Science.gov (United States)

... By comparing the behavior of individuals tackling the missionaries and cannibals problem to pairs of people solving this problem, we have been ...

International Nuclear Information System (INIS)

EPRI's Steam Generator Strategic Management Project issues an annual report on the progress being made in tackling steam generator problems worldwide, containing a wealth of detailed statistics on the status of operating units and degradation mechanisms encountered. A few highlights are presented from the latest report, issued in October 1993, which covers the period to 31 December 1992. (Author).

Energy Technology Data Exchange (ETDEWEB)

Malfunctions in machinery are often sources of reduced productivity and increased maintenance costs in various industrial applications. For this reason, machine condition monitoring is being pursued to recognise incipient faults. In this paper, the fault diagnostic problem is tackled within a neuro-fuzzy approach to pattern classification. Besides the primary purpose of a high rate of correct classification, the proposed neuro-fuzzy approach also aims at obtaining an easily interpretable classification model. The efficiency of the approach is verified with respect to a literature problem and then applied to a case of motor bearing fault classification.

International Nuclear Information System (INIS)

Analytical solutions are derived for a flow in a semi-infinite vertical porous medium with heat and mass transfer. When the temperature and mass concentration are uniform a constant pressure is possible and sustains a fully developed flow. Thereafter there is a small perturbation on the wall temperature and concentration and the subsequent two-dimensional problem is tackled for a large Prandtl number, free convection parameters and small Reynolds number. The heat transfer rate at the wall is discussed quantitatively. (author). 4 refs.

Science.gov (United States)

A series of studies conducted to identify the factors that block and unblock problem solving is described. Through the construction of an isomorph of the classic "water jar" problems developed by A. S. Luchins (1942) as a dynamic graphic micro-world, several factors involved in producing blocked states were identified. Subjects included 10 individuals and 10 pairs of subjects. By comparing the behavior of individuals tackling the "missionaries and cannibals" problem to that of pairs of subjects solving this problem, a study identified means by which problem solvers operating in a social context are able to overcome blocks that discourage individuals. These studies point to the importance of "reflection" (evaluation of problem-solving results) for flexible problem solving. This research suggests that teaching students to ...

Energy Technology Data Exchange (ETDEWEB)

The author investigates whether the international law regime so far has developed any legal principles dealing with the problem of the dumping of radioactive waste in the sub-seabed, and whether any of such provisions available adequately tackle the problem in the light of the gravity of danger emanating from radioactive waste. The study covers over 30 different texts of international treaties and protocols. Points of main interest are the London Dumping Convention and the Montego Bay Convention on the Law of the Sea. The author concludes that the disposal of radioactive waste into the seabed belongs to the permissible, although not specially allowed activities within the framework of the freedom of the high seas, and therefore urgently calls for establishing an international regulatory system pertaining to the planning and accomplishment of such activities. An outline legal concept of a regulatory system is explained. ...

Energy Technology Data Exchange (ETDEWEB)

Rehabilitation of the abandoned uranium mining areas in Saxonia and Thuringia is a task posing also legal problems. The radiation protection laws of the former GDR continued to be effective to a great extent and proved to be a legal basis not ``perfect`` in formal terms, but suitably efficient in practice to tackle the manifold problems encountered in the land reclamation and waste disposal work. Originally intended to serve as a legal interim regime awaiting amendment at a later date, the body of laws available for the task proved to be a sufficient basis. (orig./HP) [Deutsch] Das fortgeltende Strahlenschutzrecht der frueheren DDR hat sich zwar nicht als formal `perfektes`, in der Sache aber strahlenschutzgerechtes und praktikables Instrument zur Loesung der anstehenden Sanierungsaufgaben erwiesen. Bei seiner Beurteilung darf nicht ausser Acht gelassen werden, dass die Ueberleitung dieses Rechts seinerzeit aus der Not ...

CERN Document Server

Mobile entities with wireless links are able to form a mobile ad-hoc network. Such an infrastructureless network does not have to be administrated. However, self-organizing principles have to be applied to deal with upcoming problems, e.g. information dissemination. These kinds of problems are not easy to tackle, requiring complex algorithms. Moreover, the usefulness of pure ad-hoc networks is arguably limited. Hence, enthusiasm for mobile ad-hoc networks, which could eliminate the need for any fixed infrastructure, has been damped. The goal is to overcome the limitations of pure ad-hoc networks by augmenting them with instant Internet access, e.g. via integration of UMTS respectively GSM links. However, this raises multiple questions at the technical as well as the organizational level. Motivated by characteristics of small-world networks that describe an efficient network even without central or organized design, this ...

Medline Plus

... Neglect (12) Co-Occurring Disorders (75) Conduct Disorders (3) D Dementia (2) Depression (51) Driving While Intoxicated (17) ...

Medline Plus

... Spectrum Disorders (25) G Grief (3) H HIV & AIDS (15) I Infectious Diseases (22) Injection Drug Use ( ...

Energy Technology Data Exchange (ETDEWEB)

In the field of reactor and fuel cycle physics, particle transport plays and important role. Neutronic design, operation and evaluation calculations of nuclear system make use of large and powerful computer codes. However, current limitations in terms of computer resources make it necessary to introduce simplifications and approximations in order to keep calculation time and cost within reasonable limits. Two different types of methods are available in these codes. The first one is the deterministic method, which is applicable in most practical cases but requires approximations. The other method is the Monte Carlo method, which does not make these approximations but which generally requires exceedingly long running times. The main motivation of this work is to investigate the possibility of a combined use of the two methods in such a way as to retain their advantages while avoiding their drawbacks. Our work has mainly focused on the speed-up of 3-D continuous energy Monte Carlo ...

