational public English and points out the countermeasures of colloquial English large-scale class teaching of high-er vocational public English.

  12. Efficient Algorithm Based on Action Space for Solving the 2D Rectangular Packing Problem%基于动作空间求解二维矩形Packing问题的高效算法

    Institute of Scientific and Technical Information of China (English)

    何琨; 黄文奇; 金燕

    2012-01-01

    对于二维矩形Packing这一典型的NP难度问题,在黄文奇等人提出的拟人型穴度算法的基础上,通过定义动作空间来简化对不同放入动作的评价,使穴度的计算时间明显缩短,从而使算法能够快速地得到空间利用率较高的布局图案.实验测试了Hopper和Turton提出的21个著名的二维矩形Packing问题的实例.改进的算法对其中的每一个实例都得到了空间利用率为100%的最优布局,且在普通PC机上的平均计算时间未超过7分钟.实验结果表明,基于动作空间对拟人型穴度算法所进行的改进是明显而有效的.%This paper addresses a typical NP-hard problem, the two-dimensional (2D) rectangular packing problem. The study makes improvements on a quasi-human approach, a caving degree algorithm proposed by Huang Wen-Qi, et al., by defining the conception of action space such that the calculation of the caving degree is simplified. Therefore, the evaluation on different placements is reduced considerably, and good layouts could be obtained quickly. The experiments tested 21 famous instances of the 2D rectangular packing problem provided by Hopper and Turton. The improved algorithm achieved optimal layout with a space utilization of 100% for each instance, and the average computing time on a personal computer was within seven minutes. Computational results show that the improvement strategies on the quasi-human caving degree approach are evident and effective.

  13. Efficient Algorithm Based on Action Space for Solving the 2D Rectangular Packing Problem%基于动作空间求解二维矩形Packing问题的高效算法∗

    Institute of Scientific and Technical Information of China (English)

    何琨; 黄文奇; 金燕

    2013-01-01

    This paper addresses a typical NP-hard problem, the two-dimensional (2D) rectangular packing problem. The study makes improvements on a quasi-human approach, a caving degree algorithm proposed by Huang Wen-Qi, et al., by defining the conception of action space such that the calculation of the caving degree is simplified. Therefore, the evaluation on different placements is reduced considerably, and good layouts could be obtained quickly. The experiments tested 21 famous instances of the 2D rectangular packing problem provided by Hopper and Turton. The improved algorithm achieved optimal layout with a space utilization of 100% for each instance, and the average computing time on a personal computer was within seven minutes. Computational results show that the improvement strategies on the quasi-human caving degree approach are evident and effective.%  对于二维矩形Packing这一典型的NP难度问题,在黄文奇等人提出的拟人型穴度算法的基础上,通过定义动作空间来简化对不同放入动作的评价,使穴度的计算时间明显缩短,从而使算法能够快速地得到空间利用率较高的布局图案。实验测试了Hopper和Turton提出的21个著名的二维矩形Packing问题的实例。改进的算法对其中的每一个实例都得到了空间利用率为100%的最优布局,且在普通PC机上的平均计算时间未超过7分钟。实验结果表明,基于动作空间对拟人型穴度算法所进行的改进是明显而有效的。

  14. Numerical optimization method for packing regular convex polygons

    Science.gov (United States)

    Galiev, Sh. I.; Lisafina, M. S.

    2016-08-01

    An algorithm is presented for the approximate solution of the problem of packing regular convex polygons in a given closed bounded domain G so as to maximize the total area of the packed figures. On G a grid is constructed whose nodes generate a finite set W on G, and the centers of the figures to be packed can be placed only at some points of W. The problem of packing these figures with centers in W is reduced to a 0-1 linear programming problem. A two-stage algorithm for solving the resulting problems is proposed. The algorithm finds packings of the indicated figures in an arbitrary closed bounded domain on the plane. Numerical results are presented that demonstrate the effectiveness of the method.

  15. Packing of elastic wires in flexible shells

    Science.gov (United States)

    Vetter, R.; Wittel, F. K.; Herrmann, H. J.

    2015-11-01

    The packing problem of long thin filaments that are injected into confined spaces is of fundamental interest for physicists and biologists alike. How linear threads pack and coil is well known only for the ideal case of rigid containers, though. Here, we force long elastic rods into flexible spatial confinement borne by an elastic shell to examine under which conditions recently acquired knowledge on wire packing in rigid spheres breaks down. We find that unlike in rigid cavities, friction plays a key role by giving rise to the emergence of two distinct packing patterns. At low friction, the wire densely coils into an ordered toroidal bundle with semi-ellipsoidal cross-section, while at high friction, it packs into a highly disordered, hierarchic structure. These two morphologies are shown to be separated by a continuous phase transition. Our findings demonstrate the dramatic impact of friction and confinement elasticity on filamentous packing and might drive future research on such systems in physics, biology and even medical technology toward including these mutually interacting effects.

  16. Positive Solutions for Class of State Dependent Boundary Value Problems with Fractional Order Differential Operators

    Directory of Open Access Journals (Sweden)

    Dongyuan Liu

    2015-01-01

    Full Text Available We consider the following state dependent boundary-value problem D0+αy(t-pD0+βg(t,y(σ(t+f(t,y(τ(t=0, 0

  17. Battery Pack Thermal Design

    Energy Technology Data Exchange (ETDEWEB)

    Pesaran, Ahmad

    2016-06-14

    This presentation describes the thermal design of battery packs at the National Renewable Energy Laboratory. A battery thermal management system essential for xEVs for both normal operation during daily driving (achieving life and performance) and off-normal operation during abuse conditions (achieving safety). The battery thermal management system needs to be optimized with the right tools for the lowest cost. Experimental tools such as NREL's isothermal battery calorimeter, thermal imaging, and heat transfer setups are needed. Thermal models and computer-aided engineering tools are useful for robust designs. During abuse conditions, designs should prevent cell-to-cell propagation in a module/pack (i.e., keep the fire small and manageable). NREL's battery ISC device can be used for evaluating the robustness of a module/pack to cell-to-cell propagation.

  18. Close the Gaps: A Learning-while-Doing Algorithm for a Class of Single-Product Revenue Management Problems

    CERN Document Server

    Wang, Zizhuo; Ye, Yinyu

    2011-01-01

    We present a dynamic learning algorithm for a class of single-product revenue management problems. In these problems, a retailer sells a single product with limited on-hand inventory over a finite selling season. Customer demand arrives according to a Poisson process, the rate of which is influenced by a single action taken by the retailer (such as price adjustment, sales commission, advertisement intensity, etc.). The relation between the action and the demand rate is not known in advance. The retailer will learn the optimal action policy "on the fly" as she maximizes her total expected revenue based on observed demand reactions. Using the pricing problem as an example, we propose a dynamic "learning-while-doing" algorithm to achieve a near optimal performance. Furthermore, we prove that the convergence rate of our algorithm is almost the fastest among all possible algorithms in terms of asymptotic "regret" (the relative loss comparing to the full information optimal solution). Our result closes the performa...

  19. Ufa scientific school by e. a. Mukhacheva: applied operational research problems

    OpenAIRE

    Filippova, A.; Valiakhmetova, Yu; Karamova, L.

    2013-01-01

    The Ufa Scientific Group busy with the research of cutting-packing problems was founded more than 50 years ago in the Ufa Aviation Institute. The class of cutting-packing problems includes problems of various applied interpretation. They are regarded as NP-hart problems, and development and research of effective methods of their solution is actual nowadays. This paper is devoted to the review of the basic problems and the methods of their solution developed under the guidance of Prof. E. A. M...

  20. New Approach for Solving a Class of Doubly Singular Two-Point Boundary Value Problems Using Adomian Decomposition Method

    Directory of Open Access Journals (Sweden)

    Randhir Singh

    2012-01-01

    Full Text Available We propose two new modified recursive schemes for solving a class of doubly singular two-point boundary value problems. These schemes are based on Adomian decomposition method (ADM and new proposed integral operators. We use all the boundary conditions to derive an integral equation before establishing the recursive schemes for the solution components. Thus we develop recursive schemes without any undetermined coefficients while computing successive solution components, whereas several previous recursive schemes have done so. This modification also avoids solving a sequence of nonlinear algebraic or transcendental equations for the undetermined coefficients with multiple roots, which is required to complete calculation of the solution by several earlier modified recursion schemes using the ADM. The approximate solution is computed in the form of series with easily calculable components. The effectiveness of the proposed approach is tested by considering four examples and results are compared with previous known results.

  1. A combination of feature extraction methods with an ensemble of different classifiers for protein structural class prediction problem.

    Science.gov (United States)

    Dehzangi, Abdollah; Paliwal, Kuldip; Sharma, Alok; Dehzangi, Omid; Sattar, Abdul

    2013-01-01

    Better understanding of structural class of a given protein reveals important information about its overall folding type and its domain. It can also be directly used to provide critical information on general tertiary structure of a protein which has a profound impact on protein function determination and drug design. Despite tremendous enhancements made by pattern recognition-based approaches to solve this problem, it still remains as an unsolved issue for bioinformatics that demands more attention and exploration. In this study, we propose a novel feature extraction model that incorporates physicochemical and evolutionary-based information simultaneously. We also propose overlapped segmented distribution and autocorrelation-based feature extraction methods to provide more local and global discriminatory information. The proposed feature extraction methods are explored for 15 most promising attributes that are selected from a wide range of physicochemical-based attributes. Finally, by applying an ensemble of different classifiers namely, Adaboost.M1, LogitBoost, naive Bayes, multilayer perceptron (MLP), and support vector machine (SVM) we show enhancement of the protein structural class prediction accuracy for four popular benchmarks.

  2. DIY Fraction Pack.

    Science.gov (United States)

    Graham, Alan; Graham, Louise

    2003-01-01

    Describes a very successful attempt to teach fractions to year 5 pupils based on pupils making their own fraction pack. Children decided for themselves how to make the fractional slices used in the activity using colored cardboard sheets and templates of a paper circle consisting of 24 equal slices. (Author/NB)

  3. On Optimality of Greedy Policy for a Class of Standard Reward Function of Restless Multi-armed Bandit Problem

    CERN Document Server

    Liu, Quan; Chen, Lin

    2011-01-01

    In this paper,we consider the restless bandit problem, which is one of the most well-studied generalizations of the celebrated stochastic multi-armed bandit problem in decision theory. However, it is known be PSPACE-Hard to approximate to any non-trivial factor. Thus the optimality is very difficult to obtain due to its high complexity. A natural method is to obtain the greedy policy considering its stability and simplicity. However, the greedy policy will result in the optimality loss for its intrinsic myopic behavior generally. In this paper, by analyzing one class of so-called standard reward function, we establish the closed-form condition about the discounted factor \\beta such that the optimality of the greedy policy is guaranteed under the discounted expected reward criterion, especially, the condition \\beta = 1 indicating the optimality of the greedy policy under the average accumulative reward criterion. Thus, the standard form of reward function can easily be used to judge the optimality of the greed...

  4. Bio-inspired varying subspace based computational framework for a class of nonlinear constrained optimal trajectory planning problems.

    Science.gov (United States)

    Xu, Y; Li, N

    2014-09-01

    Biological species have produced many simple but efficient rules in their complex and critical survival activities such as hunting and mating. A common feature observed in several biological motion strategies is that the predator only moves along paths in a carefully selected or iteratively refined subspace (or manifold), which might be able to explain why these motion strategies are effective. In this paper, a unified linear algebraic formulation representing such a predator-prey relationship is developed to simplify the construction and refinement process of the subspace (or manifold). Specifically, the following three motion strategies are studied and modified: motion camouflage, constant absolute target direction and local pursuit. The framework constructed based on this varying subspace concept could significantly reduce the computational cost in solving a class of nonlinear constrained optimal trajectory planning problems, particularly for the case with severe constraints. Two non-trivial examples, a ground robot and a hypersonic aircraft trajectory optimization problem, are used to show the capabilities of the algorithms in this new computational framework.

  5. Rack ‘em, pack 'em and stack ‘em: challenges and opportunities in teaching large classes in higher education [v1; ref status: indexed, http://f1000r.es/nq

    OpenAIRE

    2013-01-01

    The higher education sector is undergoing tremendous change, driven by complex driving forces including financial, administrative, and organisational and stakeholder expectations. It is in this challenging environment, educators are required to maintain and improve the quality of teaching and learning outcomes while contending with increasing class sizes. Despite mixed evidence on the effectiveness of large classes on student outcomes, large classes continue to play an important part in highe...

  6. Direct contact condensation in packed beds

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yi; Klausner, James F.; Mei, Renwei; Knight, Jessica [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611 (United States)

    2006-12-15

    A diffusion driven desalination process was recently described where a very effective direct contact condenser with a packed bed is used to condense water vapor out of an air/vapor mixture. A laboratory scale direct contact condenser has been fabricated as a twin tower structure with two stages, co-current and countercurrent. Experiments have been operated in each stage with respective saturated air inlet temperatures of 36, 40 and 43{sup o}C. The temperature and humidity data have been collected at the inlet and exit of the packed bed for different water to air mass flow ratios that vary between 0 and 2.5. A one-dimensional model based on conservation principles has been developed, which predicts the variation of temperature, humidity, and condensation rate through the condenser stages. Agreement between the model and experiments is very good. It is observed that the countercurrent flow stage condensation effectiveness is significantly higher than that for the co-current stage. The condensation heat and mass transfer rates were found to decrease when water blockages occur within the packed bed. Using high-speed digital cinematography, it was observed that this problem can occur at any operating condition, and is dependent on the packing surface wetting characteristics. This observation is used to explain the requirement for two different empirical constants, depending on packing diameter, suggested by Onda for the air side mass transfer coefficient correlation. (author)

  7. Some analytical properties of dissolving operators related with the Cauchy problem for a class of nonautonomous partial differential equations. Part 1

    Directory of Open Access Journals (Sweden)

    Marzena Pytel-Kudela

    2006-01-01

    Full Text Available The analytical properties of dissolving operators related with the Cauchy problem for a class of nonautonomous partial differential equations in Hilbert spaces are studied using theory of bi-linear forms in respectively rigged Hilbert spaces triples. Theorems specifying the existence of a dissolving operator for a class of adiabatically perturbed nonautonomous partial differential equations are stated. Some applications of the results obtained are discussed.

  8. Rack ‘em, pack 'em and stack ‘em: challenges and opportunities in teaching large classes in higher education [v1; ref status: indexed, http://f1000r.es/nq

    Directory of Open Access Journals (Sweden)

    Saravana Kumar

    2013-02-01

    Full Text Available The higher education sector is undergoing tremendous change, driven by complex driving forces including financial, administrative, and organisational and stakeholder expectations. It is in this challenging environment, educators are required to maintain and improve the quality of teaching and learning outcomes while contending with increasing class sizes. Despite mixed evidence on the effectiveness of large classes on student outcomes, large classes continue to play an important part in higher education. While large classes pose numerous challenges, they also provide opportunities for innovative solutions. This paper provides an overview of these challenges and highlights opportunities for innovative solutions.

  9. The Six Pack Model

    DEFF Research Database (Denmark)

    Andersen, Henrik; Ritter, Thomas

    Ever seen a growth strategies fail because it was not connect ed to the firm’s customer base? Or a customer relationship strategy falters just because it was the wrong thing to do with that given customer? This article presents the six pack model, a tool that makes growth profitable and predictable....... Not all customers can and should grow – thus a firm needs to classify its customers in order to implement the right customer strategy....

  10. A priori estimates for the solution of the first boundary-value problem for a class of second-order parabolic systems

    Energy Technology Data Exchange (ETDEWEB)

    Kamynin, L I; Khimchenko, B N

    2001-08-31

    We consider two classes of second-order parabolic matrix-vector systems (with solutions u element of M{sub mx1}, m{>=}2) that can be reduced to a single second-order parabolic equation for a scalar function v=, where p element of M{sub mx1} is a fixed stochastic constant vector. We consider the first boundary-value problem for a scalar second-order parabolic equation (with unbounded coefficients) in a domain unbounded with respect to x under the assumption of strong absorption at infinity. We obtain an a priori estimate for solutions of the first boundary-value problem in the generalized Tikhonov-Taecklind classes. (The problem under investigation has at most one solution in these classes.)

  11. Generalization of Youden index for multiple-class classification problems applied to the assessment of externally validated cognition in Parkinson disease screening.

    Science.gov (United States)

    Nakas, Christos T; Dalrymple-Alford, John C; Anderson, Tim J; Alonzo, Todd A

    2013-03-15

    Routine cognitive screening in Parkinson disease (PD) has become essential for management, to track progression and to assess clinical status in therapeutic trials. Patients with mild cognitive impairment (PD-MCI) are more likely to progress to dementia and therefore need to be distinguished from patients with normal cognition and those with dementia. A three-class Youden index has been recently proposed to select cut-off points in three-class classification problems. In this article, we examine properties of a modification of the three-class Youden index and propose a generalization to k-class classification problems. Geometric and theoretical properties of the modified index J(k) are examined. It is shown that J(k) is equivalent to the sum of the k - 1 two-class Youden indices for the adjacent classes of the ordered alternative problem given that the ordering holds. Methods are applied in the assessment of the Montreal Cognitive Assessment test when screening cognition in PD.

  12. A three-tier parallel genetic algorithm and its application for bin-packing problem%三层并行遗传算法及装箱问题中的应用

    Institute of Scientific and Technical Information of China (English)

    张丽岩; 马健; 孙焰

    2011-01-01

    提出了一个新的基于线程构建模块(TBB)的三层并行遗传算法(TPGA)。与传统遗传算法相比.在保证了算法正确性的前提下提高了运行效率,并将遗传算法的数据编码、任务处理和数据解码分别进行并行化,提高了收敛速度。TBB是Intel提供的能够完整表现并行性的代码库。采用C++语言实现了基于TBB的TPGA和串行遗传算法(SGA),通过大量实验证明,TPGA同SGA相比,不但提高了收敛速度,而且能够取得一致的最优解。%The paper presents a novel three-tier parallel genetic algorithm (TPGA) based on multi-core computer with threading building blocks (TBB). The purpose of a new Parallel function is to improve the running efficiency. TPGA is decomposed into three- tier: data coding parallelism, task processing parallelism and data decoding parallelism and it can improve the convergence rate. TBB offers a rich and complete approach to express parallelism in a C++ program, sequential genetic algorithm (SGA) and TPGA are implemented based on TBB with C++ for bin-packing problem. Experiments show that the optimal solutions of TPGA and SGA are consistent and the running efficiency of TPGA is also sooner than one of SGA.

  13. OVERCOMING THE METER BARRIER AND THE FORMATION OF SYSTEMS WITH TIGHTLY PACKED INNER PLANETS (STIPs)

    Energy Technology Data Exchange (ETDEWEB)

    Boley, A. C. [Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, B.C. V6T 1Z1 (Canada); Morris, M. A. [Center for Meteorite Studies, Arizona State University, P.O. Box 876004, Tempe, AZ 88287-6004 (United States); Ford, E. B. [Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

    2014-09-10

    We present a solution to the long outstanding meter barrier problem in planet formation theory. As solids spiral inward due to aerodynamic drag, they will enter disk regions that are characterized by high temperatures, densities, and pressures. High partial pressures of rock vapor can suppress solid evaporation, and promote collisions between partially molten solids, allowing rapid growth. This process should be ubiquitous in planet-forming disks, which may be evidenced by the abundant class of Systems with Tightly packed Inner Planets discovered by the NASA Kepler Mission.

  14. Bin Packing via Discrepancy of Permutations

    CERN Document Server

    Eisenbrand, Friedrich; Rothvoß, Thomas

    2010-01-01

    A well studied special case of bin packing is the 3-partition problem, where n items of size >1/4 have to be packed in a minimum number of bins of capacity one. The famous Karmarkar-Karp algorithm transforms a fractional solution of a suitable LP relaxation for this problem into an integral solution that requires at most O(log n) additional bins. The three-permutations-conjecture of Beck is the following. Given any 3 permutations on n symbols, one can color the symbols red and blue, such that in any interval of any of those permutations, the number of red and blue symbols differs only by a constant. Beck's conjecture is well known in the field of discrepancy theory. We establish a surprising connection between bin packing and Beck's conjecture: If the latter holds true, then the additive integrality gap of the 3-partition linear programming relaxation is bounded by a constant. This result indicates that improving approximability results for bin packing requires a better understanding of discrepancy theory.

  15. Latent Class Analysis of Gambling Activities in a Sample of Young Swiss Men: Association with Gambling Problems, Substance Use Outcomes, Personality Traits and Coping Strategies.

    OpenAIRE

    2016-01-01

    The study aimed to identify different patterns of gambling activities (PGAs) and to investigate how PGAs differed in gambling problems, substance use outcomes, personality traits and coping strategies. A representative sample of 4989 young Swiss males completed a questionnaire assessing seven distinct gambling activities, gambling problems, substance use outcomes, personality traits and coping strategies. PGAs were identified using latent class analysis (LCA). Differences between PGAs in gamb...

  16. Packing anchored rectangles

    CERN Document Server

    Dumitrescu, Adrian

    2011-01-01

    Let $S$ be a set of $n$ points in the unit square $[0,1]^2$, one of which is the origin. We construct $n$ pairwise interior-disjoint axis-aligned empty rectangles such that the lower left corner of each rectangle is a point in $S$, and the rectangles jointly cover at least a positive constant area (about 0.09). This is a first step towards the solution of a longstanding conjecture that the rectangles in such a packing can jointly cover an area of at least 1/2.

  17. Implementing a Case-Based E-Learning Environment in a Lecture-Oriented Anaesthesiology Class: Do Learning Styles Matter in Complex Problem Solving over Time?

    Science.gov (United States)

    Choi, Ikseon; Lee, Sang Joon; Kang, Jeongwan

    2009-01-01

    This study explores how students' learning styles influence their learning while solving complex problems when a case-based e-learning environment is implemented in a conventional lecture-oriented classroom. Seventy students from an anaesthesiology class at a dental school participated in this study over a 3-week period. Five learning-outcome…

  18. Cell packing structures

    KAUST Repository

    Pottmann, Helmut

    2015-03-03

    This paper is an overview of architectural structures which are either composed of polyhedral cells or closely related to them. We introduce the concept of a support structure of such a polyhedral cell packing. It is formed by planar quads and obtained by connecting corresponding vertices in two combinatorially equivalent meshes whose corresponding edges are coplanar and thus determine planar quads. Since corresponding triangle meshes only yield trivial structures, we focus on support structures associated with quad meshes or hex-dominant meshes. For the quadrilateral case, we provide a short survey of recent research which reveals beautiful relations to discrete differential geometry. Those are essential for successfully initializing numerical optimization schemes for the computation of quad-based support structures. Hex-dominant structures may be designed via Voronoi tessellations, power diagrams, sphere packings and various extensions of these concepts. Apart from the obvious application as load-bearing structures, we illustrate here a new application to shading and indirect lighting. On a higher level, our work emphasizes the interplay between geometry, optimization, statics, and manufacturing, with the overall aim of combining form, function and fabrication into novel integrated design tools.

  19. A comparison of two approaches for teaching complex, authentic mathematics problems to adolescents in remedial math classes.

    Science.gov (United States)

    Bottge, B A; Hasselbring, T S

    1993-05-01

    Two groups of adolescents with learning difficulties in mathematics were compared on their ability to generate solutions to a contextualized problem after being taught problem-solving skills under two conditions, one involving standard word problems, the other involving a contextualized problem on videodisc. All problems focused on adding and subtracting fractions in relation to money and linear measurement. Both groups of students improved their performance on solving word problems, but students in the contextualized problem group did significantly better on the contextualized problem posttest and were able to use their skills in two transfer tasks that followed instruction.

