McKone, Thomas E.; Deshpande, Ashok W.
2004-06-14
In modeling complex environmental problems, we often fail to make precise statements about inputs and outcome. In this case the fuzzy logic method native to the human mind provides a useful way to get at these problems. Fuzzy logic represents a significant change in both the approach to and outcome of environmental evaluations. Risk assessment is currently based on the implicit premise that probability theory provides the necessary and sufficient tools for dealing with uncertainty and variability. The key advantage of fuzzy methods is the way they reflect the human mind in its remarkable ability to store and process information which is consistently imprecise, uncertain, and resistant to classification. Our case study illustrates the ability of fuzzy logic to integrate statistical measurements with imprecise health goals. But we submit that fuzzy logic and probability theory are complementary and not competitive. In the world of soft computing, fuzzy logic has been widely used and has often been the ''smart'' behind smart machines. But it will require more effort and case studies to establish its niche in risk assessment or other types of impact assessment. Although we often hear complaints about ''bright lines,'' could we adapt to a system that relaxes these lines to fuzzy gradations? Would decision makers and the public accept expressions of water or air quality goals in linguistic terms with computed degrees of certainty? Resistance is likely. In many regions, such as the US and European Union, it is likely that both decision makers and members of the public are more comfortable with our current system in which government agencies avoid confronting uncertainties by setting guidelines that are crisp and often fail to communicate uncertainty. But some day perhaps a more comprehensive approach that includes exposure surveys, toxicological data, epidemiological studies coupled with fuzzy modeling will go a long way in
Algorithmic Problem Complexity
Burgin, Mark
2008-01-01
People solve different problems and know that some of them are simple, some are complex and some insoluble. The main goal of this work is to develop a mathematical theory of algorithmic complexity for problems. This theory is aimed at determination of computer abilities in solving different problems and estimation of resources that computers need to do this. Here we build the part of this theory related to static measures of algorithms. At first, we consider problems for finite words and stud...
Bringing real-world problems into the classroom
Enserink, B.; De Haan, A.R.C.; Hermans, L.M.
2012-01-01
Real world problems are a challenge and a motivator for students to learn understanding and using the concepts of systems and actors. But using real world problems in the classroom is not without challenges and dilemmas. In the paper we explicitly address the issue of the need for quite intense supp
Bringing a Bayesian Perspective to Large Dimensional Problems in Geophysics
Duputel, Z.; Simons, M.; Jolivet, R.; Zaroli, C.; Rivera, L. A.; Ampuero, J. P.; Gombert, B.; Minson, S. E.
2015-12-01
The last decade has seen a substantial expansion of geophysical observations. Exploiting this wealth of data involves large ill-conditioned inverse problems requiring large numbers of uncertain parameters. A common approach in geophysics is to use some form of regularization that transforms the inversion into a well-conditioned optimization problem. While this approach is convenient and computationally inexpensive, the inherent non-uniqueness of our problems suggest that we should not simply search for a single optimal model, but rather attempt to describe the ensemble of plausible models that can fit the data and are consistent with prior information. This talk will present various applications of full Bayesian analysis techniques to large ill-posed inverse problems in geophysics. Despite significant computational cost, Bayesian sampling is a powerful tool to combine prior information, theoretical knowledge and data in order to address scientific problems probabilistically. We shall illustrate this by showing recent results for two types of problems: (1) the study of earthquakes sources and (2) imaging of the Earth interior. In particular, we will present different strategies that can be employed in order to achieve realistic uncertainty estimates.
PROBLEMS OF BRINGING OF FOREIGN CAPITAL IN THE UKRAINES BANKING SYSTEM
Rozhko, O.
2009-01-01
The problems and prospects of growth of bringing in foreign capital in the domestic banking system are examined in the article. The basic groups of risks, inherent development of the banking system in the conditions of activation of the foreign investing, are determined.
Problem Complexity Research from Energy Perspective
Feng, Pan; Jie, Qi
2013-01-01
Computational complexity is a particularly important objective. The idea of Landauer principle was extended through mapping three classic problems (sorting,ordered searching and max of N unordered numbers) into Maxwell demon thought experiment in this paper. The problems'complexity is defined on the entropy basis and the minimum energy required to solve them are rigorous deduced from the perspective of energy (entropy) and the second law of thermodynamics. Then the theoretical energy consumed by real program and basic operators of classical computer are both analyzed, the time complexity lower bounds of three problems'all possible algorithms are derived in this way. The lower bound is also deduced for the two n*n matrix multiplication problem. In the end, the reason why reversible computation is impossible and the possibility of super-linear energy consumption capacity which may be the power behind quantum computation are discussed, a conjecture is proposed which may prove NP!=P. The study will bring fresh an...
Problem Solving and Complex Systems
Guinand, Frédéric
2008-01-01
The observation and modeling of natural Complex Systems (CSs) like the human nervous system, the evolution or the weather, allows the definition of special abilities and models reusable to solve other problems. For instance, Genetic Algorithms or Ant Colony Optimizations are inspired from natural CSs to solve optimization problems. This paper proposes the use of ant-based systems to solve various problems with a non assessing approach. This means that solutions to some problem are not evaluated. They appear as resultant structures from the activity of the system. Problems are modeled with graphs and such structures are observed directly on these graphs. Problems of Multiple Sequences Alignment and Natural Language Processing are addressed with this approach.
Complex analogues of real problems
Esdahl-Schou, Rune
. Using geometrical interpretations we construct sets with properties similar to the sets considered in the real case. We then formulate a conjecture which can be interpreted as a complex version of Schmidt's original conjecture. Finally we construct a variant of Schmidt's game, to show a partial result......This thesis will be a mix of different problems in number theory. As such it is split into two natural parts. The rst part focuses on normal numbers and construction of numbers that are normal to a given complex base. It is written in the style of a thorough and introductory paper on that subject......, Pollington and Velani, and inspired by this An gave a different proof which provides a stronger result. The conjecture is concerned with intersections of certain sets in the plane and are as such a real problem. We will consider a slightly different setup where the real plane is replaced by the complex plane...
SCHOOL VIOLENCE: A COMPLEX PROBLEM
María del Rosario Ayala-Carrillo
2015-07-01
Full Text Available School violence is one type of violence that reflects the breakdown of current society. It is impossible to speak of school violence as an isolated phenomenon without establishing nexuses between public and private life, between collective and individual behaviors, between family and community aspects, without making reference to differences in gender and the life stories of those who are the aggressors or the victims, and without considering the patriarchal culture and interpersonal relationships. When all these factor are interrelated, they make the problem of violence a very complex one that requires us to know the different factors in order to understand it and deal with it.
Solving complex problems a handbook
Schönwandt, Walter; Grunau, Jens; Utz, Jürgen; Voermanek, Katrin
2014-01-01
When you're planning something big, problems appear rather quickly. We hear of them on a daily basis. The bigger or more complex a task, the more we have to deal with complicated, multidisciplinary task formulations. In many cases it is architecture, including urban and spatial planning, but also politics and all types of organizational forms, irrespective of whether they are public authorities or private enterprises, which are expected to deliver functional solutions for such challenges. This is precisely where this book is helpful. It introduces a methodology for developing target-specific,
Bring Your Own Device : Analys av trenden, dess möjligheter och problem
Bohman, Emma; Murphy, Joanna
2012-01-01
Syftet med denna studie är att få en grundläggande kunskap kring begreppet bring your own device. Eftersom ämnet är väldigt nytt och att det finns en viss okunnighet kring begreppet är det intressant att ta reda på varför BYOD är en uppgående trend, hur svenska verksamheter tänker inför tillåtandet, vilka krav som ställs och vilka problem som följer. För att komma fram till dessa slutsatser har intervjuer genomförts på tre olika verksamheter. Varav en verksamhet har tagit sig an BYOD och de a...
Solving complex fisheries management problems
Petter Johnsen, Jahn; Eliasen, Søren Qvist
2011-01-01
A crucial issue for the new EU common fisheries policy is how to solve the discard problem. Through a study of the institutional set up and the arrangements for solving the discard problem in Denmark, the Faroe Islands, Iceland and Norway, the article identifies the discard problem as related to...
Twelve Problems in Proof Complexity
Pudlák, Pavel
Berlin : Springer, 2008 - (Hirsch, E.; Razborov, A.; Semenov, A.; Slissenko, A.), s. 11-27 ISBN 978-3-540-79708-1. [International Computer Science Symposium in Russia, CSR 2008/3./. Moskva (RU), 07.06.2008-12.06.2008] R&D Projects: GA AV ČR IAA1019401 Institutional research plan: CEZ:AV0Z10190503 Keywords : computational complexity * bounded arithmetic * propositional calculus Subject RIV: BA - General Mathematics
Complex problem solving: a case for complex cognition?
Funke, Joachim
2010-01-01
Complex problem solving (CPS) emerged in the last 30 years in Europe as a new part of the psychology of thinking and problem solving. This paper introduces into the field and provides a personal view. Also, related concepts like macrocognition or operative intelligence will be explained in this context. Two examples for the assessment of CPS, Tailorshop and MicroDYN, are presented to illustrate the concept by means of their measurement devices. Also, the relation of complex cognition and emot...
The Complexity of Rooted Phylogeny Problems
Bodirsky, Manuel
2011-01-01
Several computational problems in phylogenetic reconstruction can be formulated as restrictions of the following general problem: given a formula in conjunctive normal form where the literals are rooted triples, is there a rooted binary tree that satisfies the formula? If the formulas do not contain disjunctions, the problem becomes the famous rooted triple consistency problem, which can be solved in polynomial time by an algorithm of Aho, Sagiv, Szymanski, and Ullman. If the clauses in the formulas are restricted to disjunctions of negated triples, Ng, Steel, and Wormald showed that the problem remains NP-complete. We systematically study the computational complexity of the problem for all such restrictions of the clauses in the input formula. For certain restricted disjunctions of triples we present an algorithm that has sub-quadratic running time and is asymptotically as fast as the fastest known algorithm for the rooted triple consistency problem. We also show that any restriction of the general rooted ph...
Quantum complexity of graph and algebraic problems
Doern, Sebastian
2008-02-04
This thesis is organized as follows: In Chapter 2 we give some basic notations, definitions and facts from linear algebra, graph theory, group theory and quantum computation. In Chapter 3 we describe three important methods for the construction of quantum algorithms. We present the quantum search algorithm by Grover, the quantum amplitude amplification and the quantum walk search technique by Magniez et al. These three tools are the basis for the development of our new quantum algorithms for graph and algebra problems. In Chapter 4 we present two tools for proving quantum query lower bounds. We present the quantum adversary method by Ambainis and the polynomial method introduced by Beals et al. The quantum adversary tool is very useful to prove good lower bounds for many graph and algebra problems. The part of the thesis containing the original results is organized in two parts. In the first part we consider the graph problems. In Chapter 5 we give a short summary of known quantum graph algorithms. In Chapter 6 to 8 we study the complexity of our new algorithms for matching problems, graph traversal and independent set problems on quantum computers. In the second part of our thesis we present new quantum algorithms for algebraic problems. In Chapter 9 to 10 we consider group testing problems and prove quantum complexity bounds for important problems from linear algebra. (orig.)
Quantum complexity of graph and algebraic problems
This thesis is organized as follows: In Chapter 2 we give some basic notations, definitions and facts from linear algebra, graph theory, group theory and quantum computation. In Chapter 3 we describe three important methods for the construction of quantum algorithms. We present the quantum search algorithm by Grover, the quantum amplitude amplification and the quantum walk search technique by Magniez et al. These three tools are the basis for the development of our new quantum algorithms for graph and algebra problems. In Chapter 4 we present two tools for proving quantum query lower bounds. We present the quantum adversary method by Ambainis and the polynomial method introduced by Beals et al. The quantum adversary tool is very useful to prove good lower bounds for many graph and algebra problems. The part of the thesis containing the original results is organized in two parts. In the first part we consider the graph problems. In Chapter 5 we give a short summary of known quantum graph algorithms. In Chapter 6 to 8 we study the complexity of our new algorithms for matching problems, graph traversal and independent set problems on quantum computers. In the second part of our thesis we present new quantum algorithms for algebraic problems. In Chapter 9 to 10 we consider group testing problems and prove quantum complexity bounds for important problems from linear algebra. (orig.)
Solving complex problems: Human identification and control of complex systems
Funke, Joachim
1991-01-01
Studying complex problem solving by means of computer-simulated scenarios has become one of the favorite themes of modern theorists in German-speaking countries who are concerned with the psychology of thinking. Following the pioneering work of Dietrich Doerner (University of Bamberg, FRG) in the mid-70s, many new scenarios have been developed and applied in correlational as well as in experimental studies (for a review see Funke, 1988). Instead of studying problem-solving behavior in restric...
Olga V. Shipulina
2013-01-01
Full Text Available The study explores how students, who had completed the AP calculus course, mathematized the optimal navigation real-life problem simulated in the Second Life Virtual Environment. The particular research interest was to investigate whether/how students’ empirical activity in VE influences the way of their mathematizing.
Gol'din, Pavel; Steeman, Mette Elstrup
2015-01-01
Miocene baleen whales were highly diverse and included tens of genera. However, their taxonomy and phylogeny, as well as relationships with living whales, are still a subject of controversy. Here, "Mesocetus" argillarius, a poorly known specimen from Denmark, is redescribed with a focus on the cranial anatomy. It was found to represent not only a new genus, Tranatocetus gen. nov., but also a new family; Tranatocetidae. The whales of this family have the rostral bones either overriding or dividing the frontals; the rostral bones are contacting the parietals and nasals dividing the maxillae on the vertex; the occipital shield is dorsoventrally bent. The tympanic bulla is particularly characteristic of this family featuring a short, narrow anterior portion with a rounded or squared anterior end and a wider and higher posterior portion that is swollen in the posteroventral area. A phylogenetic analysis including 51 taxa supports a monophyletic group comprising most Neogene and modern whales, with Tranatocetidae being possibly closer related to Balaenopteridae (rorquals) than to Cetotheriidae. Tranatocetidae exhibit a charahteristic bulla shape. In fact, all Neogene and modern mysticete families examined have a unique shape of the tympanic bulla that is diagnostic at family-level. Inclusion of problematic taxa like Tranatocetus argillarius in phylogenies brings new understanding of the distribution and diagnostic value of character traits. This underlines the need for re-examination of earlier described specimens in the light of the wealth of new information published in later years. PMID:26331471
Pavel Gol'din
Full Text Available Miocene baleen whales were highly diverse and included tens of genera. However, their taxonomy and phylogeny, as well as relationships with living whales, are still a subject of controversy. Here, "Mesocetus" argillarius, a poorly known specimen from Denmark, is redescribed with a focus on the cranial anatomy. It was found to represent not only a new genus, Tranatocetus gen. nov., but also a new family; Tranatocetidae. The whales of this family have the rostral bones either overriding or dividing the frontals; the rostral bones are contacting the parietals and nasals dividing the maxillae on the vertex; the occipital shield is dorsoventrally bent. The tympanic bulla is particularly characteristic of this family featuring a short, narrow anterior portion with a rounded or squared anterior end and a wider and higher posterior portion that is swollen in the posteroventral area. A phylogenetic analysis including 51 taxa supports a monophyletic group comprising most Neogene and modern whales, with Tranatocetidae being possibly closer related to Balaenopteridae (rorquals than to Cetotheriidae. Tranatocetidae exhibit a charahteristic bulla shape. In fact, all Neogene and modern mysticete families examined have a unique shape of the tympanic bulla that is diagnostic at family-level. Inclusion of problematic taxa like Tranatocetus argillarius in phylogenies brings new understanding of the distribution and diagnostic value of character traits. This underlines the need for re-examination of earlier described specimens in the light of the wealth of new information published in later years.
Problem based learning - 'Bringing everything together' - A strategy for Graduate Nurse Programs.
Vittrup, Ann-Charlotte; Davey, Anna
2010-03-01
This article discusses a case study that was initiated by a Graduate Nurse Coordinator of an acute care inpatient hospital in Australia. It outlines the conceptualisation and creative implementation of a structured group problem based learning activity which was a component of a Graduate Nurse Program. The learning activity was based on the beliefs that knowledge acquisition today is an active process and should focus on the learner developing strategies to obtain, review and manage information. The learning activity implemented in this case study was valuable as it recognised the benefits that can be gained for the Graduate Nurse by ensuring the context of their teaching and learning activities is grounded in practical experiences. The learning activity aimed to prepare Graduate Nurses to cope with the multiple challenges faced as they enter the nursing profession by enhancing their skills of inquiry, problem solving and reasoning. The evaluation of this case study found that the incorporation of structured group problem based learning did promote the achievement of these educational outcomes with Graduate Nurses displaying critical thinking, clinical judgment and knowledge acquisition skills. An unexpected benefit of this activity for Graduate Nurses was the enhancement of clinical practice behaviours, such as communication and interactive skills. This case study describes the positive outcomes not only for Graduates Nurses in the application of their learning but also the wider benefits which can be gained for the organisation, patient care standards and the health care team. It is anticipated that this article will be an inspiration to others who are interested in implementing innovative teaching strategies into Graduate Nurse Programs. PMID:19501549
Nature and Validity of Complex Problem Solving
Wüstenberg, Sascha
2013-01-01
This thesis investigates the nature and validity of complex problem solving (CPS). The main focus lies on analyses of three research questions dealing with CPS’ (1) internal structure, its (2) structural stability combined with comparisons of performance differences across groups, and its (3) construct validity. In previous research, results on CPS’ (1) internal factor structure have been solely based on samples with high cognitive performance, (2) structural stability of CPS across groups ha...
Modelling problems in complex systems dynamics
The research deals with different aspects of mathematical modelling and the analysis of complex dynamic non-linear systems as a consequence of applied problems in mechanics (in particular those for gyrosystems, for stabilization and orientation systems, control systems of movable objects, including the aviation and aerospace systems) Non-linearity, multi-connectedness and high dimensionness of dynamical problems, that occur at the initial full statement lead to the need of the problem narrowing, and of the decomposition of the full model, but with safe-keeping of main properties and of qualitative equivalence. The elaboration of regular methods for modelling problems in dynamics, the generalization of reduction principle are the main aims of the investigations. Here, uniform methodology, based on Lyapunov's methods, founded by N.G.Ohetayev, is developed. The objects of the investigations are considered with exclusive positions, as systems of singularly perturbed class, treated as ones with singular parametrical perturbations. It is the natural extension of the statements of N.G.Chetayev and P.A.Kuzmin for parametrical stability. In paper the systematical procedures for construction of correct simplified models (comparison ones) are developed, the validity conditions of the transition are determined the appraisals are received, the regular algorithms of engineering level are obtained. Applicabilitelly to the stabilization and orientation systems with the gyroscopic controlling subsystems, these methods enable to build the hierarchical sequence of admissible simplified models; to determine the conditions of their correctness
Dependability problems of complex information systems
Zamojski, Wojciech
2014-01-01
This monograph presents original research results on selected problems of dependability in contemporary Complex Information Systems (CIS). The ten chapters are concentrated around the following three aspects: methods for modelling of the system and its components, tasks ? or in more generic and more adequate interpretation, functionalities ? accomplished by the system and conditions for their correct realization in the dynamic operational environment. While the main focus is on theoretical advances and roadmaps for implementations of new technologies, a?much needed forum for sharing of the bes
Estimating uncertainties in complex joint inverse problems
Afonso, Juan Carlos
2016-04-01
Sources of uncertainty affecting geophysical inversions can be classified either as reflective (i.e. the practitioner is aware of her/his ignorance) or non-reflective (i.e. the practitioner does not know that she/he does not know!). Although we should be always conscious of the latter, the former are the ones that, in principle, can be estimated either empirically (by making measurements or collecting data) or subjectively (based on the experience of the researchers). For complex parameter estimation problems in geophysics, subjective estimation of uncertainty is the most common type. In this context, probabilistic (aka Bayesian) methods are commonly claimed to offer a natural and realistic platform from which to estimate model uncertainties. This is because in the Bayesian approach, errors (whatever their nature) can be naturally included as part of the global statistical model, the solution of which represents the actual solution to the inverse problem. However, although we agree that probabilistic inversion methods are the most powerful tool for uncertainty estimation, the common claim that they produce "realistic" or "representative" uncertainties is not always justified. Typically, ALL UNCERTAINTY ESTIMATES ARE MODEL DEPENDENT, and therefore, besides a thorough characterization of experimental uncertainties, particular care must be paid to the uncertainty arising from model errors and input uncertainties. We recall here two quotes by G. Box and M. Gunzburger, respectively, of special significance for inversion practitioners and for this session: "…all models are wrong, but some are useful" and "computational results are believed by no one, except the person who wrote the code". In this presentation I will discuss and present examples of some problems associated with the estimation and quantification of uncertainties in complex multi-observable probabilistic inversions, and how to address them. Although the emphasis will be on sources of uncertainty related
The Guarding Problem - Complexity and Approximation
Reddy, T. V. Thirumala; Krishna, D. Sai; Rangan, C. Pandu
Let G = (V, E) be the given graph and G R = (V R ,E R ) and G C = (V C ,E C ) be the sub graphs of G such that V R ∩ V C = ∅ and V R ∪ V C = V. G C is referred to as the cops region and G R is called as the robber region. Initially a robber is placed at some vertex of V R and the cops are placed at some vertices of V C . The robber and cops may move from their current vertices to one of their neighbours. While a cop can move only within the cops region, the robber may move to any neighbour. The robber and cops move alternatively. A vertex v ∈ V C is said to be attacked if the current turn is the robber's turn, the robber is at vertex u where u ∈ V R , (u,v) ∈ E and no cop is present at v. The guarding problem is to find the minimum number of cops required to guard the graph G C from the robber's attack. We first prove that the decision version of this problem when G R is an arbitrary undirected graph is PSPACE-hard. We also prove that the complexity of the decision version of the guarding problem when G R is a wheel graph is NP-hard. We then present approximation algorithms if G R is a star graph, a clique and a wheel graph with approximation ratios H(n 1), 2 H(n 1) and left( H(n1) + 3/2 right) respectively, where H(n1) = 1 + 1/2 + ... + 1/n1 and n 1 = ∣ V R ∣.