Medline Plus

... HIV & AIDS (15) I Infectious Diseases (21) Injection Drug Use (7) M Mental Illness (139) Mortality (7) ... Hallucinogens (5) Hashish (2) Heroin (21) I Illegal Drugs (115) Inhalants (12) K Ketamine (1) L LSD ( ...

Medline Plus

... HIV & AIDS (15) I Infectious Diseases (21) Injection Drug Use (7) M Mental Illness (139) Mortality (7) ... Hallucinogens (5) Hashish (2) Heroin (21) I Illegal Drugs (112) Inhalants (12) K Ketamine (1) L LSD ( ...

Energy Technology Data Exchange (ETDEWEB)

This work is a theoretical investigation on the physical properties of semiconductor-based two-dimensional photonic crystals, in particular for what concerns systems embedded in planar dielectric waveguides (GaAs/AlGaAs, GaInAsP/InP heterostructures, and self-standing membranes) or based on macro-porous silicon. The photonic-band structure of photonic crystals and photonic-crystal slabs is numerically computed and the associated light-line problem is discussed, which points to the issue of intrinsic out-of-lane diffraction losses for the photonic bands lying above the light line. The photonic states are then classified by the group theory formalism: each mode is related to an irreducible representation of the corresponding small point group. The optical properties are investigated by means of the scattering matrix method, which numerically implements a variable-angle-reflectance experiment; comparison with experiments is also provided. The analysis of surface ...

International Nuclear Information System (INIS)

The process of infrared multiple photon dissociation (IRMPD) of molecules is of great fundamental importance and has practical significance, such as isotope separation etc. Unfortunately, a clear insight into the process has been hindered by the bewildering array of important variables affecting MPD. The dissociation probability #gamma#(#phi#) i.e. the yield has been found to be a sensitive function of laser fluence #phi# along with numerous other parameters like laser frequency, gas pressure etc. We have shown that in single frequency IRMPD an accurate quantitative characterization of the dissociation probability can be adequately expressed by a 'power law' model with two fitting parameters namely critical fluence, #phi#c and multi photon order, m. This model was exploited in analysing our MPD results on various systems. However, the small isotope shift encountered in heavy elements and the sticking phenomenon observed in small light molecules restrict respectively the separation ...

Energy Technology Data Exchange (ETDEWEB)

Electromagnetic effects excited by intense relativistic electron beams in plasmas are investigated using a two-dimensional particle code. The simulations with dense beams show large magnetic fields excited by the Weibel instability as well as sizeable electromagnetic radiation over a significant range of frequencies. The possible relevance of beam plasma instabilities to the laser acceleration of particles is briefly discussed. 6 refs., 4 figs.

Science.gov (United States)

This paper makes a case for "good politics for good education", with special reference to Nigeria. It surveys the impact of good and bad politics on the attainment of Meaningful Access to education with special focus on Nigeria's Universal Basic Education (UBE) programme. Good politics is to be likened to what the French call "la politique au sense noble du terme" (politics in the noble sense of the term--or statesmanship) while bad politics is to be likened to a "politique politicienne" (mere divisive politicking, or politics in its raw form). Politics in its raw form is concerned with seeking power for self-aggrandisement while politics in its noble form is concerned with seeking power for public good. In situations where good politics prevails, educational policies, programmes and delivery processes tend to produce the desirable outcome of "children passing through school and the school also passing through them". By combining the seven exclusion zones used in the work of CREATE ...

CERN Document Server

In the littlest Higgs model with T-parity (LHT) the mirror quarks induce the special flavor structures and some new flavor-changing (FC) couplings which could greatly enhance the production rates of the FC processes. We in this paper study some bottom and anti-strange production processes in the LHT model at the International Linear Collider (ILC), i.e., $e^+e^-\\rightarrow b\\bar{s}$ and $\\gamma\\gamma\\rightarrow b\\bar{s}$. The results show that the production rates of these processes are sizeable for the favorable values of the parameters. Therefore, it is quite possible to test the LHT model or make some constrains on the relevant parameters of the LHT through the detection of these processes at the ILC.

International Nuclear Information System (INIS)

We have obtained radial velocities for 69 stars in the globular cluster M2 (NGC 7089). M2's rotation axis is, within sizeable uncertainties, perpendicular to the major axis determined by the flattening. The ratio of rotational to random kinetic energy agrees with that predicted from the ellipticity assuming an oblate figure and an isotropic velocity-dispersion tensor. We have fitted King-Michie models to determine M2's mass, the exponent of an assumed power-law mass function, and the anisotropy radius. The most significant sources of uncertainty in the modeling are the velocity dispersion, the distance, and the mass-luminosity relation for the cluster stars. The models favor mass functions similar to or shallower than the Salpeter initial-mass function and a moderate amount of velocity anisotropy.

Energy Technology Data Exchange (ETDEWEB)

This file is devoted to the Chernobyl accident. It is divided in four parts. The first part concerns the accident itself and its technical management. The second part is relative to the radiation doses and the different contaminations. The third part reports the sanitary effects, the determinists ones and the stochastic ones. The fourth and last part relates the consequences for the other European countries with the case of France. Through the different parts a point is tackled with the measures taken after the accident by the other countries to manage an accident, the cooperation between the different countries and the groups of research and studies about the reactors safety, and also with the international medical cooperation, specially for the children, everything in relation with the Chernobyl accident. (N.C.)