  20. Haphazard Packing of Unequal Spheres

    Institute of Scientific and Technical Information of China (English)

    叶大年; 张金民

    1991-01-01

    Haphazard packing of equal and unequal spheres can be performed for the spheres of molecular sieve material with a density of 1.80.The packing of such spheres in air is equivalent to that of nat-ural grains in water.Packing concentrations of equal spheres have been obtained for different pac-king intensities.Unequal spheres can be regarded as equal ones in a wide range of diameter ratios,so far as the packing concentration is concerned.A threshold of diameter ratio exists at 0.70,be-low which the packing concentration is expected to increase.The variation curves of concentration vs.diameter ratio were established in the experiment.The result will help us to understand the process of sedimentation and the concentration of voids in sedimentary rocks.

  1. The Holographic study for the high T_c superconductor YBCO and recent development of studies of a class of inverse problems

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A dream or interesting problem is to obtain more information based on one measurement,for example to obtain all the thermodynamic functions based on specific heat only. We call it"holographic"study.After more than 10 year's efforts,we suggest one possibility(or only one)is to solve an inverse problem(specific heat-phonon spectrum inversion,SPI).In this talk we will review recent development of studies of a class of inverse problems,including Dai's exact solution and Chen's formula and their unification.T...

  2. 合班教学问题与策略探讨%Discussion on Problems and Strategies of Mixed Classes Teaching

    Institute of Scientific and Technical Information of China (English)

    李国红

    2011-01-01

    This paper briefly analyzes and discusses the problems existed in mixed classes teaching, and sums up and puts forward the strategies of mixed classes teaching. It thinks that mixed classes teaching is a kind of universal phenomenon, of which the most outstanding problem is that the teaching effect may be unsatisfied, and the teacher of mixed classes should exert every effort to control classroom order, stir up student's potential, speak fascinating lesson, seek own reason and try to make instructors and monitors of each class to play roles in supervision and management.%文章简要分析与探讨了合班教学存在的问题,归纳和提出了合班教学的策略。认为合班教学是一种普遍现象,其最突出的问题在于教学效果可能不尽如人意,任课教师应从控制课堂秩序、激发学生潜能、把。课讲好、从自身找原因、设法使辅导员和班长发挥其监管作用等方面下功夫。

  3. A class of finite-time dual neural networks for solving quadratic programming problems and its k-winners-take-all application.

    Science.gov (United States)

    Li, Shuai; Li, Yangming; Wang, Zheng

    2013-03-01

    This paper presents a class of recurrent neural networks to solve quadratic programming problems. Different from most existing recurrent neural networks for solving quadratic programming problems, the proposed neural network model converges in finite time and the activation function is not required to be a hard-limiting function for finite convergence time. The stability, finite-time convergence property and the optimality of the proposed neural network for solving the original quadratic programming problem are proven in theory. Extensive simulations are performed to evaluate the performance of the neural network with different parameters. In addition, the proposed neural network is applied to solving the k-winner-take-all (k-WTA) problem. Both theoretical analysis and numerical simulations validate the effectiveness of our method for solving the k-WTA problem.

  4. Automating the packing heuristic design process with genetic programming.

    Science.gov (United States)

    Burke, Edmund K; Hyde, Matthew R; Kendall, Graham; Woodward, John

    2012-01-01

    The literature shows that one-, two-, and three-dimensional bin packing and knapsack packing are difficult problems in operational research. Many techniques, including exact, heuristic, and metaheuristic approaches, have been investigated to solve these problems and it is often not clear which method to use when presented with a new instance. This paper presents an approach which is motivated by the goal of building computer systems which can design heuristic methods. The overall aim is to explore the possibilities for automating the heuristic design process. We present a genetic programming system to automatically generate a good quality heuristic for each instance. It is not necessary to change the methodology depending on the problem type (one-, two-, or three-dimensional knapsack and bin packing problems), and it therefore has a level of generality unmatched by other systems in the literature. We carry out an extensive suite of experiments and compare with the best human designed heuristics in the literature. Note that our heuristic design methodology uses the same parameters for all the experiments. The contribution of this paper is to present a more general packing methodology than those currently available, and to show that, by using this methodology, it is possible for a computer system to design heuristics which are competitive with the human designed heuristics from the literature. This represents the first packing algorithm in the literature able to claim human competitive results in such a wide variety of packing domains.

  5. A modified quasi-boundary value method for a class of abstract parabolic ill-posed problems

    Directory of Open Access Journals (Sweden)

    S. Djezzar

    2006-02-01

    Full Text Available We study a final value problem for first-order abstract differential equation with positive self-adjoint unbounded operator coefficient. This problem is ill-posed. Perturbing the final condition, we obtain an approximate nonlocal problem depending on a small parameter. We show that the approximate problems are well posed and that their solutions converge if and only if the original problem has a classical solution. We also obtain estimates of the solutions of the approximate problems and a convergence result of these solutions. Finally, we give explicit convergence rates.

  6. UNIFORM PACKING DIMENSION RESULTS FOR MULTIPARAMETER STABLE PROCESSES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this article, authors discuss the problem of uniform packing dimension of the image set of multiparameter stochastic processes without random uniform H(o)lder condition, and obtain the uniform packing dimension of multiparameter stable processes.If Z is a stable (N, d, α)-process and αN ≤ d, then the following holds with probability 1 Dim Z(E) = α DimE for any Borel setE ∈ B(R+N),where Z(E) = {x: (E) t ∈ E, Z(t) = x}. Dim(E) denotes the packing dimension of E.

  7. Fast Searching in Packed Strings

    DEFF Research Database (Denmark)

    Bille, Philip

    2009-01-01

    . However, most strings are stored in a computer in a packed representation with several characters in a single word, giving us the opportunity to read multiple characters simultaneously. In this paper we study the worst-case complexity of string matching on strings given in packed representation. Let m...

  8. Optimization of heterogeneous Bin packing using adaptive genetic algorithm

    Science.gov (United States)

    Sridhar, R.; Chandrasekaran, M.; Sriramya, C.; Page, Tom

    2017-03-01

    This research is concentrates on a very interesting work, the bin packing using hybrid genetic approach. The optimal and feasible packing of goods for transportation and distribution to various locations by satisfying the practical constraints are the key points in this project work. As the number of boxes for packing can not be predicted in advance and the boxes may not be of same category always. It also involves many practical constraints that are why the optimal packing makes much importance to the industries. This work presents a combinational of heuristic Genetic Algorithm (HGA) for solving Three Dimensional (3D) Single container arbitrary sized rectangular prismatic bin packing optimization problem by considering most of the practical constraints facing in logistic industries. This goal was achieved in this research by optimizing the empty volume inside the container using genetic approach. Feasible packing pattern was achieved by satisfying various practical constraints like box orientation, stack priority, container stability, weight constraint, overlapping constraint, shipment placement constraint. 3D bin packing problem consists of ‘n’ number of boxes being to be packed in to a container of standard dimension in such a way to maximize the volume utilization and in-turn profit. Furthermore, Boxes to be packed may be of arbitrary sizes. The user input data are the number of bins, its size, shape, weight, and constraints if any along with standard container dimension. This user input were stored in the database and encoded to string (chromosomes) format which were normally acceptable by GA. GA operators were allowed to act over these encoded strings for finding the best solution.

  9. Multiple spreading phenomena for a free boundary problem of a reaction-diffusion equation with a certain class of bistable nonlinearity

    Science.gov (United States)

    Kawai, Yusuke; Yamada, Yoshio

    2016-07-01

    This paper deals with a free boundary problem for diffusion equation with a certain class of bistable nonlinearity which allows two positive stable equilibrium states as an ODE model. This problem models the invasion of a biological species and the free boundary represents the spreading front of its habitat. Our main interest is to study large-time behaviors of solutions for the free boundary problem. We will completely classify asymptotic behaviors of solutions and, in particular, observe two different types of spreading phenomena corresponding to two positive stable equilibrium states. Moreover, it will be proved that, if the free boundary expands to infinity, an asymptotic speed of the moving free boundary for large time can be uniquely determined from the related semi-wave problem.

  10. Problems

    Directory of Open Access Journals (Sweden)

    Yekini Shehu

    2010-01-01

    real Banach space which is also uniformly smooth using the properties of generalized f-projection operator. Using this result, we discuss strong convergence theorem concerning general H-monotone mappings and system of generalized mixed equilibrium problems in Banach spaces. Our results extend many known recent results in the literature.

  11. Problems and Strategies for English Majors Large Classes Teaching%英语专业大班教学的问题与对策

    Institute of Scientific and Technical Information of China (English)

    黄笑雪

    2016-01-01

    College enrollment makes large classes teaching grow popular, English majors are also not spared. Compared with small classes, large classes more challenging educational skills of teachers, curriculum planning and classroom organization and management skills. The author summarizes itself more than a decade of experience in domestic and foreign English tea-ching experience and study research on large classes, summarized the main issues several English teaching in large class of professional and propose strategies to solve these problems.%高校扩招令大班教学日渐普及,英语专业课亦不能幸免。与小班教学相比,大班教学更挑战教师的教育技能、课程规划与课堂组织管理技能。笔者通过总结自身十多年国内外英语课堂教学的经验体会与研读关于大班教学的研究成果,归纳出几个英语专业大班教学存在的主要问题并提出解决这些问题的策略。

  12. Chaotic Monkey Algorithm for a Class of Dynamic Optimization Problems%一类基于动态优化问题的混沌猴群算法

    Institute of Scientific and Technical Information of China (English)

    齐艳玉; 兰燕飞

    2013-01-01

    在混沌猴群算法(Chaotic monkey algorithm,CMA)的思想上,通过选用一个遍历性更好的混沌函数代替了原算法中的Logistic函数,并设计了一种适用于求解动态规划问题的智能算法.先对CMA进行了介绍,接着给出了一类动态优化问题的模型,并将该模型离散化为一类多维函数优化问题,给出了求解各过程的详细步骤和数值例子,说明上述方法的可行性和有效性.%Based on CMA, a chaotic function was used to solve a class of dynamic optimization problems, which has better than the Logistic function. After given the brief introduction of CMA, a class of dynamic optimization model was proposed. The class of model was discretized into a multidimensional optimization problem and then processes for solving the problem were given. To testify the feasibility and the effectiveness, one numerical example was presented.

  13. Packing of protein structures in clusters with magic numbers

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker; Bohr, Henrik

    1997-01-01

    Recently we have proposed a model for folding proteins into packed `clusters'. We have constructed a local homology measure for protein fold classes by projecting consecutively secondary structures onto a lattice. Taking into account hydrophobic forces we have found a mechanism for formation...

  14. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, J.J.

    1990-12-31

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele`s pivot. The Schiele`s pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele`s pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele`s pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  15. A Class of Quasi-Linear Riemann-Hilbert Problems for General Holomorphic Functions in the Unit Disk%一类圆域上广义解析函数拟线性Riemann-Hilbert问题

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, a class of quasi-linear Rie mann-Hilbert problems for general holomorphic functions in the unit disk was studied. Under suitable hypotheses, the existence of solutions of the Hardy class H2 to this problem was proved by means of Tikhonov' s fixed point theorem and corresponding theories for general holomorphic functions

  16. Stress, Mental Health, and Substance Abuse Problems in a Sample of Diversion Program Youths: An Exploratory Latent Class Analysis

    Science.gov (United States)

    Dembo, Richard; Briones, Rhissa; Gulledge, Laura; Karas, Lora; Winters, Ken C.; Belenko, Steven; Greenbaum, Paul E.

    2012-01-01

    Reflective of interest in mental health and substance abuse issues among youths involved with the justice system, we performed a latent class analysis on baseline information collected on 100 youths involved in two diversion programs. Results identified two groups of youths: Group 1: a majority of the youths, who had high levels of delinquency,…

  17. Supporting Collaborative Learning and Problem-Solving in a Constraint-Based CSCL Environment for UML Class Diagrams

    Science.gov (United States)

    Baghaei, Nilufar; Mitrovic, Antonija; Irwin, Warwick

    2007-01-01

    We present COLLECT-UML, a constraint-based intelligent tutoring system (ITS) that teaches object-oriented analysis and design using Unified Modelling Language (UML). UML is easily the most popular object-oriented modelling technology in current practice. While teaching how to design UML class diagrams, COLLECT-UML also provides feedback on…

  18. Compactness Theorems for Geometric Packings

    OpenAIRE

    Martin, Greg

    2000-01-01

    Moser asked whether the collection of rectangles of dimensions 1 x 1/2, 1/2 x 1/3, 1/3 x 1/4, ..., whose total area equals 1, can be packed into the unit square without overlap, and whether the collection of squares of side lengths 1/2, 1/3, 1/4, ... can be packed without overlap into a rectangle of area pi^2/6-1. Computational investigations have been made into packing these collections into squares of side length 1+epsilon and rectangles of area pi^2/6-1+epsilon, respectively, and one can c...

  19. Class and Homework Problems: The Break-Even Radius of Insulation Computed Using Excel Solver and WolframAlpha

    Science.gov (United States)

    Foley, Greg

    2014-01-01

    A problem that illustrates two ways of computing the break-even radius of insulation is outlined. The problem is suitable for students who are taking an introductory module in heat transfer or transport phenomena and who have some previous knowledge of the numerical solution of non- linear algebraic equations. The potential for computer algebra,…

  20. The Effects of Authentic Tasks on Preservice Teachers' Attitudes towards Classes and Problem Solving Skills

    Science.gov (United States)

    Kocyigit, Sinan; Zembat, Rengin

    2013-01-01

    This study aimed to investigate the effects of authentic tasks on preschool preservice teachers' attitudes towards the course and problem solving skills. The study was designed in accordance with the pretest-posttest control group model. The data were collected by using the "Problem Solving Skills Inventory", the "Course…

  1. Gender Differences in Solving Mathematics Problems among Two-Year College Students in a Developmental Algebra Class and Related Factors.

    Science.gov (United States)

    Schonberger, Ann K.

    A study was conducted at the University of Maine at Orono (UMO) to examine gender differences with respect to mathematical problem-solving ability, visual spatial ability, abstract reasoning ability, field independence/dependence, independent learning style, and developmental problem-solving ability (i.e., formal reasoning ability). Subjects…

  2. Practical use of SPRINT and a moving grid interface for a class of 1D non-linear transport problems

    NARCIS (Netherlands)

    van Eijkeren JCH; Zegeling PA; Hassanizadeh SM

    1991-01-01

    Environmental problems tend to become of still greater complexity. The mathematical formulation of these problems often results in a set of differential equations, which urges the need for robust differential equation solvers. Moreover, these solvers should be implemented within a user-friendly an

  3. A Qualitative Study on Classroom Management and Classroom Discipline Problems, Reasons, and Solutions: A Case of Information Technologies Class

    Science.gov (United States)

    Erdogan, Mehmet; Kursun, Engin; Sisman, Gulcin Tan; Saltan, Fatih; Gok, Ali; Yildiz, Ismail

    2010-01-01

    The purpose of this study was to investigate classroom management and discipline problems that Information Technology teachers have faced, and to reveal underlying reasons and possible solutions of these problems by considering the views of parents, teachers, and administrator. This study was designed as qualitative study. Subjects of this study…

  4. Sum-Rate Maximization in Two-Way AF MIMO Relaying: Polynomial Time Solutions to a Class of DC Programming Problems

    CERN Document Server

    Khabbazibasmenj, Arash; Vorobyov, Sergiy A; Haardt, Martin

    2012-01-01

    Sum-rate maximization in two-way amplify-and-forward (AF) multiple-input multiple-output (MIMO) relaying belongs to the class of difference-of-convex functions (DC) programming problems. DC programming problems occur as well in other signal processing applications and are typically solved using different modifications of the branch-and-bound method. This method, however, does not have any polynomial time complexity guarantees. In this paper, we show that a class of DC programming problems, to which the sum-rate maximization in two-way MIMO relaying belongs, can be solved very efficiently in polynomial time, and develop two algorithms. The objective function of the problem is represented as a product of quadratic ratios and parameterized so that its convex part (versus the concave part) contains only one (or two) optimization variables. One of the algorithms is called POlynomial-Time DC (POTDC) and is based on semi-definite programming (SDP) relaxation, linearization, and an iterative search over a single para...

  5. Lower bounds for 1-, 2- and 3-dimensional on-line bin packing algorithms

    NARCIS (Netherlands)

    G. Galambos; A. van Vliet (André)

    1994-01-01

    textabstractIn this paper we discuss lower bounds for the asymptotic worst case ratio of on-line algorithms for different kind of bin packing problems. Recently, Galambos and Frenk gave a simple proof of the 1.536 ... lower bound for the 1-dimensional bin packing problem. Following their ideas, we p

  6. A class of nonlocal variational problems on a vector bundle for color image local contrast reduction/enhancement

    OpenAIRE

    Bertalmío, Marcelo; Batard, Thomas

    2016-01-01

    We extend two existing variational models from the Euclidean space to a vector bundle over a Riemannian manifold. The Euclidean models, dedicated to regularize or enhance some color image features, are based on the concept of nonlocal gradient operator acting on a function of the Euclidean space. We then extend these models by generalizing this operator to a vector bundle over a Riemannian manifold with the help of the parallel transport map associated to some class of covariant derivatives. ...

  7. A Class of Nonlocal Variational Problems on a Vector Bundle for Color Image Local Contrast Reduction/Enhancement.

    OpenAIRE

    Batard, Thomas; Bertalmío, Marcelo

    2016-01-01

    We extend two existing variational models from the Euclidean space to a vector bundle over a Riemannian manifold. The Euclidean models , dedicated to regularize or enhance some color image features, are based on the concept of nonlocal gradient operator acting on a function of the Euclidean space. We then extend these models by generalizing this operator to a vector bundle over a Riemannian manifold with the help of the parallel transport map associated to some class of covariant derivatives....

  8. A Class of Optimization Method for Bilevel Multi-objective Decision Making Problem with the Help of Satisfactoriness

    Institute of Scientific and Technical Information of China (English)

    LI Tong; TENG Chun-xian; LI Hao-bai

    2002-01-01

    In the paper, it is discussed that the method on how to transform the multi-person bilevel multi-objective decision making problem into the equivalent generalized multi-objective decision making problem by using Kuhn-Tucker sufficient and necessary condition. In order to embody the decision maker's hope and transform it into single-objective decision making problem with the help of e-constraint method.Then we can obtain the global optimal solution by means of simulated annealing algorithm.

  9. Domain Discretization and Circle Packings

    DEFF Research Database (Denmark)

    Dias, Kealey

    A circle packing is a configuration of circles which are tangent with one another in a prescribed pattern determined by a combinatorial triangulation, where the configuration fills a planar domain or a two-dimensional surface. The vertices in the triangulation correspond to centers of circles......, and edges correspond to two circles (having centers corresponding to the endpoints of the edge) being tangent to each other. This circle packing creates a rigid structure having an underlying geometric triangulation, where the centers of circles again correspond to vertices in the triangulation......, and the edges are geodesic segments (Euclidean, hyperbolic, or spherical) connecting centers of circles that are tangent to each other. Three circles that are mutually tangent form a face of the triangulation. Since circle packing is closely related to triangulation, circle packing methods can be applied...

  10. An improved dual neural network for solving a class of quadratic programming problems and its k-winners-take-all application.

    Science.gov (United States)

    Hu, Xiaolin; Wang, Jun

    2008-12-01

    This paper presents a novel recurrent neural network for solving a class of convex quadratic programming (QP) problems, in which the quadratic term in the objective function is the square of the Euclidean norm of the variable. This special structure leads to a set of simple optimality conditions for the problem, based on which the neural network model is formulated. Compared with existing neural networks for general convex QP, the new model is simpler in structure and easier to implement. The new model can be regarded as an improved version of the dual neural network in the literature. Based on the new model, a simple neural network capable of solving the k-winners-take-all ( k-WTA) problem is formulated. The stability and global convergence of the proposed neural network is proved rigorously and substantiated by simulation results.

  11. Evaluation of POE and instructor-led problem-solving approaches integrated into force and motion lecture classes using a model analysis technique

    Science.gov (United States)

    Rakkapao, S.; Pengpan, T.; Srikeaw, S.; Prasitpong, S.

    2014-01-01

    This study aims to investigate the use of the predict-observe-explain (POE) approach integrated into large lecture classes on forces and motion. It is compared to the instructor-led problem-solving method using model analysis. The samples are science (SC, N = 420) and engineering (EN, N = 434) freshmen, from Prince of Songkla University, Thailand. Research findings from the force and motion conceptual evaluation indicate that the multimedia-supported POE method promotes students’ learning better than the problem-solving method, in particular for the velocity and acceleration concepts. There is a small shift of the students’ model states after the problem-solving instruction. Moreover, by using model analysis instructors are able to investigate students’ misconceptions and evaluate teaching methods. It benefits instructors in organizing subsequent instructional materials.

  12. Packing and viscosity of concentrated polydisperse coal-water slurries

    Energy Technology Data Exchange (ETDEWEB)

    Veytsman, B.; Morrison, J.; Scaroni, A.; Painter, P. [Pennsylvania State University, University Park, PA (United States). Energy Inst.

    1998-09-01

    The viscosity of polydisperse slurries close to the packing limit is discussed. It is shown that the divergence of the viscosity at the close packing limit causes the dependence of the slurry viscosity on loading to be universal. Ways of increasing the maximal loading of polydisperse slurries are described. A new theory of packing of powders based on a generalization of the Furnas telescopic tube method is proposed. Unlike the original Furnas model, this theory allows the calculation of the maximal packing for powders with an arbitrary size distribution of particles. The application of the theory to the problem of reducing the viscosity of coal-water slurries is discussed. 15 refs., 8 figs.

  13. Introduction to College Class Management Problems and Countermeasures Research%高校班级管理存在的问题及对策研究

    Institute of Scientific and Technical Information of China (English)

    马涛

    2015-01-01

    A class is the basic organization form, college students are college students self education, self management, self service main organization carrier. Classroom management is an important part of the management system of colleges and uni-versities, is one of the important link of the daily management of university counselors, is one of the main position of students of university counselors work, in class management can greatly save time, improve efficiency. This paper mainly introduces the importance of class management, as well as the problems existing in the class management in colleges and universities, and some countermeasures.%班级是大学生的基本组织形式,是大学生自我教育、自我管理、自我服务的主要组织载体.班级管理是高校管理体系的重要组成部分,是高校辅导员日常管理工作的重要环节之一,是高校辅导员学生工作的主阵地之一,以班级为单位的管理可以极大地节省时间,提高效率.本文主要介绍了班级管理的重要性,以及目前高校班级管理存在的问题及一些对策.

  14. Class III malocclusion with complex problems of lateral open bite and severe crowding successfully treated with miniscrew anchorage and lingual orthodontic brackets.

    Science.gov (United States)

    Yanagita, Takeshi; Kuroda, Shingo; Takano-Yamamoto, Teruko; Yamashiro, Takashi

    2011-05-01

    In this article, we report the successful use of miniscrews in a patient with an Angle Class III malocclusion, lateral open bite, midline deviation, and severe crowding. Simultaneously resolving such problems with conventional Class III treatment is difficult. In this case, the treatment procedure was even more challenging because the patient preferred to have lingual brackets on the maxillary teeth. As a result, miniscrews were used to facilitate significant asymmetric tooth movement in the posterior and downward directions; this contributed to the camouflage of the skeletal mandibular protrusion together with complete resolution of the severe crowding and lateral open bite. Analysis of the jaw motion showed that irregularities in chewing movement were also resolved, and a stable occlusion was achieved. Improvements in the facial profile and dental arches remained stable at the 18-month follow-up.