Solving Complex Problems: A Convergent Approach to Cognitive Load Measurement
Zheng, Robert; Cook, Anne
2012-01-01
The study challenged the current practices in cognitive load measurement involving complex problem solving by manipulating the presence of pictures in multiple rule-based problem-solving situations and examining the cognitive load resulting from both off-line and online measures associated with complex problem solving. Forty-eight participants…
Team-Based Complex Problem Solving: A Collective Cognition Perspective
Hung, Woei
2013-01-01
Today, much problem solving is performed by teams, rather than individuals. The complexity of these problems has exceeded the cognitive capacity of any individual and requires a team of members to solve them. The success of solving these complex problems not only relies on individual team members who possess different but complementary expertise,…
Complexity of valued constraint satisfaction problems
Živný, Stanislav
2012-01-01
The topic of this book is the following optimisation problem: given a set of discrete variables and a set of functions, each depending on a subset of the variables, minimise the sum of the functions over all variables. This fundamental research problem has been studied within several different contexts of discrete mathematics, computer science and artificial intelligence under different names: Min-Sum problems, MAP inference in Markov random fields (MRFs) and conditional random fields (CRFs), Gibbs energy minimisation, valued constraint satisfaction problems (VCSPs), and, for two-state variabl
Managing Complex Problems in Rangeland Ecosystems
Management of rangelands, and natural resources in general, has become increasingly complex. There is an atmosphere of increasing expectations for conservation efforts associated with a variety of issues from water quality to endangered species. We argue that many current issues are complex by their...
Modelling and simulation of complex geotechnical problems
Blaheta, Radim
Liberec : Technical University of Liberec, 2008, s. 20-24. ISBN 978-80-7372-298-2. [SNA '08 - Seminar on numerical analysis: modelling and simulation of challenging engineering problems. Liberec (CZ), 28.01.2008-01.02.2008] Grant ostatní: GA AV ČR(CZ) 1ET400300415 Institutional research plan: CEZ:AV0Z30860518 Keywords : geotechnics * challenging problems * parallel computing Subject RIV: BA - General Mathematics
Enhanced Bee Colony Algorithm for Complex Optimization Problems
S.Suriya; R. Deepalakshmi; S.Suresh kannan; Dr.S.P.SHANTHARAJAH
2012-01-01
Optimization problems are considered to be one kind of NP hard problems. Usually heuristic approaches are found to provide solutions for NP hard problems. There are a plenty of heuristic algorithmsavailable to solve optimization problems namely: Ant Colony Optimization, Particle Swarm Optimization, Bee Colony Optimization, etc. The basic Bee Colony algorithm, a population based search algorithm, is analyzed to be a novel tool for complex optimization problems. The algorithm mimics the food fo...
Automatic Algorithm Selection for Complex Simulation Problems
Ewald, Roland
2012-01-01
To select the most suitable simulation algorithm for a given task is often difficult. This is due to intricate interactions between model features, implementation details, and runtime environment, which may strongly affect the overall performance. An automated selection of simulation algorithms supports users in setting up simulation experiments without demanding expert knowledge on simulation. Roland Ewald analyzes and discusses existing approaches to solve the algorithm selection problem in the context of simulation. He introduces a framework for automatic simulation algorithm selection and
Analyzing the many skills involved in solving complex physics problems
Adams, Wendy K.; Wieman, Carl E.
2015-05-01
We have empirically identified over 40 distinct sub-skills that affect a person's ability to solve complex problems in many different contexts. The identification of so many sub-skills explains why it has been so difficult to teach or assess problem solving as a single skill. The existence of these sub-skills is supported by several studies comparing a wide range of individuals' strengths and weaknesses in these sub-skills, their "problem solving fingerprint," while solving different types of problems including a classical mechanics problem, quantum mechanics problems, and a complex trip-planning problem with no physics. We see clear differences in the problem solving fingerprint of physics and engineering majors compared to the elementary education majors that we tested. The implications of these findings for guiding the teaching and assessing of problem solving in physics instruction are discussed.
SAT is a problem with exponential complexity measured by negentropy
Pan, Feng(Department of Physics, Liaoning Normal University, Dalian 116029, China)
2014-01-01
In this paper the reason why entropy reduction (negentropy) can be used to measure the complexity of any computation was first elaborated both in the aspect of mathematics and informational physics. In the same time the equivalence of computation and information was clearly stated. Then the complexities of three specific problems: logical compare, sorting and SAT, were analyzed and measured. The result showed SAT was a problem with exponential complexity which naturally leads to the conclusio...
Solving Complex Problems to Create Charter Extension Options
Tippmann, Esther; Nell, Phillip Christopher
solution search, or activities to reconcile the need for some solution features to be locally-tailored while others can be internationally standardized, mediates the relationships between problem complexity/headquarters involvement and the capacity to create advanced solutions. An analysis of 67 projects......This study examines subsidiary-driven problem solving processes and their potential to create advanced solutions for charter extension options. Problem solving theory suggests that biases in problem formulation and solution search can confine problem solving potential. We thus argue that balanced...
Structuring and assessing large and complex decision problems using MCDA
Barfod, Michael Bruhn
This paper presents an approach for the structuring and assessing of large and complex decision problems using multi-criteria decision analysis (MCDA). The MCDA problem is structured in a decision tree and assessed using the REMBRANDT technique featuring a procedure for limiting the number of pair...
Solomon, Olga; Heritage, John; Yin, Larry; Maynard, Douglas W.; Bauman, Margaret L.
2016-01-01
Conversation and discourse analyses were used to examine medical problem presentation in pediatric care. Healthcare visits involving children with ASD and typically developing children were analyzed. We examined how children's communicative and epistemic capabilities, and their opportunities to be socialized into a competent patient role are…
New complex variable meshless method for advection-diffusion problems
Wang Jian-Fei; Cheng Yu-Min
2013-01-01
In this paper,an improved complex variable meshless method (ICVMM) for two-dimensional advection-diffusion problems is developed based on improved complex variable moving least-square (ICVMLS) approximation.The equivalent functional of two-dimensional advection-diffusion problems is formed,the variation method is used to obtain the equation system,and the penalty method is employed to impose the essential boundary conditions.The difference method for two-point boundary value problems is used to obtain the discrete equations.Then the corresponding formulas of the ICVMM for advection-diffusion problems are presented.Two numerical examples with different node distributions are used to validate and investigate the accuracy and efficiency of the new method in this paper.It is shown that ICVMM is very effective for advection-diffusion problems,and has a good convergent character,accuracy,and computational efficiency.
Enhanced Bee Colony Algorithm for Complex Optimization Problems
S.Suriya
2012-01-01
Full Text Available Optimization problems are considered to be one kind of NP hard problems. Usually heuristic approaches are found to provide solutions for NP hard problems. There are a plenty of heuristic algorithmsavailable to solve optimization problems namely: Ant Colony Optimization, Particle Swarm Optimization, Bee Colony Optimization, etc. The basic Bee Colony algorithm, a population based search algorithm, is analyzed to be a novel tool for complex optimization problems. The algorithm mimics the food foraging behavior of swarmsof honey bees. This paper deals with a modified fitness function of Bee Colony algorithm. The effect of problem dimensionality on the performance of the algorithms will be investigated. This enhanced Bee Colony Optimization will be evaluated based on the well-known benchmark problems. The testing functions like Rastrigin, Rosenbrock, Ackley, Griewank and Sphere are used to evaluavate the performance of the enhanced Bee Colony algorithm. The simulation will be developed on MATLAB.
Complexity of Some Problems Concerning 2CNF Formulas
Hans; Kleine; Büning
2003-01-01
In this paper we investigate the complexity of several problems concerning 2CNF formulas. At first, we show that the minimal unsatisfiability problem for 2CNF formulas can be solved in linear time. Then we prove that the problem determining if a 2CNF formula can be transformed to a minimal unsatisfiable formula is also solvable in linear time. Thirdly, we show the polynomial solvability of the satisfiability problem for symmetric monotone formulas in which all clauses has length 2 or ? n - k ( n is the ...
Semantic Annotation of Complex Text Structures in Problem Reports
Malin, Jane T.; Throop, David R.; Fleming, Land D.
2011-01-01
Text analysis is important for effective information retrieval from databases where the critical information is embedded in text fields. Aerospace safety depends on effective retrieval of relevant and related problem reports for the purpose of trend analysis. The complex text syntax in problem descriptions has limited statistical text mining of problem reports. The presentation describes an intelligent tagging approach that applies syntactic and then semantic analysis to overcome this problem. The tags identify types of problems and equipment that are embedded in the text descriptions. The power of these tags is illustrated in a faceted searching and browsing interface for problem report trending that combines automatically generated tags with database code fields and temporal information.
A complex variable meshless method for fracture problems
CHENG; Yumin; LI; Jiuhong
2006-01-01
Based on the moving least-square (MLS) approximation, the complex variable moving least-square approximation (CVMLS) is discussed in this paper. The complex variable moving least-square approximation cannot form ill-conditioned equations, and has greater precision and computational efficiency. Using the analytical solution near the tip of a crack, the trial functions in the complex variable moving least-square approxi- mation are extended, and the corresponding approximation function is obtained. And from the minimum potential energy principle, a complex variable meshless method for fracture problems is presented, and the formulae of the complex variable meshless method are obtained. The complex variable meshless method in this paper has greater precision and computational efficiency than the conventional meshless method. Some examples are given.
Particle swarm as optimization tool in complex nuclear engineering problems
Due to its low computational cost, gradient-based search techniques associated to linear programming techniques are being used as optimization tools. These techniques, however, when applied to multimodal search spaces, can lead to local optima. When finding solutions for complex multimodal domains, random search techniques are being used with great efficacy. In this work we exploit the swarm optimization algorithm search power capacity as an optimization tool for the solution of complex high dimension and multimodal search spaces of nuclear problems. Due to its easy and natural representation of high dimension domains, the particle swarm optimization was applied with success for the solution of complex nuclear problems showing its efficacy in the search of solutions in high dimension and complex multimodal spaces. In one of these applications it enabled a natural and trivial solution in a way not obtained with other methods confirming the validity of its application. (author)
Information-related complexity: a problem-oriented approach
Perevalov, Eugene
2013-01-01
A general notion of information-related complexity applicable to both natural and man-made systems is proposed. The overall approach is to explicitly consider a rational agent performing a certain task with a quantifiable degree of success. The complexity is defined as the minimum (quasi-)quantity of information that's necessary to complete the task to the given extent -- measured by the corresponding loss. The complexity so defined is shown to generalize the existing notion of statistical complexity when the system in question can be described by a discrete-time stochastic process. The proposed definition also applies, in particular, to optimization and decision making problems under uncertainty in which case it gives the agent a useful measure of the problem's "susceptibility" to additional information and allows for an estimation of the potential value of the latter.
On the Complexity of the Asymmetric VPN Problem
Rothvoß, Thomas; Sanità, Laura
2009-01-01
We give the first constant factor approximation algorithm for the asymmetric Virtual Private Network (VPN) problem with arbitrary concave costs. We even show the stronger result, that there is always a tree solution of cost at most 2 OPT and that a tree solution of (expected) cost at most 49.84 OPT can be determined in polynomial time. Furthermore, we answer an outstanding open question about the complexity status of the so called balanced VPN problem by proving its NP-hardn...
Particle swarm optimization for complex nonlinear optimization problems
Alexandridis, Alex; Famelis, Ioannis Th.; Tsitouras, Charalambos
2016-06-01
This work presents the application of a technique belonging to evolutionary computation, namely particle swarm optimization (PSO), to complex nonlinear optimization problems. To be more specific, a PSO optimizer is setup and applied to the derivation of Runge-Kutta pairs for the numerical solution of initial value problems. The effect of critical PSO operational parameters on the performance of the proposed scheme is thoroughly investigated.
EEG activity during the performance of complex mental problems.
Jausovec, N; Jausovec, K
2000-04-01
This study investigated differences in cognitive processes related to problem complexity. It was assumed that these differences would be reflected in respondents' EEG activity--spectral power and coherence. A second issue of the study was to compare differences between the lower (alpha(1) = 7.9-10.0 Hz), and upper alpha band (alpha(2) = 10.1-12.9 Hz). In the first experiment two well-defined problems with two levels of complexity were used. Only minor differences in EEG power and coherence measures related to problem complexity were observed. In the second experiment divergent production problems resembling tasks on creativity tests were compared with dialectic problems calling for creative solutions. Differences in EEG power measures were mainly related to the form of problem presentation (figural/verbal). In contrast, coherence was related to the level of creativity needed to solve a problem. Noticeable increased intra- and interhemispheric cooperation between mainly the far distant brain regions was observed in the EEG activity of respondents while solving the dialectic problems. These results are explained by the more intense involvement of the long cortico-cortical fiber system in creative thinking. Differences between the lower and upper alpha band were significant for the power and coherence measures. In Experiment 2, fewer differences were observed in power measures in the upper alpha band than in the lower alpha band. A reverse pattern was observed for the coherence measures. These results hint to a functional independence of the two alpha bands, however, they do not allow to draw firm conclusions about their functional meanings. The study showed that it is unlikely that individuals solve well- and ill-defined problems by employing similar cognitive strategies. PMID:10700625
Complexity and Approximation of the Fuzzy K-Means Problem
Blömer, Johannes; Brauer, Sascha; Bujna, Kathrin
2015-01-01
The fuzzy $K$-means problem is a generalization of the classical $K$-means problem to soft clusterings, i.e. clusterings where each points belongs to each cluster to some degree. Although popular in practice, prior to this work the fuzzy $K$-means problem has not been studied from a complexity theoretic or algorithmic perspective. We show that optimal solutions for fuzzy $K$-means cannot, in general, be expressed by radicals over the input points. Surprisingly, this already holds for very sim...
The Parameterized Complexity of some Permutation Group Problems
Arvind, Vikraman
2013-01-01
In this paper we study the parameterized complexity of two well-known permutation group problems which are NP-complete. 1. Given a permutation group G=, subgroup of $S_n$, and a parameter $k$, find a permutation $\\pi$ in G such that $|{i\\in [n]\\mid \\pi(i)\
What Do Employers Pay for Employees' Complex Problem Solving Skills?
Ederer, Peer; Nedelkoska, Ljubica; Patt, Alexander; Castellazzi, Silvia
2015-01-01
We estimate the market value that employers assign to the complex problem solving (CPS) skills of their employees, using individual-level Mincer-style wage regressions. For the purpose of the study, we collected new and unique data using psychometric measures of CPS and an extensive background questionnaire on employees' personal and work history.…
Approximate Counting for Complex-Weighted Boolean Constraint Satisfaction Problems
Yamakami, Tomoyuki
2010-01-01
Constraint satisfaction problems (or CSPs) have been extensively studied in AI, database theory, graph theory, etc. From an approximation viewpoint, it has been important to approximate the total number of assignments that satisfy all given Boolean constraints. There is a trichotomy theorem for such approximate counting for (non-weighted) Boolean CSPs; namely, all such counting problems are neatly classified into three categories under polynomial-time approximation-preserving reductions [Dyer, Goldberg, and Jerrum, 2010]. We extend this result to approximate counting for complex-weighted Boolean CSPs, provided that all arity-1 constraints are freely available to use. This makes a significant progress in the quest for the approximation classification of all counting Boolean CSPs in the most general form. To deal with complex weights, we employ proof techniques along the line of solving Holant problems [Valiant, 2002, 2008]. Our result also gives an approximation version of the dichotomy theorem of the complexi...
The Complex Route to Success: Complex Problem-Solving Skills in the Prediction of University Success
Stadler, Matthias J.; Becker, Nicolas; Greiff, Samuel; Spinath, Frank M.
2016-01-01
Successful completion of a university degree is a complex matter. Based on considerations regarding the demands of acquiring a university degree, the aim of this paper was to investigate the utility of complex problem-solving (CPS) skills in the prediction of objective and subjective university success (SUS). The key finding of this study was that…
Radio interferometric gain calibration as a complex optimization problem
Smirnov, Oleg
2015-01-01
Recent developments in optimization theory have extended some traditional algorithms for least-squares optimization of real-valued functions (Gauss-Newton, Levenberg-Marquardt, etc.) into the domain of complex functions of a complex variable. This employs a formalism called the Wirtinger derivative, and derives a full-complex Jacobian counterpart to the conventional real Jacobian. We apply these developments to the problem of radio interferometric gain calibration, and show how the general complex Jacobian formalism, when combined with conventional optimization approaches, yields a whole new family of calibration algorithms, including those for the polarized and direction-dependent gain regime. We further extend the Wirtinger calculus to an operator-based matrix calculus for describing the polarized calibration regime. Using approximate matrix inversion results in computationally efficient implementations; we show that some recently proposed calibration algorithms such as StefCal and peeling can be understood...
Complex network problems in physics, computer science and biology
Cojocaru, Radu Ionut
There is a close relation between physics and mathematics and the exchange of ideas between these two sciences are well established. However until few years ago there was no such a close relation between physics and computer science. Even more, only recently biologists started to use methods and tools from statistical physics in order to study the behavior of complex system. In this thesis we concentrate on applying and analyzing several methods borrowed from computer science to biology and also we use methods from statistical physics in solving hard problems from computer science. In recent years physicists have been interested in studying the behavior of complex networks. Physics is an experimental science in which theoretical predictions are compared to experiments. In this definition, the term prediction plays a very important role: although the system is complex, it is still possible to get predictions for its behavior, but these predictions are of a probabilistic nature. Spin glasses, lattice gases or the Potts model are a few examples of complex systems in physics. Spin glasses and many frustrated antiferromagnets map exactly to computer science problems in the NP-hard class defined in Chapter 1. In Chapter 1 we discuss a common result from artificial intelligence (AI) which shows that there are some problems which are NP-complete, with the implication that these problems are difficult to solve. We introduce a few well known hard problems from computer science (Satisfiability, Coloring, Vertex Cover together with Maximum Independent Set and Number Partitioning) and then discuss their mapping to problems from physics. In Chapter 2 we provide a short review of combinatorial optimization algorithms and their applications to ground state problems in disordered systems. We discuss the cavity method initially developed for studying the Sherrington-Kirkpatrick model of spin glasses. We extend this model to the study of a specific case of spin glass on the Bethe
On the Complexity of Rearrangement Problems under the Breakpoint Distance
Kovac, Jakub
2011-01-01
Tannier et al. introduced a generalization of breakpoint distance for multichromosomal genomes. They showed that the median problem under the breakpoint distance is solvable in polynomial time in the multichromosomal circular and mixed models. This is intriguing, since in all other rearrangement models (DCJ, reversal, unichromosomal or multilinear breakpoint models), the problem is NP-hard. The complexity of the small or even the large phylogeny problem under the breakpoint distance remained an open problem. We improve the algorithm for the median problem and show that it is equivalent to the problem of finding maximum cardinality non-bipartite matching (under linear reduction). On the other hand, we prove that the more general small phylogeny problem is NP-hard. Surprisingly, we show that it is already NP-hard (or even APX-hard) for 4 species (a quartet phylogeny). In other words, while finding an ancestor for 3 species is easy, already finding two ancestors for 4 species is hard. We also show that, in the u...
Data Mining and Complex Problems: Case Study in Composite Materials
Rabelo, Luis; Marin, Mario
2009-01-01
Data mining is defined as the discovery of useful, possibly unexpected, patterns and relationships in data using statistical and non-statistical techniques in order to develop schemes for decision and policy making. Data mining can be used to discover the sources and causes of problems in complex systems. In addition, data mining can support simulation strategies by finding the different constants and parameters to be used in the development of simulation models. This paper introduces a framework for data mining and its application to complex problems. To further explain some of the concepts outlined in this paper, the potential application to the NASA Shuttle Reinforced Carbon-Carbon structures and genetic programming is used as an illustration.
Measuring complex problem solving: the MicroDYN approach
Greiff, Samuel; Funke, Joachim
2009-01-01
In educational large-scale assessments such as PISA only recently an increasing interest in measuring cross-curricular competencies can be observed. These are now discovered as valuable aspects of school achievement. Complex problem solving (CPS) describes an interesting construct for the diagnostics of domain-general competencies. Here, we present MicroDYN, a new approach for computer-based assessment of CPS. We introduce the new concept, describe proper software and present first results...