International Nuclear Information System (INIS)

We have measured the lattice relaxation around As in Si at a homogeneous As concentration of 4x10"1"8 cm"-"3 by EXAFS spectroscopy. From the absorption spectra, distances up to the 4th shell could be extracted. A sizeable misfit due to an increased distance is only observed for the 1st shell. Complementing our experimental work we have performed ab initio calculations based on the density functional theory with the WIEN97 package which uses the linearised augmented plane wave method and with the FHI96md program which uses first-principles pseudo-potentials and a plane wave basis set to investigate the size dependence of the super-cells constructed around one substitutional As atom. The calculations yielded good agreement with our EXAFS experiment so that the determined relaxations can be used as a solid basis for further interpretations of derived parameters such as hyperfine interaction parameters in defect complexes.

CERN Document Server

Antideuterons are among the most promising galactic cosmic ray-related targets for dark matter indirect detection. Currently only upper limits exist on the flux, but the development of new experiments, such as GAPS and AMS-02, provides exciting perspectives for a positive measurement in the near future. In this Paper, we present a novel and updated calculation of both the secondary and primary antideuteron fluxes. We employ a two-zone diffusion model which successfully reproduces cosmic-ray nuclear data and the observed antiproton flux. We review the nuclear and astrophysical uncertainties and provide an up to date secondary (i.e. background) antideuteron flux. The primary (i.e. signal) contribution is calculated for generic WIMPs annihilating in the galactic halo: we explicitly consider and quantify the various sources of uncertainty in the theoretical evaluations. Propagation uncertainties, as is the case of antiprotons, are sizeable. Nevertheless, antideuterons ...

International Nuclear Information System (INIS)

During their catalytic cycle, proteins involved in biological signal transduction undergo unexpectedly large conformational changes, which are at the core of their biological functioning. Until now it has been extremely difficult to obtain experimental insight into the nature of these conformational changes. Mathematical modeling and time-resolved X-ray crystallography have resulted in probable routes along which these conformational changes may take place, but so far this fundamental biological phenomenon has hardly been tackled experimentally. Here, we report on an attempt to observe structural changes in Photoactive Yellow Protein with time-resolved small-angle neutron scattering using diffractometer D22 at the high-flux reactor of the Institut Laue-Langevin, Grenoble, France

CERN Document Server

A transformation monoid on a set Omega is called synchronizing if it contains an element of rank 1 (that is, mapping the whole of Omega to a single point). In this paper, I tackle the question: given n and k, what is the probability that the submonoid of the full transformation monoid T_n generated by k random transformations is synchronizing? This question is analogous to Dixon's Theorem that two random permutations generate the symmetric or alternating group with high probability. Following the technique of Dixon's theorem, we need to analyse the maximal non-synchronizing submonoids of T_n. I develop a very close connection between transformation monoids and graphs, from which we obtain a description of non-synchronizing monoids as endomorphism monoids of graphs satisfying some very strong conditions. However, counting such graphs, and dealing with the intersections of their endomorphism monoids, seems difficult.

Science.gov (United States)

PMID:4060625

Science.gov (United States)

problem similar to the Stefan problem in heat conduction [19]. ..... as the Stefan problem. Although the Stefan problem and the creep rupture ...

Science.gov (United States)

... Tower of Hanoi and Missionaries and Cannibals puzzles, of students solving algebra and physics problems, and of thinkers ...

Energy Technology Data Exchange (ETDEWEB)

The present study treats only the collective risk of ex-utero leukaemia associated with the routine releases of the nuclear industrial installations of the North Cotentin (0.0009 cases over the considered period) the uncertainty on the contribution to the collective risk of the incidents and the accidents of the nuclear installations (notably the drilling of the pipe of release in sea arisen in 1979-1980 and the fire of the waste silo on January 6. 1981, for the reprocessing plant of La Hague has not been considered. Only 45% of the risk are taken into account by the study. Every calculated value remains very inferior to the number of leukemia cases observed (4 cases observed for two expected cases) and to the risk of radioinduced leukemia any merged exposure sources, that is to say 0.84 cases. It appears thus not very probable that the nuclear installations of the North - Cotentin can explain the tendency to the excess of observed leukaemia. The limits of the study become attached for ...

International Nuclear Information System (INIS)

To ensure safe and reliable power production nuclear power plants must be operated at high level. Non destructive in-service inspections are inseparable part of the effort. Non destructive in-service inspections are essential on the ground of degradation mechanisms existence in nuclear power components. Degradation processes are constituent of operation of each industrial installation including nuclear power plants. Mission of non-destructive testing is degradation detection, closer characterization of its parameters (dimensions) and to supply as much information as possible to nuclear power plant operator. Eddy current testing method can be assigned to surface - volumetric methods. Method enables inspection of electrically conductive materials. It is particularly suitable for inspection of non-ferromagnetic materials like austenitic stainless steel and brass. The method is used for detection of stress corrosion cracking, pitting corrosion or surface corrosion. The method experienced ...

Energy Technology Data Exchange (ETDEWEB)

We present a collisional-radiative approach of the theoretical analysis of laser-induced breakdown spectroscopy (LIBS) plasmas. This model, which relies on an optimized effective potential atomic structure code, was used to simulate a pure aluminum plasma. The description of aluminum involved a set of 220 atomic levels representative of three different stages of ionization (Al{sup 0}, Al{sup +} and Al{sup ++}). The calculations were carried for stationary plasmas, with input parameters (n{sub e} and T{sub e}) ranging respectively between 10{sup 13-18} cm{sup -3} and 0.3-2 eV. A comparison of our atomic data with some existing databases is made. The code was mainly developed to address the validity of the local thermodynamic equilibrium (LTE) assumption. For usual LIBS plasma parameters, we did not reveal a sizeable discrepancy of the radiative equilibrium of the plasma towards LTE. For cases where LTE was firmly believed to stand, the Boltzmann plot outputs of this ...