  15. Compressed Subsequence Matching and Packed Tree Coloring

    DEFF Research Database (Denmark)

    Bille, Philip; Cording, Patrick Hagge; Gørtz, Inge Li

    2017-01-01

    We present a new algorithm for subsequence matching in grammar compressed strings. Given a grammar of size n compressing a string of size N and a pattern string of size m over an alphabet of size \\(\\sigma \\), our algorithm uses \\(O(n+\\frac{n\\sigma }{w})\\) space and \\(O(n+\\frac{n\\sigma }{w}+m\\log ...... a new data structure that allows us to efficiently find the next occurrence of a given character after a given position in a compressed string. This data structure in turn is based on a new data structure for the tree color problem, where the node colors are packed in bit strings....

  16. Hemiequilibrium problems

    Directory of Open Access Journals (Sweden)

    Muhammad Aslam Noor

    2004-01-01

    Full Text Available We consider a new class of equilibrium problems, known as hemiequilibrium problems. Using the auxiliary principle technique, we suggest and analyze a class of iterative algorithms for solving hemiequilibrium problems, the convergence of which requires either pseudomonotonicity or partially relaxed strong monotonicity. As a special case, we obtain a new method for hemivariational inequalities. Since hemiequilibrium problems include hemivariational inequalities and equilibrium problems as special cases, the results proved in this paper still hold for these problems.

  17. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, J.J.

    1991-09-03

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents over tightening of the retaining nut and the resulting excessive friction between stem and stem packing. 2 figures.

  18. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, John J. (Bingham County, ID)

    1991-01-01

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  19. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, J.J.

    1990-01-01

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  20. 7 CFR 51.310 - Packing requirements.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Packing requirements. 51.310 Section 51.310... STANDARDS) United States Standards for Grades of Apples Packing Requirements § 51.310 Packing requirements... the contents. (e) Tolerances: In order to allow for variations incident to proper packing, not...

  1. 7 CFR 51.1270 - Packing.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Packing. 51.1270 Section 51.1270 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Standards for Summer and Fall Pears 1 Standard Pack § 51.1270 Packing. (a) Each package shall be packed...

  2. 7 CFR 51.1311 - Packing.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Packing. 51.1311 Section 51.1311 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Standards for Winter Pears 1 Standard Pack § 51.1311 Packing. (a) Each package shall be packed so that...

  3. Assessing the Social Skills and Problem Behaviors of Adolescents With Severe Disabilities Enrolled in General Education Classes.

    Science.gov (United States)

    Lyons, Gregory L; Huber, Heartley B; Carter, Erik W; Chen, Rui; Asmus, Jennifer M

    2016-07-01

    Although enhancing the social competence of students with severe disabilities has long remained a prominent focus of school-based intervention efforts, relatively little attention has focused on identifying the most critical social and behavioral needs of students during high school. We examined the social skills and problem behaviors of 137 adolescents with severe disabilities from the vantage point of both special educators and parents. We sought to identify areas of potential intervention need, explore factors associated with social skill and problem behavior ratings, and examine the extent to which teachers and parents converged in their assessments of these needs. Our findings indicate teachers and parents of high school students with severe disabilities rated social skills as considerably below average and problem behaviors as above average. In addition, lower social skills ratings were evident for students with greater support needs, lower levels of overall adaptive behavior, and a special education label of autism. We found moderate consistency in the degree to which teachers and parents aligned in their assessments of both social skills and problem behavior. We offer recommendations for assessment and intervention focused on strengthening the social competence of adolescents with severe disabilities within secondary school classrooms, as well as promising avenues for future research.

  4. Multiple Solutions and Bifurcation for a Class of Nonlinear Sturm-Liouville Eigenvalue Problems on an Unbounded Domain.

    Science.gov (United States)

    1988-04-01

    Moreover, if e2 > 61 and we further assume (f.1) f(x,y) is locally Lipschitz continuous in y then inequalities (1.37) and (1.38) are strict. 17 Proof MI...Univ. Math. J. 20 (1971), 983-996.[I 124 18. J. A. Hempel, Superlinear variational boundary value problems and nonuniqueness , Thesis, University of

  5. Perceiving the Problem of Poverty and Schooling: Deconstructing the Class Stereotypes that Mis-Shape Education Practice and Policy

    Science.gov (United States)

    Gorski, Paul C.

    2012-01-01

    A rich history of scholarship has demonstrated the ways in which popular stereotypes of disenfranchised communities, including people living in poverty, affect individual biases and preconceptions. Less attention has been paid to the ways in which such stereotypes help frame policy and practice responses regarding social problems, such as the…

  6. Assessing the Social Skills and Problem Behaviors of Adolescents with Severe Disabilities Enrolled in General Education Classes

    Science.gov (United States)

    Lyons, Gregory L.; Huber, Heartley B.; Carter, Erik W.; Chen, Rui; Asmus, Jennifer M.

    2016-01-01

    Although enhancing the social competence of students with severe disabilities has long remained a prominent focus of school-based intervention efforts, relatively little attention has focused on identifying the most critical social and behavioral needs of students during high school. We examined the social skills and problem behaviors of 137…

  7. The Social and Emotional Situation of First Graders with Classroom Behavior Problems and Classroom Learning Difficulties in Inclusive Classes

    Science.gov (United States)

    Krull, Johanna; Wilbert, Jürgen; Hennemann, Thomas

    2014-01-01

    The inclusion of children with special educational needs (SEN) in general education classrooms in Europe due to education policy and social developments is currently up for debate, especially in Germany. This paper addresses whether or not co-education of students with and without classroom problems and/or disabilities has negative consequences…

  8. The Third Initial-boundary Value Problem for a Class of Parabolic Monge-Ampère Equations

    Institute of Scientific and Technical Information of China (English)

    Lü BO-QIANG; LI FENG-QUAN

    2012-01-01

    For the more general parabolic Monge-Ampère equations defined by the operator F(D2u + σ(x)),the existence and uniqueness of the admissible solution to the third initial-boundary value problem for the equation are established.A new structure condition which is used to get a priori estimate is established.

  9. A minimax inequality for a class of functionals and applications to the existence of solutions for two-point boundary-value problems

    Directory of Open Access Journals (Sweden)

    Ghasem Alizadeh Afrouzi

    2006-10-01

    Full Text Available In this paper, we establish an equivalent statement to minimax inequality for a special class of functionals. As an application, we prove the existence of three solutions to the Dirichlet problem $$displaylines{ -u''(x+m(xu(x =lambda f(x,u(x,quad xin (a,b,cr u(a=u(b=0, }$$ where $lambda>0$, $f:[a,b]imes mathbb{R}o mathbb{R}$ is a continuous function which changes sign on $[a,b]imes mathbb{R}$ and $m(xin C([a,b]$ is a positive function.

  10. AFPTAS results for common variants of bin packing: A new method to handle the small items

    CERN Document Server

    Epstein, Leah

    2009-01-01

    We consider two well-known natural variants of bin packing, and show that these packing problems admit asymptotic fully polynomial time approximation schemes (AFPTAS). In bin packing problems, a set of one-dimensional items of size at most 1 is to be assigned (packed) to subsets of sum at most 1 (bins). It has been known for a while that the most basic problem admits an AFPTAS. In this paper, we develop methods that allow to extend this result to other variants of bin packing. Specifically, the problems which we study in this paper, for which we design asymptotic fully polynomial time approximation schemes, are the following. The first problem is "Bin packing with cardinality constraints", where a parameter k is given, such that a bin may contain up to k items. The goal is to minimize the number of bins used. The second problem is "Bin packing with rejection", where every item has a rejection penalty associated with it. An item needs to be either packed to a bin or rejected, and the goal is to minimize the nu...

  11. Nature of packs used in propellant modeling.

    Science.gov (United States)

    Maggi, F; Stafford, S; Jackson, T L; Buckmaster, J

    2008-04-01

    In recent years we have constructed closely packed spheres using the Lubachevsky-Stillinger algorithm to generate morphological models of heterogeneous solid propellants. Improvements to the algorithm now allow us to create large polydisperse packs on a laptop computer, and to create monodisperse packs with packing fractions greater than 70% which display significant crystal order. The use of these models in the physical context motivates efforts to examine in some detail the nature of the packs, including certain statistical properties. We compare packing fractions for binary packs with long-known experimental data. Also, we discuss the near-neighbor number and the radial distribution function (RDF) for monodisperse packs and make comparisons with experimental data. We also briefly discuss the RDF for bidisperse packs. We also consider bounded monodisperse packs, and pay particular attention to the near-wall structure where we identify significant order.

  12. Problems and Countermeasures in Development of University Class Organization%大学班级组织发展面临的问题及对策

    Institute of Scientific and Technical Information of China (English)

    夏敏

    2012-01-01

    University class is the common teaching organization and management form of university. The development of university class organization is helpful to create the favorable organization atmosphere for the growth of college stfidents, and the realization of the educational objective and higher educational functions. At present, under the influence of university enrolment expansion, educational reform development, and educational concept changes, the form, scope, system and contents of university class organization have been continuously challenged by external development so that the class functions have been weakened, and the management efficiency has been lowered. To change the concept of Class organizational development, to innovate the form of class organization, to broaden the scope of organizational management, and to strengthen the organizational system construction and information construction are the necessary countermeasures for solving the problems of Chinese university class organizational development currently.%大学班级是高校普遍的教学组织和管理形式。大学班级组织的发展有助于创建大学生成长的良好组织氛围,促进教育目标和高等教育功能的实现。当前,大学班级组织在高校扩招、教育改革发展、教育理念变革的影响下,班级组织形式、范围、制度、内容不断受到外部发展的挑战,班级功能弱化,管理效率降低。转变班级组织发展观念,创新班级组织形式,拓宽组织管理范围,加强组织制度建设和信息化建设是应对当前中国大学班级组织发展问题的必要对策。

  13. Self-Adjointness of the Dirac Hamiltonian for a Class of Non-Uniformly Elliptic Boundary Value Problems

    CERN Document Server

    Finster, Felix

    2015-01-01

    We consider a boundary value problem for the Dirac equation in a four-dimensional, smooth, asymptotically flat Lorentzian manifold admitting a Killing field which is timelike near and tangential to the boundary. A self-adjoint extension of the Dirac Hamiltonian is constructed. Our results also apply to the situation that the space-time includes horizons, where the Hamiltonian fails to be elliptic.

  14. Planet Packing in Circumbinary Systems

    CERN Document Server

    Kratter, Kaitlin M

    2013-01-01

    The recent discovery of planets orbiting main sequence binaries will provide crucial constraints for theories of binary and planet formation. The formation pathway for these planets is complicated by uncertainties in the formation mechanism of the host stars. In this paper, we compare the dynamical states of single and binary star planetary systems. Specifically, we pose two questions: (1) What does it mean for a circumbinary system to be dynamically packed? (2) How many systems are required to differentiate between a population of packed or sparse planets? We determine when circumbinary systems become dynamically unstable as a function of the separation between the host-stars and the inner planet, and the first and second planets. We show that these represent unique stability constraints compared to single-star systems. We find that although the existing Kepler data is insufficient to distinguish between a population of packed or sparse circumbinary systems, a more thorough study of circumbinary TTVs combine...

  15. Cylinder valve packing nut studies

    Energy Technology Data Exchange (ETDEWEB)

    Blue, S.C. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    The design, manufacture, and use of cylinder valve packing nuts have been studied to improve their resistance to failure from stress corrosion cracking. Stress frozen photoelastic models have been analyzed to measure the stress concentrations at observed points of failure. The load effects induced by assembly torque and thermal expansion of stem packing were observed by strain gaging nuts. The effects of finishing operations and heat treatment were studied by the strain gage hole boring and X-ray methods. Modifications of manufacturing and operation practices are reducing the frequency of stress corrosion failures.

  16. A Geometric-Structure Theory for Maximally Random Jammed Packings

    Science.gov (United States)

    Tian, Jianxiang; Xu, Yaopengxiao; Jiao, Yang; Torquato, Salvatore

    2015-11-01

    Maximally random jammed (MRJ) particle packings can be viewed as prototypical glasses in that they are maximally disordered while simultaneously being mechanically rigid. The prediction of the MRJ packing density ϕMRJ, among other packing properties of frictionless particles, still poses many theoretical challenges, even for congruent spheres or disks. Using the geometric-structure approach, we derive for the first time a highly accurate formula for MRJ densities for a very wide class of two-dimensional frictionless packings, namely, binary convex superdisks, with shapes that continuously interpolate between circles and squares. By incorporating specific attributes of MRJ states and a novel organizing principle, our formula yields predictions of ϕMRJ that are in excellent agreement with corresponding computer-simulation estimates in almost the entire α-x plane with semi-axis ratio α and small-particle relative number concentration x. Importantly, in the monodisperse circle limit, the predicted ϕMRJ = 0.834 agrees very well with the very recently numerically discovered MRJ density of 0.827, which distinguishes it from high-density “random-close packing” polycrystalline states and hence provides a stringent test on the theory. Similarly, for non-circular monodisperse superdisks, we predict MRJ states with densities that are appreciably smaller than is conventionally thought to be achievable by standard packing protocols.

  17. To improve class existing problems and countermeasures of teaching materials of college English language and culture classes%大学英语语言文化类提高课现行教材的问题及对策

    Institute of Scientific and Technical Information of China (English)

    朱珠

    2015-01-01

    大学英语教学指南(征求意见稿)全新定义了大学英语课程的性质,这对大学英语及其相关课程的教材出版来说,无疑也意味着有了新的指挥棒。本文分析了大学英语语言文化类提高课教材的现状及问题,也讨论了改进此类教材的方法和对策。%College English teaching guidelines (draft) newly defines the nature of the college English courses, to the college English publications, it seems like a new baton. This paper analyzes the university English language culture present situation and problems of class teaching materials and also discussed the improvement methods and countermeasures of such materials.

  18. 一类VRP问题的改进PSO算法求解%Improved PSO Algorithm Solution of a Class of VRP Problem

    Institute of Scientific and Technical Information of China (English)

    王一川

    2012-01-01

    VRP issue is a hot research problem in the field of logistics. A mathematical model of a typical class of VRP problem is established, and an improved particle swarm optimization algorithm is proposed to solve the model. This algorithm designs the sequence coding scheme for problems, and introduces the local search algorithm to improve the local search capabilities. The simulation results show the effectiveness of the mentioned discrete particle swarm optimization algorithm to solve such VRP problem.%VRP问题是物流领域的热点研究问题.在对一类典型的VRP问题建立了数学模型,提出了一种改进粒子群优化算法以求解该模型.算法针对问题设计了顺序编码方案,并引入了局部搜索以提高算法的局部搜索能力.仿真结果表明了所提离散粒子群优化算法求解此类VRP问题的有效性.

  19. The Existence of Solutions to a Class of Multi-point Boundary Value Problem of Fractional Differential Equation

    Institute of Scientific and Technical Information of China (English)

    Xiaohong HAO; Zongfu ZHOU

    2013-01-01

    In this paper,we consider the following multi-point boundary value problem of fractional differential equation Dα0+u(t) =f(t,u(t),Dα-10+ u(t),Dα+20u(t),Dα-30u(t)),t ∈ (0,1),I4-α0+u(0) =0,Dα-10+u(0) =nΣi=1αi Dα-10+u(ξi),Dα-20+u(1) =nΣj=1 βjDα-20+ u(ηj),Dα-30+u(1)-Dα-30+u(0) =Dα-20+2u(1/2),where 3 < α ≤ 4 is a real number.By applying Mawhin coincidence degree theory and constructing suitable operators,some existence results of solutions can be established.

  20. Pack cementation coatings for alloys

    Energy Technology Data Exchange (ETDEWEB)

    He, Yi-Rong; Zheng, Minhui; Rapp, R.A. [Ohio State Univ., Columbus, OH (United States)

    1996-08-01

    The halide-activated pack cementation process was modified to produce a Ge-doped silicide diffusion coating on a Cr-Cr{sub 2}Nb alloy in a single processing step. The morphology and composition of the coating depended both on the composition of the pack and on the composition and microstructure of the substrate. Higher Ge content in the pack suppressed the formation of CrSi{sub 2} and reduced the growth kinetics of the coating. Ge was not homogeneously distributed in the coatings. In cyclic and isothermal oxidation in air at 700 and 1050{degrees}C, the Ge-doped silicide coating protected the Cr-Nb alloys from significant oxidation by the formation of a Ge-doped silica film. The codeposition and diffusion of aluminum and chromium into low alloy steel have been achieved using elemental Al and Cr powders and a two-step pack cementation process. Sequential process treatments at 925{degrees}C and 1150{degrees}C yield dense and uniform ferrite coatings, whose compositions are close to either Fe{sub 3}Al or else FeAl plus a lower Cr content, when processed under different conditions. The higher content of Al in the coatings was predicted by thermodynamic calculations of equilibrium in the gas phase. The effect of the particle size of the metal powders on the surface composition of the coating has been studied for various combinations of Al and Cr powders.

  1. Wire and Packing Tape Sandwiches

    Science.gov (United States)

    Rabinowitz, Sandy

    2009-01-01

    In this article, the author describes how students can combine craft wire with clear packing tape to create a two-dimensional design that can be bent and twisted to create a three-dimensional form. Students sandwich wire designs between two layers of tape. (Contains 1 online resource.)

  2. High-performance liquid chromatography with packed microchips

    OpenAIRE

    Ehlert, Steffen

    2011-01-01

    This work is explaining the importance of generating a densely packed chromatographic bed to achieve optimum separation efficiency in miniaturized liquid chromatography. The reduction of peak dispersion and enhancement of separation efficiency is the important problem in micro- and nano-separation that is to be solved to generate highly efficient chromatographic systems that can exploit all advantages of miniaturization. Therefore...

  3. Inferior venacaval compression due to excessive abdominal packing

    Directory of Open Access Journals (Sweden)

    M.C.B. Santhosh

    2014-06-01

    Full Text Available Inferior venacaval compression is a common problem in late pregnancy. It can also occur due to compression of inferior venacava by abdominal or pelvic tumors. We report a case of acute iatrogenic inferior venacaval compression due to excessive abdominal packing during an intraabdominal surgery.

  4. The close-packed triple helix as a possible new structural motif for collagen

    DEFF Research Database (Denmark)

    Bohr, Jakob; Olsen, Kasper

    2010-01-01

    The one-dimensional problem of selecting the triple helix with the highest volume fraction is solved and hence the condition for a helix to be close-packed is obtained. The close-packed triple helix is shown to have a pitch angle of v CP = 43.3°. Contrary to the conventional notion, we suggest...... that close packing form the underlying principle behind the structure of collagen, and the implications of this suggestion are considered. Further, it is shown that the unique zero-twist structure with no strain-twist coupling is practically identical to the close-packed triple helix. Some...

  5. A Problem on the Addition of Residue Classes by Sark?zy%Sark?zy的一个加法剩余类问题

    Institute of Scientific and Technical Information of China (English)

    杨仕椿; 汤建钢

    2013-01-01

    The characteristic of the A+B and A+^B,is a difficult topic in number theory and combinatorics,and plays an important and profound role. In this paper,we first noted that under normal circumstances,the answer of a problem on the addition of residue classes by Sark?zy is negative. Secondly,for the mode even number m of irreducible residue system, using Cauchy-Davenport theorem,we give the problem in two preliminary results when m=2 p,2k p(k≥2),where p is a prime number. Finally,we presented some problems and conjectures to be studied.%关于A+B以及A+^B的性质问题,一直是数论与组合数学中的困难课题和重要问题。本文首先指出,在一般情况下,关于Sark?zy的一个加法剩余类猜想的答案是否定的。其次,对于模偶数 m的既约剩余系,利用Cauchy-Davenport定理,给出当m=2p,2kp(k≥2)时该问题的两个初步的结果,这里p为素数。最后,提出一些待研究的问题和猜想。

  6. Packing Different Cuboids with Rotations and Spheres into a Cuboid

    Directory of Open Access Journals (Sweden)

    Y. G. Stoyan

    2014-01-01

    Full Text Available The paper considers a packing optimization problem of different spheres and cuboids into a cuboid of the minimal height. Translations and continuous rotations of cuboids are allowed. In the paper, we offer a way of construction of special functions (Φ-functions describing how rotations can be dealt with. These functions permit us to construct the mathematical model of the problem as a classical mathematical programming problem. Basic characteristics of the mathematical model are investigated. When solving the problem, the characteristics allow us to apply a number of original and state-of-the-art efficient methods of local and global optimization. Numerical examples of packing from 20 to 300 geometric objects are given.

  7. Measured black carbon deposition on the Sierra Nevada snow pack and implication for snow pack retreat

    Directory of Open Access Journals (Sweden)

    O. L. Hadley

    2010-04-01

    Full Text Available Modeling studies show that the darkening of snow and ice by black carbon (BC deposition is a major factor for the rapid disappearance of arctic sea ice, mountain glaciers and snow packs. This study provides one of the first direct measurements for the efficient removal of black carbon from the atmosphere by snow and its subsequent deposition on the snow packs of California. The early melting of the snow packs in the Sierras is one of the contributing factors to the severe water problems in California. BC concentrations in falling snow were measured at two mountain locations and in rain at a coastal site. All three stations reveal large BC concentrations in precipitation, ranging from 1.7 ng/g to 12.9 ng/g. The BC concentrations in the air after the snow fall were negligible suggesting an extremely efficient removal of BC by snow. The data suggest that below cloud scavenging, rather than ice nuclei, was the dominant source of BC in the snow. A five-year comparison of BC, dust, and total fine aerosol mass concentrations at multiple sites reveals that the measurements made at the sampling sites were representative of large scale deposition in the Sierra Nevada. The relative concentration of iron and calcium in the mountain aerosol indicates that one-quarter to one-third of the BC may have been transported from Asia.

  8. Measured black carbon deposition on the Sierra Nevada snow pack and implication for snow pack retreat

    Directory of Open Access Journals (Sweden)

    O. L. Hadley

    2010-08-01

    Full Text Available Modeling studies show that the darkening of snow and ice by black carbon deposition is a major factor for the rapid disappearance of arctic sea ice, mountain glaciers and snow packs. This study provides one of the first direct measurements for the efficient removal of black carbon from the atmosphere by snow and its subsequent deposition to the snow packs of California. The early melting of the snow packs in the Sierras is one of the contributing factors to the severe water problems in California. BC concentrations in falling snow were measured at two mountain locations and in rain at a coastal site. All three stations reveal large BC concentrations in precipitation, ranging from 1.7 ng/g to 12.9 ng/g. The BC concentrations in the air after the snow fall were negligible suggesting an extremely efficient removal of BC by snow. The data suggest that below cloud scavenging, rather than ice nuclei, was the dominant source of BC in the snow. A five-year comparison of BC, dust, and total fine aerosol mass concentrations at multiple sites reveals that the measurements made at the sampling sites were representative of large scale deposition in the Sierra Nevada. The relative concentration of iron and calcium in the mountain aerosol indicates that one-quarter to one-third of the BC may have been transported from Asia.

  9. Measured Black Carbon Deposition on the Sierra Nevada Snow Pack and Implication for Snow Pack Retreat

    Energy Technology Data Exchange (ETDEWEB)

    Hadley, O.L.; Corrigan, C.E.; Kirchstetter, T.W.; Cliff, S.S.; Ramanathan, V.

    2010-01-12

    Modeling studies show that the darkening of snow and ice by black carbon deposition is a major factor for the rapid disappearance of arctic sea ice, mountain glaciers and snow packs. This study provides one of the first direct measurements for the efficient removal of black carbon from the atmosphere by snow and its subsequent deposition to the snow packs of California. The early melting of the snow packs in the Sierras is one of the contributing factors to the severe water problems in California. BC concentrations in falling snow were measured at two mountain locations and in rain at a coastal site. All three stations reveal large BC concentrations in precipitation, ranging from 1.7 ng/g to 12.9 ng/g. The BC concentrations in the air after the snow fall were negligible suggesting an extremely efficient removal of BC by snow. The data suggest that below cloud scavenging, rather than ice nuclei, was the dominant source of BC in the snow. A five-year comparison of BC, dust, and total fine aerosol mass concentrations at multiple sites reveals that the measurements made at the sampling sites were representative of large scale deposition in the Sierra Nevada. The relative concentration of iron and calcium in the mountain aerosol indicates that one-quarter to one-third of the BC may have been transported from Asia.