Filip Kolář
Full Text Available Polyploidization is one of the leading forces in the evolution of land plants, providing opportunities for instant speciation and rapid gain of evolutionary novelties. Highly selective conditions of serpentine environments act as an important evolutionary trigger that can be involved in various speciation processes. Whereas the significance of both edaphic speciation on serpentine and polyploidy is widely acknowledged in plant evolution, the links between polyploid evolution and serpentine differentiation have not yet been examined. To fill this gap, we investigated the evolutionary history of the perennial herb Knautia arvensis (Dipsacaceae, a diploid-tetraploid complex that exhibits an intriguing pattern of eco-geographic differentiation. Using plastid DNA sequencing and AFLP genotyping of 336 previously cytotyped individuals from 40 populations from central Europe, we unravelled the patterns of genetic variation among the cytotypes and the edaphic types. Diploids showed the highest levels of genetic differentiation, likely as a result of long term persistence of several lineages in ecologically distinct refugia and/or independent immigration. Recurrent polyploidization, recorded in one serpentine island, seems to have opened new possibilities for the local serpentine genotype. Unlike diploids, the serpentine tetraploids were able to escape from the serpentine refugium and spread further; this was also attributable to hybridization with the neighbouring non-serpentine tetraploid lineages. The spatiotemporal history of K. arvensis allows tracing the interplay of polyploid evolution and ecological divergence on serpentine, resulting in a complex evolutionary pattern. Isolated serpentine outcrops can act as evolutionary capacitors, preserving distinct karyological and genetic diversity. The serpentine lineages, however, may not represent evolutionary 'dead-ends' but rather dynamic systems with a potential to further influence the surrounding
Parameterized Complexity of the k-anonymity Problem
Bonizzoni, Paola; Dondi, Riccardo; Pirola, Yuri
2009-01-01
The problem of publishing personal data without giving up privacy is becoming increasingly important. An interesting formalization that has been recently proposed is the $k$-anonymity. This approach requires that the rows of a table are partitioned in clusters of size at least $k$ and that all the rows in a cluster become the same tuple, after the suppression of some entries. The natural optimization problem, where the goal is to minimize the number of suppressed entries, is known to be APX-hard even when the records values are over a binary alphabet and $k=3$, and when the records have length at most 8 and $k=4$ . In this paper we study how the complexity of the problem is influenced by different parameters. In this paper we follow this direction of research, first showing that the problem is W[1]-hard when parameterized by the size of the solution (and the value $k$). Then we exhibit a fixed parameter algorithm, when the problem is parameterized by the size of the alphabet and the number of columns. Finally...
The Similar Structures and Control Problems of Complex Systems
无
2002-01-01
In this paper, the naturally evolving complex systems, such as biotic and social ones, are considered. Focusing on their structures, a feature is noteworthy, i.e., the similarity in structures. The relations between the functions and behaviors of these systems and their similar structures will be studied. Owing to the management of social systems and the course of evolution of biotic systems may be regarded as control processes, the researches will be within the scope of control problems. Moreover, since it is difficult to model for biotic and social systems, it will start with the control problems of complex systems, possessing similar structures, in engineering.The obtained results show that for either linear or nonlinear systems and for a lot of control problemssimilar structures lead to a series of simplifications. In general, the original system may be decomposed into reduced amount of subsystems with lower dimensions and simpler structures. By virtue of such subsystems, the control problems of original system can be solved more simply.At last, it turns round to observe the biotic and social systems and some analyses are given.
Complexity indices for the travelling salesman problem and data mining
Dragos Cvetković
2012-03-01
Full Text Available In this survey paper we extend our previous work on complexity indices for the travelling salesman problem (TSP, summarized in cite{CvCK3}, using graph spectral techniques of data mining. A complexity index is an invariant of an instance $I$ by which we can predict the execution time of an exact algorithm for TSP for $I$. We consider the symmetric travelling salesman problem with instances $I$ represented by complete graphs $G$ with distances between vertices (cities as edge weights (lengths. Intuitively, the hardness of an instance $G$ depends on the distribution of short edges within $G$. Therefore we consider some short edge subgraphs of $G$ (minimal spanning tree, critical connected subgraph, and several others as non-weighted graphs and several their invariants as potential complexity indices. Here spectral invariants (e.g. spectral radius of the adjacency matrix play an important role since, in general, there are intimate relations between eigenvalues and the structure of a graph. Since hidden details of short edge subgraphs really determine the hardness of the instance, we use techniques of data mining to find them. In particular, spectral clustering algorithms are used including information obtained from the spectral gap in Laplacian spectra of short edge subgraphs.
Application of Artificial Neural Networks to Complex Groundwater Management Problems
As water quantity and quality problems become increasingly severe, accurate prediction and effective management of scarcer water resources will become critical. In this paper, the successful application of artificial neural network (ANN) technology is described for three types of groundwater prediction and management problems. In the first example, an ANN was trained with simulation data from a physically based numerical model to predict head (groundwater elevation) at locations of interest under variable pumping and climate conditions. The ANN achieved a high degree of predictive accuracy, and its derived state-transition equations were embedded into a multiobjective optimization formulation and solved to generate a trade-off curve depicting water supply in relation to contamination risk. In the second and third examples, ANNs were developed with real-world hydrologic and climate data for different hydrogeologic environments. For the second problem, an ANN was developed using data collected for a 5-year, 8-month period to predict heads in a multilayered surficial and limestone aquifer system under variable pumping, state, and climate conditions. Using weekly stress periods, the ANN substantially outperformed a well-calibrated numerical flow model for the 71-day validation period, and provided insights into the effects of climate and pumping on water levels. For the third problem, an ANN was developed with data collected automatically over a 6-week period to predict hourly heads in 11 high-capacity public supply wells tapping a semiconfined bedrock aquifer and subject to large well-interference effects. Using hourly stress periods, the ANN accurately predicted heads for 24-hour periods in all public supply wells. These test cases demonstrate that the ANN technology can solve a variety of complex groundwater management problems and overcome many of the problems and limitations associated with traditional physically based flow models
Complex Langevin: Etiology and Diagnostics of its Main Problem
Aarts, Gert; Seiler, Erhard; Stamatescu, Ion-Olimpiu
2011-01-01
The complex Langevin method is a leading candidate for solving the so-called sign problem occurring in various physical situations. Its most vexing problem is that in some cases it produces `convergence to the wrong limit'. In the first part of the paper we go through the formal justification of the method, identify points at which it may fail and identify a necessary and sufficient criterion for correctness. This criterion would, however, require checking infinitely many identities, and therefore is somewhat academic. We propose instead a truncation to the check of a few identities; this still gives a necessary criterion, but a priori it is not clear whether it remains sufficient. In the second part we carry out a detailed study of two toy models: first we identify the reasons why in some cases the method fails, second we test the efficiency of the truncated criterion and find that it works perfectly at least in the toy models studied.
Complex Langevin: etiology and diagnostics of its main problem
Aarts, Gert; James, Frank A. [Swansea University, Department of Physics, Swansea (United Kingdom); Seiler, Erhard [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Muenchen (Germany); Stamatescu, Ion-Olimpiu [Universitaet Heidelberg and FEST, Institut fuer Theoretische Physik, Heidelberg (Germany)
2011-10-15
The complex Langevin method is a leading candidate for solving the so-called sign problem occurring in various physical situations. Its most vexing problem is that sometimes it produces 'convergence to the wrong limit'. In this paper we carefully revisit the formal justification of the method, identifying points at which it may fail and derive a necessary and sufficient criterion for correctness. This criterion is, however, not practical, since its application requires checking an infinite tower of identities. We propose instead a practical test involving only a check of the first few of those identities; this raises the question of the 'sensitivity' of the test. This sensitivity as well as the general insights into the possible reasons of failure (the etiology) are then tested in two toy models where the correct answer is known. At least in those models the test works perfectly. (orig.)
Complexity and Approximation of a Geometric Local Robot Assignment Problem
Bonorden, Olaf; Degener, Bastian; Kempkes, Barbara; Pietrzyk, Peter
We introduce a geometric multi-robot assignment problem. Robots positioned in a Euclidean space have to be assigned to treasures in such a way that their joint strength is sufficient to unearth a treasure with a given weight. The robots have a limited range and thus can only be assigned to treasures in their proximity. The objective is to unearth as many treasures as possible. We investigate the complexity of several variants of this problem and show whether they are in {mathcal P} or are mathcal{ NP}-complete. Furthermore, we provide a distributed and local constant-factor approximation algorithm using constant-factor resource augmentation for the two-dimensional setting with {mathcal O}(log^*n) communication rounds.
Overcoming Problems in the Measurement of Biological Complexity
Cebrian, Manuel; Ortega, Alfonso
2010-01-01
In a genetic algorithm, fluctuations of the entropy of a genome over time are interpreted as fluctuations of the information that the genome's organism is storing about its environment, being this reflected in more complex organisms. The computation of this entropy presents technical problems due to the small population sizes used in practice. In this work we propose and test an alternative way of measuring the entropy variation in a population by means of algorithmic information theory, where the entropy variation between two generational steps is the Kolmogorov complexity of the first step conditioned to the second one. As an example application of this technique, we report experimental differences in entropy evolution between systems in which sexual reproduction is present or absent.
Problems of development of fuel-power complex of Russia
The problems on developing the fuel-power complex (FPC) in Russia which provides for vital activities of other branches of the national economy of the country are discussed. The taxation policy of the State plays an important role in stabilization of the financial situation at the FPC enterprises. Special attention is paid to the improvement of the system for the FPC products price formation. The forecast of the FPC development in Russia for the period of 2005 to 2010 years is presented. The diagrams for the coal, natural gas and oil mining and electrical power production by two scenarios of the FPC development for 2000 up to 2010 years are also presented
2016-01-01
This book captures current trends and developments in the field of systems thinking and soft operations research which can be applied to solve today's problems of dynamic complexity and interdependency. Such ‘wicked problems’ and messes are seemingly intractable problems characterized as value-laden, ambiguous, and unstable, that resist being tamed by classical problem solving. Actions and interventions associated with this complex problem space can have highly unpredictable and unintended consequences. Examples of such complex problems include health care reform, global climate change, transnational serious and organized crime, terrorism, homeland security, human security, disaster management, and humanitarian aid. Moving towards the development of solutions to these complex problem spaces depends on the lens we use to examine them and how we frame the problem. It will be shown that systems thinking and soft operations research has had great success in contributing to the management of complexity. .
Human opinion dynamics: An inspiration to solve complex optimization problems
Kaur, Rishemjit; Kumar, Ritesh; Bhondekar, Amol P.; Kapur, Pawan
2013-10-01
Human interactions give rise to the formation of different kinds of opinions in a society. The study of formations and dynamics of opinions has been one of the most important areas in social physics. The opinion dynamics and associated social structure leads to decision making or so called opinion consensus. Opinion formation is a process of collective intelligence evolving from the integrative tendencies of social influence with the disintegrative effects of individualisation, and therefore could be exploited for developing search strategies. Here, we demonstrate that human opinion dynamics can be utilised to solve complex mathematical optimization problems. The results have been compared with a standard algorithm inspired from bird flocking behaviour and the comparison proves the efficacy of the proposed approach in general. Our investigation may open new avenues towards understanding the collective decision making.
Complex-Dynamical Approach to Cosmological Problem Solution
Kirilyuk, A P
2005-01-01
Universe structure emerges in the unreduced, complex-dynamic interaction process with the simplest initial configuration (two attracting homogeneous fields). The unreduced interaction analysis, avoiding any perturbative model, gives intrinsically creative cosmology describing the real, explicitly emerging world structure with dynamic randomness on each scale. Without imposing any postulates or additional entities, we obtain physically real, three-dimensional space, irreversibly flowing time, elementary particles with their detailed structure and intrinsic properties, causally complete and unified version of quantum and relativistic behaviour, the origin and number of naturally unified fundamental forces, classical behaviour emergence in a closed system, and true quantum chaos. Major problems of standard cosmology and astrophysics are consistently solved in this extended picture, including those of quantum cosmology and gravity, entropy growth and time arrow, "hierarchy" of elementary particles (Planckian unit...
Applied social and behavioral science to address complex health problems.
Livingood, William C; Allegrante, John P; Airhihenbuwa, Collins O; Clark, Noreen M; Windsor, Richard C; Zimmerman, Marc A; Green, Lawrence W
2011-11-01
Complex and dynamic societal factors continue to challenge the capacity of the social and behavioral sciences in preventive medicine and public health to overcome the most seemingly intractable health problems. This paper proposes a fundamental shift from a research approach that presumes to identify (from highly controlled trials) universally applicable interventions expected to be implemented "with fidelity" by practitioners, to an applied social and behavioral science approach similar to that of engineering. Such a shift would build on and complement the recent recommendations of the NIH Office of Behavioral and Social Science Research and require reformulation of the research-practice dichotomy. It would also require disciplines now engaged in preventive medicine and public health practice to develop a better understanding of systems thinking and the science of application that is sensitive to the complexity, interactivity, and unique elements of community and practice settings. Also needed is a modification of health-related education to ensure that those entering the disciplines develop instincts and capacities as applied scientists. PMID:22011425
Complexity of Decision Problems for Mixed and Modal Specifications
Antonik, Adam; Huth, Michael; Nyman, Ulrik Mathias; Larsen, Kim Guldstrand; Wasowski, Andrzej
We consider decision problems for modal and mixed transition systems used as specifications: the common implementation problem (whether a set of specifications has a common implementation), the consistency problem (whether a single specification has an implementation), and the thorough refinement...
Leppavirta, J.; Kettunen, H.; Sihvola, A.
2011-01-01
Complex multistep problem exercises are one way to enhance engineering students' learning of electromagnetics (EM). This study investigates whether exposure to complex problem exercises during an introductory EM course improves students' conceptual and procedural knowledge. The performance in complex problem exercises is compared to prior success…
Making mobility-related disability better: a complex response to a complex problem
Rockwood Kenneth
2012-10-01
Full Text Available Abstract Mobility disability in older adults can arise from single system problems, such as discrete musculoskeletal injury. In frail older adults, however, mobility disability is part of a complex web of problems. The approach to their rehabilitation must take that complexity into account, as is reported by Fairhall et al. First, their overall health state must be assessed, which is achieved by a comprehensive geriatric assessment. The assessment can show how a particular patient came to be disabled, so that an individualized care plan can be worked out. Whether this approach works in general can be evaluated by looking at group differences in mean mobility test scores. Knowing whether it has worked in the individual patient requires an individualized measure. This is because not every patient starts from the same point, and not every patient achieves success by aiming for the same goal. For one patient, walking unassisted for three metres would be a triumph; for another it would be a tragedy. Unless we understand the complexity of the needs of frail older adults, we will neither be able to treat them effectively nor evaluate our efforts sensibly. Please see related article http://www.biomedcentral.com/1741-7015/10/120
Inverse Problems in Complex Models and Applications to Earth Sciences
Bosch, M. E.
2015-12-01
The inference of the subsurface earth structure and properties requires the integration of different types of data, information and knowledge, by combined processes of analysis and synthesis. To support the process of integrating information, the regular concept of data inversion is evolving to expand its application to models with multiple inner components (properties, scales, structural parameters) that explain multiple data (geophysical survey data, well-logs, core data). The probabilistic inference methods provide the natural framework for the formulation of these problems, considering a posterior probability density function (PDF) that combines the information from a prior information PDF and the new sets of observations. To formulate the posterior PDF in the context of multiple datasets, the data likelihood functions are factorized assuming independence of uncertainties for data originating across different surveys. A realistic description of the earth medium requires modeling several properties and structural parameters, which relate to each other according to dependency and independency notions. Thus, conditional probabilities across model components also factorize. A common setting proceeds by structuring the model parameter space in hierarchical layers. A primary layer (e.g. lithology) conditions a secondary layer (e.g. physical medium properties), which conditions a third layer (e.g. geophysical data). In general, less structured relations within model components and data emerge from the analysis of other inverse problems. They can be described with flexibility via direct acyclic graphs, which are graphs that map dependency relations between the model components. Examples of inverse problems in complex models can be shown at various scales. At local scale, for example, the distribution of gas saturation is inferred from pre-stack seismic data and a calibrated rock-physics model. At regional scale, joint inversion of gravity and magnetic data is applied
Abele, John
2011-01-01
Boston Scientific founder John Abele has been party to his share of groundbreaking innovations over the years. But the revolutionary advances in medical science that these breakthroughs brought about were not the efforts of one firm alone, let alone one inventor. Abele tells two fascinating stories of collaboration--one about Jack Whitehead's upending of hospitals' blood and urine testing procedures and the other about Andreas Gruentzig's success in bringing balloon catheterization into the cardiology mainstream. Both Whitehead and Gruentzig spearheaded the emergence of entirely new fields, bringing together scientist-customers to voluntarily develop standards, training programs, new business models, and even a specialized language to describe their new field. The process of collaboration, Abete says, is fraught with contradictions and subtlety. It takes consummate leadership skills to persuade others to spend countless hours solving important problems in partnership with people they don't necessarily like. Moreover, managing egos so that each person's commitment, energy, and creativity is unleashed in a way that doesn't disadvantage others requires an impresario personality. Finally, true authenticity--something that few people can project--is critical for earning customers' trust and convincing them that their valuable contributions won't be used for anything other than moving the technology forward. PMID:21800473
An analytical approach to managing complex process problems
Ramstad, Kari; Andersen, Espen; Rohde, Hans Christian; Tydal, Trine
2006-03-15
The oil companies are continuously investing time and money to ensure optimum regularity on their production facilities. High regularity increases profitability, reduces workload on the offshore organisation and most important; - reduces discharge to air and sea. There are a number of mechanisms and tools available in order to achieve high regularity. Most of these are related to maintenance, system integrity, well operations and process conditions. However, for all of these tools, they will only be effective if quick and proper analysis of fluids and deposits are carried out. In fact, analytical backup is a powerful tool used to maintain optimised oil production, and should as such be given high priority. The present Operator (Hydro Oil and Energy) and the Chemical Supplier (MI Production Chemicals) have developed a cooperation to ensure that analytical backup is provided efficiently to the offshore installations. The Operator's Research and Development (R and D) departments and the Chemical Supplier have complementary specialties in both personnel and equipment, and this is utilized to give the best possible service when required from production technologists or operations. In order for the Operator's Research departments, Health, Safety and Environment (HSE) departments and Operations to approve analytical work performed by the Chemical Supplier, a number of analytical tests are carried out following procedures agreed by both companies. In the present paper, three field case examples of analytical cooperation for managing process problems will be presented. 1) Deposition in a Complex Platform Processing System. 2) Contaminated Production Chemicals. 3) Improved Monitoring of Scale Inhibitor, Suspended Solids and Ions. In each case the Research Centre, Operations and the Chemical Supplier have worked closely together to achieve fast solutions and Best Practice. (author) (tk)
Eye-Tracking Study of Complexity in Gas Law Problems
Tang, Hui; Pienta, Norbert
2012-01-01
This study, part of a series investigating students' use of online tools to assess problem solving, uses eye-tracking hardware and software to explore the effect of problem difficulty and cognitive processes when students solve gas law word problems. Eye movements are indices of cognition; eye-tracking data typically include the location,…
Electromagnetic waves in complex systems selected theoretical and applied problems
Velychko, Lyudmyla
2016-01-01
This book gives guidance to solve problems in electromagnetics, providing both examples of solving serious research problems as well as the original results to encourage further investigations. The book contains seven chapters on various aspects of resonant wave scattering, each solving one original problem. All of them are unified by the authors’ desire to show advantages of rigorous approaches at all stages, from the formulation of a problem and the selection of a method to the interpretation of results. The book reveals a range of problems associated with wave propagation and scattering in natural and artificial environments or with the design of antennas elements. The authors invoke both theoretical (analytical and numerical) and experimental techniques for handling the problems. Attention is given to mathematical simulations, computational efficiency, and physical interpretation of the experimental results. The book is written for students, graduate students and young researchers. .
Control problem organization in the U-70 complex control system
The technological subsystem (TS) may be considered from the viewpoint of the U-70 control system (CS) as a set of interrelated control and measurement sections. According the CS problem on servicing the technological subsystem is reduced to separate control and measurement problems, composed in form of three types of the basic problems combinations. The basic problem of each type realizes one of the functions: data measurement, data review and data control. Presently the control and measurement problems of all TS of the U-70 CS organized according to the rules, described in the report. The CS dialogue menu contains 4068 items. In spite of the great volume the work with the above menu does not cause difficulties by the users, because it adequately reflects the TS structure and the rules of its structural scheme are logical and correspond to the needs both of operational control of the accelerating facilities, and research problems, solved by means of the CS
A note on the Dirichlet problem for model complex partial differential equations
Ashyralyev, Allaberen; Karaca, Bahriye
2016-08-01
Complex model partial differential equations of arbitrary order are considered. The uniqueness of the Dirichlet problem is studied. It is proved that the Dirichlet problem for higher order of complex partial differential equations with one complex variable has infinitely many solutions.
The Interfacial Interaction Problem in Complex Multiple Porosity Fractured Reservoirs
Suarez-Arriaga, Mario-Cesar
2003-04-01
Many productive reservoirs (oil, gas, water, geothermal) are associated to natural fracturing. Fault zones and fractures act as open networks for fluid and energy flow from depth. Their petrophysical parameters are heterogeneous and randomly distributed, conforming extremely complex natural systems. Here, the simultaneous heat and mass flows are coupled to the deformation of thermoporoelastic rocks. The system's volume is divided into N interacting continua, each one occupying a region of space Vn wrapped by a surface Sn (n=1,N). The mass flow is represented by: ∂/∂t ∫ Vn ρf φdV + ∫ Sn F⃗M ṡ n⃗dS = ∫ Vn qMdV (3) Taking into account a non-isothermal process the coupled equation of energy is: ∂/∂t ∫ Vn [φρf hf + (1 - φ)ρrhr]dV + ∫ Sn F⃗E ṡ n⃗dS = ∫ Vn qEdV (4) Where t means time, φ is porosity, ρf, ρr are fluid and rock densities, F⃗M and F⃗E are total mass and energy flows, qM and qE are volumetric mass and energy extracted or injected into Vn, hf and hr are specific enthalpies for fluid and rock respectively. Rock deformation is coupled through the equation: ∇⃗ ṡ (ρf/μK ṡ ∇⃗pφ)Vn = φ (Dtρf + ρf/VφdVφ/dt)Vn (5) K is the absolute permeability tensor, μ means dynamic fluid viscosity, Dt is a total derivative, pφ is pore pressure and Vφ is the volume of pores in Vn. The N media interact with each other, every one has its own parameters and its own interporosity flow. Modelling these coupled phenomena requires to average highly contrasting physical properties, independently of the method used in the solution of equations. A lot of attention has been devoted to develop realistic numerical models to describe flows in reservoirs under exploitation. But to the best of our knowledge very little attention has been focused on the problem of interfacial interaction and averaging petrophysical parameters in multiple porosity reservoirs.