Science.gov (United States)

PMID:13840258

Science.gov (United States)

This report gives an overview of KIDS (Kestrel Interactive Development System). We describe a program derived with KIDS to solve the Missionaries and Cannibals problem (MC PROBLEM), a classical AI planning problem. Our interest in this problem arose as th...

Science.gov (United States)

PMID:21877636

Science.gov (United States)

... Accession Number : ADP004921. Title : The Stefan Problem of Detonation Theory,. Corporate Author : CORNELL UNIV ...

Science.gov (United States)

... Accession Number : ADA079641. Title : Relation of the One-Phase Stefan Problem to the Seepage of Liquids and Electrochemical Machining,. ...

Energy Technology Data Exchange (ETDEWEB)

Optimization methods are applied to complex problems power systems, economics, and geodesy. Transformation methods and conjugated gradient methods are used to solve the constrained problems in power systems and economics. Conjugated gradient methods are used to solve the unconstrained geodesy problem. Broad applications of the transformation methods are emphasized. In the geodesy problem, the computational efficiency of the Fletcher-Reeves method for optimization of quadratic functions is emphasized. In this problem special storage schemes were used. The method of solution of the economics problem is compared with Beale's method.

Energy Technology Data Exchange (ETDEWEB)

The first analysis of inelastic J/{psi} meson production in photoproduction (Q{sup 2}<2.5 GeV{sup 2}) of the H1 experiment for the second phase of HERA (HERA II) is presented. The analysis is carried out at low and medium elasticities. The production of heavy quarks (charm, or bottom) is of special interest since the mass of the quarks provides a hard scale for the application of perturbative QCD. The muonic decay channel is used to select the J/{psi} mesons. The data was collected by the H1 detector during the period 2003-2005, and corresponds to an integrated luminosity of 133 pb{sup -1}. However only a subset of this data could be analysed. At the start of HERA II the trigger system was affected by a sizeable background. Then a fault was introduced in the trigger software during the summer 2004 and was only discovered and solved in April 2006. This means that approximately 80 % of the triggered events at medium elasticities and 65 % at low elasticities ...

International Nuclear Information System (INIS)

1 - Description of program or function: This program solves an eigenvalue problem zBx=Ax where A and B are real block tri-diagonal matrices. This eigenvalue problem is derived from a reduced set of linear resistive MHD equations which is often employed to study tokamak plasma stability problem. 2 - Method of solution: Both the determinant and inverse iteration methods are employed. 3 - Restrictions on the complexity of the problem: The eigenvalue z must be real

Energy Technology Data Exchange (ETDEWEB)

Approximate methods are presented for solving nonlinear boundary value problems with an unknown (free) boundary, such as the Stefan problem in heat conductivity. Examples of this kind of problems in thermal physics, hydrodynamics, elasticity, and plasma physics are examined. Attention is given to the principal computational methods for solving stationary problems for second- and fourth-order elliptic equations, such as the domain transformation and penalty methods. To illustrate the capabilities of the methods presented here, examples of numerical solutions are presented for various specific applied problems. 255 references.

CERN Document Server

In this survey paper, we present open problems and conjectures on visibility graphs of points, segments and polygons along with necessary backgrounds for understanding them.

UK PubMed Central (United Kingdom)

The author reviews the growth of the insecticide-resistance problem throughout the world during the period between July 1956 and November 1957, and the developments in research on the subject during...Full Text Available

Science.gov (United States)

... Title : Selection, Training, and Control Problems in the Use of the Military Working Dog. Descriptive Note : Final rept. 15 Jan 72-14 Sep 73,. ...

UK PubMed Central (United Kingdom)

The physical demands of performing on musical instruments can cause pain, sensory loss, and lack of coordination. Five cases illustrate common problems. Knowledge of the interaction between the technique...Full Text Available

International Nuclear Information System (INIS)

During Phase 2 of our study of the CIXS conceptual design we have tackled additional important issues that are unique to the ITER environment. These include the thermal control of the crystal and detector enclosures located in an environment with a 100-250 C ambient temperature, tritium containment, and the range of crystal and detector movement based on the need for spectral adjustments and the desire to make measurements of colder plasmas. In addressing these issues we have selected a ''Dewar''-type enclosure for the crystals and detectors. Applying realistic view factors for radiant heat and making allowance for conduction we have made engineering studies of this enclosure and showed that the cooling requirements can be solved and the temperature can be kept sufficiently constant without compromising the specification parameters of the CIXS. We have chosen a minimum 3 mm combined thickness of the six beryllium windows needed in a Dewar-type enclosure and showed ...

International Nuclear Information System (INIS)

There are several concerns which bring to consider natural gas as a viable alternative to liquid fuels in transport. First, natural gas allows the curbing of global pollution in this steadily growing industry. Indeed, decoupling greenhouse gas emissions from transport growth has become a major issue in tackling climate change. Second, a more extensive use of natural gas would relieve city air quality, which is presently at levels harmful of human health. Nonetheless, this is just one side of the coin. The other side entails building a refuelling station network, and this carries financial requirements. The financing fraction holds a pivotal role in deciding whether natural gas for automotive purposes is an efficient solution. The final aim of this work is, therefore, to compare the natural gas advantages, stemming from avoided global and local emission, with the economic rationale of engaging in supplementary model network investments. A system dynamics model ...

International Nuclear Information System (INIS)

... Polskiego Towarzystwa Fizycznego (Poland) Polskie Towarzystwo Fizyczne;

British Library Electronic Table of Contents (United Kingdom)

A boundary value problem for Laplace?s equation in a bounded two-dimensional domain filled with a piecewise homogeneous medium is considered. The boundary of the inhomogeneity is assumed to be unknown. The inverse problem of determining the inhomogeneity boundary and the solution of the equation given the solution and its normal derivative on the boundary of the domain is discussed. Numerical methods are proposed for solving the inverse problem, and the results of numerical experiments are presented.