  10. Performance characteristics of a new structured packing

    OpenAIRE

    Bessou, Vincent; Rouzineau, David; Prevost, Michel; Abbé, François; Dumont, Charles; Maumus, Jean-Pierre; Meyer, Michel

    2010-01-01

    A new structured packing using carbon fibres, called Sepcarb® 4D, is presented. This packing has several attractive properties, such as high voidage (ε=94%) and high effective area (a=420 m2 m−3). These properties are advantageous for packing used as a gas–liquid contactor for separation units. To determine the internal characteristics of this packing, we performed several experiments using a 150-mm-internal-diameter column. Firstly, hydrodynamics experiments were conducted using an air–water...

  11. Complications of balloon packing in epistaxis

    NARCIS (Netherlands)

    Vermeeren, Lenka; Derks, Wynia; Fokkens, Wytske; Menger, Dirk Jan

    2015-01-01

    Although balloon packing appears to be efficient to control epistaxis, severe local complications can occur. We describe four patients with local lesions after balloon packing. Prolonged balloon packing can cause damage to nasal mucosa, septum and alar skin (nasal mucosa, the cartilaginous skeleton

  12. Random packing of colloids and granular matter

    NARCIS (Netherlands)

    Wouterse, A.

    2008-01-01

    This thesis deals with the random packing of colloids and granular matter. A random packing is a stable disordered collection of touching particles, without long-range positional and orientational order. Experimental random packings of particles with the same shape but made of different materials sh

  13. Packing Superballs from Codes and Algebraic Curves

    Institute of Scientific and Technical Information of China (English)

    Li LIU; Chao Ping XING

    2008-01-01

    In the present paper, we make use of codes with good parameters and algebraic curves over finite fields with many rational points to construct dense packings of superballs. It turns out that our packing density is quite reasonable. In particular, we improve some values for the best-known lower bounds on packing density.

  14. 7 CFR 51.1527 - Standard pack.

    Science.gov (United States)

    2010-01-01

    ... package. The number of plums or prunes in California peach boxes or lug boxes shall not vary more than 4... Standards for Grades of Fresh Plums and Prunes Standard Pack § 51.1527 Standard pack. (a) Packing. (1) All... plums or prunes in the top layer of any package shall be reasonably representative in quality and...

  15. Characteristics of fluidized-packed beds

    Science.gov (United States)

    Gabor, J. D.; Mecham, W. J.

    1968-01-01

    Study of fluidized-packed bed includes investigation of heat transfer, solids-gas mixing, and elutriation characteristics. A fluidized-packed bed is a system involving the fluidization of small particles in the voids of a packed bed of larger nonfluidized particles.

  16. Packing defects into ordered structures

    DEFF Research Database (Denmark)

    Bechstein, R.; Kristoffersen, Henrik Høgh; Vilhelmsen, L.B.

    2012-01-01

    We have studied vicinal TiO2(110) surfaces by high-resolution scanning tunneling microscopy and density functional theory calculations. On TiO2 surfaces characterized by a high density of ⟨11̅ 1⟩ steps, scanning tunneling microscopy reveals a high density of oxygen-deficient strandlike adstructur...... because building material is available at step sites. The strands on TiO2(110) represent point defects that are densely packed into ordered adstructures....

  17. Diffusion in Jammed Particle Packs.

    Science.gov (United States)

    Bolintineanu, Dan S; Grest, Gary S; Lechman, Jeremy B; Silbert, Leonardo E

    2015-08-21

    Using random walk simulations we explore diffusive transport through monodisperse sphere packings over a range of packing fractions ϕ in the vicinity of the jamming transition at ϕ(c). Various diffusion properties are computed over several orders of magnitude in both time and packing pressure. Two well-separated regimes of normal "Fickian" diffusion, where the mean squared displacement is linear in time, are observed. The first corresponds to diffusion inside individual spheres, while the latter is the long-time bulk diffusion. The intermediate anomalous diffusion regime and the long-time value of the diffusion coefficient are both shown to be controlled by particle contacts, which in turn depend on proximity to ϕ(c). The time required to recover normal diffusion t* scales as (ϕ-ϕ(c))(-0.5) and the long-time diffusivity D(∞)∼(ϕ-ϕ(c))0.5, or D(∞)∼1/t*. It is shown that the distribution of mean first passage times associated with the escape of random walkers between neighboring particles controls both t* and D(∞) in the limit ϕ→ϕ(c).

  18. Vibrational Collapse of Hexapod Packings

    Science.gov (United States)

    Zhao, Yuchen; Ding, Jingqiu; Barés, Jonathan; Dierichs, Karola; Behringer, Robert

    2016-11-01

    Columns made of convex noncohesive grains like sand collapse after being released from a confining container. However, structures built from concave grains can be stable without external support. Previous research show that the stability of the columns depends on column diameter and height, by observing column stability after carefully lifting their confinement tubes. Thinner and taller columns collapse with higher probability. While the column stability weakly depends on packing density, it strongly depends on inter-particle friction. Experiments that cause the column to collapse also reveal similar trends, as more effort (such as heavier loading or shearing) is required to destabilize columns that are intrinsically more stable. In the current experiments, we invesitage the effect of vibration on destructing a column. Short columns collapse following the relaxation dynamics of disorder systems, which coincides with similar experiments on staple packings. However, tall columns collapse faster at the beginning, in addition to the relaxation process coming after. Using high-speed imaging, we analyze column collapse data from different column geometries. Ongoing work is focusing on characterizing the stability of hexapod packings to vibration. We thanks NSF-DMR-1206351 and the William M. Keck Foundation.

  19. Routing Trains Through Railway Junctions: A New Set Packing Approach

    DEFF Research Database (Denmark)

    Lusby, Richard; Larsen, Jesper; Ryan, David

    The problem of routing trains through railway junctions is an integral part of railway operations. Large junctions are highly interconnected networks of track where multiple railway lines meet, intersect, and split. The number of possible routings makes this a very complicated problem. Here we show...... how the problem can be formulated as a set packing model. To exploit the structure of the problem we present a solution procedure which entails solving the dual of this formulation through the dynamic addition of violated cuts (primal variables). A discussion of the variable (train path) generation...

  20. Latent Class Analysis of Gambling Activities in a Sample of Young Swiss Men: Association with Gambling Problems, Substance Use Outcomes, Personality Traits and Coping Strategies.

    Science.gov (United States)

    Studer, Joseph; Baggio, Stéphanie; Mohler-Kuo, Meichun; Simon, Olivier; Daeppen, Jean-Bernard; Gmel, Gerhard

    2016-06-01

    The study aimed to identify different patterns of gambling activities (PGAs) and to investigate how PGAs differed in gambling problems, substance use outcomes, personality traits and coping strategies. A representative sample of 4989 young Swiss males completed a questionnaire assessing seven distinct gambling activities, gambling problems, substance use outcomes, personality traits and coping strategies. PGAs were identified using latent class analysis (LCA). Differences between PGAs in gambling and substance use outcomes, personality traits and coping strategies were tested. LCA identified six different PGAs. With regard to gambling and substance use outcomes, the three most problematic PGAs were extensive gamblers, followed by private gamblers, and electronic lottery and casino gamblers, respectively. By contrast, the three least detrimental PGAs were rare or non-gamblers, lottery only gamblers and casino gamblers. With regard to personality traits, compared with rare or non-gamblers, private and casino gamblers reported higher levels of sensation seeking. Electronic lottery and casino gamblers, private gamblers and extensive gamblers had higher levels of aggression-hostility. Extensive and casino gamblers reported higher levels of sociability, whereas casino gamblers reported lower levels of anxiety-neuroticism. Extensive gamblers used more maladaptive and less adaptive coping strategies than other groups. Results suggest that gambling is not a homogeneous activity since different types of gamblers exist according to the PGA they are engaged in. Extensive gamblers, electronic and casino gamblers and private gamblers may have the most problematic PGAs. Personality traits and coping skills may predispose individuals to PGAs associated with more or less negative outcomes.

  1. 求解随机互补问题的Levenberg-Marquardt方法%A Levenberg-Marquardt Algorithm for Solving a Class of Stochastic Complementarity Problem

    Institute of Scientific and Technical Information of China (English)

    李玲; 凌晨

    2014-01-01

    研究含有限样本的随机非线性互补问题的数值求解方法。在将问题等价转化为非线性方程组的基础上,给出一个光滑化Levenberg-Marquardt算法。该算法具有全局收敛性,并在局部误差界条件下,还拥有局部的二次收敛性质。所做的数值例子结果表明,所给算法具有较好的实际计算效果。%A class of stochastic nonlinear complementary problems ( SNCP) with finite elements is studied in this paper .Based upon converting the original problem to nonlinear equations equally , a smoothing Levenberg-Marquardt algorithm for solving SNCP is presented , which is shown to be globally convergent .Moreover, this algorithm is shown to converge locally quadratically under an error bound condition .Some numerical results show that presented algorithm has good actual properties .

  2. Packing of charged chains on toroidal geometries

    Science.gov (United States)

    Yao, Zhenwei; de la Cruz, Monica Olvera

    2013-01-01

    We study a strongly adsorbed flexible polyelectrolyte chain on tori. In this generalized Thomson problem, the patterns of the adsorbed chain are analyzed in the space of the toroidal coordinates and in terms of the orientation of each chain segment. Various patterns are found, including double spirals, disclination-like structures, Janus tori, and uniform wrappings, arising from the long-range electrostatic interaction and the toroidal geometry. Their broken mirror symmetry is quantitatively characterized by introducing an order parameter, an integral of the torsion. The uniform packing, which breaks the mirror symmetry the least, has the lowest value of the order parameter. In addition, it is found that the electrostatic energy of confined chains on tori conforms to a power law regardless of the screening effect in some typical cases studied. Furthermore, we study random walks on tori that generate chain configurations in the large screening limit or at large thermal fluctuation; some features associated with the toroidal geometry are discussed.

  3. PBL教学在大班口腔医学课程中的应用%Application of problem-based learning in large class in Stomatology course

    Institute of Scientific and Technical Information of China (English)

    秦兴军; 於丽乔; 代炜; 王绪凯; 卢利

    2012-01-01

    目的 确定在大班口腔医学课程中实施PBL教学的可行性以及学生中先前有PBL学习经验是否是必要的.方法 选择中国医科大学2个大班的总计236名学生.一个班级(118名学生)先前有PBL教学的学习经验,而另一个班级(113名学生)没有.每个班级被细分为15个小组(每组7~8名学生),每周由相同的教师进行2次单独的100 min的PBL教学课程.每个PBL课程班级有2名助教,一个是本专业的助教,另一个是非本专业的助教.理论考试和病例分析考试的成绩采用t检验进行统计分析;调查问卷用来评估学生和助教的反馈意见,调查结果采用秩和检验进行分析.结果 来自学生和助教的反馈意见是积极的.调查问卷显示,有PBL经验和没有PBL经验的学生都认为教学方法是快乐和有效的.分析结果显示学生已经完成了学习目标.理论和病例分析考试的结果显示:有PBL经验和没有PBL经验的班级之间不存在显著差异.在该课程中学生每周课后的平均学习时间:没有PBL经验的学生为(6.3±1.1)h,而有PBL经验的学生为(4.7±0.981)h(t=11.94,P<0.001).没有PBL经验的学生表现出对本专业的助教更加依赖.结论 在大班中实施PBL是可行的,可以不在有限的教育资源中占用更多.先前的PBL学习经验是有益的,但不是必需的.%Objective To determine the feasibility of implementing problem-based learning (PBL) in a large class and whether previous PBL experience was necessary. Methods A total of 236 students from 2 large classes of China Medical University were enrolled. One class (118 students) had had a previous small-group PBL experience and the other class (113 students) had not. Each class was subdivided into 15 groups (7 to 8 students/group) . The same teacher gave 2 separate 100-minute PBL sessions per week. Each PBL class had 2 teaching assistants. One was in this major and the other was not. The results of the theoretical

  4. Adhesive loose packings of small dry particles

    Science.gov (United States)

    Liu, Wenwei; Li, Shuiqing; Baule, Adrian; Makse, Hernán A.

    We explore adhesive loose packings of dry small spherical particles of micrometer size using 3D discrete-element simulations with adhesive contact mechanics. A dimensionless adhesion parameter ($Ad$) successfully combines the effects of particle velocities, sizes and the work of adhesion, identifying a universal regime of adhesive packings for $Ad>1$. The structural properties of the packings in this regime are well described by an ensemble approach based on a coarse-grained volume function that includes correlations between bulk and contact spheres. Our theoretical and numerical results predict: (i) An equation of state for adhesive loose packings that appears as a continuation from the frictionless random close packing (RCP) point in the jamming phase diagram; (ii) The existence of a maximal loose packing point at the coordination number $Z=2$ and packing fraction $\\phi=1/2^{3}$. Our results highlight that adhesion leads to a universal packing regime at packing fractions much smaller than the random loose packing, which can be described within a statistical mechanical framework. We present a general phase diagram of jammed matter comprising frictionless, frictional, adhesive as well as non-spherical particles, providing a classification of packings in terms of their continuation from the spherical frictionless RCP.

  5. A Quasi-physical Algorithm Based on Coarse and Fine Adjustment for Solving Circles Packing Problem with Constraints of Equilibrium%基于粗精调技术的求解带平衡约束圆形Packing问题的拟物算法

    Institute of Scientific and Technical Information of China (English)

    何琨; 莫旦增; 许如初; 黄文奇

    2013-01-01

    The circles packing problem with constraints of equilibrium,as a two-dimensional packing problem with the background of satellite module layout design,is an NP hard layout optimization problem.A mathematical model and two new physical models are established for this problem.And inspired by the process of coarse and fine adjustment in the industry,a QuasiPhysical algorithm based on Coarse and Fine Adjustment (QPCFA) is proposed.Not only can QPCFA keep the diversity of the searching space to facilitate the global search,but also it can do fine search in promising local areas to find the corresponding local optimal solutions.Moreover,the taboo method and the jump pit strategy are combined to improve the performance of this algorithm.Experiments on 11 representative instances show that QPCFA achieve new and better results on seven ones and matched the current best records on the other four.In addition,the calculation accuracy is improved considerably.%带平衡约束的圆形Packing问题是以卫星舱布局为背景的具有NP难度的布局优化问题.文中建立了此问题相应的数学模型,同时提出了两个新的物理模型,并受工艺加工过程中“粗精加工”现象的启发,提出了基于粗精调技术的拟物算法QPCFA.该算法既兼顾了搜索空间的多样性以利于全局搜索,又能对有前途的局部区域进行精细搜索以找到相应的局部最优解.同时,在计算过程中引入禁忌技术和跳坑策略,以提高算法的求解质量.对国际上11个代表性的算例进行了计算,QPCFA更新了其中7个算例的最好记录,其余4个与目前的最好记录基本持平,且与目前的最好结果相比在计算精度上均有较大的提高.

  6. Evaluation of Diagnostic Tests Using Information Theory for Multi-Class Diagnostic Problems and its Application for the Detection of Occlusal Caries Lesions

    Science.gov (United States)

    Arslan, Umut; Karaağaoğlu, Ergun; Özkan, Gökhan; Kanlı, Aydan

    2014-01-01

    Background: Several methods are available to evaluate the performance of the tests when the purpose of the diagnostic test is to discriminate between two possible disease states. However multi-class diagnostic problems frequently appear in many areas of medical science. Hence, there is a need for methods which will enable us to characterize the accuracy of diagnostic tests when there are more than two possible disease states. Aims: To show that two information theory measures, information content (IC) and proportional reduction in diagnostic uncertainty (PRDU), can be used for the evaluation of the performance of diagnostic tests for multi-class diagnostic problems that may appear in different areas of medical science. Study Design: Diagnostic accuracy study. Methods: Sixty freshly extracted permanent human molar and pre-molar teeth suspected to have occlusal caries lesions were selected for the study and were assessed by two experienced examiners. Each examiner performed two evaluations. Histological examination was used as the gold standard. The scores of the histological examination were defined as sound (n=11), enamel caries (n=22) and dentin caries (n=27). Diagnostic performance of i) visual inspection, ii) radiography, iii) laser fluorescence (LF) and iv) micro-computed tomography (M-CT) caries detection methods was evaluated by calculating IC and PRDU. Results: Micro-computed tomography examination was the best method among the diagnostic techniques for the diagnosis of occlusal caries in terms of both IC and PRDU. M-CT examination supplied the maximum diagnostic information about the diagnosis of occlusal caries in the first (IC: 1.056; p<0.05), (PRDU: 70.5%) and second evaluation (IC: 1.105; p<0.05), (PRDU: 73.8%) for the first examiner. M-CT examination was the best method among the diagnostic techniques for the second examiner in both the first (IC:1.105; p<0.05), (PRDU:73.8%) and second evaluation (IC:1.061; p<0.05), (PRDU:70.8%). IC and PRDU were

  7. “90后”大学生班级管理中的问题及对策研究%Research on the Problems and Countermeasures of Class Management for College Students after 90s

    Institute of Scientific and Technical Information of China (English)

    解滨羽

    2012-01-01

    By the work of class teachers, to collect information and student-depth interviews, study on "90" college students' class, found the problems that: the lack of a culture of learning classes, in class time, students' serious mobile Internet; class lack of cohesion, the students do not positive participate in class activities; students' low self-discipline, morning exercises and study up attendance is poor; the class poverty gap. And put forward corresponding countermeasures for the above problems.%通过班主任工作,收集资料和学生深度访谈,文章就"90后"大学生班级进行了研究,发现存在的问题有:班级学习风气不足,上课时间学生手机上网现象严重;班级缺乏凝聚力,学生参加班级活动不积极;学生自我约束力低,早操和晚自习出勤较差;班级贫富差距较大。并针对以上问题提出了相应的对策。

  8. Solving a Class of Brouwer Fixed-point Problems via a Modified Aggregate Constraint Homotopy Method%用改进的凝聚约束同伦方法求解一类Brouwer不动点问题

    Institute of Scientific and Technical Information of China (English)

    苏孟龙; 吕显瑞

    2007-01-01

    In this paper, we provide an aggregate function homotopy interior point method to solve a class of Brouwer fixed-point problems. Compared with the homotopy method (proposed by Yu and Lin, Appl. Math. Comput., 74(1996), 65), the main adavantages of this method are as follows: on the one hand, it can solve the Brouwer fixed-point problems in a broader class of nonconvex subsets Ω in Rn (in this paper, we let Ω = [x ∈ Rn: gi(x) ≤ 0, i = 1,… ,m]); on the other hand, it can also deal with the subsets Ω with larger amount of constraints more effectively.

  9. The “Theoreticals” Pack

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    The Particle Zoo is a colourful set of hand-made soft toys representing the particles in the Standard Model and beyond. It includes a “theoreticals” pack where you can find yet undiscovered particles: the best-selling Higgs boson, the graviton, the tachyon, and dark matter. Supersymmetric particle soft toys are also available on demand. But what would happen to the zoo if Nature had prepared some unexpected surprises? Julie Peasley, the zookeeper, is ready to sew new smiling faces…   The "Theoreticals" pack in the Particle Zoo. There is only one place in the world where you can buy a smiling Higgs boson and it’s not at CERN, although this is where scientists hope to observe it. The blue star-shaped particle is the best seller of Julie Peasley’s Particle Zoo – a collection of tens of soft toys representing all sorts of particles, including composite and decaying particles.  Over the years Julie’s zoo ...

  10. On a class of functional equations of the Wiener-Hopf type and their applications in n-part scattering problems

    Science.gov (United States)

    Idemen, Mithat; Alkumru, Ali

    2003-12-01

    An asymptotic theory for the functional equation K{phi} = f, where K : X [->] Y stands for a matrix-valued linear operator of the form K = K1P1 + K2P2 + ... + KnPn, is developed. Here X and Y refer to certain Hilbert spaces, {P{alpha}} denotes a partition of the unit operator in X while K{alpha} are certain operators from X to Y. One assumes that the partition {P{alpha}} as well as the operators K{alpha} depend on a complex parameter {nu} such that all K{alpha} are multi-valued around certain branch points at {nu} = k+ and {nu} = k- while the inverse operators K-1{alpha} exist and are bounded in the appropriately cut {nu}-plane except for certain poles. Then, for a class of {P{alpha}} having certain analytical properties, an asymptotic solution valid for |k{+/-}| [->] {infty} is given. The basic idea is the decomposition of {phi} into a sum of projections on n mutually orthogonal subspaces of X. The results can be extended in a straightforward manner to the cases of no or more branch points. If there is no branch point or n = 2, then the results are all exact. The theory may have effective applications in solving some direct and inverse multi-part boundary-value problems connected with high-frequency waves. An illustrative example shows the applicability as well as the effectiveness of the method.

  11. 甲类建筑抗震设防的超越概率问题%The Problem of Exceeding Probability for First Class Architecture Seismic Precaution

    Institute of Scientific and Technical Information of China (English)

    王国昌

    2013-01-01

    The value of exceeding probability is one of the main factors influencing design parameters of ground mo-tion,because there aren ’ t quantitative indicators of exceeding probability for first class architecture seismic precaution in current seismic design specification ,so ease to cause chaos among practical works .Through theoretical analyzing and il-lustrating ,point out that we should solve this problem as soon as possible .%超越概率的取值是影响设计地震动参数的主要因数之一,现行的抗震设计方面的规范对甲类建筑抗震设防的超越概率取值没有给出具体的定量指标,易引起实际工作中的混乱。通过理论分析和举例说明,指出应尽快解决此问题。

  12. INTERVAL ADJUSTABLE ENTROPY ALGORITHM FOR A CLASS OF UNCONSTRAINED DISCRETE MINIMAX PROBLEMS%一类无约束离散Minimax问题的区间调节熵算法

    Institute of Scientific and Technical Information of China (English)

    李苏北; 曹德欣; 王海军; 邓喀中

    2004-01-01

    In this paper, a class of unconstrained discrete minimax problems is described, in which the objective functions are in C1. The paper deals with this problem by means of taking the place of maximum-entropy function with adjustable entropy function. By constructing an interval extension of adjustable entropy function and some region deletion test rules, a new interval algorithm is presented. The relevant properties are proven. The minimax value and the localization of the minimax points of the problem can be obtained by this method. This method can overcome the flow problem in the maximum-entropy algorithm. Both theoretical and numerical results show that the method is reliable and efficient.

  13. Protein packing quality using Delaunay complexes

    DEFF Research Database (Denmark)

    Fonseca, Rasmus; Winter, Pawel; Karplus, Kevin

    2011-01-01

    A new method for estimating the packing quality of protein structures is presented. Atoms in high quality protein crystal structures are very uniformly distributed which is difficult to reproduce using structure prediction methods. Packing quality measures can therefore be used to assess structures...... of low quality and even to refine them. Previous methods mainly use the Voronoi cells of atoms to assess packing quality. The presented method uses only the lengths of edges in the Delaunay complex which is faster to compute since volumes of Voronoi cells are not evaluated explicitly. This is a novel...... application of the Delaunay complex that can improve the speed of packing quality computations. Doing so is an important step for, e.g., integrating packing measures into structure refinement methods. High- and low-resolution X-ray crystal structures were chosen to represent well- and poorly-packed structures...