Asbestos quantification in track ballast, a complex analytical problem
Cavallo, Alessandro
2016-04-01
Track ballast forms the trackbeb upon which railroad ties are laid. It is used to bear the load from the railroad ties, to facilitate water drainage, and also to keep down vegetation. It is typically made of angular crushed stone, with a grain size between 30 and 60 mm, with good mechanical properties (high compressive strength, freeze - thaw resistance, resistance to fragmentation). The most common rock types are represented by basalts, porphyries, orthogneisses, some carbonatic rocks and "green stones" (serpentinites, prasinites, amphibolites, metagabbros). Especially "green stones" may contain traces, and sometimes appreciable amounts of asbestiform minerals (chrysotile and/or fibrous amphiboles, generally tremolite - actinolite). In Italy, the chrysotile asbestos mine in Balangero (Turin) produced over 5 Mt railroad ballast (crushed serpentinites), which was used for the railways in northern and central Italy, from 1930 up to 1990. In addition to Balangero, several other serpentinite and prasinite quarries (e.g. Emilia Romagna) provided the railways ballast up to the year 2000. The legal threshold for asbestos content in track ballast is established in 1000 ppm: if the value is below this threshold, the material can be reused, otherwise it must be disposed of as hazardous waste, with very high costs. The quantitative asbestos determination in rocks is a very complex analytical issue: although techniques like TEM-SAED and micro-Raman are very effective in the identification of asbestos minerals, a quantitative determination on bulk materials is almost impossible or really expensive and time consuming. Another problem is represented by the discrimination of asbestiform minerals (e.g. chrysotile, asbestiform amphiboles) from the common acicular - pseudo-fibrous varieties (lamellar serpentine minerals, prismatic/acicular amphiboles). In this work, more than 200 samples from the main Italian rail yards were characterized by a combined use of XRD and a special SEM
Substantiation of Resource Territories Development: Complex «Meso-Level» Problem
Valeriy Anatolievich Kryukov
2015-12-01
Full Text Available The paper presents an approach to the analysis and evaluation of integrated investment projects, which consist of infrastructure facilities and industrial clusters, allocated in poorly developed areas rich with natural resources. It shows the feasibility of a public-private partnership during the construction of infrastructure facilities in order to minimize the risks and maximize the benefits. The conceptual framework of developed approach is associated with the ideas and principles of the «impact investing» («creating shared values» and inclusive economic development. These are increasingly used in the world, especially to accelerate the socio-economic development of the backward countries and territories. The article describes an international experience and justifies the relevance of the application of these concepts to the Russian context. We revealed methodical problems associated with the applying of traditional methods to evaluate economic effects of the project investment in conditions of high uncertainty. It is necessary to use models and methods (real options analysis, fuzzy cognitive models, which allow directly to take into account uncertainty and project risks. The novelty of the article consists in methodical tools for evaluating the socio-economic efficiency of the complex projects for infrastructure development and resources development. The elaborated approach has been applied for substantiation of the road construction project in the Berezovsky district of Khanty-Mansi Autonomous Okrug. It is shown that there are opportunities to generate a complex of institutional, organizational and financial conditions, under which the implementation of the project will be attractive for investors and for the state and will bring socio-economic benefits to the territory. The proposed approach and tools can be used in the socio-economic strategic planning under the justification of infrastructure projects in the new development areas of
Some open problems in real and complex dynamical systems
Theory of dynamical systems may be split into two parts. The larger one, dealing with multidimensional systems: flows in dim 3 and higher, diffeomorphisms in dim 2 and higher, may be called the realm of chaos. The smaller one, dealing with planar differential equations, may be called the realm of order. The problems below deal with both parts. (open problem)
An adaptive finite element strategy for complex flow problems
Oden, J. T.; Strouboulis, T.; Devloo, PH.; Spradley, L. W.; Price, J.
1987-01-01
Adaptive finite element methods for steady and unsteady flow problems in two-dimensional domains are described. Details of a data management scheme are given that provide for the rapid implementation of various CFD algorithms on changing unstructured meshes. The results of several numerical experiments on subsonic and supersonic flow problems are discussed.
de Leeuw, L.
Sixty-four fifth and sixth-grade pupils were taught number series extrapolation by either an algorithm, fully prescribed problem-solving method or a heuristic, less prescribed method. The trained problems were within categories of two degrees of complexity. There were 16 subjects in each cell of the 2 by 2 design used. Aptitude Treatment…
The Fallacy of Univariate Solutions to Complex Systems Problems.
Lessov-Schlaggar, Christina N; Rubin, Joshua B; Schlaggar, Bradley L
2016-01-01
Complex biological systems, by definition, are composed of multiple components that interact non-linearly. The human brain constitutes, arguably, the most complex biological system known. Yet most investigation of the brain and its function is carried out using assumptions appropriate for simple systems-univariate design and linear statistical approaches. This heuristic must change before we can hope to discover and test interventions to improve the lives of individuals with complex disorders of brain development and function. Indeed, a movement away from simplistic models of biological systems will benefit essentially all domains of biology and medicine. The present brief essay lays the foundation for this argument. PMID:27375425
Variational Problem with Complex Coefficient of a Nonlinear Schrödinger Equation
Nigar Yildirim Aksoy; Bunyamin Yildiz; Hakan Yetiskin
2012-08-01
An optimal control problem governed by a nonlinear Schrödinger equation with complex coefficient is investigated. The paper studies existence, uniqueness and optimality conditions for the control problem.
Problems of empathy. Difficulties of emotive understanding and social complexity.
Maurizio Fabbri
2007-01-01
The Author analyses certain problems concerning the transformation of styles in educational experience. Refering also to neuroscientific studies, more radical model of empaty, that enable the interpretation of historical change, are proposed.
Problems of empathy. Difficulties of emotive understanding and social complexity.
Maurizio Fabbri
2007-07-01
Full Text Available The Author analyses certain problems concerning the transformation of styles in educational experience. Refering also to neuroscientific studies, more radical model of empaty, that enable the interpretation of historical change, are proposed.
The bees algorithm: Modelling nature to solve complex optimisation problems
Pham, Duc; Le-Thi, Hoai; Castellani, Marco
2013-01-01
The Bees Algorithm models the foraging behaviour of honey bees in order to solve optimisation problems. The algorithm performs a kind of exploitative neighbourhood search combined with random explorative search. This paper describes the Bees Algorithm and presents two application examples: the training of neural networks to predict the energy efficiency of buildings, and the solution of the protein folding problem. The Bees Algorithm proved its effectiveness and speed, and obtained very compe...
On the complexity of some quadratic Euclidean 2-clustering problems
Kel'manov, A. V.; Pyatkin, A. V.
2016-03-01
Some problems of partitioning a finite set of points of Euclidean space into two clusters are considered. In these problems, the following criteria are minimized: (1) the sum over both clusters of the sums of squared pairwise distances between the elements of the cluster and (2) the sum of the (multiplied by the cardinalities of the clusters) sums of squared distances from the elements of the cluster to its geometric center, where the geometric center (or centroid) of a cluster is defined as the mean value of the elements in that cluster. Additionally, another problem close to (2) is considered, where the desired center of one of the clusters is given as input, while the center of the other cluster is unknown (is the variable to be optimized) as in problem (2). Two variants of the problems are analyzed, in which the cardinalities of the clusters are (1) parts of the input or (2) optimization variables. It is proved that all the considered problems are strongly NP-hard and that, in general, there is no fully polynomial-time approximation scheme for them (unless P = NP).
Noise problems in coal mining complex- a case discussion
Noise monitoring study was conducted at Moonidih mining complex of Jharia coal-field. The study included monitoring and analysis of ambient as well as workplace noise levels. An attempt has been made to critically analyse the noise situation through octave band analysis, thereby identifying alarming noise frequencies for each noise generating equipment having Leq level more than 90 dBA. A noise model has also been developed to draw noise contours of the entire mining complex. Based on these studies, suitable control measures have been suggested. (author). 6 refs., 3 figs
Client-Centered Problem-Solving Networks in Complex Organizations.
Tucker, Charles; Hanna, Michael
Employees in different kinds of organizations were surveyed for their perceptions of their companies' client and operational problem-solving networks. The individuals came from a manufacturing firm, a community college, a telephone company, a farmers' cooperative, and a hospital. Interviews were conducted with those people reporting numerous…
Reduced-Complexity Semidefinite Relaxations of Optimal Power Flow Problems
Andersen, Martin Skovgaard; Hansson, Anders; Vandenberghe, Lieven
2014-01-01
We propose a new method for generating semidefinite relaxations of optimal power flow problems. The method is based on chordal conversion techniques: by dropping some equality constraints in the conversion, we obtain semidefinite relaxations that are computationally cheaper, but potentially weake...
Complexity of Data Dependence problems for Program Schemas with Concurrency
Danicic, Sebastian; Laurence, Michael R
2010-01-01
The problem of deciding whether one point in a program is data dependent upon another is fundamental to program analysis and has been widely studied. In this paper we consider this problem at the abstraction level of program schemas, in which computations occur in the Herbrand domain of terms and predicate symbols, which represent arbitrary predicate functions, are allowed. Given a vertex l in the flowchart of a schema S having only equality assignments and variables v,w, we show that it is PSPACE-hard to decide whether there exists an execution of a program defined by S in which v holds the initial value of w at at least one occurrence of l on the path of execution, with membership in PSPACE holding provided there is a constant upper bound on the arity of any predicate in S. We also consider the `dual' problem in which v is required to hold the initial value of w at every occurrence of l, for which the analogous results hold. Additionally, the former problem for programs with non-deterministic branching (in ...
Problem-solving with multiple interdependent criteria: better solution to complex problems
We consider multiple objective programming (MOP) problems with additive interdependencies, this is when the states of some chosen objective are attained through supportive or inhibitory feed-backs from several other objectives. MOP problems with independent objectives (when the cause-effect relations between the decision variables and the objectives are completely known) will be treated as special cases of the MOP in which we have interdependent objectives. We illustrate our ideas by a simple three-objective real-life problem
Solomon, Olga; Heritage, John; Yin, Larry; Maynard, Douglas W; Bauman, Margaret L
2016-02-01
Conversation and discourse analyses were used to examine medical problem presentation in pediatric care.Healthcare visits involving children with ASD and typically developing children were analyzed. We examined how children’s communicative and epistemic capabilities, and their opportunities to be socialized into a competent patient role are interactionally achieved. We found that medical problem presentation is designed to contain a ‘pre-visit’ account of the interactional and epistemic work that children and caregivers carry out at home to identify the child’s health problems; and that the intersubjective accessibility of children’s experiences that becomes disrupted by ASD presents a dilemma to all participants in the visit. The article examines interactional roots of unmet healthcare needs and foregone medical care of people with ASD. PMID:26463739
The Bright Side of Being Blue: Depression as an Adaptation for Analyzing Complex Problems
Andrews, Paul W.; Thomson, J. Anderson, Jr.
2009-01-01
Depression is the primary emotional condition for which help is sought. Depressed people often report persistent rumination, which involves analysis, and complex social problems in their lives. Analysis is often a useful approach for solving complex problems, but it requires slow, sustained processing, so disruption would interfere with problem…
The problem of creating a full scale computer simulation code complex for NPPs with RBMK reactors
The presented paper reviews the problem of choice and justification of digital solution algorithms of spatial model and its realization on computers, as well as research technical problems which deal with the creation of the full scale modelling complex and special dialog system of communication with this complex system that will be applicable to NPP reactors of the channel type. 2 figs
Games that Enlist Collective Intelligence to Solve Complex Scientific Problems
Burnett, Stephen; Furlong, Michelle; Melvin, Paul Guy; Singiser, Richard
2016-01-01
There is great value in employing the collective problem-solving power of large groups of people. Technological advances have allowed computer games to be utilized by a diverse population to solve problems. Science games are becoming more popular and cover various areas such as sequence alignments, DNA base-pairing, and protein and RNA folding. While these tools have been developed for the general population, they can also be used effectively in the classroom to teach students about various topics. Many games also employ a social component that entices students to continue playing and thereby to continue learning. The basic functions of game play and the potential of game play as a tool in the classroom are discussed in this article. PMID:27047610
Games that Enlist Collective Intelligence to Solve Complex Scientific Problems.
Burnett, Stephen; Furlong, Michelle; Melvin, Paul Guy; Singiser, Richard
2016-03-01
There is great value in employing the collective problem-solving power of large groups of people. Technological advances have allowed computer games to be utilized by a diverse population to solve problems. Science games are becoming more popular and cover various areas such as sequence alignments, DNA base-pairing, and protein and RNA folding. While these tools have been developed for the general population, they can also be used effectively in the classroom to teach students about various topics. Many games also employ a social component that entices students to continue playing and thereby to continue learning. The basic functions of game play and the potential of game play as a tool in the classroom are discussed in this article. PMID:27047610
Games that Enlist Collective Intelligence to Solve Complex Scientific Problems
Stephen Burnett
2015-09-01
Full Text Available There is great value in employing the collective problem-solving power of large groups of people. Technological advances have allowed computer games to be utilized by a diverse population to solve problems. Science games are becoming more popular and cover various areas such as sequence alignments, DNA base-pairing, and protein and RNA folding. While these tools have been developed for the general population, they can also be used effectively in the classroom to teach students about various topics. Many games also employ a social component that entices students to continue playing and thereby to continue learning. The basic functions of game play and the potential of game play as a tool in the classroom are discussed in this article.
The problems of the complex sentences with complements in Bulgarian
Nicolova Ruselina
2008-01-01
Full Text Available The investigation of the complex sentences with complements in Bulgarian is a multifactor analysis, which has to take into account the following issues: a the lexical meaning of the main predicate, which determines the meaning of the complement in general; b the grammatical meanings of the main predicate - person (a special role plays the opposition between the speaker and the other participants in communication, number, tense, mood, evidentiality affirmativity or negation; c the functions of the linking words - complementizers, particles, interrogatives, relatives; d the meaning of the complement and its related presuppositions or implications (if any, its modality, its illocutionary force, its formal structure, its syntactic position in the complex sentence; e the combinatorial potential of the matrix sentence and the complement in both aspects - semantic and formal.
On the Complexity of the Asymmetric VPN Problem
Rothvoß, Thomas; Sanità, Laura
We give the first constant factor approximation algorithm for the asymmetric Virtual Private Network (textsc{Vpn}) problem with arbitrary concave costs. We even show the stronger result, that there is always a tree solution of cost at most 2·OPT and that a tree solution of (expected) cost at most 49.84·OPT can be determined in polynomial time.
Sequence Annotation with HMMs: New Problems and Their Complexity
Nánási, Michal; Vinař, Tomáš; Brejová, Broňa
2012-01-01
Hidden Markov models (HMMs) and their variants were successfully used for several sequence annotation tasks. Traditionally, inference with HMMs is done using the Viterbi and posterior decoding algorithms. However, recently a variety of different optimization criteria and associated computational problems were proposed. In this paper, we consider three HMM decoding criteria and prove their NP hardness. These criteria consider the set of states used to generate a certain sequence, but abstract ...
Presenilins and the γ-secretase: still a complex problem
Small David H
2010-02-01
Full Text Available Abstract The presenilins form part of a complex of membrane proteins that are involved in the proteolytic cleavage of cell-surface molecules. This article reviews the history of the discovery of the presenilins, their role in the pathogenesis of Alzheimer's disease and in the metabolism of the amyloid-β precursor protein. Unanswered questions about their biochemical mechanism of action and their effects on Ca2+ homeostasis are examined.
Complex Datasets and Inverse Problems. Tomography, Networks and Beyond
Liu, Regina; Strawderman, William; Zhang, Cun-Hui
2007-01-01
This book is a collection of papers dedicated to the memory of Yehuda Vardi. Yehuda was the chair of the Department of Statistics of Rutgers University when he passed away unexpectedly on January 13, 2005. On October 21--22, 2005, some 150 leading scholars from many different fields, including statistics, telecommunications, biomedical engineering, bioinformatics, biostatistics and epidemiology, gathered at Rutgers in a conference in his honor. This conference was on ``Complex Datasets and In...
The problems of the complex sentences with complements in Bulgarian
Nicolova Ruselina
2008-01-01
The investigation of the complex sentences with complements in Bulgarian is a multifactor analysis, which has to take into account the following issues: a) the lexical meaning of the main predicate, which determines the meaning of the complement in general; b) the grammatical meanings of the main predicate - person (a special role plays the opposition between the speaker and the other participants in communication), number, tense, mood, evidentiality affirmativity or negation; c) the function...
Complexity of the FIFO Stack-Up Problem
Gurski, Frank; Rethmann, Jochen; Wanke, Egon
2013-01-01
We study the combinatorial FIFO stack-up problem. In delivery industry, bins have to be stacked-up from conveyor belts onto pallets with respect to customer orders. Given k sequences q_1, ..., q_k of labeled bins and a positive integer p, the aim is to stack-up the bins by iteratively removing the first bin of one of the k sequences and put it onto an initially empty pallet of unbounded capacity located at one of p stack-up places. Bins with different pallet labels have to be placed on differ...
Acid rain legislation's complex problem - Fair and efficient emissions limitation
The writers of this article take a gloomier view of the potential of an emissions reduction compliance market. It cannot be relied upon to even out disparities in the costs which different utility systems will have to incur, they say - i.e., promote fairness - and it will have the added disadvantage that it will work against the entry of nonutility electricity generators into this field. The monopolistic and noncompetitive nature of the electric utility industry is seen as a major problem by these writers - one which will preclude operation of an emissions market
Developing a computer-based assessment of complex problem solving in Chemistry
Scherer, Ronny; Meßinger-Koppelt, Jenny; Tiemann, Rüdiger
2014-01-01
Background Complex problem-solving competence is regarded as a key construct in science education. But due to the necessity of using interactive and intransparent assessment procedures, appropriate measures of the construct are rare. This paper consequently presents the development and validation of a computer-based problem-solving environment, which can be used to assess students' performance on complex problems in Chemistry. The test consists of four scales, namely, under...
Various complexity results for computational mass spectrometry problems
Böcker, Francois Nicolas Sebastian
2011-01-01
Define Minimum \\pbsul{} (MinSU) as the following optimization problem: given a $k$-tuple $(X_1, X_2,..., X_k)$ of finite integer sets, find a $k$-tuple $(t_1, t_2,..., t_k)$ of integers that minimizes the cardinality of $(X_1 + t_1) \\cup (X_2 + t_2) \\cup...\\cup (X_n + t_k)$. We show that MinSU is NP-complete, APX-hard, and polynomial for fixed $k$. MinSU appears naturally in the context of protein shotgun sequencing: Here, the protein is cleaved into short and overlapping peptides, which are then analyzed by tandem mass spectrometry. To improve the quality of such spectra, one then asks for the mass of the unknown prefix (the shift) of the spectrum, such that the resulting shifted spectra show a maximum agreement. For real-world data the problem is even more complicated than our definition of MinSU; but our intractability results clearly indicate that it is unlikely to find a polynomial time algorithm for shotgun protein sequencing.
Resolving the Complexity of Some Data Privacy Problems
Blocki, Jeremiah
2010-01-01
We formally study two methods for data sanitation that have been used extensively in the database community: k-anonymity and l-diversity. We settle several open problems concerning the difficulty of applying these methods optimally, proving both positive and negative results: 1. 2-anonymity is in P. 2. The problem of partitioning the edges of a triangle-free graph into 4-stars (degree-three vertices) is NP-hard. This yields an alternative proof that 3-anonymity is NP-hard even when the database attributes are all binary. 3. 3-anonymity with only 27 attributes per record is MAX SNP-hard. 4. For databases with n rows, k-anonymity is in O(4^n poly(n)) time for all k > 1. 5. For databases with n rows and l <= log_{2c+2} log n attributes over an alphabet of cardinality c = O(1), k-anonymity is in P. Assuming c, l = O(1), k-anonymity is in O(n). 6. 3-diversity with binary attributes is NP-hard, with one sensitive attribute. 7. 2-diversity with binary attributes is NP-hard, with three sensitive attributes.
Simulation Gaming as a Social Development Instrument: Dealing with Complex Problems
Klievink, B.; Janssen, M.
Improving public service delivery is a very complex domain and the complexity is difficult to grasp by stakeholders having various degree of knowledge and involvement. An emergent and promising method for dealing with complex problems is simulation gaming, which can be used to capitalize the intrins
The update complexity of selection and related problems
Gupta, Manoj; Sen, Sandeep
2011-01-01
We present a framework for computing with input data specified by intervals, representing uncertainty in the values of the input parameters. To compute a solution, the algorithm can query the input parameters that yield more refined estimates in form of sub-intervals and the objective is to minimize the number of queries. The previous approaches address the scenario where every query returns an exact value. Our framework is more general as it can deal with a wider variety of inputs and query responses and we establish interesting relationships between them that have not been investigated previously. Although some of the approaches of the previous restricted models can be adapted to the more general model, we require more sophisticated techniques for the analysis and we also obtain improved algorithms for the previous model. We address selection problems in the generalized model and show that there exist 2-update competitive algorithms that do not depend on the lengths or distribution of the sub-intervals and ...
Nuclear processing - a simple cost equation or a complex problem?