Science.gov (United States)

Overloaded transmission lines are only part of the problem. The ability of the network to carry power is also limited by the supply of reactive power and by frequency stability. Reactive power problems must be corrected in minutes, frequency stability problems in seconds. There is no way that market forces can handle these problems. Reactive power must be supplied to all long transmission and distribution lines to compensate for the loss of reactive volt-amperes - and resulting voltage drop - in the reactance along the line`s length. 7 figs.

CERN Document Server

Fermat's last theorem

Science.gov (United States)

No abstract available.

British Library Electronic Table of Contents (United Kingdom)

Recreational Programming (RecPro) is the discipline that encourages the study of computer programming through ludic problems. Problems that are typically studied within this discipline are similar to those of Recreational Mathematics (RecMat), which sometimes leads to the confusion of these two disciplines. The objective for RecPro is to write programs, while RecMat practitioners can use these programs to state (and prove if possible) conjectures about the solution. This interaction leads to a mathematical quality production. In an educational framework, problems in elemental number theory (those that are formulated with a basic knowledge of arithmetic) are very interesting, leading to the revision of classical unsolved problems. One of these problems is the general form of Zumkeller numbe...

CERN Document Server

Let us call a sequence of numbers heapable if they can be sequentially inserted to form a binary tree with the heap property, where each insertion subsequent to the first occurs at a leaf of the tree, i.e. below a previously placed number. In this paper we consider a variety of problems related to heapable sequences and subsequences that do not appear to have been studied previously. Our motivation for introducing these concepts is two-fold. First, such problems correspond to natural extensions of the well-known secretary problem for hiring an organization with a hierarchical structure. Second, from a purely combinatorial perspective, our problems are interesting variations on similar longest increasing subsequence problems, a problem paradigm that has led to many deep mathematical connections. We provide several basic results. We obtain an efficient algorithm ...

UK PubMed Central (United Kingdom)

PurposeThis study aimed to evaluate weight and height status and their relationship with psychological problems among elementary schoolchildren.Materials and...Full Text Available

Science.gov (United States)

A certain model of one-dimensional detonation waves leads to a Stefan problem: the unknown f satisfies Burgers equations on the two sides of a moving discontinuity at which it is given (f, say) and the jump in it derivative (corresponding to the exothermi...

UK PubMed Central (United Kingdom)

Dependent variables in research on problem behavior typically are based on measures of response repetition, but these measures may be problematic when behavior poses high risk or when its occurrence...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

We study a rapidly convergent modification of a two-sided method for the approximate integration of a boundary-value problem with parameters in boundary conditions for a system of quasilinear second-order differential equations.

Energy Technology Data Exchange (ETDEWEB)

The induction of voltages on pipelines and railroad signal wires can be a problem when high-voltage transmission lines share the right of way. A handbook and two computer programs provide the analytic tools for utilities to avoid the problem.

Energy Technology Data Exchange (ETDEWEB)

The supersymmetry in quantum mechanics and shape invariance condition are applied as an algebraic method to solving the Dirac-Coulomb problem. The ground state and the excited states are investigated via new generalized ladder operators. (author)

Science.gov (United States)

The report gives a comprehensive summary of the experience gained and the problems encountered during the Cat-Ox demonstration program. The report outlines the process design and construction, as well as operating experience and problems. Test results and conclusions derived from...

UK PubMed Central (United Kingdom)

BackgroundThe search for cluster structure in microarray datasets is a base problem for the so-called "-omic sciences". A difficult problem in clustering is how to handle data with...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Problems of classification and regression estimation in which objects are represented by multidimensional arrays of features are considered. Many practical statements can be reduced to such problems, for example, the popular approach to the description of images as a set of patches and a set of descriptors in each patch or the description of an object in the form of a set of distances from it to certain support objects selected based on a set of features. For solving problems concerning the objects thus described, a generalization of the relevance vector model is proposed. In this generalization, specific regularization coefficients are defined for each dimension of the multidimensional array of the object description; the resultant regularization coefficient for a given element in the mul...

Science.gov (United States)

... The general two-phase Stefan problem with supercooling, superheating, and capillarity, was studied [T19] in collaboration ...

Energy Technology Data Exchange (ETDEWEB)

A study was undertaken of problems encountered in the use of thermal power station coal ash and red mud (an aluminium smelting residue) as a banking or filling material, the aim being the effective utilization of these substances. Like clinker, coal ash and red mud can also be used as improvers, but there are various problems such as absorption swelling, strong alkalinity, and the difficulty of controlling the moisture content. Certain measures have to be carried out in on-site use to combat these problems. (11 refs.)

Science.gov (United States)

... Effect of checkpointing and queueing on program performance ... and a large class of stochastic linear ... problem is intrinsically related to K-terminal ...

Science.gov (United States)

... mutagenic, while two potential environmental transformation products, 1,4- diaminoanthraq Ynone and 1,4-dihydroxyanthraquinone are strongly ...

Science.gov (United States)

... without the problem of purple plague. The Au-Ni-In evaporated ... surface and bonding degradation (purple plague) St step-stress ...

Energy Technology Data Exchange (ETDEWEB)

This paper presents a new algorithm for the optimal long-range generation planning for a thermal system with pumped-storage plants. The algorithm is based upon the analytical production costing model developed under the assumption of Gaussian probabilistic distribution of random load fluctuations and plant outages. The optimization problem consists of the master problem to determine the annual investment, and the pumped-storage subproblem to determine the optimal pumped-storage operation. The master problem is formulated as a Hamiltonian minimization problem, and the pumped-storage subproblem is solved using the concept of peak-shaving operation on the original load curve.