  14. Designing Drill-in Fluids by Using Ideal Packing Technique

    Institute of Scientific and Technical Information of China (English)

    Feng Wenqiang; Yan Jienian

    2007-01-01

    Selecting bridging agents properly is a critical factor in designing non-damaging or low-damaging drill-in fluids.Historically,Abrams' rule has been used for this purpose.However,Abrams' rule only addresses the size of particle required to initiate a bridge.The rule does not give an optimum size nor an ideal packing sequence for minimizing fluid invasion and optimizing sealing.This paper elaborates an ideal packing approach to solving the sealing problem by sealing pores with different sizes,especially those large pores which usually make dominant contribution to permeability and thereby effectively preventing the solids and filtrate of drill-in fluids from invading into formations,compared with the conventionally used techniques.Practical software has been developed to optimize the blending proportion of several bridging agents,so as to achieve ideal packing effectiveness.The method and its use in selecting the best blending proportion of several bridging agents are also discussed in this paper.A carefully designed drill-in fluid by using the ideal packing technique (named the IPT fluid) for offshore drilling operations at the Weizhou Oilfield,Nanhai West Company,CNOOC is presented.The near 100% return permeabilities from the dynamic damage tests using reservoir cores demonstrated the excellent bridging effect provided by this drill-in fluid.

  15. Minimally packed phases in holography

    CERN Document Server

    Donos, Aristomenis

    2015-01-01

    We numerically construct asymptotically AdS black brane solutions of $D=4$ Einstein-Maxwell theory coupled to a pseudoscalar. The solutions are holographically dual to $d=3$ CFTs held at constant chemical potential and magnetic field that spontaneously break translation invariance leading to the spontaneous formation of abelian and momentum magnetisation currents flowing around the plaquettes of a periodic Bravais lattice. We analyse the three-dimensional moduli space of lattice solutions, which are generically oblique, and show that the free energy is minimised by the triangular lattice, associated with minimal packing of circles in the plane. The triangular structure persists at low temperatures indicating the existence of novel crystalline ground states.

  16. A honeycomb-tube packing medium and its application to column flotation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Min; SHI Chang-sheng; LIU Jiong-tian; ZHAI Ai-feng

    2009-01-01

    We address problems in the development of large-scale flotation columns that use short cylinders. As a starting point, we investigated the packing medium to identify a highly efficient internal packing for the flotation column. The chosen packing was a honeycomb structure with an aperture diameter of 80 mm, a web thickness of 0.80 mm, a film height of 1000 mm, packed into a 400 mm diameter space, which completely filled the vessel at optimal cost. The column consisted of a modular ring of single-hole hexagonal honeycomb tube packing made from atactic polyproplene (PP-R). The packing was tested in a cyclonic, static mi-cro-bubble flotation column. Computational fluid dynamic modeling was used to analyze the flotation fluid in a honeycomb tube packed flotation column. Our results show that the fluid axial movement was maximized and that the transverse fluid velocities were zero in the vicinity of axial flow. Using the honeycomb tube packing for copper sulfide flotation we observed that the average concentration in the product was increased to 25.41%, from an average feed concentration of 0.729%, with an average recovery of 92.92%. The demands of on-site industrial production were met.

  17. Non standard pallet series designing problem in ammunition supply system

    Institute of Scientific and Technical Information of China (English)

    Li Liangchun; Guo Min; Wang Hongwei

    2005-01-01

    According to the compound packing problem in ammunition supply system in our army, the non-standard pallet series design model is proposed, and the original problem that can be solved as a set cover problem with a nested bin-packing problem, is analyzed, then two heuristic algorithms are applied to solve the problem.

  18. A Plan for Individualizing Instruction for the Senior Government Class Through Use of Problem Solving Units. Colorado Western States Small Schools Project Documentation (Silverton High School, Silverton, Colorado, 1963-64).

    Science.gov (United States)

    Higgs, Norman E.

    During the 1963-64 school year, a secondary teacher from the rurally isolated area of Silverton, Colorado initiated an individualized program in problem solving for a senior social studies class (N=8-10). Utilizing community resources, the instructor planned several units on government, while the students selected resource materials from the…

  19. Confined disordered strictly jammed binary sphere packings

    Science.gov (United States)

    Chen, D.; Torquato, S.

    2015-12-01

    Disordered jammed packings under confinement have received considerably less attention than their bulk counterparts and yet arise in a variety of practical situations. In this work, we study binary sphere packings that are confined between two parallel hard planes and generalize the Torquato-Jiao (TJ) sequential linear programming algorithm [Phys. Rev. E 82, 061302 (2010), 10.1103/PhysRevE.82.061302] to obtain putative maximally random jammed (MRJ) packings that are exactly isostatic with high fidelity over a large range of plane separation distances H , small to large sphere radius ratio α , and small sphere relative concentration x . We find that packing characteristics can be substantially different from their bulk analogs, which is due to what we term "confinement frustration." Rattlers in confined packings are generally more prevalent than those in their bulk counterparts. We observe that packing fraction, rattler fraction, and degree of disorder of MRJ packings generally increase with H , though exceptions exist. Discontinuities in the packing characteristics as H varies in the vicinity of certain values of H are due to associated discontinuous transitions between different jammed states. When the plane separation distance is on the order of two large-sphere diameters or less, the packings exhibit salient two-dimensional features; when the plane separation distance exceeds about 30 large-sphere diameters, the packings approach three-dimensional bulk packings. As the size contrast increases (as α decreases), the rattler fraction dramatically increases due to what we call "size-disparity" frustration. We find that at intermediate α and when x is about 0.5 (50-50 mixture), the disorder of packings is maximized, as measured by an order metric ψ that is based on the number density fluctuations in the direction perpendicular to the hard walls. We also apply the local volume-fraction variance στ2(R ) to characterize confined packings and find that these

  20. Intelligent 3D packing using a grouping algorithm for automotive container engineering

    Directory of Open Access Journals (Sweden)

    Youn-Kyoung Joung

    2014-04-01

    Full Text Available Storing, and the loading and unloading of materials at production sites in the manufacturing sector for mass production is a critical problem that affects various aspects: the layout of the factory, line-side space, logistics, workers’ work paths and ease of work, automatic procurement of components, and transfer and supply. Traditionally, the nesting problem has been an issue to improve the efficiency of raw materials; further, research into mainly 2D optimization has progressed. Also, recently, research into the expanded usage of 3D models to implement packing optimization has been actively carried out. Nevertheless, packing algorithms using 3D models are not widely used in practice, due to the large decrease in efficiency, owing to the complexity and excessive computational time. In this paper, the problem of efficiently loading and unloading freeform 3D objects into a given container has been solved, by considering the 3D form, ease of loading and unloading, and packing density. For this reason, a Group Packing Approach for workers has been developed, by using analyzed truck packing work patterns and Group Technology, which is to enhance the efficiency of storage in the manufacturing sector. Also, an algorithm for 3D packing has been developed, and implemented in a commercial 3D CAD modeling system. The 3D packing method consists of a grouping algorithm, a sequencing algorithm, an orientating algorithm, and a loading algorithm. These algorithms concern the respective aspects: the packing order, orientation decisions of parts, collision checking among parts and processing, position decisions of parts, efficiency verification, and loading and unloading simulation. Storage optimization and examination of the ease of loading and unloading are possible, and various kinds of engineering analysis, such as work performance analysis, are facilitated through the intelligent 3D packing method developed in this paper, by using the results of the 3D

  1. Method of immersion of a problem of comparison financial conditions of the enterprises in an expert cover in a class algorithms of artificial intelligence

    Directory of Open Access Journals (Sweden)

    S. V. Bukharin

    2016-01-01

    Full Text Available The financial condition of the enterprise can be estimated by a set of characteristics (solvency and liquidity, structure of the capital, profitability, etc.. The part of financial coefficients is low-informative, and other part contains the interconnected sizes. Therefore for elimination of ambiguity we will pass to the generalized indicators – rating numbers, and as the main means of research it is offered to use the theory of expert systems. As characteristic of the modern theory of expert systems it is necessary to consider application of intellectual ways of data processing of data mining, or simply data mining. The method of immersion of a problem of comparison of a financial condition of economic objects in an expert cover in a class of systems of artificial intelligence is offered (algorithms of a method of the analysis of hierarchies, contiguity leaning of a neural network, algorithm of training with function of activation softmax. The generalized indicator of structure of the capital in the form of rating number is entered and the sign (factorial space for seven concrete enterprises is created. Quantitative signs (financial coefficients of structure of the capital are allocated and their normalization by rules of the theory of expert systems is carried out. To the received set of the generalized indicators the method of the analysis of hierarchies is applied: on the basis of a linguistic scale of T. Saaty the ranks of signs reflecting the relative importance of various financial coefficients are defined and the matrix of pair comparisons is constructed. The vector of priority signs on the basis of the solution of the equation for own numbers and own vectors of the mentioned matrix is calculated. As a result the visualization of the received results which has allowed to eliminate difficulties of interpretation of small and negative values of the generalized indicator is carried out. The neural network with contiguity leaning and

  2. Particle-size distribution and packing fraction of geometric random packings

    NARCIS (Netherlands)

    Brouwers, H.J.H.

    2006-01-01

    This paper addresses the geometric random packing and void fraction of polydisperse particles. It is demonstrated that the bimodal packing can be transformed into a continuous particle-size distribution of the power law type. It follows that a maximum packing fraction of particles is obtained when t

  3. 7 CFR 51.1217 - Standard pack.

    Science.gov (United States)

    2010-01-01

    ... be ring faced and tightly packed with sufficient bulge to prevent any appreciable movement of the... the box. (d) Peaches packed in other type boxes such as wire-bound boxes and fiber-board boxes may be... than 10 percent of the packages in any lot may not meet these requirements. (i) “Well filled”...

  4. 7 CFR 29.1048 - Packing.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Packing. 29.1048 Section 29.1048 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1048 Packing. A lot of tobacco consisting of a number of packages submitted as...

  5. 7 CFR 29.6031 - Packing.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Packing. 29.6031 Section 29.6031 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6031 Packing. A lot of tobacco consisting of a number of...

  6. 7 CFR 29.3538 - Packing.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Packing. 29.3538 Section 29.3538 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3538 Packing. A lot of tobacco consisting of a number of packages submitted as...

  7. Difference packing arrays and systematic authentication codes

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    In this paper, a type of combinatorial design (called difference packing array)is proposed and used to give a construction of systematic authentication codes. Taking advantage of this construction, some new series of systematic authentication codes are obtainable in terms of existing difference packing arrays.

  8. 7 CFR 29.2541 - Packing.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Packing. 29.2541 Section 29.2541 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2541 Packing. A lot of tobacco consisting...

  9. 7 CFR 29.3048 - Packing.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Packing. 29.3048 Section 29.3048 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Packing. A lot of tobacco consisting of a number of packages submitted as one definite unit for...

  10. 7 CFR 29.2289 - Packing.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Packing. 29.2289 Section 29.2289 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Packing. A lot of tobacco consisting of a number of packages submitted as one definite unit for...

  11. Monitoring three-dimensional packings in microgravity.

    NARCIS (Netherlands)

    Yu, Peidong; Frank-Richter, Stefan; Börngen, Alexander; Sperl, Matthias

    2014-01-01

    We present results from experiments with granular packings in three dimensions in microgravity as realized on parabolic flights. Two different techniques are employed to monitor the inside of the packings during compaction: (1) X-ray radiography is used to measure in transmission the integrated fluc

  12. Pack formation in cycling and orienteering.

    Science.gov (United States)

    Ackland, G J; Butler, D

    2001-09-13

    In cycling and orienteering competitions, competitors can become bunched into packs, which may mask an individual's true ability. Here we model this process with a view to determining when competitors' times are determined more by others than by their own ability. Our results may prove useful in helping to stage events so that pack formation can be avoided.

  13. BIPP (BISMUTH IODINE PARAFFINE PASTE PACK REVISITED

    Directory of Open Access Journals (Sweden)

    Balasubramanian Thiagarajan

    2011-09-01

    Full Text Available This review article takes a new look at the use of BIPP pack following nasal and ear surgeries. It lists the advantages and pitfalls of using this packing material. Pubmed search revealed very little material on this topic hence I compiled existing data to bring out an article.

  14. HEXAGONAL CLOSE-PACKED C-60

    NARCIS (Netherlands)

    de Boer, Jan; van Smaalen, Sander; Petricek, Vaclav; Dusek, Michal P.; Verheijen, Marcel A.; Meijer, G.

    1994-01-01

    C60 crystals were grown from purified powder material with a multiple sublimation technique. In addition to crystals wit a cubic close-packed (ccp) arrangement, crystals were found with a hexagonal close-packed (hcp) structure. Detailed crystallographic evidence is given, including complete refineme

  15. Cluster and constraint analysis in tetrahedron packings.

    Science.gov (United States)

    Jin, Weiwei; Lu, Peng; Liu, Lufeng; Li, Shuixiang

    2015-04-01

    The disordered packings of tetrahedra often show no obvious macroscopic orientational or positional order for a wide range of packing densities, and it has been found that the local order in particle clusters is the main order form of tetrahedron packings. Therefore, a cluster analysis is carried out to investigate the local structures and properties of tetrahedron packings in this work. We obtain a cluster distribution of differently sized clusters, and peaks are observed at two special clusters, i.e., dimer and wagon wheel. We then calculate the amounts of dimers and wagon wheels, which are observed to have linear or approximate linear correlations with packing density. Following our previous work, the amount of particles participating in dimers is used as an order metric to evaluate the order degree of the hierarchical packing structure of tetrahedra, and an order map is consequently depicted. Furthermore, a constraint analysis is performed to determine the isostatic or hyperstatic region in the order map. We employ a Monte Carlo algorithm to test jamming and then suggest a new maximally random jammed packing of hard tetrahedra from the order map with a packing density of 0.6337.

  16. 48 CFR 552.211-87 - Export packing.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Export packing. 552.211-87... packing. As prescribed in 511.204(b)(7), insert the following clause: Export Packing (JAN 2010) (a... packing. Military export packing, if offered, shall be in accordance with Mil-Std-2073-1 Level A or B...

  17. 7 CFR 51.2840 - Export packing requirements.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Export packing requirements. 51.2840 Section 51.2840...) Export Packing Requirements § 51.2840 Export packing requirements. Onions specified as meeting Export Packing Requirements shall be packed in containers having a net capacity of 25 kilograms (approximately...

  18. Student Engagement in a Large Classroom: Using Technology to Generate a Hybridized Problem-based Learning Experience in a Large First Year Undergraduate Class

    Directory of Open Access Journals (Sweden)

    Sherry Fukuzawa

    2016-06-01

    Full Text Available Large first year undergraduate courses have unique challenges in the promotion of student engagement and self-directed learning due to resource constraints that prohibit small group discussions with instructors. The Monthly Virtual Mystery was developed to increase student engagement in a large (N = 725 first year undergraduate class in anthropology at the University of Toronto Mississauga. The teaching challenge was to develop a participation component (worth 6% of the final grade that would increase student engagement without incurring any additional resource costs. The goal of the virtual mystery was to incorporate the principles of problem-based learning to engage students in self-directed learning through an online medium. Groups of approximately 50 students collaborated on a series of “virtual” case studies in a discussion board. Students submitted comments or questions each week to identify the information they needed to solve the mystery. A facilitator oversaw the discussion board to guide students in collaboration and resource acquisition. The final grades of students who participated in the virtual mystery (N=297 were compared to students who participated in a passive online learning exercise that involved watching weekly online videos and answering questions in a course reader (N = 347. Student self-selection determined group participation. Participation completion for both the virtual mystery and the course reader were high (78.8% and 91.6% respectively. There were no significant differences in the distribution of final grades between the participation options. The high completion rate of the virtual mystery demonstrated that an active learning project can be implemented using problem-based learning principles through an online discussion board; however, the large online group collaborations were problematic. Students were frustrated with repetition and inequitable participation in such large groups; however, students evaluated

  19. "Racializing" Class

    Science.gov (United States)

    Hatt-Echeverria, Beth; Urrieta, Luis, Jr.

    2003-01-01

    In an effort to explore how racial and class oppressions intersect, the authors use their autobiographical narratives to depict cultural and experiential continuity and discontinuity in growing up white working class versus Chicano working class. They specifically focus on "racializing class" due to the ways class is often used as a copout by…

  20. Hawking Colloquium Packed CERN Auditoriums

    CERN Multimedia

    2006-01-01

    Stephen Hawking's week long visit to CERN included an 'exceptional CERN colloquium' which filled six auditoriums. Stephen Hawking during his visit to the ATLAS experiment. Stephen Hawking, Lucasian Professor of Cambridge University, visited the Theory Unit of the Physics Department from 24 September to 1 October 2006. As part of his visit, he gave two lectures in the main auditorium - a theoretical seminar on 'The Semi-Classical Birth of The Universe', attended by about 120 specialists; and a colloquium titled 'The Origin of The Universe'. As a key public figure in theoretical physics, his presence was eagerly awaited on both occasions. Those who wanted to attend the colloquium had to arrive early and be equipped with plenty of patience. An hour before it was due to begin, the 400 capacity of the main auditorium was already full. The lecture, simultaneously broadcast to five other fully packed CERN auditoriums, was attended by an estimated total of 850. Stephen Hawking attracted a large CERN crowd, filling ...

  1. Percolation of disordered jammed sphere packings

    Science.gov (United States)

    Ziff, Robert M.; Torquato, Salvatore

    2017-02-01

    We determine the site and bond percolation thresholds for a system of disordered jammed sphere packings in the maximally random jammed state, generated by the Torquato–Jiao algorithm. For the site threshold, which gives the fraction of conducting versus non-conducting spheres necessary for percolation, we find {{p}\\text{c}}=0.3116(3) , consistent with the 1979 value of Powell 0.310(5) and identical within errors to the threshold for the simple-cubic lattice, 0.311 608, which shares the same average coordination number of 6. In terms of the volume fraction ϕ, the threshold corresponds to a critical value {φ\\text{c}}=0.199 . For the bond threshold, which apparently was not measured before, we find {{p}\\text{c}}=0.2424(3) . To find these thresholds, we considered two shape-dependent universal ratios involving the size of the largest cluster, fluctuations in that size, and the second moment of the size distribution; we confirmed the ratios’ universality by also studying the simple-cubic lattice with a similar cubic boundary. The results are applicable to many problems including conductivity in random mixtures, glass formation, and drug loading in pharmaceutical tablets.

  2. Fast searching in packed strings

    DEFF Research Database (Denmark)

    Bille, Philip

    2011-01-01

    Given strings P and Q the (exact) string matching problem is to find all positions of substrings in Q matching P. The classical Knuth–Morris–Pratt algorithm [SIAM J. Comput. 6 (2) (1977) 323–350] solves the string matching problem in linear time which is optimal if we can only read one character ...

  3. An amino acid code to define a protein's tertiary packing surface.

    Science.gov (United States)

    Fraga, Keith J; Joo, Hyun; Tsai, Jerry

    2016-02-01

    One difficult aspect of the protein-folding problem is characterizing the nonspecific interactions that define packing in protein tertiary structure. To better understand tertiary structure, this work extends the knob-socket model by classifying the interactions of a single knob residue packed into a set of contiguous sockets, or a pocket made up of 4 or more residues. The knob-socket construct allows for a symbolic two-dimensional mapping of pockets. The two-dimensional mapping of pockets provides a simple method to investigate the variety of pocket shapes to understand the geometry of protein tertiary surfaces. The diversity of pocket geometries can be organized into groups of pockets that share a common core, which suggests that some interactions in pockets are ancillary to packing. Further analysis of pocket geometries displays a preferred configuration that is right-handed in α-helices and left-handed in β-sheets. The amino acid composition of pockets illustrates the importance of nonpolar amino acids in packing as well as position specificity. As expected, all pocket shapes prefer to pack with hydrophobic knobs; however, knobs are not selective for the pockets they pack. Investigating side-chain rotamer preferences for certain pocket shapes uncovers no strong correlations. These findings allow a simple vocabulary based on knobs and sockets to describe protein tertiary packing that supports improved analysis, design, and prediction of protein structure.

  4. Packing a Box with Bricks.

    Science.gov (United States)

    Jepsen, Charles H.

    1991-01-01

    Presented are solutions to variations of a combinatorics problem from a recent International Mathematics Olympiad. In particular, the matrix algebra solution illustrates an interaction among the undergraduate areas of geometry, combinatorics, linear algebra, and group theory. (JJK)

  5. Integer Programming Formulations for Approximate Packing Circles in a Rectangular Container

    Directory of Open Access Journals (Sweden)

    Igor Litvinchev

    2014-01-01

    Full Text Available A problem of packing a limited number of unequal circles in a fixed size rectangular container is considered. The aim is to maximize the (weighted number of circles placed into the container or minimize the waste. This problem has numerous applications in logistics, including production and packing for the textile, apparel, naval, automobile, aerospace, and food industries. Frequently the problem is formulated as a nonconvex continuous optimization problem which is solved by heuristic techniques combined with local search procedures. New formulations are proposed for approximate solution of packing problem. The container is approximated by a regular grid and the nodes of the grid are considered as potential positions for assigning centers of the circles. The packing problem is then stated as a large scale linear 0-1 optimization problem. The binary variables represent the assignment of centers to the nodes of the grid. Nesting circles inside one another is also considered. The resulting binary problem is then solved by commercial software. Numerical results are presented to demonstrate the efficiency of the proposed approach and compared with known results.

  6. Estimating the richness of a population when the maximum number of classes is fixed: a nonparametric solution to an archaeological problem.

    Directory of Open Access Journals (Sweden)

    Metin I Eren

    Full Text Available BACKGROUND: Estimating assemblage species or class richness from samples remains a challenging, but essential, goal. Though a variety of statistical tools for estimating species or class richness have been developed, they are all singly-bounded: assuming only a lower bound of species or classes. Nevertheless there are numerous situations, particularly in the cultural realm, where the maximum number of classes is fixed. For this reason, a new method is needed to estimate richness when both upper and lower bounds are known. METHODOLOGY/PRINCIPAL FINDINGS: Here, we introduce a new method for estimating class richness: doubly-bounded confidence intervals (both lower and upper bounds are known. We specifically illustrate our new method using the Chao1 estimator, rarefaction, and extrapolation, although any estimator of asymptotic richness can be used in our method. Using a case study of Clovis stone tools from the North American Lower Great Lakes region, we demonstrate that singly-bounded richness estimators can yield confidence intervals with upper bound estimates larger than the possible maximum number of classes, while our new method provides estimates that make empirical sense. CONCLUSIONS/SIGNIFICANCE: Application of the new method for constructing doubly-bound richness estimates of Clovis stone tools permitted conclusions to be drawn that were not otherwise possible with singly-bounded richness estimates, namely, that Lower Great Lakes Clovis Paleoindians utilized a settlement pattern that was probably more logistical in nature than residential. However, our new method is not limited to archaeological applications. It can be applied to any set of data for which there is a fixed maximum number of classes, whether that be site occupancy models, commercial products (e.g. athletic shoes, or census information (e.g. nationality, religion, age, race.