BNFL has extensive experience of nuclear processing plant from concept through to decommissioning, at all stages of the fuel cycle. Nexia Solutions (formerly BNFL's R and D Division) has always supported BNFL in development of concept plant, including the development of costed plant designs for the purpose of economic evaluation and technology selection. Having undertaken such studies over a number of years, this has enabled Nexia Solutions to develop a portfolio of costed plant designs for a broad range of nuclear processes, throughputs and technologies. This work has led to an extensive understanding of the relationship of the cost of nuclear processing plant, and how this can be impacted by scale of process, and the selection of design philosophy. The relationship has been seen to be non linear and so simplistic equations do not apply, the relationship is complex due to the variety of contributory factors. This is particularly evident when considering the scale of a process, for example how step changes in design occurs with increasing scale, how the applicability of technology options can vary with scale etc... This paper will explore the contributory factor of scale to nuclear processing plant costs. (authors)
Markov Renewal Methods in Restart Problems in Complex Systems
Asmussen, Søren; Lipsky, Lester; Thompson, Stephen
general alternating Markov renewal model is proposed and an asymptotic exponential form P(X > x) ∼ Ce−γx identified for the case of a deterministic task time L ≡ `. The rate γ is given by equating the spectral radius of a certain matrix to 1, and the asymptotic form of γ = γ(`) as ` → ∞ is derived......A task with ideal execution time L such as the execution of a computer program or the transmission of a file on a data link may fail, and the task then needs to be restarted. The task is handled by a complex system with features similar to the ones in classical reliability: failures may be......, leading to the asymptotics of P(X > x) for random task times L. A main finding is that X is always heavy-tailed if L has unbounded support. The case where the Markov renewal model is derived by lumping in a continuous-time finite Markov process with exponential holding times is given special attention...
Nonlinear problems of complex natural systems: Sun and climate dynamics
Bershadskii, A
2012-01-01
Universal role of the nonlinear one-third subharmonic resonance mechanism in generation of the strong fluctuations in such complex natural dynamical systems as global climate and global solar activity is discussed using wavelet regression detrended data. Role of the oceanic Rossby waves in the year-scale global temperature fluctuations and the nonlinear resonance contribution to the El Nino phenomenon have been discussed in detail. The large fluctuations of the reconstructed temperature on the millennial time-scales (Antarctic ice cores data for the past 400,000 years) are also shown to be dominated by the one-third subharmonic resonance, presumably related to Earth precession effect on the energy that the intertropical regions receive from the Sun. Effects of Galactic turbulence on the temperature fluctuations are discussed in this content. It is also shown that the one-third subharmonic resonance can be considered as a background for the 11-years solar cycle, and again the global (solar) rotation and chaoti...
Bactrocera dorsalis complex and its problem in control
Eight species of fifty-two in the Bactrocera dorsalis complex are serious pests in the Asia-Pacific region. Of these, all except one are attracted to methyl eugenol. Four of these pests B. carambolae, B. dorsalis, B. papayae and B. philippinesis are polyphagous species and infest 75, 117, 195 and 18 fruit host species respectively. Common names for B. carambalae and B. papayae (sympatric species) have caused confusion. Both species can interbreed and produce viable offspring; and their natural hybrids have been collected. Bactrocera dorsalis and B. papayae can interbreed readily and produce viable offspring in the laboratory as males produce identical booster sex and aggregation pheromonal components after consuming methyl eugenol. The DNA sequences of one of their respective allelic introns of the actin gene are also identical which suggests that they are not distinct genetic species. Protein bait application and male annihilation techniques have been successful in the management of fruit flies in many cases but they have to compete with natural sources of lures. SIT is amenable for non-methyl engenol species; but for methyl eugenol sensitive species, sterile makes should be allowed to consume methyl eugenol before release to have an equal mating competitiveness with wild males. (author)
Bringing focus to entrepreneurship
T. Skelton (Tim); J.J.P. Jansen (Justin)
2013-01-01
textabstractFostering entrepreneurship has long been a core part of the RSM ethos. But a new centre bringing together some key players promises to take this philosophy to a new and even more successful level.
无
2001-01-01
This paper deals with boundary value problems for linear uniformly elliptic systems. First the general linear uniformly elliptic system of the first order equations is reduced to complex form, and then the compound boundary value problem for the complex equations of the first order is discussed. The approximate solutions of the boundary value problem are found by the variation-difference method, and the error estimates for the approximate solutions are derived.Finally the approximate method of the oblique derivative problem for linear uniformly elliptic equations of the second or der is introduced.
Vorozheikin, A.; Gonchar, T.; Panfilov, I.; Sopov, E.; Sopov, S.
2009-01-01
A new algorithm for the solution of complex constrained optimization problems based on the probabilistic genetic algorithm with optimal solution prediction is proposed. The efficiency investigation results in comparison with standard genetic algorithm are presented.
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...
Metapsi: a Web-based metacomputing problem-solving environment for buiding complex applications
Baraglia, Ranieri; Laforenza, Domenico
2001-01-01
The increasing complexity of large distributed scientific applications raises the problem of the coordination of diverse computational resources (computers, data bases, etc.). Multi-disciplinary applications often make use of coupled computational resources that cannot be replicated at a single site. There is the need for smart and user-friendly Problem-Solving Environments (PSE) that free scientists from concerns related to the location and complexity of the computing platform being used.
The information-based complexity of approximation problem by adaptive Monte Carlo methods
2008-01-01
In this paper, we study the complexity of information of approximation problem on the multivariate Sobolev space with bounded mixed derivative MWpr,α(Td), 1 < p < ∞, in the norm of Lq(Td), 1 < q < ∞, by adaptive Monte Carlo methods. Applying the discretization technique and some properties of pseudo-s-scale, we determine the exact asymptotic orders of this problem.
Upper estimates of complexity of algorithms for multi-peg Tower of Hanoi problem
Sergey Novikov
2007-06-01
Full Text Available There are proved upper explicit estimates of complexity of lgorithms: for multi-peg Tower of Hanoi problem with the limited number of disks, for Reve's puzzle and for $5$-peg Tower of Hanoi problem with the free number of disks.
The one-way communication complexity of the Boolean Hidden Matching Problem
Kerenidis, I; Kerenidis, Iordanis; Raz, Ran
2006-01-01
We give a tight lower bound of Omega(\\sqrt{n}) for the randomized one-way communication complexity of the Boolean Hidden Matching Problem [BJK04]. Since there is a quantum one-way communication complexity protocol of O(\\log n) qubits for this problem, we obtain an exponential separation of quantum and classical one-way communication complexity for partial functions. A similar result was independently obtained by Gavinsky, Kempe, de Wolf [GKdW06]. Our lower bound is obtained by Fourier analysis, using the Fourier coefficients inequality of Kahn Kalai and Linial [KKL88].
Nuclear three-body problem in the complex energy plane: Complex-Scaling-Slater method
Kruppa, A T; Nazarewicz, W; Michel, N
2013-01-01
The physics of open quantum systems is an interdisciplinary area of research. The nuclear "openness" manifests itself through the presence of the many-body continuum representing various decay, scattering, and reaction channels. As the radioactive nuclear beam experimentation extends the known nuclear landscape towards the particle drip lines, the coupling to the continuum space becomes exceedingly more important. Of particular interest are weakly bound and unbound nuclear states appearing around particle thresholds. Theories of such nuclei must take into account their open quantum nature. To describe open quantum systems, we introduce a Complex Scaling (CS) approach in the Slater basis. We benchmark it with the complex-energy Gamow Shell Model (GSM) by studying energies and wave functions of the bound and unbound states of the two-neutron halo nucleus 6He viewed as an $\\alpha$+ n + n cluster system. In the CS approach, we use the Slater basis, which exhibits the correct asymptotic behavior at large distances...
The Streaming Complexity of Cycle Counting, Sorting by Reversals, and Other Problems
Verbin, Elad; Yu, Wei
2011-01-01
-way. By designing reductions from BHH, we prove lower bounds for the streaming complexity of approximating the sorting by reversal distance, of approximately counting the number of cycles in a 2-regular graph, and of other problems. For example, here is one lower bound that we prove, for a cycle-counting problem......In this paper we introduce a new technique for proving streaming lower bounds (and one-way communication lower bounds), by reductions from a problem called the Boolean Hidden Hypermatching problem (BHH). BHH is a gener- alization of the well-known Boolean Hidden Matching problem, which was used...... two-way communication, but it requires pn communication if Alice is only allowed to send messages to Bob, and not vice-versa. This one-wayness allows us to prove lower bounds, via reductions, for streaming problems and related communication problems whose hardness is also inherently one...
Steen-Eibensteiner, Janice Lee
2006-07-01
A strong science knowledge base and problem solving skills have always been highly valued for employment in the science industry. Skills currently needed for employment include being able to problem solve (Overtoom, 2000). Academia also recognizes the need for effectively teaching students to apply problem solving skills in clinical settings. This thesis investigates how students solve complex science problems in an academic setting in order to inform the development of problem solving skills for the workplace. Students' use of problem solving skills in the form of learned concepts and procedural knowledge was studied as students completed a problem that might come up in real life. Students were taking a community college sophomore biology course, Human Anatomy & Physiology II. The problem topic was negative feedback inhibition of the thyroid and parathyroid glands. The research questions answered were (1) How well do community college students use a complex of conceptual knowledge when solving a complex science problem? (2) What conceptual knowledge are community college students using correctly, incorrectly, or not using when solving a complex science problem? (3) What problem solving procedural knowledge are community college students using successfully, unsuccessfully, or not using when solving a complex science problem? From the whole class the high academic level participants performed at a mean of 72% correct on chapter test questions which was a low average to fair grade of C-. The middle and low academic participants both failed (F) the test questions (37% and 30% respectively); 29% (9/31) of the students show only a fair performance while 71% (22/31) fail. From the subset sample population of 2 students each from the high, middle, and low academic levels selected from the whole class 35% (8/23) of the concepts were used effectively, 22% (5/23) marginally, and 43% (10/23) poorly. Only 1 concept was used incorrectly by 3/6 of the students and identified as
A new complex variable meshless method for transient heat conduction problems
In this paper, based on the improved complex variable moving least-square (ICVMLS) approximation, a new complex variable meshless method (CVMM) for two-dimensional (2D) transient heat conduction problems is presented. The variational method is employed to obtain the discrete equations, and the essential boundary conditions are imposed by the penalty method. As the transient heat conduction problems are related to time, the Crank-Nicolson difference scheme for two-point boundary value problems is selected for the time discretization. Then the corresponding formulae of the CVMM for 2D heat conduction problems are obtained. In order to demonstrate the applicability of the proposed method, numerical examples are given to show the high convergence rate, good accuracy, and high efficiency of the CVMM presented in this paper. (general)
A new complex variable meshless method for transient heat conduction problems
Wang Jian-Fei; Cheng Yu-Min
2012-01-01
In this paper,based on the improved complex variable moving least-square (ICVMLS) approximation,a new complex variable meshless method (CVMM) for two-dimensional (2D) transient heat conduction problems is presented.The variational method is employed to obtain the discrete equations,and the essential boundary conditions are imposed by the penalty method.As the transient heat conduction problems are related to time,the Crank-Nicolson difference scheme for two-point boundary value problems is selected for the time discretization.Then the corresponding formulae of the CVMM for 2D heat conduction problems are obtained.In order to demonstrate the applicability of the proposed method,numerical examples are given to show the high convergence rate,good accuracy,and high efficiency of the CVMM presented in this paper.
Complex variable method for plane elasticity of icosahedral quasicrystals and elliptic notch problem
2008-01-01
The complex variable method for the plane elasticity theory of icosahedral quasicrystals is developed. Based on the general solution obtained previously, complex representations of stress and displacement components of phonon and phason fields in the quasicrystals are given. With the help of conformal transformation, an analytic solution for the elliptic notch problem of the material is presented. The solution of the Griffith crack problem can be observed as a special case of the results. The stress intensity factor and energy release rate of the crack are also obtained.
A method for evaluating the problem complex of choosing the ventilation system for a new building
Hviid, Christian Anker; Svendsen, Svend
2007-01-01
The application of a ventilation system in a new building is a multidimensional complex problem that involves quantifiable and non-quantifiable data like energy consump¬tion, indoor environment, building integration and architectural expression. This paper presents a structured method for...... evaluating the performance of a ventilation system in the design proces by treating quantifiable and non-quantifiable datasets together. The method is based on general morphological analysis and applies cross-consistency assessment for reducing the problem complex, thus treating the multi-dimensionality, the...
Complexity Indicators applied to the Job Shop Scheduling Problem to discriminate the best Algorithm
Jorge A. Ruiz-Vanoye
2011-01-01
Full Text Available In this paper, we propose the application of discriminant analysis to select appropriately the algorithm that better solves an instance of the Job Shop Scheduling Problem. The discriminant analysis was used as a method of machine learning to find the relation between the characteristics of the problem (complexity indicators and the performance of algorithms. The prediction of the classification obtained of the discriminant analysis was 60%.
Kostas Tolidis; Efi Dimopoulou
2012-01-01
This paper discusses the issue of land use planning and land policy making for mountain regions, considered as regions with specific characteristics (natural, cultural, etc.), but also development constraints. Spatial decision making in such regions is characterized by complexity (semi-structured spatial decision problems) and multiplicity of problems. These indicate the need for qualitative information in support of the decision-making process, in order to improve effectiveness in decision m...
Defining Urban Complex Problems with Fuzzy Analysis: The Case of Söke Settlement in Turkey
Kozaman, Senem; Sengezer, Betul; Altinok, Emrah
2011-01-01
This article aims to follow the application of fuzzy approach in the analysis of urban complex problems; classifying urban problems according to different criteria. It proposes a methodology to combine different dimensions of quality of life, with the economic (income, employment), social (education) physical (health and infrastructure) indicators into Quality of Life Index (QLI) by applying Totally Fuzzy Analysis (TFA). The objective of the present work is to identify, based on survey data o...
A new ant colony optimization model for complex graph-based problems
González-Pardo, Antonio
2014-01-01
Tesis doctoral inédita leída en la Universidad Autónoma de Madrid. Escuela Politécnica Superior, Departamento de Ingeniería Informática. Fecha de lectura: julio de 2014 Nowadays, there is a huge number of problems that due to their complexity have employed heuristic-based algorithms to search for near-to-optimal (or even optimal) solutions. These problems are usually NP-complete, so classical algorithms are not the best candidates to address these problems because they need a larg...
Qu Chiwen
2016-01-01
Full Text Available The standard cuckoo search algorithm is of low accuracy and easy to fall into local optimal value in the later evolution. In this paper, an improved cuckoo algorithm is proposed. Dynamic change of parameter of probability is introduced to improve the convergence speed. Complex method is quoted to improve the capabilities of local search algorithm. A non-fixed multi-segment mapping penalty function is adopted to realize constraint processing algorithms. The results of the optimization problem constrained by standard test functions and two engineering design show that this algorithm is effective for solving constrained optimization problems and suitable for engineering design and other constrained optimization problems.
Stability of Complex-Rotation Method on a Simple Resonant Scattering Problem
SHEN Li; WANG Lei; LIU Xiao-Jun; SHI Ting-Yun; LIU Hong-Ping
2008-01-01
@@ The stability of the complex-rotation method in B-spline basis for a simple atomic resonant scattering problem in free field is investigated. The numerical calculation shows that this method has a feature that the solution will not change in a wide range of rotation angle θ. Our determined scattering resonant energies and widths exactly coincide with the popularly accepted values. A new resonance is identified numerically although it is very broad.The norm of the complex eigenvalue, [E], is proposed to investigate and to evaluate the stability of the obtained complex eigenvalues.
Bringing "indigenous" ownership back
Kragelund, Peter
2012-01-01
policies thrive again, this time disguised in terms such as ‘empowerment’, but just as politicised as in the 1970s. Zambia is at the heart of this development. In the light of liberalisation, booming commodity prices and the increasing importance of Chinese investors, this article seeks to further our...... understanding of how processes of exclusion interact with domestic politics in Zambia. It argues that the Citizens Economic Empowerment Commission, a new institution to bring ownership back to Zambians, builds on a long tradition of nationalist policies in Zambia, while its actual work is strictly related to...
On the Critical Behaviour, Crossover Point and Complexity of the Exact Cover Problem
Morris, Robin D.; Smelyanskiy, Vadim N.; Shumow, Daniel; Koga, Dennis (Technical Monitor)
2003-01-01
Research into quantum algorithms for NP-complete problems has rekindled interest in the detailed study a broad class of combinatorial problems. A recent paper applied the quantum adiabatic evolution algorithm to the Exact Cover problem for 3-sets (EC3), and provided an empirical evidence that the algorithm was polynomial. In this paper we provide a detailed study of the characteristics of the exact cover problem. We present the annealing approximation applied to EC3, which gives an over-estimate of the phase transition point. We also identify empirically the phase transition point. We also study the complexity of two classical algorithms on this problem: Davis-Putnam and Simulated Annealing. For these algorithms, EC3 is significantly easier than 3-SAT.
Mathematical optimization model of avionics complexation problem on early stage of designing
V.M. Vorobyov
2006-01-01
Full Text Available The article is the sequel of another one of this digest of authors “Approximate optimization solution by Pareto of discrete extremal problem of complexation of new generation avionics” and its development in the direction of creating optimization model and organization under synthesis of avionics structure.
Ecosystem services and cooperative fisheries research to address a complex fishery problem
The St. Louis River represents a complex fishery management problem. Current fishery management goals have to be developed taking into account bi-state commercial, subsistence and recreational fisheries which are valued for different characteristics by a wide range of anglers, as...
Learning about Complex Multi-Stakeholder Issues: Assessing the Visual Problem Appraisal
Witteveen, L.M.; Put, M.; Leeuwis, C.
2010-01-01
This paper presents an evaluation of the visual problem appraisal (VPA) learning environment in higher education. The VPA has been designed for the training of competences that are required in complex stakeholder settings in relation to sustainability issues. The design of VPA incorporates a diversi
Learning about Complex Multi-Stakeholder Issues: Assessing the Visual Problem Appraisal
Witteveen, Loes; Put, Marcel; Leeuwis, Cees
2010-01-01
This paper presents an evaluation of the visual problem appraisal (VPA) learning environment in higher education. The VPA has been designed for the training of competences that are required in complex stakeholder settings in relation to sustainability issues. The design of VPA incorporates a diversity of instruction strategies to accommodate the…
Small-Group Problem-Based Learning as a Complex Adaptive System
Mennin, Stewart
2007-01-01
Small-group problem-based learning (PBL) is widely embraced as a method of study in health professions schools and at many different levels of education. Complexity science provides a different lens with which to view and understand the application of this method. It presents new concepts and vocabulary that may be unfamiliar to practitioners of…
Kartal, Ozgul; Dunya, Beyza Aksu; Diefes-Dux, Heidi A.; Zawojewski, Judith S.
2016-01-01
Critical to many science, technology, engineering, and mathematics (STEM) career paths is mathematical modeling--specifically, the creation and adaptation of mathematical models to solve problems in complex settings. Conventional standardized measures of mathematics achievement are not structured to directly assess this type of mathematical…
The Development of Complex Problem Solving in Adolescence: A Latent Growth Curve Analysis
Frischkorn, Gidon T.; Greiff, Samuel; Wüstenberg, Sascha
2014-01-01
Complex problem solving (CPS) as a cross-curricular competence has recently attracted more attention in educational psychology as indicated by its implementation in international educational large-scale assessments such as the Programme for International Student Assessment. However, research on the development of CPS is scarce, and the few…
An Iterative Layered Tabu Search Algorithm for Complex Job Shop Scheduling Problem
LIUMin; DONGMingyu; WUCheng
2005-01-01
In this paper, aiming at the complex characteristics that there exist two interrelated decision processes: job-assignment decision and job-sequencing decision in the complex job shop scheduling problem with parallel machines and technical constraints, we propose an Iterative layered tabu search algorithm (ILTSA), which combines the iterative and layered mechanism with tabu search algorithm. In ILTSA, we define the notation of the optimization layer including the job-assignment optimization layer and the job-sequencing optimization layer which correspond to the above two interrelated decision processes respectively. On the basis, we use the corresponding tabu search algorithms in different optimization layers and switch iteratively the above two tabu search algorithms between the two optimization layers to improve the performance of the scheduling algorithm effectively. In the above two TS algorithms, the measuring functions are the objective of the whole scheduling problem. At last, we make numerical computations for different scale scheduling problems of minimizing the makespan and minimizing the total number of tardy jobs respectively, and numerical computational results show that ILTSA is very efficient and suitable for solving larger scale job shop scheduling problem with parallel machines and technical constraints. Also, we apply successfully ILTSA to a practical complex job shop scheduling problem with parallel machines and technical constraints in one of the largest cotton colored weaving enterprises in China.
A new complex variable element-free Galerkin method for two-dimensional potential problems
Cheng Yu-Min; Wang Jian-Fei; Bai Fu-Nong
2012-01-01
In this paper,based on the element-free Galerkin (EFG) method and the improved complex variable moving least-square (ICVMLS) approximation,a new meshless method,which is the improved complex variable element-free Galerkin (ICVEFG) method for two-dimensional potential problems,is presented. In the method,the integral weak form of control equations is employed,and the Lagrange multiplier is used to apply the essential boundary conditions.Then the corresponding formulas of the ICVEFG method for two-dimensional potential problems are obtained.Compared with the complex variable moving least-square (CVMLS) approximation proposed by Cheng,the functional in the ICVMLS approximation has an explicit physical meaning.Furthermore,the ICVEFG method has greater computational precision and efficiency.Three numerical examples are given to show the validity of the proposed method.
Muñoz, Rodrigo; Adami, Fovad
2012-01-01
Detta examensarbete har genomförts i samarbete med Sourcecom Svenska AB. Sourcecom Svenska AB arbetar med kommunikationslösningar inom IT-kommunikation, IT-säkerhet och telefoni. Examensarbetet går ut på att undersöka konceptet Bring Your Own Device (BYOD) och föreslå olika lösningar beroende på företagets informationssäkerhetskrav. För att förstå konceptet BYOD behövs först en inblick i hur ett policybaserat system fungerar. Rapporten undersöker och förklarar tre olika Network Access Control...