Science.gov (United States)

... Progress: For a one-dimensional two-phase degenerate Stefan problem, it was proved that the boundary and the solutions up to the boundary are C ...

Energy Technology Data Exchange (ETDEWEB)

The quality of fuel oils is discussed. The problems that the fuel oil marketer must deal with that relate to the quality of the fuel oil are described.

Science.gov (United States)

... The nature of the vacuum breakdown mechanism presents just such a problem and the relative significance or total absence of several processes ...

Science.gov (United States)

... The fundamental problem of diaphragm rupture was studied experimentally to determine the effects on an expanding flow in an evacuated tube. ...

International Nuclear Information System (INIS)

... Union (INTAS), Brussels (Belgium) Science and Technology Center in Unkraine,

British Library Electronic Table of Contents (United Kingdom)

This paper considers location?allocation problem in the real uncertain world and develops a possibilistic non-linear programming model to deal with this problem. Fuzzy decision making in fuzzy environment concept is used to determine possibility distribution of location and allocation variables. To solve this model, a novel approach based on genetic algorithm structure is developed. As the proposed model includes both deterministic (location) and uncertain (allocation) parameters, the developed solution algorithm uses a hybrid chromosome structure. Also, to cover continuous nature of the problem and prevent GA from early convergence, a new crossover operator is introduced. Finally, performance of the developed algorithm is evaluated by an example.

Energy Technology Data Exchange (ETDEWEB)

Lining of fused cast basalt tiles is recommended for various pieces of equipment constituting a coal preparation plant.

Science.gov (United States)

... A classic example is rewriting the missionaries and cannibals (M and C) problem [Ama68] phrased in terms of individuals into a formulation that is ...

Science.gov (United States)

We solve an R -linear problem for a multiple-connected circular domain in a class of doubly periodic functions in analytic form by a method of functional equations. This problem models transport properties of two-dimensional composite materials made from a collection of disks embedded in an otherwise uniform host.

Energy Technology Data Exchange (ETDEWEB)

Researchers investigated several supercomputer architectures in the context of assessing their performance in solving PDE problems. Main results are: assessed various classes of paralled and vector supercomputers and parallel software issues toward solving PDE problems; developed a multipipeline networking technique for compound vector processing; developed an orthogonal multiprocessor for large-grain scientific computations; improved parallel efficiency of a domain decomposition method, the DD algorithm.

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

The paper shortly recapitulates the background to and the importance of the principle of channeling of liability to the operator, contained in the international Conventions in the field of nuclear liability. It tries to outline the main problems involved in the process of backfitting in some more detail and to describe part of the work that has been done in Sweden and elsewhere to try to solve them. Finally, the paper contains some concluding remarks indicating that no entirely satisfactory solution to the problem is presently at hand. (orig./HP)

Science.gov (United States)

The current methods used by the tissue analysis program at LASL for the determination of americium and plutonium in autopsy tissue are described. Problems affecting radiochemical yield are discussed. Included are problems associated with sample preparation, separation of plutonium from large amounts of bone ash, and reagent contamination. The average /sup 242/Pu tracer yield for 1800 Pu determinations is 78 +- 12%. The average /sup 242/Am tracer yield is 85 +- 7% for 40 determinations.

British Library Electronic Table of Contents (United Kingdom)

We investigate an application of the method of fundamental solutions (MFS) to the one-dimensional inverse Stefan problem for the heat equation by extending the MFS proposed in [5] for the one-dimensional direct Stefan problem. The sources are placed outside the space domain of interest and in the time interval (-T,T). Theoretical properties of the method, as well as numerical investigations, are included, showing that accurate and stable results can be obtained efficiently with small computational cost.

Energy Technology Data Exchange (ETDEWEB)

Very large sparse linear least-squares problems arise in a variety of applications, such as geodetic network adjustments, photogrammetry, earthquake studies, and certain types of finite element analysis. Many of these problems are so large that it is impossible to solve them without using auxiliary storage devices. Some problems are so massive that the storage needed for their solution exceeds the virtual address space of the largest machines. A method for solving such problems on a typical (large) computer is described, and the results of some experiments illustrating the effectiveness of this approach are provided. The method includes an automatic partitioning scheme that is essential to the efficient management of the data on auxiliary files. 8 figures, 2 tables

CERN Document Server

Heterogeneous anisotropic diffusion problems arise in the various areas of science and engineering including plasma physics, petroleum engineering, and image processing. Standard numerical methods can produce spurious oscillations when they are used to solve those problems. A common approach to avoid this difficulty is to design a proper numerical scheme and/or a proper mesh so that the numerical solution validates the discrete counterpart (DMP) of the maximum principle satisfied by the continuous solution. A well known mesh condition for the DMP satisfaction by the linear finite element solution of isotropic diffusion problems is the non-obtuse angle condition that requires the dihedral angles of mesh elements to be non-obtuse. In this paper, a generalization of the condition, the so-called anisotropic non-obtuse angle condition, is developed for the finite element solution of heterogeneous anisotropic diffusion ...

Science.gov (United States)

This presentation concerns our continued research on adjoint--based optimization of viscous incompressible flows (the Navier--Stokes problem) coupled with heat conduction involving change of phase (the Stefan problem), and occurring in domains with variable boundaries. This problem is motivated by optimization of advanced welding techniques used in automotive manufacturing, where the goal is to determine an optimal heat input, so as to obtain a desired shape of the weld pool surface upon solidification. We argue that computation of sensitivities (gradients) in such free--boundary problems requires the use of the shape--differential calculus as a key ingredient. We also show that, with such tools available, the computational solution of the direct and inverse (optimization) problems can in fact be achieved in a similar manner and in a comparable computational time. Our presentation ...