  7. The Algorithm to Select Security Classes for Objects in Distributed Information Systems and Place Data in the Objects Through Reducing the Optimization Problem to the Theory of Games with Non-conflicting Interests

    Directory of Open Access Journals (Sweden)

    A. Yu. Bykov

    2016-01-01

    Full Text Available Modern methods to solve the practical problems related to the information security system design in multipurpose distributed systems often use optimization models. The paper formulates a problem statement of bilinear Boolean programming with the quality score that determines the level of the system security to select classes of protected objects in distributed systems and allocate databases in these objects. Restrictions specify the maximum cost of protection and the recommended amount of data stored in the object. To solve this problem, using the algorithms of discrete programming is possible, but the accurate algorithms, generally, are exponentially timeconsuming. To find a solution the paper proposes to interpret this problem as a problem of two players with non-conflicting interests. The first player is responsible for the assignment of security classes for the system objects, and the second player is responsible for the distribution of databases between the objects. To find solutions the use of a Nash equilibrium criterion is offered.To find the equilibrium solution is developed an algorithm and are proved its convergence, and the fact that it really allows us to obtain the Nash equilibrium position. Using the problem-solving approach related to reducing the original optimization problem to a two-player game with nonconflicting interests allowed a decreasing dimension of the original problem, because at each step of the algorithm is solved the problem of discrete optimization of a smaller dimension than the original problem of Boolean programming.The paper presents results of solving the problem, as well as research results on the time complexity of represented algorithms. It conducts a comparative analysis of the two approaches: an approach based on solving a discrete optimization problem and an approach based on reducing the problem to a two-player game with non-conflicting interests. An approach based on reducing the initial problem to a

  8. A lifelong learning hyper-heuristic method for bin packing.

    Science.gov (United States)

    Sim, Kevin; Hart, Emma; Paechter, Ben

    2015-01-01

    We describe a novel hyper-heuristic system that continuously learns over time to solve a combinatorial optimisation problem. The system continuously generates new heuristics and samples problems from its environment; and representative problems and heuristics are incorporated into a self-sustaining network of interacting entities inspired by methods in artificial immune systems. The network is plastic in both its structure and content, leading to the following properties: it exploits existing knowledge captured in the network to rapidly produce solutions; it can adapt to new problems with widely differing characteristics; and it is capable of generalising over the problem space. The system is tested on a large corpus of 3,968 new instances of 1D bin-packing problems as well as on 1,370 existing problems from the literature; it shows excellent performance in terms of the quality of solutions obtained across the datasets and in adapting to dynamically changing sets of problem instances compared to previous approaches. As the network self-adapts to sustain a minimal repertoire of both problems and heuristics that form a representative map of the problem space, the system is further shown to be computationally efficient and therefore scalable.

  9. Packing of ganglioside-phospholipid monolayers

    DEFF Research Database (Denmark)

    Majewski, J.; Kuhl, T.L.; Kjær, K.

    2001-01-01

    DPPE monolayer and does not distort the hexagonal in-plane unit cell or out-of-plane two-dimensional (2-D) packing compared with a pure DPPE monolayer. The oligosaccharide headgroups were found to extend normally from the monolayer surface, and the incorporation of these glycolipids into DPPE...... monolayers did not affect hydrocarbon tail packing (fluidization or condensation of the hydrocarbon region). This is in contrast to previous investigations of lipopolymer-lipid mixtures, where the packing structure of phospholipid monolayers was greatly altered by the inclusion of lipids bearing hydrophilic...... polymer groups. Indeed, the lack of packing disruptions by the oligosaccharide groups indicates that protein-GM, interactions, including binding, insertion, chain fluidization, and domain formation (lipid rafts), can be studied in 2-D monolayers using scattering techniques....

  10. Electroosmotic Driving Liquid Using Nanosilica Packed Column

    Institute of Scientific and Technical Information of China (English)

    Ling Xin CHEN; Guo An LUO; Tao WEN

    2005-01-01

    The electroosmotic pump (EOP) using nanosilica particles packed-bed column was experimentally studied. The relationship between flowrate, pressure and applied voltage of the pump, and pressure-flowrate (P-Q) characteristic were investigated.

  11. Packing circles and spheres on surfaces

    KAUST Repository

    Schiftner, Alexander

    2009-12-01

    Inspired by freeform designs in architecture which involve circles and spheres, we introduce a new kind of triangle mesh whose faces\\' incircles form a packing. As it turns out, such meshes have a rich geometry and allow us to cover surfaces with circle patterns, sphere packings, approximate circle packings, hexagonal meshes which carry a torsion-free support structure, hybrid tri-hex meshes, and others. We show how triangle meshes can be optimized so as to have the incircle packing property. We explain their relation to conformal geometry and implications on solvability of optimization. The examples we give confirm that this kind of meshes is a rich source of geometric structures relevant to architectural geometry.

  12. Packing circles and spheres on surfaces

    KAUST Repository

    Schiftner, Alexander

    2009-01-01

    Inspired by freeform designs in architecture which involve circles and spheres, we introduce a new kind of triangle mesh whose faces\\' incircles form a packing. As it turns out, such meshes have a rich geometry and allow us to cover surfaces with circle patterns, sphere packings, approximate circle packings, hexagonal meshes which carry a torsion-free support structure, hybrid tri-hex meshes, and others. We show how triangle meshes can be optimized so as to have the incircle packing property. We explain their relation to conformal geometry and implications on solvability of optimization. The examples we give confirm that this kind of meshes is a rich source of geometric structures relevant to architectural geometry. © 2009 ACM.

  13. 高校班级管理工作存在的问题及对策%Problems and Countermeasures in Class Management in Colleges and Universities

    Institute of Scientific and Technical Information of China (English)

    陈悦; 刘畅; 佟明光

    2012-01-01

    班级管理是对班级所拥有的资源进行有效计划、组织、领导和控制的过程,是高校管理工作的辅助,是实现培养目标的重要手段和保证。班级管理工作的好坏直接反映了一个学校的管理水平和办学水平。%Class management is the process of effective planning, organization, leading and control of class resources, assistance to the college management and important means & guarantee for realization of student cultivation goal. The performance of class management reflects directly the management and education levels of a college.

  14. 求解一类广义均衡问题的交替方向法%Alternating Direction Method of Multipliers for Solving a Class of General Equilibrium Problem

    Institute of Scientific and Technical Information of China (English)

    徐洁; 张俊容; 刘佳

    2016-01-01

    The alternating direction method is one of the classic methods for solving optimization problems with a separable structure .Its essence is lies in that applying the original problem 'solution equivalent to the saddle point of the augmented Lagrangian function to iterative the parameters ,and then finding out the solution of the original problem .This paper corrects Lagrangian multipliers to construct a new alternating direction method for solving a class of general equilibrium problem ,and then analyzes the properties of the alternating direction method and derives the convergence of the alternating direction method .%通过修正拉格朗日乘子构造了一种新的交替方向法求解一类广义均衡问题,分析了该算法的收敛性及其所产生序列的特性。

  15. Phyllotaxis, disk packing, and Fibonacci numbers

    Science.gov (United States)

    Mughal, A.; Weaire, D.

    2017-02-01

    We consider the evolution of the packing of disks (representing the position of buds) that are introduced at the top of a surface which has the form of a growing stem. They migrate downwards, while conforming to three principles, applied locally: dense packing, homogeneity, and continuity. We show that spiral structures characterized by the widely observed Fibonacci sequence (1, 1, 2, 3, 5, 8, 13, ...), as well as related structures, occur naturally under such rules. Typical results are presented in an animation.

  16. Hexagonal packing of Drosophila wing epithelial cells by the planar cell polarity pathway.

    Science.gov (United States)

    Classen, Anne-Kathrin; Anderson, Kurt I; Marois, Eric; Eaton, Suzanne

    2005-12-01

    The mechanisms that order cellular packing geometry are critical for the functioning of many tissues, but they are poorly understood. Here, we investigate this problem in the developing wing of Drosophila. The surface of the wing is decorated by hexagonally packed hairs that are uniformly oriented by the planar cell polarity pathway. They are constructed by a hexagonal array of wing epithelial cells. Wing epithelial cells are irregularly arranged throughout most of development, but they become hexagonally packed shortly before hair formation. During the process, individual cell boundaries grow and shrink, resulting in local neighbor exchanges, and Cadherin is actively endocytosed and recycled through Rab11 endosomes. Hexagonal packing depends on the activity of the planar cell polarity proteins. We propose that these proteins polarize trafficking of Cadherin-containing exocyst vesicles during junction remodeling. This may be a common mechanism for the action of planar cell polarity proteins in diverse systems.

  17. Multi objective optimization of line pack management of gas pipeline system

    Science.gov (United States)

    Chebouba, A.

    2015-01-01

    This paper addresses the Line Pack Management of the "GZ1 Hassi R'mell-Arzew" gas pipeline. For a gas pipeline system, the decision-making on the gas line pack management scenarios usually involves a delicate balance between minimization of the fuel consumption in the compression stations and maximizing gas line pack. In order to select an acceptable Line Pack Management of Gas Pipeline scenario from these two angles for "GZ1 Hassi R'mell- Arzew" gas pipeline, the idea of multi-objective decision-making has been introduced. The first step in developing this approach is the derivation of a numerical method to analyze the flow through the pipeline under transient isothermal conditions. In this paper, the solver NSGA-II of the modeFRONTIER, coupled with a matlab program was used for solving the multi-objective problem.

  18. Patchy particle packing under electric fields.

    Science.gov (United States)

    Song, Pengcheng; Wang, Yufeng; Wang, Yu; Hollingsworth, Andrew D; Weck, Marcus; Pine, David J; Ward, Michael D

    2015-03-01

    Colloidal particles equipped with two, three, or four negatively charged patches, which endow the particles with 2-fold, 3-fold, or tetrahedral symmetries, form 1D chains, 2D layers, and 3D packings when polarized by an AC electric field. Two-patch particles, with two patches on opposite sides of the particle (2-fold symmetry) pack into the cmm plane group and 3D packings with I4mm space group symmetry, in contrast to uncharged spherical or ellipsoidal colloids that typically crystallize into a face-centered ABC layer packing. Three-patch particles (3-fold symmetry) form chains having a 21 screw axis symmetry, but these chains pair in a manner such that each individual chain has one-fold symmetry but the pair has 21 screw axis symmetry, in an arrangement that aligns the patches that would favor Coulombic interactions along the chain. Surprisingly, some chain pairs form unanticipated double-helix regions that result from mutual twisting of the chains about each other, illustrating a kind of polymorphism that may be associated with nucleation from short chain pairs. Larger 2D domains of the three-patch particles crystallize in the p6m plane group with alignment (with respect to the field) and packing densities that suggest random disorder in the domains, whereas four-patch particles form 2D domains in which close-packed rows are aligned with the field.

  19. Genetic algorithm for short-term scheduling of make-and-pack batch production process

    Institute of Scientific and Technical Information of China (English)

    Wuthichai Wongthatsanekorn; Busaba Phruksaphanrat

    2015-01-01

    This paper considers a scheduling problem in industrial make-and-pack batch production process. This process equips with sequence-dependent changeover time, multipurpose storage units with limited capacity, storage time, batch splitting, partial equipment connectivity and transfer time. The objective is to make a production plan to satisfy al constraints while meeting demand requirement of packed products from various product fam-ilies. This problem is NP-hard and the problem size is exponentially large for a realistic-sized problem. Therefore, we propose a genetic algorithm to handle this problem. Solutions to the problems are represented by chromo-somes of product family sequences. These sequences are decoded to assign the resource for producing packed products according to forward assignment strategy and resource selection rules. These techniques greatly reduce unnecessary search space and improve search speed. In addition, design of experiment is carefully utilized to de-termine appropriate parameter settings. Ant colony optimization and Tabu search are also implemented for com-parison. At the end of each heuristics, local search is applied for the packed product sequence to improve makespan. In an experimental analysis, al heuristics show the capability to solve large instances within reason-able computational time. In al problem instances, genetic algorithm averagely outperforms ant colony optimiza-tion and Tabu search with slightly longer computational time.

  20. Dependent Classes

    DEFF Research Database (Denmark)

    Gasiunas, Vaidas; Mezini, Mira; Ostermann, Klaus

    2007-01-01

    Virtual classes allow nested classes to be refined in subclasses. In this way nested classes can be seen as dependent abstractions of the objects of the enclosing classes. Expressing dependency via nesting, however, has two limitations: Abstractions that depend on more than one object cannot...... be modeled and a class must know all classes that depend on its objects. This paper presents dependent classes, a generalization of virtual classes that expresses similar semantics by parameterization rather than by nesting. This increases expressivity of class variations as well as the flexibility...... of their modularization. Besides, dependent classes complement multi-methods in scenarios where multi-dispatched abstractions rather than multi-dispatched method are needed. They can also be used to express more precise signatures of multi-methods and even extend their dispatch semantics. We present a formal semantics...

  1. On the weak solution of a three-point boundary value problem for a class of parabolic equations with energy specification

    Directory of Open Access Journals (Sweden)

    Abdelfatah Bouziani

    2003-01-01

    Full Text Available This paper deals with weak solution in weighted Sobolev spaces, of three-point boundary value problems which combine Dirichlet and integral conditions, for linear and quasilinear parabolic equations in a domain with curved lateral boundaries. We, firstly, prove the existence, uniqueness, and continuous dependence of the solution for the linear equation. Next, analogous results are established for the quasilinear problem, using an iterative process based on results obtained for the linear problem.

  2. Student Engagement in a Large Classroom: Using Technology to Generate a Hybridized Problem- Based Learning Experience in a Large First Year Undergraduate Class

    Science.gov (United States)

    Fukuzawa, Sherry; Boyd, Cleo

    2016-01-01

    Large first year undergraduate courses have unique challenges in the promotion of student engagement and self-directed learning due to resource constraints that prohibit small group discussions with instructors. The Monthly Virtual Mystery was developed to increase student engagement in a large (N = 725) first year undergraduate class in…

  3. 一类积微分方程(组)的Cauchy问题%The Cauchy Problem for a Class of Intergrodifferential Equations

    Institute of Scientific and Technical Information of China (English)

    杨成荣

    2000-01-01

    The existence, uniqueness of bounded and continuous solutions of a class of integrodifferential equations and some estimates of solutions are established. Applying these results to integrodifferential systems with a small parameter ε>0, we obtain, in particular, some estimates of solutions uniform in ε.

  4. LONG TIME BEHAVIOR FOR SOLUTION OF INITIAL-BOUNDARY VALUE PROBLEM OF ONE CLASS OF SYSTEMS WITH MULTIDIMENSIONAL INHOMOGENEOUS GBBM EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    FANG Shao-mei; GUO Bo-ling

    2005-01-01

    The following initial-boundary value problem for the systems with multidimensional inhomogeneous generalized Benjamin-Bona-Mahony (GBBM)equations is reviewed. The existence of global attractors of this problem was proved by means of a uniform priori estimate for time.

  5. How to beat the sphere-packing bound with feedback

    OpenAIRE

    Sahai, Anant

    2006-01-01

    The sphere-packing bound $E_{sp}(R)$ bounds the reliability function for fixed-length block-codes. For symmetric channels, it remains a valid bound even when strictly causal noiseless feedback is allowed from the decoder to the encoder. To beat the bound, the problem must be changed. While it has long been known that variable-length block codes can do better when trading-off error probability with expected block-length, this correspondence shows that the {\\em fixed-delay} setting also present...

  6. Using distributed genetic algorithms in three-dimensional bin packing for rapid prototyping machines

    Science.gov (United States)

    Lewis, James E.; Ragade, Rammohan K.; Kumar, Anup; Biles, William E.; Ikonen, Ilkka T.

    1998-10-01

    Genetic algorithms (GAs) are excellent approaches to solving complex problems in optimization with difficult constraints, and in high state space dimensionality problems. The classic bin-packing optimization problem has been shown to be a NP- complete problem. There are GA applications to variations of the bin-packing problem for stock cutting, vehicle loading, air container loading, scheduling, and the knapsack problem. Mostly, these are based on a 1D or 2D considerations. Ikonen et. al. have developed a GA for rapid prototyping called GARP, which utilizes a 3D chromosome structure for the bin- packing of the Sinterstation 2000's build cylinder. GARP allows the Sinterstation to be used more productively. The GARP application was developed for a single CPU machine. Anticipating greater use of time compression technologies, this paper examines the framework necessary to reduce GARP's execution time. This framework is necessary to speed-up the bin-packing evaluation, by the use of distributed or parallel GAs. In this paper, a framework for distribution techniques to improve the efficiency of GARP, and to improve the quality of GARPis solutions is proposed.

  7. 48 CFR 1846.672-6 - Packing list instructions.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Packing list instructions... ADMINISTRATION CONTRACT MANAGEMENT QUALITY ASSURANCE Material Inspection and Receiving Reports 1846.672-6 Packing list instructions. Copies of the MIRR may be used as a packing list. The packing list copies shall...

  8. 46 CFR 160.043-6 - Marking and packing.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Marking and packing. 160.043-6 Section 160.043-6... Marking and packing. (a) General. Jackknives specified by this subpart shall be stamped or otherwise... opener. (c) Packing. Each jackknife, complete with lanyard attached, shall be packed in a heat-sealed...

  9. Packing parameters effect on injection molding of polypropylene nanostructured surfaces

    DEFF Research Database (Denmark)

    Calaon, Matteo; Tosello, Guido; Hansen, Hans Nørgaard

    2012-01-01

    having a diameter of 500 nm was employed. The tool insert surface was produced using chemical-based-batch techniques such aluminum anodization and nickel electroplating. During the injection molding process, polypropylene (PP) was employed as material and packing phase parameters (packing time, packing...... to the polymer part was mainly influenced by packing pressure level and distance from the gate....

  10. 27 CFR 24.308 - Bottled or packed wine record.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bottled or packed wine... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.308 Bottled or packed wine record. A proprietor who bottles, packs, or receives bottled or packed beverage wine in bond...

  11. Efficient linear programming algorithm to generate the densest lattice sphere packings.

    Science.gov (United States)

    Marcotte, Étienne; Torquato, Salvatore

    2013-06-01

    Finding the densest sphere packing in d-dimensional Euclidean space R(d) is an outstanding fundamental problem with relevance in many fields, including the ground states of molecular systems, colloidal crystal structures, coding theory, discrete geometry, number theory, and biological systems. Numerically generating the densest sphere packings becomes very challenging in high dimensions due to an exponentially increasing number of possible sphere contacts and sphere configurations, even for the restricted problem of finding the densest lattice sphere packings. In this paper we apply the Torquato-Jiao packing algorithm, which is a method based on solving a sequence of linear programs, to robustly reproduce the densest known lattice sphere packings for dimensions 2 through 19. We show that the TJ algorithm is appreciably more efficient at solving these problems than previously published methods. Indeed, in some dimensions, the former procedure can be as much as three orders of magnitude faster at finding the optimal solutions than earlier ones. We also study the suboptimal local density-maxima solutions (inherent structures or "extreme" lattices) to gain insight about the nature of the topography of the "density" landscape.

  12. Discipline Problems in The EFL Class: Is There a Cure? Problemas con la disciplina en el aula de inglés: ¿Existe una cura?

    Directory of Open Access Journals (Sweden)

    Doris de Almeida Soares

    2007-12-01

    Full Text Available This article discusses the findings of an action research project carried out to minimize the negative class participation of 10 EFL pre-intermediate students, aged-11-14, in a language school in Rio de Janeiro, Brazil. First, some theoretical issues concerning discipline in the language class will be discussed. Second, the original project I developed in 1995 to minimize the negative class participation of 14 EFL beginner students, aged 1 -15, will be reviewed. Next, the experiment with the 003 group will be described. The results seem to confirm that, although some adaptations to the original project were necessary, when students reflect upon their importance in the lessons, they tend to behave better in class and to show a more positive attitude towards learning.Este artículo discute los resultados de una investigación acción realizada para minimizar los problemas de disciplina en una clase de 10 alumnos de inglés, de nivel pre-intermedio, con edades entre 11-14 años, en un instituto de Rio de Janeiro, Brasil. En primer lugar, se discuten algunos presupuestos teóricos; en segundo lugar, presento el proyecto original que desarrollé en 1995 para trabajar con la indisciplina en mi clase de 14 alumnos principiantes en inglés, con edad entre 1 -15 años. A continuación, se describe el experimento realizado con el grupo de 003. Los resultados parecen confirmar que, aunque fueron necesarias algunas adaptaciones al proyecto inicial, cuando los alumnos reflexionan sobre su importancia para las clases, tienden a portarse mejor y demuestran una actitud más positiva hacia el aprendizaje.

  13. Quasistatic packings of droplets in flat microfluidic channels

    Science.gov (United States)

    Kadivar, Erfan

    2016-02-01

    As observed in recent experiments, monodisperse droplets self-assemble spontaneously in different ordered packings. In this work, we present a numerical study of the droplet packings in the flat rectangular microfluidic channels. Employing the boundary element method, we numerically solve the Stokes equation in two-dimension and investigate the appearance of droplet packing and transition between one and two-row packings of monodisperse emulsion droplets. By calculating packing force applied on the droplet interface, we investigate the effect of flow rate, droplet size, and surface tension on the packing configurations of droplets and transition between different topological packings.

  14. 支持向量机多分类问题研究%Research on the Multi-class Classification Problem of Support Vector Machine

    Institute of Scientific and Technical Information of China (English)

    肖晓; 张敏

    2014-01-01

    The support vector machine (SVM)is a typical two-class classification methods and how to extend it to multi-class classification has been increasingly a hotspot in the research of scholars.Experiments with the standard datasets were carried retrospectively on the existing methods of SVM multiclass classification,such as one against one method,one against rest meth-od and directed acyclic graph,showed their respective merits and defects.The results indicate that directed acyclic graph is naturally suitable for the multi-class classification of large-scale data with ideal training speed,which has a certain reference value.%支持向量机是典型的两类分类方法,如何将其推广到多分类问题是学者们正在研究的一个热点。对比分析几种常用的多类方法的优缺点,利用标准数据集对多类支持向量机的速度和精度两方面进行试验分析。研究表明,对于大规模的多类分类问题,有向无环图简单易行,具有理想的训练速度与精度,具有一定的参考价值。

  15. Coalescence preference in dense packing of bubbles

    Science.gov (United States)

    Kim, Yeseul; Gim, Bopil; Gim, Bopil; Weon, Byung Mook

    2015-11-01

    Coalescence preference is the tendency that a merged bubble from the contact of two original bubbles (parent) tends to be near to the bigger parent. Here, we show that the coalescence preference can be blocked by densely packing of neighbor bubbles. We use high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence phenomenon which occurs in micro scale seconds and inside dense packing of microbubbles with a local packing fraction of ~40%. Previous theory and experimental evidence predict a power of -5 between the relative coalescence position and the parent size. However, our new observation for coalescence preference in densely packed microbubbles shows a different power of -2. We believe that this result may be important to understand coalescence dynamics in dense packing of soft matter. This work (NRF-2013R1A22A04008115) was supported by Mid-career Researcher Program through NRF grant funded by the MEST and also was supported by Ministry of Science, ICT and Future Planning (2009-0082580) and by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry and Education, Science and Technology (NRF-2012R1A6A3A04039257).

  16. Perfect arborescence packing in preflow mincut graphs

    Energy Technology Data Exchange (ETDEWEB)

    Gabow, H.N. [Univ. of Colorado, Boulder, CO (United States)

    1996-12-31

    In a digraph with distinguished vertex a, for any vertex v {ne} a let {lambda}(v) equal the value of a maximum flow from a to v. A perfect packing of a-arborescences contains each vertex in {lambda}(v) arborescences and contains some fixed vertex in every arborescence. Determining if an arbitrary graph has a perfect packing is NP-complete. We present the most general known condition that guarantees the existence of a perfect packing: each vertex v {ne} a is separated from a by a set that has in-degree {lambda}(v) and out-degree no greater. This result is based on other useful properties of such graphs, e.g., they always have a pair of edges that can be {open_quotes}split off{close_quotes} preserving, values. We show a perfect packing can be found in O(nm{sup 2}) time, where n (m) is the number of vertices (edges). If the graph has a capacity function the time is the same as computing O(n{sup 2}) maximum network flows. We also show a preflow mincut graph has a fractional perfect packing using only m + n - 2 distinct arborescences.