Computational complexity of classical problems for hereditary clique-helly graphs
Flavia Bonomo
2004-12-01
Full Text Available A graph is clique-Helly when its cliques satisfy the Helly property. A graph is hereditary clique-Helly when every induced subgraph of it is clique-Helly. The decision problems associated to the stability, chromatic, clique and clique-covering numbers are NP-complete for clique-Helly graphs. In this note, we analyze the complexity of these problems for hereditary clique-Helly graphs. Some of them can be deduced easily by known results. We prove that the clique-covering problem remains NP-complete for hereditary clique-Helly graphs. Furthermore, the decision problems associated to the clique-transversal and the clique-independence numbers are analyzed too. We prove that they remain NP-complete for a smaller class: hereditary clique-Helly split graphs.
The Subset Sum Problem: Reducing Time Complexity of NP-Completeness with Quantum Search
Bo Moon
2012-01-01
Full Text Available The Subset Sum Problem is a member of the NP-complete class, so no known polynomial time algorithm exists for it. Although there are polynomial time approximations and heuristics, these are not always acceptable, yet exact-solution algorithms are unfeasible for large input. Quantum computation offers new insights for not only the Subset Sum Problem but also the entire NP-complete class; most notably, Grover's quantum algorithm for an unstructured database search can be tailored to identify solutions to problems within mathematics and computer science. This paper discusses the physical and conceptual feasibility of quantum computation and demonstrates the utility of quantum search by analyzing the time complexities of the classical dynamic programming algorithm and Grover's algorithm in solving the Subset Sum Problem, evincing the implications this has on the NP-complete class in general.
The Consensus String Problem and the Complexity of Comparing Hidden Markov Models
Lyngsø, Rune Bang; Pedersen, Christian Nørgaard Storm
2002-01-01
The basic theory of hidden Markov models was developed and applied to problems in speech recognition in the late 1960s, and has since then been applied to numerous problems, e.g. biological sequence analysis. Most applications of hidden Markov models are based on efficient algorithms for computing...... the probability of generating a given string, or computing the most likely path generating a given string. In this paper we consider the problem of computing the most likely string, or consensus string, generated by a given model, and its implications on the complexity of comparing hidden Markov...... models. We show that computing the consensus string, and approximating its probability within any constant factor, is NP-hard, and that the same holds for the closely related labeling problem for class hidden Markov models. Furthermore, we establish the NP-hardness of comparing two hidden Markov models...
Bringing up Gender: Academic Abjection?
Henderson, Emily F.
2014-01-01
The principal questions raised in this article are: what does it mean to bring up the topic of gender in a space where it is not known, and how can this moment of bringing up gender--or not bringing it up--be conceptualised? The article departs from the thoughts and questions that were provoked by an interview conducted with a Gender Studies…
A study of "Theory U" and its application to a complex Japanese Maritime Self-Defense Force problem
Yamauchi, Yusuke
2014-01-01
Approved for public release; distribution is unlimited The more an organization develops complex systems to perform increasingly complex tasks, the more challenging problems become and increasingly difficult to solve. This thesis recommends to the Japan Maritime Self-Defense Force (JMSDF) a better framework to solve these complex, multisystem problems through systems thinking and a new approach to this way of thinking, called Theory U. This thesis describes the types of problems that requi...
Angelsky, O. V.; Gorsky, M. P.; Hanson, Steen Grüner;
2014-01-01
We propose an optical correlation algorithm illustrating a new general method for reconstructing the phase skeleton of complex optical fields from the measured two-dimensional intensity distribution. The core of the algorithm consists in locating the saddle points of the intensity distribution and...... connecting such points into nets by the lines of intensity gradient that are closely associated with the equi-phase lines of the field. This algorithm provides a new partial solution to the inverse problem in optics commonly referred to as the phase problem....
Hayes, Thomas P.
2011-01-01
For every positive integer k, we construct an explicit family of functions f : \\0, 1\\(n) -\\textgreater \\0, 1\\ which has (k + 1) - party communication complexity O(k) under every partition of the input bits into k + 1 parts of equal size, and k-party communication complexity Omega (n/k(4)2(k)) under every partition of the input bits into k parts. This improves an earlier hierarchy theorem due to V. Grolmusz. Our construction relies on known explicit constructions for a famous open problem of K...
Watts, C
1999-01-01
Robert Cailliau argues that the explosion of advertising on the web is limiting its' usefulness. He suggests that 'licensing' users may be the only way to stop additional problems such as pornography, spam email and viruses (1 page).
Yang Xiu-Li; Dai Bao-Dong; Zhang Wei-Wei
2012-01-01
Based on the complex variable moving least-square (CVMLS) approximation and a local symmetric weak form,the complex variable meshless local Petrov-Galerkin (CVMLPG) method of solving two-dimensional potential problems is presented in this paper.In the present formulation,the trial function of a two-dimensional problem is formed with a one-dimensional basis function.The number of unknown coefficients in the trial function of the CVMLS approximation is less than that in the trial function of the moving least-square (MLS) approximation.The essential boundary conditions are imposed by the penalty method.The main advantage of this approach over the conventional meshless local PetrovGalerkin (MLPG) method is its computational efficiency.Several numerical examples are presented to illustrate the implementation and performance of the present CVMLPG method.
Cybersecurity vulnerabilities in medical devices: a complex environment and multifaceted problem.
Williams, Patricia Ah; Woodward, Andrew J
2015-01-01
The increased connectivity to existing computer networks has exposed medical devices to cybersecurity vulnerabilities from which they were previously shielded. For the prevention of cybersecurity incidents, it is important to recognize the complexity of the operational environment as well as to catalog the technical vulnerabilities. Cybersecurity protection is not just a technical issue; it is a richer and more intricate problem to solve. A review of the factors that contribute to such a potentially insecure environment, together with the identification of the vulnerabilities, is important for understanding why these vulnerabilities persist and what the solution space should look like. This multifaceted problem must be viewed from a systemic perspective if adequate protection is to be put in place and patient safety concerns addressed. This requires technical controls, governance, resilience measures, consolidated reporting, context expertise, regulation, and standards. It is evident that a coordinated, proactive approach to address this complex challenge is essential. In the interim, patient safety is under threat. PMID:26229513
Cybersecurity vulnerabilities in medical devices: a complex environment and multifaceted problem
Williams, Patricia AH; Woodward, Andrew J
2015-01-01
The increased connectivity to existing computer networks has exposed medical devices to cybersecurity vulnerabilities from which they were previously shielded. For the prevention of cybersecurity incidents, it is important to recognize the complexity of the operational environment as well as to catalog the technical vulnerabilities. Cybersecurity protection is not just a technical issue; it is a richer and more intricate problem to solve. A review of the factors that contribute to such a potentially insecure environment, together with the identification of the vulnerabilities, is important for understanding why these vulnerabilities persist and what the solution space should look like. This multifaceted problem must be viewed from a systemic perspective if adequate protection is to be put in place and patient safety concerns addressed. This requires technical controls, governance, resilience measures, consolidated reporting, context expertise, regulation, and standards. It is evident that a coordinated, proactive approach to address this complex challenge is essential. In the interim, patient safety is under threat. PMID:26229513
A method for evaluating the problem complex of choosing the ventilation system for a new building
Hviid, Christian Anker; Svendsen, Svend
2007-01-01
The application of a ventilation system in a new building is a multidimensional complex problem that involves quantifiable and non-quantifiable data like energy consump¬tion, indoor environment, building integration and architectural expression. This paper presents a structured method for evaluat......’. Herein the designer may view multiple ventilation solutions and navigate between them, evaluate the differences and choose the best ventilation system scenario in terms of energy consumption, indoor environment and architectural quality.......The application of a ventilation system in a new building is a multidimensional complex problem that involves quantifiable and non-quantifiable data like energy consump¬tion, indoor environment, building integration and architectural expression. This paper presents a structured method for...
Borot, Gaëtan
2011-01-01
Complex analysis is a powerful tool to study classical integrable systems, statistical physics on the random lattice, random matrix theory, topological string theory, … All these topics share certain relations, called "loop equations" or "Virasoro constraints". In the simplest case, the complete solution of those equations was found recently : it can be expressed in the framework of differential geometry over a certain Riemann surface which depends on the problem : the "spectral curve". This ...
Stable finite element pair for Stokes problem and discrete Stokes complex on quadrilateral grids
Zhang, Shuo
2013-01-01
In this paper, we first construct a nonconforming finite element pair for the incompressible Stokes problem on quadrilateral grids, and then construct a discrete Stokes complex associated with that finite element pair. The finite element spaces involved consist of piecewise polynomials only, and the divergence-free condition is imposed in a primal formulation. Combined with some existing results, these constructions can be generated onto grids that consist of both triangular and quadrilateral...
Higher complexity search problems for bounded arithmetic and a formalized no-gap theorem
Thapen, Neil
2011-01-01
Roč. 50, 7-8 (2011), s. 665-680. ISSN 1432-0665 R&D Projects: GA AV ČR IAA100190902; GA MŠk LC505; GA MŠk(CZ) 1M0545 Institutional research plan: CEZ:AV0Z10190503 Keywords : bounded arithmetic * proof complexity * search problems Subject RIV: BA - General Mathematics Impact factor: 0.341, year: 2011 http://www.springerlink.com/content/l19kr20362065t86/
We introduce a new technique transforming a holomorphic curve into a higher dimensional projective algebraic variety, f : C → X, to a system of holomorphic maps between appropriate Riemann surfaces, {λ : Yλ → Sλ}. Then we apply this transformation and its modifications to settle the conjectural Second Main Theorem in Nevanlinna theory for holomorphic curves into smooth complex projective algebraic varieties. Applications to geometric Diophantine problems are discussed. (author). 25 refs
Qu Chiwen; He Wei
2016-01-01
The standard cuckoo search algorithm is of low accuracy and easy to fall into local optimal value in the later evolution. In this paper, an improved cuckoo algorithm is proposed. Dynamic change of parameter of probability is introduced to improve the convergence speed. Complex method is quoted to improve the capabilities of local search algorithm. A non-fixed multi-segment mapping penalty function is adopted to realize constraint processing algorithms. The results of the optimization problem ...
Solving the three-body Coulomb breakup problem using exterior complex scaling
McCurdy, C.W.; Baertschy, M.; Rescigno, T.N.
2004-05-17
Electron-impact ionization of the hydrogen atom is the prototypical three-body Coulomb breakup problem in quantum mechanics. The combination of subtle correlation effects and the difficult boundary conditions required to describe two electrons in the continuum have made this one of the outstanding challenges of atomic physics. A complete solution of this problem in the form of a ''reduction to computation'' of all aspects of the physics is given by the application of exterior complex scaling, a modern variant of the mathematical tool of analytic continuation of the electronic coordinates into the complex plane that was used historically to establish the formal analytic properties of the scattering matrix. This review first discusses the essential difficulties of the three-body Coulomb breakup problem in quantum mechanics. It then describes the formal basis of exterior complex scaling of electronic coordinates as well as the details of its numerical implementation using a variety of methods including finite difference, finite elements, discrete variable representations, and B-splines. Given these numerical implementations of exterior complex scaling, the scattering wave function can be generated with arbitrary accuracy on any finite volume in the space of electronic coordinates, but there remains the fundamental problem of extracting the breakup amplitudes from it. Methods are described for evaluating these amplitudes. The question of the volume-dependent overall phase that appears in the formal theory of ionization is resolved. A summary is presented of accurate results that have been obtained for the case of electron-impact ionization of hydrogen as well as a discussion of applications to the double photoionization of helium.
This paper presents a transportation tracking system (designated TRANSCOM) developed under the direction of the Department of Energy (DOE) in response to three institutional concerns about shipments of large quantities of radioactive materials: routing, prenotification, and emergency response. This tracking system consists of a geographical location system, a system for communicating with the vehicle operator while en route, and an information management system that appropriately distributes shipment information to DOE headquarters, field offices, and key state officials. This paper presents the development, testing, and demonstration efforts undertaken to bring the prototype system to a fully operational status. The LORAN-C locating system has proved to be acceptable as a geographical location system for TRANSCOM equipped vehicles. The satellite communications technology employed has demonstrated timely radio transmission regarding location and communication with the vehicle operator. This paper also discusses the interim developmental TRANSCOM Control Center, the Oak Ridge Operations TRANSCOM Control Center, software, hardware, operational issues, and the tracking of a WIPP TRUPACT-II demonstration trailer
The Complexity of Checking Consistency of Pedigree Information and Related Problems
Luca Aceto; Jens A. Hansen; Anna Ingólfsdóttir; Jacob Johnsen; John Knudsen
2004-01-01
Consistency checking is a fundamental computational problem in genetics. Given a pedigree and information on the genotypes (of some) of the individuals in it, the aim of consistency checking is to determine whether these data are consistent with the classic Mendelian laws of inheritance. This problem arose originally from the geneticists' need to filter their input data from erroneous information, and is well motivated from both a biological and a sociological viewpoint. This paper shows that consistency checking is NP-complete, even with focus on a single gene and in the presence of three alleles. Several other results on the computational complexity of problems from genetics that are related to consistency checking are also offered. In particular, it is shown that checking the consistency of pedigrees over two alleles, and of pedigrees without loops, can be done in polynomial time.
Theoretical understanding of the problem with a singular drift term in the complex Langevin method
Nishimura, Jun
2015-01-01
The complex Langevin method aims at performing path integral with a complex action numerically based on complexification of the original real dynamical variables. One of the poorly understood issues concerns occasional failure in the presence of logarithmic singularities in the action, which appear, for instance, from the fermion determinant in finite density QCD. We point out that the failure should be attributed to the breakdown of the relation between the complex weight that satisfies the Fokker-Planck equation and the probability distribution associated with the stochastic process. In fact, this problem can occur in general when the stochastic process involves a singular drift term. We show, however, in a simple example that there exists a parameter region in which the method works although the standard reweighting method is hardly applicable.
Understanding the problem with logarithmic singularities in the complex Langevin method
Nishimura, Jun
2015-01-01
In recent years, there has been remarkable progress in theoretical justification of the complex Langevin method, which is a promising method for evading the sign problem in the path integral with a complex weight. There still remains, however, an issue concerning occasional failure of this method in the case where the action involves logarithmic singularities such as the one appearing from the fermion determinant in finite density QCD. In this talk, we point out that this failure is due to the breakdown of the relation between the complex weight which satisfies the Fokker-Planck equation and the probability distribution generated by the stochastic process. In fact, this kind of failure can occur in general when the stochastic process involves a singular drift term. We show, however, in simple examples, that there exists a parameter region in which the method works although the standard reweighting method is hardly applicable.
Truthful Complex-valued Knapsack Problem and Discrete Optimization in A/C Electrical Grid
Chau, Chi-Kin
2012-01-01
Since efficient power allocation is a critical requirement for smart grid, we study an important basic setting -- "knapsack problem with selfish users", whereby we design a mechanism to find a utility-maximizing allocation for a group of users with inelastic demands, such that users truthfully reveal their private utility information. As a departure from the traditional setting, complex-valued entities (e.g. power, voltage, and current) are common in A/C electrical grid. There were only few results in the literature concerning complex-valued entities for discrete optimization, because they are substantially more challenging. In this paper, we introduce a non-trivial generalization of knapsack problem with a complex-valued constraint on A/C power, which casts fundamental insight to discrete optimization for smart grid. We provide results of approximability (the existence of a (1/2- e-approximation algorithm) and inapproximability (the absence of FPTAS unless P = NP) for a class of complex-valued knapsack probl...
Norsk, P.; Shelhamer, M.
2016-01-01
This panel will present NASA's plans for ongoing and future research to define the requirements for Artificial Gravity (AG) as a countermeasure against the negative health effects of long-duration weightlessness. AG could mitigate the gravity-sensitive effects of spaceflight across a host of physiological systems. Bringing gravity to space could mitigate the sensorimotor and neuro-vestibular disturbances induced by G-transitions upon reaching a planetary body, and the cardiovascular deconditioning and musculoskeletal weakness induced by weightlessness. Of particular interest for AG during deep-space missions is mitigation of the Visual Impairment Intracranial Pressure (VIIP) syndrome that the majority of astronauts exhibit in space to varying degrees, and which presumably is associated with weightlessness-induced fluid shift from lower to upper body segments. AG could be very effective for reversing the fluid shift and thus help prevent VIIP. The first presentation by Dr. Charles will summarize some of the ground-based and (very little) space-based research that has been conducted on AG by the various space programs. Dr. Paloski will address the use of AG during deep-space exploration-class missions and describe the different AG scenarios such as intra-vehicular, part-of-vehicle, or whole-vehicle centrifugations. Dr. Clement will discuss currently planned NASA research as well as how to coordinate future activities among NASA's international partners. Dr. Barr will describe some possible future plans for using space- and ground-based partial-G analogs to define the relationship between physiological responses and G levels between 0 and 1. Finally, Dr. Stenger will summarize how the human cardiovascular system could benefit from intermittent short-radius centrifugations during long-duration missions.
Castelvecchi, Davide
2007-01-01
The world's most powerful atom smasher turns on this year. The author foresees some breakthroughts - and more than a few tricky problems: the most likely scenario is that we're going to have a ton of weird stuff to explain. (3 pages)
Goode, Natassia; Beckmann, Jens F.
2010-01-01
This study investigates the relationships between structural knowledge, control performance and fluid intelligence in a complex problem solving (CPS) task. 75 participants received either complete, partial or no information regarding the underlying structure of a complex problem solving task, and controlled the task to reach specific goals.…
How to solve complex problems in foundry plants - future of casting simulation -
Ohnaka, I.
2015-06-01
Although the computer simulation of casting has progressed dramatically over the last decades, there are still many challenges and problems. This paper discusses how to solve complex engineering problems in foundry plants and what we should do in the future, in particular, for casting simulation. First, problem solving procedures including application of computer simulation are demonstrated and various difficulties are pointed-out exemplifying mainly porosity defects in sand castings of spheroidal graphite cast irons. Next, looking back conventional scientific and engineering research to understand casting phenomena, challenges and problems are discussed from problem solving view point, followed by discussion on the issues we should challenge such as how to integrate huge amount of dispersed knowledge in various disciplines, differentiation of science-oriented and engineering-oriented models, professional ethics, how to handle fluctuating materials, initial and boundary conditions, error accumulation, simulation codes as black-box, etc. Finally some suggestions are made on how to challenge the issues such as promotion of research on the simulation based on the science- oriented model and publication of reliable data of casting phenomena in complicated-shaped castings including reconsideration of the evaluation system.
2000-01-01
`I'm doing a physics that is pulling me towards it.' `I like the course being more up to date.' `You learn the physics but you also think ``well I actually see a point in knowing this physics''.' `This course presents physics in a more interesting way as it focuses on practical activity and applications of physics.' `The industrial visit gives students the opportunity to look for science in action.' These are just some of the comments from students and teachers piloting the new Salters Horners Advanced Physics course (SHAP). Contexts and applications drive the course, providing interest and motivation for students and alerting them to some of the many career areas that involve physics. For example, the operation of a CD player leads to a study of waves and superposition; archaeological surveying and analysis brings in d.c. circuitry and x-ray diffraction; consideration of safety in rail transport involves learning about mechanics and electromagnetism. The course is produced by a team directed from the University of York and funded by a consortium of industrial and charitable sponsors. It is examined by Edexcel and support materials are published by Heinemann. The pilot, involving some 50 centres, began in September 1998 with the new subject core and the AS qualification intermediate between GCSE and the full A-level standard. The course has been fully approved by QCA, and from September 2000 it will be open to all. For comprehensive information about SHAP, visit the project's website: www.york.ac.uk/org/seg/salters/physics . Pilot materials for students, teachers and technicians are available from Heinemann. They will be re-edited and published in full colour for September 2000. Members of the team will attend the annual ASE meeting in Leeds this month; there will be a talk and a hands-on workshop where student activities can be sampled. Materials will be on view at the University of York stand. In addition, Edexcel and the York team are running a series of
Arithmetic of Complex Manifolds
Lange, Herbert
1989-01-01
It was the aim of the Erlangen meeting in May 1988 to bring together number theoretists and algebraic geometers to discuss problems of common interest, such as moduli problems, complex tori, integral points, rationality questions, automorphic forms. In recent years such problems, which are simultaneously of arithmetic and geometric interest, have become increasingly important. This proceedings volume contains 12 original research papers. Its main topics are theta functions, modular forms, abelian varieties and algebraic three-folds.
Understanding and quantifying cognitive complexity level in mathematical problem solving items
SUSAN E. EMBRETSON
2008-09-01
Full Text Available The linear logistic test model (LLTM; Fischer, 1973 has been applied to a wide variety of new tests. When the LLTM application involves item complexity variables that are both theoretically interesting and empirically supported, several advantages can result. These advantages include elaborating construct validity at the item level, defining variables for test design, predicting parameters of new items, item banking by sources of complexity and providing a basis for item design and item generation. However, despite the many advantages of applying LLTM to test items, it has been applied less often to understand the sources of complexity for large-scale operational test items. Instead, previously calibrated item parameters are modeled using regression techniques because raw item response data often cannot be made available. In the current study, both LLTM and regression modeling are applied to mathematical problem solving items from a widely used test. The findings from the two methods are compared and contrasted for their implications for continued development of ability and achievement tests based on mathematical problem solving items.