International Nuclear Information System (INIS)

Due to the increased computer power and advanced algorithms, quantum mechanical calculations based on Density Functional Theory are more and more widely used to solve real materials science problems. In this context large nonlinear generalized eigenvalue problems must be solved repeatedly to calculate the electronic ground state of a solid or molecule. Due to the nonlinear nature of this problem, an iterative solution of the eigenvalue problem can be more efficient provided it does not disturb the convergence of the self-consistent-field problem. The blocked Davidson method is one of the widely used and efficient schemes for that purpose, but its performance depends critically on the preconditioning, i.e. the procedure to improve the search space for an accurate solution. For more diagonally dominated problems, which appear typically for plane wave based ...

Science.gov (United States)

The study is concerned with the Stefan problem of evaporation of a volatile component from its solution with a virtually non-volatile material. The analysis provides an analytical solution to the problem based on mass-transfer fundamentals. Results yield the evaporation rate, interfacial mole fractions, concentration profiles in the gas and liquid phases, and the location of the evaporation front. The analysis can be used to provide the binary liquid diffusion coefficient of the volatile component based on experimental data for the liquid gas interface position as a function of time. The requirements for such a measurement are discussed in terms of the volatility of the evaporating component and its initial concentration in the liquid mixture.[Figure not available: see fulltext.

British Library Electronic Table of Contents (United Kingdom)

Previous research has characterized insight as the product of internal processes, and has thus investigated the cognitive and motivational processes that immediately precede it. In this research, however, we investigate whether insight can be catalyzed by a cultural artifact, an external object imbued with learned meaning. Specifically, we exposed participants to an illuminating lightbulb - an iconic image of insight - prior to or during insight problem-solving. Across four studies, exposing participants to an illuminating lightbulb primed concepts associated with achieving an insight, and enhanced insight problem-solving in three different domains (spatial, verbal, and mathematical), but did not enhance general (non-insight) problem-solving.

CERN Document Server

The article presents an approach to interactively solve multi-objective optimization problems. While the identification of efficient solutions is supported by computational intelligence techniques on the basis of local search, the search is directed by partial preference information obtained from the decision maker. An application of the approach to biobjective portfolio optimization, modeled as the well-known knapsack problem, is reported, and experimental results are reported for benchmark instances taken from the literature. In brief, we obtain encouraging results that show the applicability of the approach to the described problem.

Energy Technology Data Exchange (ETDEWEB)

The various factors that affect the open-circuit voltage ([ital V][sub oc]) of a two-terminal GaInP[sub 2]/GaAs tandem cell are examined. These include a) an anomalous problem associated with the GaAs bottom cell and b) back surface passivation of the thin GaInP[sub 2] top cell. Solutions to these problems are presented and yield tandem [ital V][sub oc]s close to the practical theoretical limits.

British Library Electronic Table of Contents (United Kingdom)

Different approaches to expertise and argumentation are discussed. After introducing the problem of expertise and its present day significance in a historical context, various connections with the study of arguments are highlighted. The need for and potential of argumentation analysis to contribute to existing research in social epistemology, science studies, and cognitive science, is discussed, touching on the problems of reasoning and argumentation, embodiment, tacit knowledge, expert context versus public context, expert disagreement, persuasion versus justification, and argument analysis as meta-expertise. As the arguments used by experts constitute a boundary object, we presume that a dialogue format is suitable to address central problems of the special issue ?Rethinking Arguments fr...

International Nuclear Information System (INIS)

Problem areas in BWRs, PWRs and PHWRs, from the viewpoint of chemistry, and the problem of fission product release in nuclear reactors are discussed. These problem areas are : fuel performance, off-normal water chemistry due to condenser leaks, the transport and deposition of the activated corrosion and fission products, denting in steam generators (in the case of PWRs), ingress of air in the cover gas helium and consequent radiolysis of D_2O in the moderator circuit (in the case of PHWRs). (M.G.B.).

British Library Electronic Table of Contents (United Kingdom)

In this paper we present a new, accurate form of the heat balance integral method, termed the combined integral method (CIM). The application of this method to Stefan problems is discussed. For simple test cases the results are compared with exact and asymptotic limits. In particular, it is shown that the CIM is more accurate than the second order, large Stefan number, perturbation solution for a wide range of Stefan numbers. In the initial examples it is shown that the CIM reduces the standard problem, consisting of a PDE defined over a domain specified by an ODE, to the solution of one or two algebraic equations. The latter examples, where the boundary temperature varies with time, reduce to a set of three first order ODEs.

Science.gov (United States)

... of Hanoi or Missionaries and Cannibals, It is not immediately obvious what constitutes a "move"--that is, what actual manipulations of the physical ...

Energy Technology Data Exchange (ETDEWEB)

Building complex knowledge based applications requires encoding large amounts of domain knowledge. After acquiring knowledge from domain experts, much of the effort in building a knowledge base goes into verifying that the knowledge is encoded correctly. We consider the problem of verifying hybrid knowledge bases that contain both Horn rules and a terminology in a description logic. Our approach to the verification problem is based on showing a close relationship to the problem of query containment. Our first contribution, based on this relationship, is presenting a thorough analysis of the decidability and complexity of the verification problem, for knowledge bases containing recursive rules and the interpreted predicates =, {le}, < and {ne}. Second, we show that important new classes of constraints on correct inputs and outputs can be expressed in a hybrid setting, in which a description logic ...

International Nuclear Information System (INIS)

The problem of fast wave plasma heating in reactor-torsatron at the ICRF range in scenarios, optimal for fusion reactor, is numerically studied.