  17. Minimal $N$-Point Diameters and $f$-Best-Packing Constants in $R^d$

    CERN Document Server

    Bondarenko, A V; Saff, E B

    2012-01-01

    In terms of the minimal $N$-point diameter $D_d(N)$ for $R^d,$ we determine, for a class of continuous real-valued functions $f$ on $[0,+\\infty],$ the $N$-point $f$-best-packing constant $\\min\\{f(\\|x-y\\|)\\, :\\, x,y\\in \\R^d\\}$, where the minimum is taken over point sets of cardinality $N.$ We also show that $$ N^{1/d}\\Delta_d^{-1/d}-2\\le D_d(N)\\le N^{1/d}\\Delta_d^{-1/d}, \\quad N\\ge 2,$$ where $\\Delta_d$ is the maximal sphere packing density in $\\R^d$. Further, we provide asymptotic estimates for the $f$-best-packing constants as $N\\to\\infty$.

  18. On the Problems of College English Teaching and Countermeasures in Large Classes%地方高校英语大班教学中的问题及对策

    Institute of Scientific and Technical Information of China (English)

    王盈盈

    2015-01-01

    大学英语大班教学是目前地方高校英语教学采用的主要方式,结合地方高校英语教学中教师、学生及师生关系等方面存在的现状及问题,探求教师在教学水平、师生关系及培养学生学习能力方面采取的对策,从而提高大班英语教学效率。%Teaching College English in large classes is the main form of foreign language teaching currently in China's institutions of higher learning.Problems in teaching English practice in large classes are discussed, which include the teachers' teaching ways, the students' learning attitude and the relation between the teachers and the students; on the other hand, it aims to explore the countermeasures to be taken to solve these problems, in the hope of improving the efficiency and quality of large classes teaching.

  19. Deterioration of organic packing materials commonly used in air biofiltration: effect of VOC-packing interactions.

    Science.gov (United States)

    Lebrero, Raquel; Estrada, José M; Muñoz, Raúl; Quijano, Guillermo

    2014-05-01

    The abiotic deterioration of three conventional organic packing materials used in biofiltration (compost, wood bark and Macadamia nutshells) caused by their interaction with toluene (used as a model volatile organic compound) was here studied. The deterioration of the materials was evaluated in terms of structural damage, release of co-substrates and increase of the packing biodegradability. After 21 days of exposure to toluene, all packing materials released co-substrates able to support microbial growth, which were not released by the control materials not exposed to toluene. Likewise, the exposure to toluene increased the packing material biodegradability by 26% in wood bark, 20% in compost and 17% in Macadamia nutshells. Finally, scanning electron microscopy analysis confirmed the deterioration in the structure of the packing materials evaluated due to the exposure to toluene, Macadamia nutshells being the material with the highest resistance to volatile organic compound attack.

  20. Nasal packing aspiration in a patient with Alzheimer’s disease: a rare complication

    Directory of Open Access Journals (Sweden)

    Papadakis I

    2012-07-01

    Full Text Available Eleftherios Koudounarakis, Nikolaos Chatzakis, Ioannis Papadakis, Irene Panagiotaki, George VelegrakisDepartment of Otorhinolaryngology, University Hospital of Heraklion, Crete, GreeceAbstract: Nasal bleeding is a frequent problem for patients receiving anticoagulant agents. Most cases are successfully managed with anterior or posterior nasal packing. However, the complications of nasal packing should be always considered. We report the case of a 78-year-old man with Alzheimer’s disease who was treated for anterior epistaxis with anterior nasal packing using three pieces of antibiotic-soaked gauze. Two days later, the patient was admitted to the emergency department in respiratory distress. A chest x-ray demonstrated atelectasis of the right lung. During an examination of the nasal cavities, the nasal packing was removed, and one of the gauze pieces was missing. The patient underwent rigid bronchoscopy, and the missing gauze was found to be obstructing the right main bronchus. The patient’s respiratory function improved considerably after removal of the foreign body. It is assumed that gauze packs should be used with caution in patients with an impaired level of consciousness and neurodegenerative diseases.Keywords: epistaxis, nasal packing, aspiration, Alzheimer’s disease, cough reflex

  1. Safety considerations for fabricating lithium battery packs

    Science.gov (United States)

    Ciesla, J. J.

    1986-09-01

    Lithium cell safety is a major issue with both manufacturers and end users. Most manufacturers have taken great strides to develop the safest cells possible while still maintaining performance characteristics. The combining of lithium cells for higher voltages, currents, and capacities requires the fabricator of lithium battery packs to be knowledgable about the specific electrochemical system being used. Relatively high rate, spirally wound (large surface area) sulfur oxychloride cells systems, such as Li/Thionyl or Sulfuryl chloride are considered. Prior to the start of a design of a battery pack, a review of the characterization studies for the cells should be conducted. The approach for fabricating a battery pack might vary with cell size.

  2. Characterization of maximally random jammed sphere packings. II. Correlation functions and density fluctuations

    Science.gov (United States)

    Klatt, Michael A.; Torquato, Salvatore

    2016-08-01

    In the first paper of this series, we introduced Voronoi correlation functions to characterize the structure of maximally random jammed (MRJ) sphere packings across length scales. In the present paper, we determine a variety of different correlation functions that arise in rigorous expressions for the effective physical properties of MRJ sphere packings and compare them to the corresponding statistical descriptors for overlapping spheres and equilibrium hard-sphere systems. Such structural descriptors arise in rigorous bounds and formulas for effective transport properties, diffusion and reactions constants, elastic moduli, and electromagnetic characteristics. First, we calculate the two-point, surface-void, and surface-surface correlation functions, for which we derive explicit analytical formulas for finite hard-sphere packings. We show analytically how the contact Dirac delta function contribution to the pair correlation function g2(r ) for MRJ packings translates into distinct functional behaviors of these two-point correlation functions that do not arise in the other two models examined here. Then we show how the spectral density distinguishes the MRJ packings from the other disordered systems in that the spectral density vanishes in the limit of infinite wavelengths; i.e., these packings are hyperuniform, which means that density fluctuations on large length scales are anomalously suppressed. Moreover, for all model systems, we study and compute exclusion probabilities and pore size distributions, as well as local density fluctuations. We conjecture that for general disordered hard-sphere packings, a central limit theorem holds for the number of points within an spherical observation window. Our analysis links problems of interest in material science, chemistry, physics, and mathematics. In the third paper of this series, we will evaluate bounds and estimates of a host of different physical properties of the MRJ sphere packings that are based on the

  3. Lattice approaches to packed column simulations

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This work presents a review of the findings into the ability of a digitally based particle packing algorithm, called DigiPac, to predict bed structure in a variety of packed columns, for a range of generic pellet shapes frequently used in the chemical and process engineering industries.Resulting macroscopic properties are compared with experimental data derived from both invasive and non-destructive measurement techniques.Additionally, fluid velocity distributions, through samples of the resulting bed structures, are analysed using lattice Boltzmann method (LBM) simulations and are compared against experimental data from the literature.

  4. Non-Crystallographic Symmetry in Packing Spaces

    Directory of Open Access Journals (Sweden)

    Valery G. Rau

    2013-01-01

    Full Text Available In the following, isomorphism of an arbitrary finite group of symmetry, non-crystallographic symmetry (quaternion groups, Pauli matrices groups, and other abstract subgroups, in addition to the permutation group, are considered. Application of finite groups of permutations to the packing space determines space tilings by policubes (polyominoes and forms a structure. Such an approach establishes the computer design of abstract groups of symmetry. Every finite discrete model of the real structure is an element of symmetry groups, including non-crystallographic ones. The set packing spaces of the same order N characterizes discrete deformation transformations of the structure.

  5. Imaging of drug smuggling by body packing.

    Science.gov (United States)

    Sica, Giacomo; Guida, Franco; Bocchini, Giorgio; Iaselli, Francesco; Iadevito, Isabella; Scaglione, Mariano

    2015-02-01

    Body packing, pushing, and stuffing are hazardous practices with complex medicolegal and social implications. A radiologist plays both a social and a medicolegal role in their assessment, and it should not be limited only to the identification of the packages but must also provide accurate information about their number and their exact location so as to prevent any package remains in the body packer. Radiologists must also be able to recognize the complications associated with these risky practices. Imaging assessment of body packing is performed essentially through plain abdominal X-ray and computed tomography scans. Ultrasound and magnetic resonance imaging, although with some advantages, actually have a limited use.

  6. Packing Transitions in Nanosized Li Clusters

    CERN Document Server

    Sung, M W; Weare, J H; Sung, Ming Wen; Kawai, Ryoichi; Weare, John H.

    1994-01-01

    Packing transitions in the lowest energy structures of Li clusters as a function of size have been identified via simulated annealing. For N>21, the large $p$ character of Li leads to unexpected ionic structures. At N~25, a packing pattern based on interpenetrating 13-atom icosahedra and similar to that of Na and K appears. This pattern persists until at N=55, where another transition to a structure based on a Mackay icosahedron occurs. For clusters of size 55 and 147, the optimized FCC structure representative of the bulk is still slightly higher in energy than the optimal MIC. (RK-94-03)

  7. Simulating the pervasive fracture and fragmentation of materials and structures using randomly close-packed Voronoi tessellations.

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, Joseph E.

    2008-09-01

    Under extreme loading conditions most often the extent of material and structural fracture is pervasive in the sense that a multitude of cracks are nucleating, propagating in arbitrary directions, coalescing, and branching. Pervasive fracture is a highly nonlinear process involving complex material constitutive behavior, material softening, localization, surface generation, and ubiquitous contact. Two primary applications in which pervasive fracture is encountered are (1) weapons effects on structures and (2) geomechanics of highly jointed and faulted reservoirs. A pure Lagrangian computational method based on randomly close-packed Voronoi tessellations is proposed as a rational approach for simulating the pervasive fracture of materials and structures. Each Voronoi cell is formulated as a finite element using the reproducing kernel method. Fracture surfaces are allowed to nucleate only at the intercell faces. The randomly seeded Voronoi cells provide an unbiased network for representing cracks. In this initial study two approaches for allowing the new surfaces to initiate are studied: (1) dynamic mesh connectivity and the instantaneous insertion of a cohesive traction when localization is detected, and (2) a discontinuous Galerkin approach in which the interelement tractions are an integral part of the variational formulation, but only become active once localization is detected. Pervasive fracture problems are extremely sensitive to initial conditions and system parameters. Dynamic problems exhibit a form of transient chaos. The primary numerical challenge for this class of problems is the demonstration of model objectivity and, in particular, the identification and demonstration of a measure of convergence for engineering quantities of interest.

  8. Submaximal Riemann-Roch expected curves and symplectic packing.

    Directory of Open Access Journals (Sweden)

    Wioletta Syzdek

    2007-06-01

    Full Text Available We study Riemann-Roch expected curves on $mathbb{P}^1 imes mathbb{P}^1$ in the context of the Nagata-Biran conjecture. This conjecture predicts that for sufficiently large number of points multiple points Seshadri constants of an ample line bundle on algebraic surface are maximal. Biran gives an effective lower bound $N_0$. We construct examples verifying to the effect that the assertions of the Nagata-Biran conjecture can not hold for small number of points. We discuss cases where our construction fails. We observe also that there exists a strong relation between Riemann-Roch expected curves on $mathbb{P}^1 imes mathbb{P}^1$ and the symplectic packing problem. Biran relates the packing problem to the existence of solutions of certain Diophantine equations. We construct such solutions for any ample line bundle on $mathbb{P}^1 imes mathbb{P}^1$ and a relatively smallnumber of points. The solutions geometrically correspond to Riemann-Roch expected curves. Finally we discuss in how far the Biran number $N_0$ is optimal in the case of mathbb{P}^1 imes mathbb{P}^1. In fact we conjecture that it can be replaced by a lower number and we provide evidence justifying this conjecture.

  9. On the convergence of a perturbation approach for a class of optimization problems with complementarity constraints%一类互补约束优化问题的一个扰动方法的收敛性

    Institute of Scientific and Technical Information of China (English)

    张立卫; Robert Ebihart Msigwa

    2014-01-01

    Mathematical programs with complementarity constraints are an important class of optimi-zation problems ,which have important applications in science and engineering .For examples ,the road capacity expansion problem in transportation and the DICE model in economics are such kind of problems .Traditional nonlinear programming solvers can not be used to solve mathematical programs with complementarity constraints ,because conventional constraint qualifications do not hold for the constraint sets ,and smooth approximationmethods are proposed to overcome such a difficulty .This paper considers the perturbation approach based on the smoothed Fischer-Burmeister function for a class of optimization problems with complementarity constraints .We prove that the optimal value of the perturbed problem converges to that of the original problem and the outer limit of the solution set for the perturbed problem is contained in the solution set of the original problem w hen the smoothing parameter μ↘0 .We explain w hy the conventionally used constraint qualifications are easily satisfied and present the first-order necessary optimality conditions and the second-order sufficient optimality conditions for the perturbed problems .%互补约束优化问题是一类重要的最优化问题,在科学和工程中有着重要的应用。交通规划的道路扩容问题,经济学领域的DICE模型都是互补约束优化问题。这类问题因为约束集合不满足通常的约束规范而不能用传统的非线性规划方法处理,往往用光滑近似的方法来克服这一困难。考虑一类互补约束优化问题的基于光滑化Fischer-Burmeister 函数的扰动方法。证明了当光滑化参数μ↘0时扰动问题的值收敛到原问题的最优值,扰动问题的最优解集合的外极限包含在问题最优解集合中。说明扰动问题很容易满足通常的约束规范,并给出扰动问题的一阶必要性最优条件和二阶充分性最优条件。

  10. Cylinder packing by simulated annealing

    Directory of Open Access Journals (Sweden)

    M. Helena Correia

    2000-12-01

    Full Text Available This paper is motivated by the problem of loading identical items of circular base (tubes, rolls, ... into a rectangular base (the pallet. For practical reasons, all the loaded items are considered to have the same height. The resolution of this problem consists in determining the positioning pattern of the circular bases of the items on the rectangular pallet, while maximizing the number of items. This pattern will be repeated for each layer stacked on the pallet. Two algorithms based on the meta-heuristic Simulated Annealing have been developed and implemented. The tuning of these algorithms parameters implied running intensive tests in order to improve its efficiency. The algorithms developed were easily extended to the case of non-identical circles.Este artigo aborda o problema de posicionamento de objetos de base circular (tubos, rolos, ... sobre uma base retangular de maiores dimensões. Por razões práticas, considera-se que todos os objetos a carregar apresentam a mesma altura. A resolução do problema consiste na determinação do padrão de posicionamento das bases circulares dos referidos objetos sobre a base de forma retangular, tendo como objetivo a maximização do número de objetos estritamente posicionados no interior dessa base. Este padrão de posicionamento será repetido em cada uma das camadas a carregar sobre a base retangular. Apresentam-se dois algoritmos para a resolução do problema. Estes algoritmos baseiam-se numa meta-heurística, Simulated Annealling, cuja afinação de parâmetros requereu a execução de testes intensivos com o objetivo de atingir um elevado grau de eficiência no seu desempenho. As características dos algoritmos implementados permitiram que a sua extensão à consideração de círculos com raios diferentes fosse facilmente conseguida.

  11. Effects of Problem-Based Learning Model versus Expository Model and Motivation to Achieve for Student's Physic Learning Result of Senior High School at Class XI

    Science.gov (United States)

    Prayekti

    2016-01-01

    "Problem-based learning" (PBL) is one of an innovative learning model which can provide an active learning to student, include the motivation to achieve showed by student when the learning is in progress. This research is aimed to know: (1) differences of physic learning result for student group which taught by PBL versus expository…

  12. Multi-Objective Predictive Balancing Control of Battery Packs Based on Predictive Current

    Directory of Open Access Journals (Sweden)

    Wenbiao Li

    2016-04-01

    Full Text Available Various balancing topology and control methods have been proposed for the inconsistency problem of battery packs. However, these strategies only focus on a single objective, ignore the mutual interaction among various factors and are only based on the external performance of the battery pack inconsistency, such as voltage balancing and state of charge (SOC balancing. To solve these problems, multi-objective predictive balancing control (MOPBC based on predictive current is proposed in this paper, namely, in the driving process of an electric vehicle, using predictive control to predict the battery pack output current the next time. Based on this information, the impact of the battery pack temperature caused by the output current can be obtained. Then, the influence is added to the battery pack balancing control, which makes the present degradation, temperature, and SOC imbalance achieve balance automatically due to the change of the output current the next moment. According to MOPBC, the simulation model of the balancing circuit is built with four cells in Matlab/Simulink. The simulation results show that MOPBC is not only better than the other traditional balancing control strategies but also reduces the energy loss in the balancing process.

  13. A numerical method with properties of consistency in the energy domain for a class of dissipative nonlinear wave equations with applications to a Dirichlet boundary-value problem

    CERN Document Server

    Macías-Díaz, J E; 10.1002/zamm.200700172

    2011-01-01

    In this work, we present a conditionally stable finite-difference scheme that consistently approximates the solution of a general class of (3+1)-dimensional nonlinear equations that generalizes in various ways the quantitative model governing discrete arrays consisting of coupled harmonic oscillators. Associated with this method, there exists a discrete scheme of energy that consistently approximates its continuous counterpart. The method has the properties that the associated rate of change of the discrete energy consistently approximates its continuous counterpart, and it approximates both a fully continuous medium and a spatially discretized system. Conditional stability of the numerical technique is established, and applications are provided to the existence of the process of nonlinear supratransmission in generalized Klein-Gordon systems and the propagation of binary signals in semi-unbounded, three-dimensional arrays of harmonic oscillators coupled through springs and perturbed harmonically at the bound...

  14. 7 CFR 920.13 - Pack.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Pack. 920.13 Section 920.13 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE KIWIFRUIT GROWN IN CALIFORNIA...

  15. Computational Modelling of Particle Packing in Concrete

    NARCIS (Netherlands)

    He, H.

    2010-01-01

    Physical particle packing is becoming a hot topic in concrete technology as more and more types of granular materials are used in concrete either for ecological or for engineering purposes. Although various analytical methods have been developed for optimum mixture design, comprehensive information

  16. Bacteriological Survey of AFD (Meat Packing Plant

    Directory of Open Access Journals (Sweden)

    T. N. Rawal

    1974-04-01

    Full Text Available The paper describes the manufacturing process of freeze dried mutton from slaughtering to packing and makes an assessment of microbial build-up on equipment, hands of workers and environment in which the mutton comes in contact during processing.

  17. A Set Packing Inspired Method for Real-Time Junction Train Routing

    DEFF Research Database (Denmark)

    Lusby, Richard Martin; Larsen, Jesper; Ehrgott, Matthias

    . In this paper we describe a set packing inspired formulation of this problem and develop a branch-and-price based solution approach. A real life test instance arising in Germany and supplied by the major German railway company, Deutsche Bahn, indicates the efficiency of the proposed approach by confirming...

  18. A set packing inspired method for real-time junction train routing

    DEFF Research Database (Denmark)

    Lusby, Richard Martin; Larsen, Jesper; Ehrgott, Matthias

    2013-01-01

    . In this paper we describe a set packing inspired formulation of this problem and develop a branch-and-price based solution approach. A real life test instance arising in Germany and supplied by the major German railway company, Deutsche Bahn, indicates the efficiency of the proposed approach by confirming...

  19. The P.E.A.C.E. Pack: A Computerized Online Assessment of School Bullying

    Science.gov (United States)

    Slee, Phillip T.; Mohyla, Jury

    2014-01-01

    School bullying is an international problem with harmful outcomes for those involved. This study describes the design and field testing of an innovative computer-based social learning tool for assessing student perceptions of bullying developed for an Australian intervention program called the P.E.A.C.E. Pack. Students rate their peer group…

  20. Word classes

    DEFF Research Database (Denmark)

    Rijkhoff, Jan

    2007-01-01

    This article provides an overview of recent literature and research on word classes, focusing in particular on typological approaches to word classification. The cross-linguistic classification of word class systems (or parts-of-speech systems) presented in this article is based on statements found...... – Adverb, because they have properties that are strongly associated with at least two of these four traditional word classes (e.g. Adjective and Adverb). Finally, this article discusses some of the ways in which word class distinctions interact with other grammatical domains, such as syntax and morphology....

  1. 普通高校体育课堂管理学生问题行为研究%Research on the Management of Student Problems Behavior in PE Class of Ordinary Universities

    Institute of Scientific and Technical Information of China (English)

    臧彤

    2012-01-01

    Using paper documents, questionnaire survey, expert interviews, statistics, logical analysis and so on methods to understand the class Management situation of ordinary universities, the results showed that: student problem behavior could be divided into antagonistic behavior, disruptive behavior, inconspicuous behavior, blindly rebellious behavior, resist the behavior, etc. Main classroom Management strategies remained in class direct criticism, mildly criticized in class and after- school education.%采用文献资料法、问卷调查法、专家访谈法、数理统计法等研究方法了解山东省普通高校教师课堂管理现状,研究结果显示:学生问题行为主要可分为对抗性行为、扰乱秩序行为、惹人注意行为、盲目逆反行为、抗拒行为等。大部分的课堂管理策略基本保持在课上直接批评、课上婉转批评和课后教育方面。

  2. An unusual case of duodenal perforation caused by a blister pack: A case report and literature review

    OpenAIRE

    Si-Yuan Yao; Yugo Matsui; Souichi Shiotsu

    2015-01-01

    Introduction: Ingestion of foreign bodies is a relatively common clinical problem. Blister packs have been known to be a causative agent of gastrointestinal perforation. We report a rare case of duodenal perforation caused by a blister pack, which was complicated by retroperitoneal abscess and having a poor outcome. Presentation of case: A 72 year-old man with a history of dementia presented to the emergency department with a 2-day history of backache. Upon radiological findings, perforate...

  3. 大学英语听说课自主学习的现状与对策%The Problems and Suggestions of the Autonomy Learning in the Listening and Speaking Class of College English

    Institute of Scientific and Technical Information of China (English)

    向云

    2015-01-01

    近年来,大学英语听说课在网络环境下进行了全新的教学模式变革,其信息化、个性化、自主化的学习平台得到了广大师生的赞评,但在教学实践过程中也凸显出不少问题。本文在分析和探讨相关问题的基础上提出关于大学英语听说课教学的几点建议。%Nowadays, the listening and speaking class of college English has been reformed in the teaching mode based on Internet circumstances. This total new mode with its large amounts of information, individual and autonomous feature is popular among teachers and students. But there exists several problems in teaching practice. Therefore, the author makes suggestions on the teach⁃ing practice of listening and speaking class by analyzing and discussing their problems.

  4. On generalized entropy solutions of the Cauchy problem for a first-order quasilinear equation in the class of locally summable functions

    Energy Technology Data Exchange (ETDEWEB)

    Panov, E Yu [Novgorod State University, Novgorod (Russian Federation)

    2002-12-31

    We construct a theory of locally summable generalized entropy solutions (g.e. solutions) of the Cauchy problem for a first-order non-homogeneous quasilinear equation with continuous flux vector satisfying a linear restriction on its growth. We prove the existence of greatest and least g.e. solutions, suggest sufficient conditions for uniqueness of g.e. solutions, prove several versions of the comparison principle, and obtain estimates for the L{sup p}-norms of solution with respect to the space variables. We establish the uniqueness of g.e. solutions in the case when the input data are periodic functions of the space variables.