1 - Description of problem or function: FOCUS enables the calculation of any quantity related to neutron transport in reactor or shielding problems, but was especially designed to calculate differential quantities, such as point values at one or more of the space, energy, direction and time variables of quantities like neutron flux, detector response, reaction rate, etc. or averages of such quantities over a small volume of the phase space. Different types of problems can be treated: systems with a fixed neutron source which may be a mono-directional source located out- side the system, and Eigen function problems in which the neutron source distribution is given by the (unknown) fundamental mode Eigen function distribution. Using Monte Carlo methods complex 3- dimensional geometries and detailed cross section information can be treated. Cross section data are derived from ENDF/B, with anisotropic scattering and discrete or continuous inelastic scattering taken into account. Energy is treated as a continuous variable and time dependence may also be included. 2 - Method of solution: A transformed form of the adjoint Boltzmann equation in integral representation is solved for the space, energy, direction and time variables by Monte Carlo methods. Adjoint particles are defined with properties in some respects contrary to those of neutrons. Adjoint particle histories are constructed from which estimates are obtained of the desired quantity. Adjoint cross sections are defined with which the nuclide and reaction type are selected in a collision. The energy after a collision is selected from adjoint energy distributions calculated together with the adjoint cross sections in advance of the actual Monte Carlo calculation. For multiplying systems successive generations of adjoint particles are obtained which will die out for subcritical systems with a fixed neutron source and will be kept approximately stationary for Eigen function problems. Completely arbitrary problems can
Terekhoff, Serge A.
1997-04-01
This paper summarizes theoretical findings and applications of artificial neural networks to modeling of complex engineered system response in the abnormal environments. The thermal fire impact on the industrial container for waste and fissile materials was investigated using model and experimental data. Solutions for the direct problem show that the generalization properties of neural network based model are significantly better than those for standard interpolation methods. Minimal amount of data required for good prediction of system response is estimated in computer experiments with MLP network. It was shown that Kohonen's self-organizing map with counterpropagation may also estimate local accuracy of regularized solution for inverse and combined problems. Feature space regions of partial correctness of the inverse model can be automatically extracted using adaptive clustering. Practical findings include time strategy recommendations for fire-safe services when industrial or transport accidents occur.
A Hybrid Genetic Algorithm for Vehicle Routing Problem with Complex Constraints
CHEN Yan; LU Jun; LI Zeng-zhi
2006-01-01
Most research on the Vehicle Routing Problem (VRP) is focused on standard conditions, which is not suitable for specific cases. A Hybrid Genetic Algorithm is proposed to solve a Vehicle Routing Problem (VRP) with complex side constraints. A novel coding method is designed especially for side constraints. A greedy algorithm combined with a random algorithm is introduced to enable the diversity of the initial population, as well as a local optimization algorithm employed to improve the searching efficiency. In order to evaluate the performance, this mechanism has been implemented in an oil distribution center, the experimental and executing results show that the near global optimal solution can be easily and quickly obtained by this method, and the solution is definitely satisfactory in the VRP application.
Nanotechnology is widely associated with the promise of positively contributing to sustainability. However, this view often focuses on end-of-pipe applications, for instance, for water purification or energy efficiency, and relies on a narrow concept of sustainability. Approaching sustainability problems and solution options from a comprehensive and systemic perspective instead may yield quite different conclusions about the contribution of nanotechnology to sustainability. This study conceptualizes sustainability problems as complex constellations with several potential intervention points and amenable to different solution options. The study presents results from interdisciplinary workshops and literature reviews that appraise the contribution of the selected nanotechnologies to mitigate such problems. The study focuses exemplarily on the urban context to make the appraisals tangible and relevant. The solution potential of nanotechnology is explored not only for well-known urban sustainability problems such as water contamination and energy use but also for less obvious ones such as childhood obesity. Results indicate not only potentials but also limitations of nanotechnology’s contribution to sustainability and can inform anticipatory governance of nanotechnology in general, and in the urban context in particular.
Wiek, Arnim, E-mail: arnim.wiek@asu.edu; Foley, Rider W. [Arizona State University, School of Sustainability (United States); Guston, David H. [Arizona State University, Center for Nanotechnology in Society, Consortium for Science, Policy and Outcomes (United States)
2012-09-15
Nanotechnology is widely associated with the promise of positively contributing to sustainability. However, this view often focuses on end-of-pipe applications, for instance, for water purification or energy efficiency, and relies on a narrow concept of sustainability. Approaching sustainability problems and solution options from a comprehensive and systemic perspective instead may yield quite different conclusions about the contribution of nanotechnology to sustainability. This study conceptualizes sustainability problems as complex constellations with several potential intervention points and amenable to different solution options. The study presents results from interdisciplinary workshops and literature reviews that appraise the contribution of the selected nanotechnologies to mitigate such problems. The study focuses exemplarily on the urban context to make the appraisals tangible and relevant. The solution potential of nanotechnology is explored not only for well-known urban sustainability problems such as water contamination and energy use but also for less obvious ones such as childhood obesity. Results indicate not only potentials but also limitations of nanotechnology's contribution to sustainability and can inform anticipatory governance of nanotechnology in general, and in the urban context in particular.
Tahvili, Sahar; Österberg, Jonas; Silvestrov, Sergei; Biteus, Jonas
2014-12-01
One of the most important factors in the operations of many cooperations today is to maximize profit and one important tool to that effect is the optimization of maintenance activities. Maintenance activities is at the largest level divided into two major areas, corrective maintenance (CM) and preventive maintenance (PM). When optimizing maintenance activities, by a maintenance plan or policy, we seek to find the best activities to perform at each point in time, be it PM or CM. We explore the use of stochastic simulation, genetic algorithms and other tools for solving complex maintenance planning optimization problems in terms of a suggested framework model based on discrete event simulation.
One of the most important factors in the operations of many cooperations today is to maximize profit and one important tool to that effect is the optimization of maintenance activities. Maintenance activities is at the largest level divided into two major areas, corrective maintenance (CM) and preventive maintenance (PM). When optimizing maintenance activities, by a maintenance plan or policy, we seek to find the best activities to perform at each point in time, be it PM or CM. We explore the use of stochastic simulation, genetic algorithms and other tools for solving complex maintenance planning optimization problems in terms of a suggested framework model based on discrete event simulation
Tahvili, Sahar [Mälardalen University (Sweden); Österberg, Jonas; Silvestrov, Sergei [Division of Applied Mathematics, Mälardalen University (Sweden); Biteus, Jonas [Scania CV (Sweden)
2014-12-10
One of the most important factors in the operations of many cooperations today is to maximize profit and one important tool to that effect is the optimization of maintenance activities. Maintenance activities is at the largest level divided into two major areas, corrective maintenance (CM) and preventive maintenance (PM). When optimizing maintenance activities, by a maintenance plan or policy, we seek to find the best activities to perform at each point in time, be it PM or CM. We explore the use of stochastic simulation, genetic algorithms and other tools for solving complex maintenance planning optimization problems in terms of a suggested framework model based on discrete event simulation.
Cybersecurity vulnerabilities in medical devices: a complex environment and multifaceted problem
Williams PAH
2015-07-01
Full Text Available Patricia AH Williams, Andrew J Woodward eHealth Research Group and Security Research Institute, Edith Cowan University, Perth, WA, Australia Abstract: The increased connectivity to existing computer networks has exposed medical devices to cybersecurity vulnerabilities from which they were previously shielded. For the prevention of cybersecurity incidents, it is important to recognize the complexity of the operational environment as well as to catalog the technical vulnerabilities. Cybersecurity protection is not just a technical issue; it is a richer and more intricate problem to solve. A review of the factors that contribute to such a potentially insecure environment, together with the identification of the vulnerabilities, is important for understanding why these vulnerabilities persist and what the solution space should look like. This multifaceted problem must be viewed from a systemic perspective if adequate protection is to be put in place and patient safety concerns addressed. This requires technical controls, governance, resilience measures, consolidated reporting, context expertise, regulation, and standards. It is evident that a coordinated, proactive approach to address this complex challenge is essential. In the interim, patient safety is under threat. Keywords: cybersecurity, security, safety, wireless, risk, medical devices
The problem of sustainability within the complexity of agricultural production systems
The problem of sustainability is a topic that since the end of the XX century has been worrying more the different sectors of society; becoming one of the topics of greatest interest for managers, consumers, academics and investigators that conform the different agricultural food chains of the world. This paper presents from the general systems theory point of view some elements of critical reflection, approaching the problem of sustainability from the complexity of agricultural production systems, beginning with the original philosophical conception of agricultural and ending by outlining some considerations that should be kept in mind for the development of scientific and technological advances concordant with the agricultural food chain needs of the XX century; which permit an orientation of not only work by profession is who lead the processes of animal and vegetable production, but also creates a sense of pertinence in all of the participants in the chain, highlighting the importance of studying by means of systemic thought, agronomy and animal science, as disciplines that approach to complexities of agriculture which is the angular stone of civilization, such as we know it at the moment
The environmental impacts and waste problems of the Russian Nuclear complex
Russia as a successor state of the former Soviet Union with its big nuclear industry is one of the countries where a big amount of nuclear waste exists and where some regions are strongly affected by radioactive contaminations. In June 2001 the Russian State Duma passed an amendment to the Law on Environmental Protection and paved the way to import nuclear waste in large. The proponents of the law stress that the import will be important for the development of Russian industry and science and Russian authorities believe the income from the spent nuclear fuel import will total at least $20 billions. In view of Russia's problems with the management of the nuclear waste already existing and with the cleaning up of contaminated areas, environmentalists fear that the earnings neither will reach that level nor will be used for cleaning up the many dangerously contaminated areas, and that the massive import of nuclear waste will increase the danger of an environmental catastrophe to occur. Against this background the study gives a view over the most important components of the Russian nuclear complex and discusses its risks and problems as well as the effects on man and nature. National and international measures and aid programmes to remove the problems with the nuclear waste are represented. In comparison with Russia and with regard to the planned nuclear imports international practice of nuclear waste disposal and its problems are discussed. At the end recommendations are formulated which measures should be taken by Russia to decrease security risks by nuclear waste disposal, to reduce the amount of nuclear waste and to foster the search for suitable possibilities of permanent disposal. (orig.)
Perfect absorption in Schr\\"odinger-like problems using non-equidistant complex grids
Weinmüller, Markus; Rohland, Jonathan; Scrinzi, Armin
2015-01-01
Two non-equidistant grid implementations of infinite range exterior complex scaling are introduced that allow for perfect absorption in the time dependent Schr\\"odinger equation. Finite element discrete variables grid discretizations provide as efficient absorption as the corresponding finite elements basis set discretizations. This finding is at variance with results reported in literature [L. Tao et al., Phys. Rev. A 48, 063419 (2009)]. For finite differences, a new class of generalized $Q$-point schemes for non-equidistant grids is derived. Convergence of absorption is exponential $\\sim \\Delta x^{Q-1}$ and numerically robust. Local relative errors $\\sim10^{-9}$ are achieved in a standard problem of strong-field ionization.
Communication: Overcoming the root search problem in complex quantum trajectory calculations
Zamstein, Noa; Tannor, David J. [Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100 (Israel)
2014-01-28
Three new developments are presented regarding the semiclassical coherent state propagator. First, we present a conceptually different derivation of Huber and Heller's method for identifying complex root trajectories and their equations of motion [D. Huber and E. J. Heller, J. Chem. Phys. 87, 5302 (1987)]. Our method proceeds directly from the time-dependent Schrödinger equation and therefore allows various generalizations of the formalism. Second, we obtain an analytic expression for the semiclassical coherent state propagator. We show that the prefactor can be expressed in a form that requires solving significantly fewer equations of motion than in alternative expressions. Third, the semiclassical coherent state propagator is used to formulate a final value representation of the time-dependent wavefunction that avoids the root search, eliminates problems with caustics and automatically includes interference. We present numerical results for the 1D Morse oscillator showing that the method may become an attractive alternative to existing semiclassical approaches.
Communication: Overcoming the root search problem in complex quantum trajectory calculations
Three new developments are presented regarding the semiclassical coherent state propagator. First, we present a conceptually different derivation of Huber and Heller's method for identifying complex root trajectories and their equations of motion [D. Huber and E. J. Heller, J. Chem. Phys. 87, 5302 (1987)]. Our method proceeds directly from the time-dependent Schrödinger equation and therefore allows various generalizations of the formalism. Second, we obtain an analytic expression for the semiclassical coherent state propagator. We show that the prefactor can be expressed in a form that requires solving significantly fewer equations of motion than in alternative expressions. Third, the semiclassical coherent state propagator is used to formulate a final value representation of the time-dependent wavefunction that avoids the root search, eliminates problems with caustics and automatically includes interference. We present numerical results for the 1D Morse oscillator showing that the method may become an attractive alternative to existing semiclassical approaches
Computational researches about a problem of experiments on target complex TS-1
A benchmark problem presented at the '10th International meetings of the working group on advanced nuclear reactors thermal-hydraulics' in Obninsk, Russia, in 2001, is the starting point for some computational researches validated against experiments on target complex TS-1. The window model of the Accelerator Driven System (ADS) target TS-1, is under development in the State Scientific Center of Russian Federation Institute of Physics and Power Engineering (SSC RF IPPE) and Joint Design Bureau 'Gidropress' for accelerator LANSCE in Los Alamos National Laboratory. The experiments were carried out with sodium-potassium eutectic alloy: 22% Na + 78% K. Different grids, different turbulence models, and different assumptions were tried using the CFD (Computational Fluid Dynamics) codes STAR-CD and FLUENT. It is a big challenge for these CFD codes, to simulate flows with low Prandtl number fluids, such as the liquid metals. (author)
On the Over-Fitting Problem of Complex Feature Selection Methods
Somol, Petr; Novovičová, Jana; Pudil, Pavel
Káhira: Cairo University, 2009, s. 12-17. [5th International Computer Engineering Conference - A better Information Society Through the e@. Káhira (EG), 27.12.2009-28.12.2009] R&D Projects: GA MŠk 1M0572; GA ČR GA102/07/1594; GA ČR GA102/08/0593 Grant ostatní: GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : feature selection * overfitting * overselection Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2010/RO/somol-on the over-fitting problem of complex feature selection methods.pdf
Environmental epidemiology: Epidemiological investigation of community environmental health problems
Goldsmith, J.R.
1985-01-01
This volume brings together the experiences of practicing epidemiologists in solving world-wide community environmental health problems. Emphasis is placed on problems facing the community, methods of analysis, and means and results of action. Actual case histories of various complexity provide exercises in solving community health problems using applicable elementary concepts of statistics.
Angeli, Charoula; Valanides, Nicos
2013-01-01
The present study investigated the problem-solving performance of 101 university students and their interactions with a computer modeling tool in order to solve a complex problem. Based on their performance on the hidden figures test, students were assigned to three groups of field-dependent (FD), field-mixed (FM), and field-independent (FI)…
Eseryel, Deniz; Ifenthaler, Dirk; Ge, Xun
2013-01-01
The important but little understood problem that motivated this study was the lack of research on valid assessment methods to determine progress in higher-order learning in situations involving complex and ill-structured problems. Without a valid assessment method, little progress can occur in instructional design research with regard to designing…
Winkel, Brian
2008-01-01
A complex technology-based problem in visualization and computation for students in calculus is presented. Strategies are shown for its solution and the opportunities for students to put together sequences of concepts and skills to build for success are highlighted. The problem itself involves placing an object under water in order to actually see…
Efstratiadis, Andreas; Tsoukalas, Ioannis; Kossieris, Panayiotis; Karavokiros, George; Christofides, Antonis; Siskos, Alexandros; Mamassis, Nikos; Koutsoyiannis, Demetris
2015-04-01
Modelling of large-scale hybrid renewable energy systems (HRES) is a challenging task, for which several open computational issues exist. HRES comprise typical components of hydrosystems (reservoirs, boreholes, conveyance networks, hydropower stations, pumps, water demand nodes, etc.), which are dynamically linked with renewables (e.g., wind turbines, solar parks) and energy demand nodes. In such systems, apart from the well-known shortcomings of water resources modelling (nonlinear dynamics, unknown future inflows, large number of variables and constraints, conflicting criteria, etc.), additional complexities and uncertainties arise due to the introduction of energy components and associated fluxes. A major difficulty is the need for coupling two different temporal scales, given that in hydrosystem modeling, monthly simulation steps are typically adopted, yet for a faithful representation of the energy balance (i.e. energy production vs. demand) a much finer resolution (e.g. hourly) is required. Another drawback is the increase of control variables, constraints and objectives, due to the simultaneous modelling of the two parallel fluxes (i.e. water and energy) and their interactions. Finally, since the driving hydrometeorological processes of the integrated system are inherently uncertain, it is often essential to use synthetically generated input time series of large length, in order to assess the system performance in terms of reliability and risk, with satisfactory accuracy. To address these issues, we propose an effective and efficient modeling framework, key objectives of which are: (a) the substantial reduction of control variables, through parsimonious yet consistent parameterizations; (b) the substantial decrease of computational burden of simulation, by linearizing the combined water and energy allocation problem of each individual time step, and solve each local sub-problem through very fast linear network programming algorithms, and (c) the substantial
Most elliptic interface solvers become complicated for complex interface problems at those “exceptional points” where there are not enough neighboring interior points for high order interpolation. Such complication increases especially in three dimensions. Usually, the solvers are thus reduced to low order accuracy. In this paper, we classify these exceptional points and propose two recipes to maintain order of accuracy there, aiming at improving the previous coupling interface method [26]. Yet the idea is also applicable to other interface solvers. The main idea is to have at least first order approximations for second order derivatives at those exceptional points. Recipe 1 is to use the finite difference approximation for the second order derivatives at a nearby interior grid point, whenever this is possible. Recipe 2 is to flip domain signatures and introduce a ghost state so that a second-order method can be applied. This ghost state is a smooth extension of the solution at the exceptional point from the other side of the interface. The original state is recovered by a post-processing using nearby states and jump conditions. The choice of recipes is determined by a classification scheme of the exceptional points. The method renders the solution and its gradient uniformly second-order accurate in the entire computed domain. Numerical examples are provided to illustrate the second order accuracy of the presently proposed method in approximating the gradients of the original states for some complex interfaces which we had tested previous in two and three dimensions, and a real molecule ( (1D63)) which is double-helix shape and composed of hundreds of atoms
Managing the Complexity of Design Problems through Studio-Based Learning
Cennamo, Katherine; Brandt, Carol; Scott, Brigitte; Douglas, Sarah; McGrath, Margarita; Reimer, Yolanda; Vernon, Mitzi
2011-01-01
The ill-structured nature of design problems makes them particularly challenging for problem-based learning. Studio-based learning (SBL), however, has much in common with problem-based learning and indeed has a long history of use in teaching students to solve design problems. The purpose of this ethnographic study of an industrial design class,…
Bringing Reading Research to Life
McKeown, Margaret G., Ed.; Kucan, Linda, Ed.
2009-01-01
This book brings together some of the world's foremost literacy scholars to discuss how research influences what teachers actually do in the classroom. Chapters describe the current state of knowledge about such key topics as decoding, vocabulary, comprehension, digital literacies, reading disabilities, and reading reform. At the same time, the…
... Contact Us More COPD: Lifestyle Management Avoiding Infections Breathing Retraining Techniques to Bring Up Mucus Exercises Giving Up Smoking ... mucus is allowed to collect in the airways, breathing may become difficult and infection may occur. Techniques to remove mucus are often done after using ...
Bringing science to the people
This is an opinion editorial piece about the International Society for Horticultural Science (ISHS). It describes the active role that the ISHS takes in bringing scientific information to people throughout the world. The society holds periodic symposia on 10 different crops and 14 different cross-co...
Bringing Globalization into the Classroom
Billings, Nancy Carter
2006-01-01
Some of the most effective resources for bringing the concept of globalization into the classroom is through the personal and professional experiences of the classroom teacher, the personal experiences of students from diverse cultures, the inclusion of curriculum activities with a global context, and the involvement of guest speakers with global…
Neubert, Jonas; Mainert, Jakob; Kretzschmar, André; Greiff, Samuel
2015-01-01
In the current paper, we highlight why and how industrial and organizational psychology can take advantage of research on 21st century skills and their assessment. We present vital theoretical perspectives, a suitable framework for assessment, and exemplary instruments with a focus on advances in the assessment of Human Capital. Specifically, Complex Problem Solving (CPS) and Collaborative Problem Solving (ColPS) are two transversal skills (i.e., skills that span multiple domains) that are...
World, We Have Problems: Simulation for Large Complex, Risky Projects, and Events
Elfrey, Priscilla
2010-01-01
Prior to a spacewalk during the NASA STS/129 mission in November 2009, Columbia Broadcasting System (CBS) correspondent William Harwood reported astronauts, "were awakened again", as they had been the day previously. Fearing something not properly connected was causing a leak, the crew, both on the ground and in space, stopped and checked everything. The alarm proved false. The crew did complete its work ahead of schedule, but the incident reminds us that correctly connecting hundreds and thousands of entities, subsystems and systems, finding leaks, loosening stuck valves, and adding replacements to very large complex systems over time does not occur magically. Everywhere major projects present similar pressures. Lives are at - risk. Responsibility is heavy. Large natural and human-created disasters introduce parallel difficulties as people work across boundaries their countries, disciplines, languages, and cultures with known immediate dangers as well as the unexpected. NASA has long accepted that when humans have to go where humans cannot go that simulation is the sole solution. The Agency uses simulation to achieve consensus, reduce ambiguity and uncertainty, understand problems, make decisions, support design, do planning and troubleshooting, as well as for operations, training, testing, and evaluation. Simulation is at the heart of all such complex systems, products, projects, programs, and events. Difficult, hazardous short and, especially, long-term activities have a persistent need for simulation from the first insight into a possibly workable idea or answer until the final report perhaps beyond our lifetime is put in the archive. With simulation we create a common mental model, try-out breakdowns of machinery or teamwork, and find opportunity for improvement. Lifecycle simulation proves to be increasingly important as risks and consequences intensify. Across the world, disasters are increasing. We anticipate more of them, as the results of global warming
On Bringing Industry English Teaching into College English Course
魏圆圆
2016-01-01
With the development of global economy, it’s becoming increasingly important to bring industry English into College English Course. But there are still many problems about industry English teaching in most colleges. This paper will analyze these problems and put forward effective measures to promote industry English teaching.