  5. Mass transfer characteristics in a rotating packed bed with split packing

    Institute of Scientific and Technical Information of China (English)

    Youzhi Liu; Deyin Gu; Chengcheng Xu; Guisheng Qi; Weizhou Jiao

    2015-01-01

    The rotating packed bed (RPB) with split packing is a novel gas–liquid contactor, which intensifies the mass transfer processes controlled by gas-side resistance. To assess its efficacy, the mass transfer characteristics with adjacent rings in counter-rotation and co-rotation modes in a split packing RPB were studied experimentally. The physical absorption system NH3–H2O was used for characterizing the gas volumetric mass transfer coeffi-cient (kyae) and the effective interfacial area (ae) was determined by chemical absorption in the CO2–NaOH sys-tem. The variation in kyae and ae with the operating conditions is also investigated. The experimental results indicated that kyae and ae for counter-rotation of the adjacent packing rings in the split packing RPB were higher than those for co-rotation, and both counter-rotation and co-rotation of the split packing RPB were superior over conventional RPBs under the similar operating conditions.

  6. Dimensions of a class of high-dimensional homogeneous Moran sets and Moran classes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A class of high-dimensional homogeneous Moran sets and Moran classes are introduced and some dimensional properties are studied. The Hausdorff dimension, modified lower box-counting dimension, lower and upper box-counting dimension, and packing dimension of high-dimensional homogeneous and partial homogeneous Cantor sets are determined. Moreover, a kind of fractal E is obtained, which is not regular but with the property Dimw(Ed)=dDimw(E), where w denotes any of the dimensions mentioned above.

  7. The L(2,1)-labeling Problem on Several Classes of Graphs%关于几类图的L(2,1)标号问题

    Institute of Scientific and Technical Information of China (English)

    邵振东; 刘家壮

    2004-01-01

    An L(2,1) labeling of a graph G is a function f from the vertex set V(G) to the set of all nonnegative integers such that | f(x) - f(y)|≥ 2 ifd(x,y) = 1 and |f(x) - f(y) |≥ 1 if d(x,y) = 2. The L(2,1)- labeling number λ(G) of G is the smallest number k such that G has an L(2,1)-labeling with max{ f(v): v ∈ V(G)) = k. Griggs and Yeh conjecture thatλ(G) ≤△2 for any simple graph with maximum degree△. In this paper, we derive the upper bounds of λ(G) of Kneser graph,Mycielski graph,Descartes graph, Halin graph, and prove that the conjecture is true for the above several classes of graphs.%图G的L(2,1)标号是一个从顶点集V(G)到非负整数集的函数f(x),使得若d(x,y)=1,则 |f(x)-f(y)|≥2;若d(x,y)=2,则 |f(x)-f(y)|≥1.图G的L(2,1)-标号数λ(G)是使得G有max{f(v):v∈V(G)}=k的L(2,1)标号中的最小数k.Griggs和Yeh猜想对最大度为△的一般图G,有λ(G)≤△2.本文给出了Kneser图,Mycieklski图,Descartes图,Halin图的λ值的上界,并证明了上述猜想对以上几类图成立.

  8. Аsymptotic solution of a class thermoelasticity nonclassical boundary value problems for the package of an orthotropic plate of variable thickness

    Directory of Open Access Journals (Sweden)

    Aghalovyan M.L.

    2014-03-01

    Full Text Available We solve the non-classical boundary value problem for an orthotropic packet when on one of its front surface the corresponding components of the stress tensor are equal to zero and sets the value of the displacement vector. The task, in particular, is modeling the behavior of the lithospheric plates of the Earth, or a specific region of the earth's crust subject to tectonic movements of the fixed seismic stations, GPS and other measuring instruments. On the basis of three-dimensional equations of thermo-elasticity asymptotic method derived recurrence equations allow for a package of orthotropic layers of varying thickness. We derive recursive formulas for determining the components of the stress tensor and the displacement vector.

  9. Two Bandwidth Packing Algorithms for the Centralized Wireless Network and Their Average-case Analysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents a detail analysis of two bandwidth packing algorithms, used for processing connection requests in the centralized wireless network. Each call comes with a specific bandwidth request. A request can be satisfied only if there is sufficient bandwidth available during resource scheduling and allocation. Unsatisfied requests were held in a queue. The metric of bandwidth utilization ratio was used to quantify the performance of our algorithms. By theoretical analysis, our algorithms can improve the average bandwidth usage ratio significantly,about 8%~ 10% without adding much computation complexity. Moreover, our algorithms outperform next fit with fragmentation (NFF) algorithm when the bandwidth resource is scarce. In this paper, the contributions follows: Introducing bandwidth packing problem into wireless network; Proposing two new bandwidth packing algorithms for wireless network where the complicate scheduling algorithms are prohibited; Studying the average performance of our algorithms mathematically, which agree well with the simulation results.

  10. 29 CFR 784.135 - “Packing.”

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false âPacking.â 784.135 Section 784.135 Labor Regulations... First Processing, Canning, Or Packing of Marine Products Under Section 13(a)(5) § 784.135 “Packing.” The packing of the various named marine products at sea as an incident to, or in conjunction with, the...

  11. Helix-packing motifs in membrane proteins.

    Science.gov (United States)

    Walters, R F S; DeGrado, W F

    2006-09-12

    The fold of a helical membrane protein is largely determined by interactions between membrane-imbedded helices. To elucidate recurring helix-helix interaction motifs, we dissected the crystallographic structures of membrane proteins into a library of interacting helical pairs. The pairs were clustered according to their three-dimensional similarity (rmsd universe of common transmembrane helix-pairing motifs is relatively simple. The largest cluster, which comprises 29% of the library members, consists of an antiparallel motif with left-handed packing angles, and it is frequently stabilized by packing of small side chains occurring every seven residues in the sequence. Right-handed parallel and antiparallel structures show a similar tendency to segregate small residues to the helix-helix interface but spaced at four-residue intervals. Position-specific sequence propensities were derived for the most populated motifs. These structural and sequential motifs should be quite useful for the design and structural prediction of membrane proteins.

  12. Pattern Generation by Bubble Packing Method

    Directory of Open Access Journals (Sweden)

    Goel V.K.

    2013-06-01

    Full Text Available This paper presents a new computational method forornamental Pattern design. The work is a concerted effort ofevaluation of various methods and the comparatively betterprocess is used for designing keeping in mind the accuracyrequirement for such Indian traditional ethnic designs. The firststep in the process to apply the CAD tools to design the patterns.Small semantics (profile are made using the mathematicalmodelling to make different pattern. Geometric constraints suchas scaling, rotation, transformation etc. are applied to make andmodify the profiles. To create patterns, obtains node locationsthrough a physically based particle simulation, which we call'bubble packing. Bubbles are closely packed on the corners,edges and on the surface domain, and nodes are placed at thecenters of the bubbles. Experimental results show that ourmethod can create high quality ornamental patterns. Thefabrication of the ornaments is on rapid prototype machine.

  13. Is incest common in gray wolf packs?

    Science.gov (United States)

    Smith, D.; Meier, T.; Geffen, E.; Mech, L.D.; Burch, J.W.; Adams, L.G.; Wayne, R.K.

    1997-01-01

    Wolf packs generally consist of a breeding pair and their maturing offspring that help provision and protect pack young. Because the reproductive tenure in wolves often is short, reproductively mature offspring might replace their parents, resulting in sibling or parent-offspring matings. To determine the extent of incestuous pairings, we measure relatedness based on variability in 20 microsatellite loci of mated pairs, parent-offspring pairs and siblings in two populations of gray wolves. Our 16 sampled mated pairs had values of relatedness not overlapping those of known parent-offspring or sibling dyads, which is consistent with their being unrelated or distantly related. These results suggest that full siblings or a parent and their offspring rarely mate and that incest avoidance is an important constraint on gray wolf behavioral ecology.

  14. Packing and Disorder in Substituted Fullerenes

    KAUST Repository

    Tummala, Naga Rajesh

    2016-07-15

    Fullerenes are ubiquitous as electron-acceptor and electron-transport materials in organic solar cells. Recent synthetic strategies to improve the solubility and electronic characteristics of these molecules have translated into a tremendous increase in the variety of derivatives employed in these applications. Here, we use molecular dynamics (MD) simulations to examine the impact of going from mono-adducts to bis- and tris-adducts on the structural, cohesive, and packing characteristics of [6,6]-phenyl-C60-butyric acid methyl ester (PCBM) and indene-C60. The packing configurations obtained at the MD level then serve as input for density functional theory calculations that examine the solid-state energetic disorder (distribution of site energies) as a function of chemical substitution. The variations in structural and site-energy disorders reflect the fundamental materials differences among the derivatives and impact the performance of these materials in thin-film electronic devices.

  15. The close-packed triple helix as a possible new structural motif for collagen

    CERN Document Server

    Bohr, Jakob

    2010-01-01

    The one-dimensional problem of selecting the triple helix with the highest volume fraction is solved and hence the condition for a helix to be close-packed is obtained. The close-packed triple helix is shown to have a pitch angle of $v_{CP} =43.3 ^\\circ$. Contrary to the conventional notion, we suggest that close packing form the underlying principle behind the structure of collagen, and the implications of this suggestion are considered. Further, it is shown that the unique zero-twist structure with no strain-twist coupling is practically identical to the close-packed triple helix. Some of the difficulties for the current understanding of the structure of collagen are reviewed: The ambiguity in assigning crystal structures for collagen-like peptides, and the failure to satisfactorily calculate circular dichroism spectra. Further, the proposed new geometrical structure for collagen is better packed than both the 10/3 and the 7/2 structure. A feature of the suggested collagen structure is the existence of a ce...

  16. CoolPack – Simulation tools for refrigeration systems

    DEFF Research Database (Denmark)

    Jakobsen, Arne; Rasmussen, Bjarne D.; Andersen, Simon Engedal

    1999-01-01

    CoolPack is a collection of programs used for energy analysis and optimisation of refrigeration systems. CoolPack is developed at the Department of Energy Engineering at the Technical University of Denmark. The Danish Energy Agency finances the project. CoolPack is freeware and can be downloaded...

  17. 48 CFR 552.211-75 - Preservation, Packaging and Packing.

    Science.gov (United States)

    2010-10-01

    ... and Packing. 552.211-75 Section 552.211-75 Federal Acquisition Regulations System GENERAL SERVICES....211-75 Preservation, Packaging and Packing. As prescribed in 511.204(b)(2), insert the following clause: Preservation, Packaging, and Packing (FEB 1996) Unless otherwise specified, all items shall...

  18. 27 CFR 24.255 - Bottling or packing wine.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bottling or packing wine..., DEPARTMENT OF THE TREASURY LIQUORS WINE Storage, Treatment and Finishing of Wine Bottling, Packing, and Labeling of Wine § 24.255 Bottling or packing wine. (a) General. Proprietors of a bonded wine premises...

  19. 7 CFR 319.37-9 - Approved packing material.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Approved packing material. 319.37-9 Section 319.37-9..., and Other Plant Products 1,2 § 319.37-9 Approved packing material. Any restricted article at the time of importation or offer for importation into the United States shall not be packed in a...

  20. 48 CFR 211.272 - Alternate preservation, packaging, and packing.

    Science.gov (United States)

    2010-10-01

    ..., packaging, and packing. 211.272 Section 211.272 Federal Acquisition Regulations System DEFENSE ACQUISITION... Requirements Documents 211.272 Alternate preservation, packaging, and packing. Use the provision at 252.211-7004, Alternate Preservation, Packaging, and Packing, in solicitations which include...

  1. 75 FR 31283 - Clarification of Parachute Packing Authorization

    Science.gov (United States)

    2010-06-03

    ... Federal Aviation Administration 14 CFR Part 65 RIN 2120-AJ08 Clarification of Parachute Packing...) was expressly limited to packing a main parachute of a dual-parachute system for personal use...'' situations, parachute packing must be accomplished by or overseen by an appropriate current...

  2. 48 CFR 452.247-73 - Packing for Overseas Shipment.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Packing for Overseas Shipment. 452.247-73 Section 452.247-73 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE... Packing for Overseas Shipment. As prescribed in 447.305-10(c), insert the following clause: Packing...

  3. 48 CFR 452.247-72 - Packing for Domestic Shipment.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Packing for Domestic Shipment. 452.247-72 Section 452.247-72 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE... Packing for Domestic Shipment. As prescribed in 447.305-10(b), insert the following clause: Packing...

  4. 7 CFR 51.2927 - Marking and packing requirements.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Marking and packing requirements. 51.2927 Section 51... STANDARDS) United States Standards for Grades of Apricots Marking and Packing Requirements § 51.2927 Marking and packing requirements. The minimum size or numerical count of the apricots in any package shall...

  5. 48 CFR 852.214-73 - Alternate packaging and packing.

    Science.gov (United States)

    2010-10-01

    ... packing. 852.214-73 Section 852.214-73 Federal Acquisition Regulations System DEPARTMENT OF VETERANS....214-73 Alternate packaging and packing. As prescribed in 814.201-6(b)(3), insert the following provision: Alternate Packaging and Packing (JAN 2008) The bidder's offer must clearly indicate the...

  6. 48 CFR 552.211-77 - Packing List.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Packing List. 552.211-77... FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of Provisions and Clauses 552.211-77 Packing List. As prescribed in 511.204(c), insert the following clause: Packing List (FEB 1996) (a) A...

  7. 36 CFR 1002.16 - Horses and pack animals.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Horses and pack animals. 1002... AND RECREATION § 1002.16 Horses and pack animals. The following are prohibited: (a) The use of animals other than those designated as “pack animals” for purposes of transporting equipment. (b) The use...

  8. 36 CFR 34.10 - Saddle and pack animals.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Saddle and pack animals. 34... INTERIOR EL PORTAL ADMINISTRATIVE SITE REGULATIONS § 34.10 Saddle and pack animals. The use of saddle and pack animals is prohibited without a permit from the Superintendent....

  9. 36 CFR 2.16 - Horses and pack animals.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Horses and pack animals. 2.16... RESOURCE PROTECTION, PUBLIC USE AND RECREATION § 2.16 Horses and pack animals. The following are prohibited: (a) The use of animals other than those designated as “pack animals” for purposes of...

  10. 普通高校军事理论课教育问题初探%The Ordinary University Military Theory Class Education Problems

    Institute of Scientific and Technical Information of China (English)

    王大洋

    2015-01-01

    军事理论教育是国防教育的关键环节,当今社会正处于发展、变革的关键期,国际形势瞬息万变,作为国家发展、社会进步的关键力量,当代大学生们身负建设祖国的历史重任.国家发展进程中,国防事业又是最重要的环节之一,因此大学生必须掌握一定的国防知识,树立热爱祖国、保卫祖国的意识,坚定为祖国国防事业奉献终身的信念.军事理论课的开展有利于增强大学生的国防意识和国防行为能力;有利于培养大学生爱国主义精神和提高综合素质;有利于强化大学生的集体主义观念和组织纪律性,为中国人民解放军训练后备力量和培养预备役军官打下坚实的基础.%Military theory education of university students is a key link in the process of national defense education, today's society is in a great development and change of critical period, the international situation is changing, as the key part of the national development and social progress, construction of contemporary college students with the his-torical task of the motherland. In the process of national development, national defense is one of the most important link, as a proud of university students must master a certain defense consciousness, sets up the love the mother-land, the consciousness of defending the motherland, contribution for China's national defense lifelong faith. The development of military theory class, which is beneficial to strengthen college students' consciousness of national de-fense and national defense behavior ability, to improve college students' patriotism spirit and comprehensive quality, to strengthen college students' concept of collectivism and organizational discipline, and for training reserve person-nel and training of the Chinese people's liberation army reserve officers to lay a solid foundation.

  11. Sensory Analysis of Stored Tray Pack Foods

    Science.gov (United States)

    1989-12-01

    Milk chocolate brown. ODOR: Sweet, typical of heat processed milk cocoa . FLAVOR: Sweet, full milk cocoa flavor. TEXTURE: Smooth, medium thick...7B DEGREES 100 DEGREES 6. DESSERTS Chocolate Pudding There was no significant finding with this Tray Pack item. Marble Cake At 70°F, the effect...and 6 months. The main effect of temperature on acceptability of this item was not significant. Chocolate Cake At 70°F, there was a significant

  12. Flaming Pear Creative Pack1.0

    Institute of Scientific and Technical Information of China (English)

    Kane

    2003-01-01

    Flaming Pear是个一直给我留下深刻印象的软件开发公司。我以前评论过很多这个公司的插件,每一次都是不错的经历。同样的优良传统同样体现在Flaming Pear的新品Creative Pack1.0

  13. A Controlled New Process of Pack Aluminization

    Institute of Scientific and Technical Information of China (English)

    HUANG Zhi-rong; MA Liu-bao; LI Pei-ning; XU Hong

    2004-01-01

    Aluminum diffusion coatings are often prepared by a pack aluminization technique, which is a specific variety of chemical vapor deposition (CVD) method. The coating process takes place in a bed containing a mixed powder that serves as a source of the coatings forming element. The phase composition of the diffusion layer obtained depends on the activity of the Al during the pack aluminization processing. In this work, the proportion of Al to special additive powder in the pack and the treatment temperature are adjusted to achieve the desired surface composition of aluminized layer. The aluminized 20 plain carbon steel and HK40 austenitic steel were investigated by optical microscopy (OM) , X-ray diffraction (XRD)and microsclerometer. The results showed that the desired FeAl, Fe3Al and NiAl were respectively formed on the 20 plain carbon steel and HK40 austenitic steel, and the aluminides FeAl3, Fe2Al5 or Ni2Al3, NiAl3 could be inhibited.

  14. A Controlled New Process of Pack Aluminization

    Institute of Scientific and Technical Information of China (English)

    HUANGZhi-rong; MALiu-bao; LIPei-ning; XUHong

    2004-01-01

    Aluminum diffusion coatings are often prepared by a pack aluminization technique, which is a specific variety of chemical vapor deposition (CVD) method. The coating process takes place in a bed containing a mixed powder that serves as a source of the coatings forming element. The phase composition of the diffusion layer obtained depends on the activity of the Al during the pack aluminization processing. In this work, the proportion of Al to special additive powder in the pack and the treatment temperature are adjusted to achieve the desired surface composition of aluminized layer. The aluminized 20 plain carbon steel and HK40 austenitic steel were investigated by optical microscopy (OM) , X-ray diffraction (XRD) and microsclerometer. The results showed that the desired FeAl, Fe3Al and NiAl were respectively formed on the 20 plain carbon steel and HK40 austenitic steel, and the aluminides FeAl3, Fe2Al5 or Ni2Al3, NiAl3 could be inhibited.

  15. 一类带约束动态多目标优化问题的进化算法%Evolutionary algorithm for class of constrained dynamic multi-objective optimization problems

    Institute of Scientific and Technical Information of China (English)

    杨亚强; 刘淳安

    2012-01-01

    Dynamic multi-objective constrained optimization problem is a kind of NP-hard problem. The rank and the scalar constraint violation of the individual for evolution population under the dynamic environments are defined. Based on the two definitions, a new selection operator is presented. Based on an environment changing operator, a new dynamic constrained multi-objective optimization evolutionary algorithm, which is used to solve a class of constrained dynamic multi-objective optimization problems in which the environment variable is defined on the positive integer set, is given. The proposed algorithm has been tested on two constrained dynamic multi-objective optimization benchmark problems. The results obtained have been compared with the other algorithm. Simulations demonstrate the new algorithm can obtain good quality and uniformed distribution solution set in different environments for constrained dynamic multi-objective optimization problems.%动态多目标约束优化问题是一类NP-Hard问题,定义了动态环境下进化种群中个体的序值和个体的约束度,结合这两个定义给出了一种选择算子.在一种环境变化判断算子下给出了求解环境变量取值于正整数集Z+的一类带约束动态多目标优化问题的进化算法.通过几个典型的Benchmark函数对算法的性能进行了测试,其结果表明新算法能够较好地求出带约束动态多目标优化问题在不同环境下质量较好、分布较均匀的Pareto最优解集.

  16. The mechanical behaviour of packed particulates

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, R

    1998-01-01

    Within the Canadian Nuclear Fuel Waste Management program, the central concept is to package used fuel in containers that would be deposited in an underground vault in a plutonic rock formation. To provide internal mechanical support for the container, the reference design specifies it to be filled with a matrix of compacted particulate material (called 'packed particulate'), such as quartz sand granules. The focus of this report is on the mechanical properties of the packed-particulate material, based on information drawn from the extant literature. We first consider the packing density of particulate matrices to minimize the remnant porosity and maximize mechanical stability under conditions of external pressure. Practical methods, involving vibratory packing, are reviewed and recommendations made to select techniques to achieve optimum packing density. The behaviour of particulates under compressive loading has been of interest to the powder metallurgy industry (i.e., the manufacture of products from pressed/sintered metal and ceramic powders) since the early decades of this century. We review the evidence showing that in short timescales, stress induced compaction occurs by particle shuffling and rearrangement, elastic distortion, plastic yielding and microfracturing. Analytical expressions are available to describe these processes in a semiquantitative fashion. Time-dependent compaction, mainly via creep mechanisms, is more complex. Much of the theoretical and experimental information is confined to higher temperatures (> 500 degrees C), where deformation rates are more rapid. Thus, for the relatively low ambient temperatures of the waste container ({approx}100 degrees C), we require analytical techniques to extrapolate the collective particulate creep behaviour. This is largely accomplished by employing current theories of creep deformation, particularly in the form of Deformation Mechanism Maps, which allow estimation of creep rates over a wide

  17. Constellation choosing based on multi-dimensional sphere packing technique

    Science.gov (United States)

    Jinghe, Li; Guijun, Hu; Kashero, Enock; Zhaoxi, Li

    2016-09-01

    In this paper we address the sphere packing lattice points selection problem being used as constellation points in high-dimensional modulation. We propose a new type of points selection method based on threshold theory. Theoretically, this method improves the transmission performance of high-dimensional signal modulation systems. We find that the BER of a 4D modulation signal using the threshold value points selection method reduces. We also compared random and distant points selection methods in a BER of 10-3 and obtained a reduced SNR of about 2 db. At a 10-3 BER, a 8D modulation signal with points selected using the threshold selection methods obtained a reduced SNR of about 3 db. At a 10-3 BER, a 16D modulation signal with points selected using the threshold selection methods obtained a reduced SNR of about 3.5 db.

  18. Highly efficient capillary columns packed with superficially porous particles via sequential column packing.

    Science.gov (United States)

    Treadway, James W; Wyndham, Kevin D; Jorgenson, James W

    2015-11-27

    Highly efficient capillary columns packed with superficially porous particles were created for use in ultrahigh pressure liquid chromatography. Superficially porous particles around 1.5μm in diameter were packed into fused silica capillary columns with 30, 50, and 75μm internal diameters. To create the columns, several capillary columns were serially packed from the same slurry, with packing progress plots being generated to follow the packing of each column. Characterization of these columns using hydroquinone yielded calculated minimum reduced plate heights as low as 1.24 for the most efficient 30μm internal diameter column, corresponding to over 500,000plates/m. At least one highly efficient column (minimum reduced plate height less than 2) was created for all three of the investigated column inner diameters, with the smallest diameter columns having the highest efficiency. This study proves that highly efficient capillary columns can be created using superficially porous particles and shows the efficiency potential of these particles.

  19. Class size versus class composition

    DEFF Research Database (Denmark)

    Jones, Sam

    Raising schooling quality in low-income countries is a pressing challenge. Substantial research has considered the impact of cutting class sizes on skills acquisition. Considerably less attention has been given to the extent to which peer effects, which refer to class composition, also may affect...... bias from omitted variables, the preferred IV results indicate considerable negative effects due to larger class sizes and larger numbers of overage-for-grade peers. The latter, driven by the highly prevalent practices of grade repetition and academic redshirting, should be considered an important...

  20. The Paradox of Paperless Classes.

    Science.gov (United States)

    Lackie, Paula

    1998-01-01

    Describes paperless classes developed at Carleton College that augment traditional classes by giving students and faculty the ability to share digital course-related materials via the campus computer network. Presents a case study of a managerial economics course, and includes problems with various aspects of the course and solutions. (LRW)