Evolving hard problems: Generating human genetics datasets with a complex etiology
Himmelstein Daniel S
2011-07-01
Full Text Available Abstract Background A goal of human genetics is to discover genetic factors that influence individuals' susceptibility to common diseases. Most common diseases are thought to result from the joint failure of two or more interacting components instead of single component failures. This greatly complicates both the task of selecting informative genetic variants and the task of modeling interactions between them. We and others have previously developed algorithms to detect and model the relationships between these genetic factors and disease. Previously these methods have been evaluated with datasets simulated according to pre-defined genetic models. Results Here we develop and evaluate a model free evolution strategy to generate datasets which display a complex relationship between individual genotype and disease susceptibility. We show that this model free approach is capable of generating a diverse array of datasets with distinct gene-disease relationships for an arbitrary interaction order and sample size. We specifically generate eight-hundred Pareto fronts; one for each independent run of our algorithm. In each run the predictiveness of single genetic variation and pairs of genetic variants have been minimized, while the predictiveness of third, fourth, or fifth-order combinations is maximized. Two hundred runs of the algorithm are further dedicated to creating datasets with predictive four or five order interactions and minimized lower-level effects. Conclusions This method and the resulting datasets will allow the capabilities of novel methods to be tested without pre-specified genetic models. This allows researchers to evaluate which methods will succeed on human genetics problems where the model is not known in advance. We further make freely available to the community the entire Pareto-optimal front of datasets from each run so that novel methods may be rigorously evaluated. These 76,600 datasets are available from http://discovery.dartmouth.edu/model_free_data/.
Untangling the Complex Needs of People Experiencing Gambling Problems and Homelessness
Holdsworth, Louise; Tiyce, Margaret
2013-01-01
People with gambling problems are now recognised among those at increased risk of homelessness, and the link between housing and gambling problems has been identified as an area requiring further research. This paper discusses the findings of a qualitative study that explored the relationship between gambling problems and homelessness. Interviews…
Anagnostopoulos, K. N.; Nishimura, J.
2002-11-01
Monte Carlo simulations of a system whose action has an imaginary part are considered to be extremely difficult. We propose a new approach to this ``complex-action problem,'' which utilizes a factorization property of distribution functions. The basic idea is quite general, and it removes the so-called overlap problem completely. Here we apply the method to a nonperturbative study of superstring theory using its matrix formulation. In this particular example, the distribution function turns out to be positive definite, which allows us to reduce the problem even further. Our numerical results suggest an intuitive explanation for the dynamical generation of 4D space-time.
A correct even-odd algorithm for the point-in-polygon (PIP) problem for complex polygons
Galetzka, Michael; Glauner, Patrick O.
2012-01-01
Determining if a point is in a polygon or not is used by a lot of applications in computer graphics, computer games and geoinformatics. Implementing this check is error-prone since there are many special cases to be considered. In this paper we present a simple even-odd algorithm to solve this problem for complex polygons in linear time.
Greiff, Samuel; Wustenberg, Sascha; Molnar, Gyongyver; Fischer, Andreas; Funke, Joachim; Csapo, Beno
2013-01-01
Innovative assessments of cross-curricular competencies such as complex problem solving (CPS) have currently received considerable attention in large-scale educational studies. This study investigated the nature of CPS by applying a state-of-the-art approach to assess CPS in high school. We analyzed whether two processes derived from cognitive…
Muis, Krista R.; Psaradellis, Cynthia; Chevrier, Marianne; Di Leo, Ivana; Lajoie, Susanne P.
2016-01-01
We developed an intervention based on the learning by teaching paradigm to foster self-regulatory processes and better learning outcomes during complex mathematics problem solving in a technology-rich learning environment. Seventy-eight elementary students were randomly assigned to 1 of 2 conditions: learning by preparing to teach, or learning for…
Modelling of Octahedral Manganese II Complexes with Inorganic Ligands: A Problem with Spin-States
Ludwik Adamowicz
2003-08-01
Full Text Available Abstract: Quantum mechanical ab initio UHF, MP2, MC-SCF and DFT calculations with moderate Gaussian basis sets were performed for MnX6, X = H2O, F-, CN-, manganese octahedral complexes. The correct spin-state of the complexes was obtained only when the counter ions neutralizing the entire complexes were used in the modelling at the B3LYP level of theory.
Yates, Jennifer L.
2011-01-01
The purpose of this research study was to explore the process of learning and development of problem solving skills in radiologic technologists. The researcher sought to understand the nature of difficult problems encountered in clinical practice, to identify specific learning practices leading to the development of professional expertise, and to…
On the Combinatorics of SAT and the Complexity of Planar Problems
Talebanfard, Navid
In this thesis we study several problems arising in Boolean satisfiability ranging from lower bounds for SAT algorithms and proof systems to extremal properties of formulas. The first problem is about construction of hard instances for k-SAT algorithms. For PPSZ algorithm [40] we give the first...
Exponential-Time Algorithms and Complexity of NP-Hard Graph Problems
Taslaman, Nina Sofia
NP-hard problems are deemed highly unlikely to be solvable in polynomial time. Still, one can often find algorithms that are substantially faster than brute force solutions. This thesis concerns such algorithms for problems from graph theory; techniques for constructing and improving this type of...
Introducing the Hero Complex and the Mythic Iconic Pathway of Problem Gambling
Nixon, Gary; Solowoniuk, Jason
2009-01-01
Early research into the motivations behind problem gambling reflected separate paradigms of thought splitting our understanding of the gambler into divergent categories. However, over the past 25 years, problem gambling is now best understood to arise from biological, environmental, social, and psychological processes, and is now encapsulated…
Numerical nonlinear complex geometrical optics algorithm for the 3D Calderón problem
Delbary, Fabrice; Knudsen, Kim
2014-01-01
The Calderon problem is the mathematical formulation of the inverse problem in Electrical Impedance Tomography and asks for the uniqueness and reconstruction of an electrical conductivity distribution in a bounded domain from the knowledge of the Dirichlet-to-Neumann map associated to the...
Bringing nursing to the public.
Kazis, Cornelia; Schwendimann, René
2009-11-01
For the past 5 years, an unusual program has been evolving in the University of Basel's Institute of Nursing Science master's program in Basel, Switzerland. A special course designed to help nurses master public communication skills requires students to play the roles of journalist, exhibition curator, conference organizer, radio reporter, and news producer. Two faculty members, an experienced radio and newspaper journalist and a nurse scientist, teach and support the students. By developing their competence in media relations, participants prepare themselves to tackle the course's long-term goal of bringing the nursing profession into the public eye. PMID:19731893
Analysis and formulation of a class of complex dynamic optimization problems
Kameswaran, Shivakumar
The Direct Transcription approach, also known as the direct simultaneous approach, is a widely used solution strategy for the solution of dynamic optimization problems involving differential-algebraic equations (DAEs). Direct transcription refers to the procedure of approximating the infinite dimensional problem by a finite dimensional one, which is then solved using a nonlinear programming (NLP) solver tailored to large-scale problems. Systems governed by partial differential equations (PDEs) can also be handled by spatially discretizing the PDEs to convert them to a system of DAEs. The objective of this thesis is firstly to ensure that direct transcription using Radau collocation is provably correct, and secondly to widen the applicability of the direct simultaneous approach to a larger class of dynamic optimization and optimal control problems (OCPs). This thesis aims at addressing these issues using rigorous theoretical tools and/or characteristic examples, and at the same time use the results for solving large-scale industrial applications to realize the benefits. The first part of this work deals with the analysis of convergence rates for direct transcription of unconstrained and final-time equality constrained optimal control problems. The problems are discretized using collocation at Radau points. Convergence is analyzed from an NLP/matrix-algebra perspective, which enables the prediction of the conditioning of the direct transcription NLP as the mesh size becomes finer. Several convergence results are presented along with tests on numerous example problems. These convergence results lead to an adjoint estimation procedure given the Lagrange multipliers for the large-scale NLP. The work also reveals the role of process control concepts such as controllability on the convergence analysis, and provides a very important link between control and optimization inside the framework of dynamic optimization. As an effort to extend the applicability of the direct
Computer Security Team
2013-01-01
Have you ever heard of “BYOD”? No, it is not a pop band. Try again. It is short for “Bring Your Own Device” (the French use “AVEC” - “Apporter Votre Equipement personnel de Communication”) and describes an option long since offered at CERN: the possibility to bring along your personal laptop, smartphone or PDA, use it on CERN premises and connect it to the CERN office network. But hold on. As practical as it is, there is also a dark side. The primary advantage, of course, is having a digital work environment tuned to your needs and preferences. It allows you to continue working at home. Similarly, you always have your music, address books and bookmarks with you. However, as valuable as this is, it is also a responsibility. Laptop theft is happening - outside CERN but also on site. In France, 30% of stolen laptops were stolen out of cars or homes, and 10% during travel. At CERN, on average one ...
Bringing Technology into Physics Classrooms
Zettlili, Nouredine
2009-05-01
Through our outreach initiative at Jacksonville State University, we have been supporting a number of school districts in Northeast Alabama to improve the teaching of physics at the high school level. This initiative is part of Project IMPACTSEED (IMproving Physics And Chemistry Teaching in SEcondary Education), a grant funded by the Alabama Commission on Higher Education. This project is motivated by a major pressing local need: A large number of high school physics teachers teach out of field. The main aim of project IMPACTSEED is to help teachers learn and master the various physics topics required by the Alabama Course of Study. Teachers are offered year-round support through a rich variety of program. In this presentation, we want to present ideas on ways of bringing technology to physics classrooms. We have identified a number of ways of bringing technology into physics classrooms, most notably through a series of make-and-take technology workshops that were developed over several years of research. In turn, when the teachers assign these make-an-take projects to their students, the students will be able to see first-hand---by doing, rather than being told---that physics is not a dry, abstract subject. We found this approach to be particularly effective in heightening the students' interest in math and science.
Mayo, L. H.
1975-01-01
The contextual approach is discussed which undertakes to demonstrate that technology assessment assists in the identification of the full range of implications of taking a particular action and facilitates the consideration of alternative means by which the total affected social problem context might be changed by available project options. It is found that the social impacts of an application on participants, institutions, processes, and social interests, and the accompanying interactions may not only induce modifications in the problem contest delineated for examination with respect to the design, operations, regulation, and use of the posited application, but also affect related social problem contexts.
On the Complexity of the Minimum Latency Scheduling Problem on the Euclidean Plane
Lin, Henry
2012-01-01
We show NP-hardness of the minimum latency scheduling (MLS) problem under the physical model of wireless networking. In this model a transmission is received successfully if the Signal to Interference-plus-Noise Ratio (SINR), is above a given threshold. In the minimum latency scheduling problem, the goal is to assign a time slot and power level to each transmission, so that all the messages are received successfully, and the number of distinct times slots is minimized. Despite its seeming simplicity and several previous hardness results for various settings of the minimum latency scheduling problem, it has remained an open question whether or not the minimum latency scheduling problem is NP-hard, when the nodes are placed in the Euclidean plane and arbitrary power levels can be chosen for the transmissions. We resolve this open question for all path loss exponent values $\\alpha \\geq 3$.
Fajstrup, Lisbeth
2005-01-01
computer science disciplines which attract geometric methods is concurrency. Modern computers have more than one processor, and hence the execution of a program will often be distributed to different processors who then have to exchange information, to share memory, printers etc. For a fast execution, it...... is preferable that many processors work concurrently. On the other hand, the non-determinism introduced by various processors with their own local time and pace is problematic in verification that executions will do what they are expected to. Another problem introduced is the vast number of states in...... such a concurrent program - to check that a program will always behave correctly involves checking that all possible states are acceptable. This problem is referred to as the state space explosion problem. To discuss the problems, one needs a good model for concurrency. A model describing a program...
Local Fourier Analysis of the Complex Shifted Laplacian preconditioner for Helmholtz problems
Cools, Siegfried
2011-01-01
In this paper we solve the Helmholtz equation with multigrid preconditioned Krylov subspace methods. The class of Shifted Laplacian preconditioners are known to significantly speed-up Krylov convergence. However, these preconditioners have a parameter \\beta, a measure of the complex shift. Due to contradictory requirements for the multigrid and Krylov convergence, the choice of this shift parameter can be a bottleneck in applying the method. In this paper, we propose a wavenumber-dependent minimal complex shift parameter which is predicted by a rigorous k-grid Local Fourier Analysis (LFA) of the multigrid scheme. We claim that, given any (regionally constant) wavenumber, this minimal complex shift parameter provides the reader with a parameter choice that leads to efficient Krylov convergence. Numerical experiments in one and two spatial dimensions validate the theoretical results. It appears that the proposed complex shift is both the minimal requirement for a multigrid V-cycle to converge, as well as being ...
Theses of reports of the Fourth youth scientifically-practical conference Nuclear-industrial complex of Ural: problems and prospects (18-20 April 2007, Ozersk) are presented. The book contains theses of reports of the seventh subject sections: NFC: science and industry; Ecological problems in NFC development: radiation safety, radioecology and radiobiology; Nuclear power engineering: economics, safety, field experience; Atomic branch: history, today and future; New technologies in education. Education and training for NFC plants, public opinion; Information technologies and telecommunications; Long-term science intensive technologies and new materials
Does song complexity correlate with problem-solving performance in flocks of zebra finches?
Templeton, Christopher Neal; Laland, Kevin Neville; Boogert, Neeltje Janna
2014-01-01
The ‘cognitive capacity hypothesis’ states that song complexity could potentially be used by prospective mates to assess an individual's overall cognitive ability. Several recent studies have provided support for the cognitive capacity hypothesis, demonstrating that individuals with more complex songs or larger song repertoires performed better on various learning tasks. These studies all measured individuals' learning performance in social isolation. However, for gregarious species such as t...
Odendaal, Karen
2015-01-01
Accounting transactions are becoming more complex, and more extensive accounting guidance is provided on a continuous basis in the accounting standards. In addition, accounting guidance changes often and additional guidance is added to the standards regularly. In view of this immense amount of accounting knowledge that an accountant can be expected to have, exacerbated by often multifaceted structures in accounting problems, it can be challenging and onerous to solve certain ac...
Modeling of the conjugate radiation and conduction problem in a 3D complex multi-burner furnace
Lari Khosro; Gandjalikhan Nassab Abdolreza Seyyed
2012-01-01
Radiation is a major component of heat transfer in the modeling of furnaces. In this study, coupled radiative and conductive heat transfer problems are analyzed in complex geometries with inhomogeneous and anisotropic scattering participating media. A three-dimensional model is developed using combination of the discrete ordinates method and blocked-off-region procedure. The finite volume method has been adopted to solve the energy equation and the radiative source term in the energy eq...
SIPPI: A Matlab toolbox for sampling the solution to inverse problems with complex prior information
Hansen, Thomas Mejer; Cordua, Knud Skou; Looms, Majken Caroline;
2013-01-01
We present an application of the SIPPI Matlab toolbox, to obtain a sample from the a posteriori probability density function for the classical tomographic inversion problem. We consider a number of different forward models, linear and non-linear, such as ray based forward models that rely on the...... high frequency approximation of the wave-equation and ‘fat’ ray based forward models relying on finite frequency theory. In order to sample the a posteriori probability density function we make use of both least squares based inversion, for linear Gaussian inverse problems, and the extended Metropolis...... sampler, for non-linear non-Gaussian inverse problems. To illustrate the applicability of the SIPPI toolbox to a tomographic field data set we use a cross-borehole traveltime data set from Arrenæs, Denmark. Both the computer code and the data are released in the public domain using open source and open...
Martín H, José Antonio
2013-01-01
Many practical problems in almost all scientific and technological disciplines have been classified as computationally hard (NP-hard or even NP-complete). In life sciences, combinatorial optimization problems frequently arise in molecular biology, e.g., genome sequencing; global alignment of multiple genomes; identifying siblings or discovery of dysregulated pathways. In almost all of these problems, there is the need for proving a hypothesis about certain property of an object that can be present if and only if it adopts some particular admissible structure (an NP-certificate) or be absent (no admissible structure), however, none of the standard approaches can discard the hypothesis when no solution can be found, since none can provide a proof that there is no admissible structure. This article presents an algorithm that introduces a novel type of solution method to "efficiently" solve the graph 3-coloring problem; an NP-complete problem. The proposed method provides certificates (proofs) in both cases: present or absent, so it is possible to accept or reject the hypothesis on the basis of a rigorous proof. It provides exact solutions and is polynomial-time (i.e., efficient) however parametric. The only requirement is sufficient computational power, which is controlled by the parameter α∈N. Nevertheless, here it is proved that the probability of requiring a value of α>k to obtain a solution for a random graph decreases exponentially: P(α>k)≤2(-(k+1)), making tractable almost all problem instances. Thorough experimental analyses were performed. The algorithm was tested on random graphs, planar graphs and 4-regular planar graphs. The obtained experimental results are in accordance with the theoretical expected results. PMID:23349711
Hyytinen, Heidi; Holma, Katariina; Toom, Auli; Shavelson, Richard J.; Lindblom-Ylänne, Sari
2014-01-01
The study utilized a multi-method approach to explore the connection between critical thinking and epistemological beliefs in a specific problem-solving situation. Data drawn from a sample of ten third-year bioscience students were collected using a combination of a cognitive lab and a performance task from the Collegiate Learning Assessment…
SIPPI: A Matlab toolbox for sampling the solution to inverse problems with complex prior information
Hansen, Thomas Mejer; Cordua, Knud Skou; Caroline Looms, Majken; Mosegaard, Klaus
2013-01-01
solution. The combined states of information (i.e. the solution to the inverse problem) is a probability density function typically referred to as the a posteriori probability density function. We present a generic toolbox for Matlab and Gnu Octave called SIPPI that implements a number of methods for...
Isoperimetric Functions of Groups and Computational Complexity of the Word Problem
Birget, J. -C.; Olshanskii, A. Yu.; Rips, E.; Sapir, M.
1998-01-01
We prove that the word problem of a finitely generated group $G$ is in NP (solvable in polynomial time by a non-deterministic Turing machine) if and only if this group is a subgroup of a finitely presented group $H$ with polynomial isoperimetric function. The embedding can be chosen in such a way that $G$ has bounded distortion in $H$.
Forecasting of Processes in Complex Systems for Real-World Problems
Pelikán, Emil
2014-01-01
Roč. 24, č. 6 (2014), s. 567-589. ISSN 1210-0552 Institutional support: RVO:67985807 Keywords : complex systems * data assimilation * ensemble forecasting * forecasting * global solar radiation * judgmental forecasting * multimodel forecasting * pollution Subject RIV: IN - Informatics, Computer Science Impact factor: 0.479, year: 2014
Foucault as Complexity Theorist: Overcoming the Problems of Classical Philosophical Analysis
Olssen, Mark
2008-01-01
This article explores the affinities and parallels between Foucault's Nietzschean view of history and models of complexity developed in the physical sciences in the twentieth century. It claims that Foucault's rejection of structuralism and Marxism can be explained as a consequence of his own approach which posits a radical ontology whereby the…
Eseryel, Deniz; Ge, Xun; Ifenthaler, Dirk; Law, Victor
2011-01-01
Following a design-based research framework, this article reports two empirical studies with an educational MMOG, called "McLarin's Adventures," on facilitating 9th-grade students' complex problem-solving skill acquisition in interdisciplinary STEM education. The article discusses the nature of complex and ill-structured problem solving and,…
Zhang, Hao; Trias, F Xavier; Yu, Aibing; Tan, Yuanqiang; Oliva, Assensi
2015-01-01
In our recent work [H. Zhang, F.X. Trias, A. Oliva, D. Yang, Y. Tan, Y. Sheng. PIBM: Particulate immersed boundary method for fluid-particle interaction problems. Powder Technology. 272(2015), 1-13.], a particulate immersed boundary method (PIBM) for simulating fluid-particle multiphase flow was proposed and assessed in both two- and three-dimensional applications. In this study, the PIBM was extended to solve thermal interaction problems between spherical particles and fluid. The Lattice Boltzmann Method (LBM) was adopted to solve the fluid flow and temperature fields, the PIBM was responsible for the non-slip velocity and temperature boundary conditions at the particle surface, and the kinematics and trajectory of the solid particles were evaluated by the Discrete Element Method (DEM). Four case studies were implemented to demonstrate the capability of the current coupling scheme. Firstly, numerical simulation of natural convection in a two-dimensional square cavity with an isothermal concentric annulus was...
Complexity of matrix organization and problems caused by its inadequate implementation
Janićijević Nebojša
2007-01-01
Full Text Available Matrix organization model is a sophisticated structure intended to combine both the efficiency and effectiveness of the functional and the product/service/customer/area dimensions. From the moment it was introduced in practice, this organizational architecture was accepted with enthusiasm, because it represented a complex organizational response adequate to the conditions which most of the companies in the world have been facing since 1970s. Although matrix organization is not a novelty, it is still a controversial model of organization design. The aim of this paper is to provide a deeper insight into the causes and effects of organizational misfits which appear in the implementation phase of three-dimensional matrix organization, as well as to offer some practical recommendations for managers on how to improve their capacities for successful management of complex matrix organization architecture in their organizations.