UK PubMed Central (United Kingdom)

Dengue, a major public health problem throughout subtropical and tropical regions, is an acute infectious disease characterized by biphasic fever, headache, pain in various parts of the body, prostration,...Full Text Available

Science.gov (United States)

... and 7 survey papers. On the inverse Stefan problem he wrote 3 research papers and 1 survey paper. The papers on inverse ...

International Nuclear Information System (INIS)

The author attempts to clear up the causal 'paradox' often associated with the existence of tacyons. This leads to a discussion of the nature of tachyon messages and the problems involved in their interpretation. (W.D.L.).

Science.gov (United States)

... Missionaries and cannibals [MaC] (Newell, McDermott and Forgy, 1977, p. 63): Three missionaries and three cannibals must cross a river in a two ...

Energy Technology Data Exchange (ETDEWEB)

The inverse problem of interpreting the SS 433 optical light curves is solved for a geometrically thick model accretion disk around the compact relativistic object: most likely a black hole.

Medline Plus

Enter Search terms A-Z Index Home Food Drugs Medical Devices Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Radiation-Emitting Products Tobacco ...

Science.gov (United States)

missionaries and cannibals puzzle. He noted that in order to be able to use a boat to cross a river one would need ... a quali cation that the vertical exhaust stack ...

Energy Technology Data Exchange (ETDEWEB)

A strong necessary condition is given for the principal stabiliser of the action of a compact Lie group to have a non-zero centre. An application to the monopole problem in Yang-Mills-Higgs models is discussed.

Science.gov (United States)

... And those who study cognition select problems (eg, tower of Hanoi, missionaries and cannibals, logic theorems) with minimal perceptual and motor ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to relate some of the commonly encountered problems with operational procedures in the nuclear industry and offer practical suggestions for their elimination. The paper is based on recent consultant experience in assisting industry clients with human performance related design and assessment initiatives. Operational procedures are a key part of an integrated system design. Procedures provide the specified instructions for actions people are to undertake in operating a facility to achieve production and safety goals. While organizations continue to make substantial investments in procedure development and maintenance, problems with procedures continue to occur, as evidenced through operating inefficiencies, errors, and events. The paper reviews the role procedures play in facility operations, comments on current development and maintenance practices, discusses the extent of human performance related ...

UK PubMed Central (United Kingdom)

BackgroundThe ongoing epidemiological transition in Mexico minimizes the relative impact of neurocysticercosis (NC) on public health. However, hard data on the disease frequency...Full Text Available

Science.gov (United States)

nances, an iron ore sintering plant, and several fuel oil boilers.***. The use of undemonstrated technology presents problems for evaluatingi ...

Science.gov (United States)

This paper proposes an approach that mitigates the problem of verification of network security system properties over concurrent processes.

UK PubMed Central (United Kingdom)

Because resistance to new insecticides may develop rapidly and cross resistance is often encountered, even between insecticides of different classes, there is a continual demand for the development...Full Text Available

UK PubMed Central (United Kingdom)

Since the last review of the problem of insecticide-resistance was presented in this journal at the beginning of 1958, resistance has been discovered in 16 new species, and in at least 14 species both...Full Text Available

Wastenet

Hexavalent chromium in corrosion preventive coating 64 ...To prevent corrosion of rims, weights can be provided with a coating. ...integrated clips brought up technical problems due to corrosion

Science.gov (United States)

... laws between particles (modeling UGV/UAV/UUV collectives) to ... A mobile robot test-bed is used in ... of this work on mobile robots executing pursuit ...

British Library Electronic Table of Contents (United Kingdom)

Children with attention-deficit/hyperactivity disorder (ADHD) often have poor relationships with peers. However, research on this topic has predominantly focused on boys. This study considered child gender, ADHD status, and dimensionally assessed conduct problems as predictors of peer relationship difficulties. Participants were 125 children (ages 6-10; 67% male), 63 with clinical diagnoses of ADHD and 62 non-ADHD comparison youth. Conduct problems were reported by teachers and observed in a lab playgroup. Peer relationships were assessed by parent report, teacher report, and peer sociometric nominations in the playgroup. Results suggested that children with ADHD, as well as those with high conduct problems, displayed more impaired peer relationships than did comparison children and those ...

Science.gov (United States)

flow separation occurred at the junction of the tip fin and the fuselage. ...... Systems, presented at the AGARD Guidance and Control and Flight Mechanics ...

Science.gov (United States)

... defense's weapons are Space-based kinetic-kill vehicles ... I ti I obtained by dividing the weapons as ... of the optimal weapon-arge assigntments and ...

Science.gov (United States)

Government policies that encourage exploitation--in particular excessive logging and clearing for ranches and farms--are largely to blame for the accelerating destruction of tropical forests. This paper surveys the problem in detail and briefly recommends potential solutions.

UK PubMed Central (United Kingdom)

Chlamydia trachomatis has been recognized as a pathogen of trachoma, nongonococcal urethritis, salpingitis, endocervicitis, pelvic inflammatory disease, inclusion conjunctivitis of...Full Text Available

Science.gov (United States)

The goal of this effort Composability, Provability, Reusability (CPR) for Survivability is to address the problem of composition of survivable systems. The particular objective of this project is to construct a formal specification of the Java Virtual Mac...

CERN Document Server

We introduce the {\\sc classified stable matching} problem, a problem motivated by academic hiring. Suppose that a number of institutes are hiring faculty members from a pool of applicants. Both institutes and applicants have preferences over the other side. An institute classifies the applicants based on their research areas (or any other criterion), and, for each class, it sets a lower bound and an upper bound on the number of applicants it would hire in that class. The objective is to find a stable matching from which no group of participants has reason to deviate. Moreover, the matching should respect the upper/lower bounds of the classes. In the first part of the paper, we study classified stable matching problems whose classifications belong to a fixed set of ``order types.'' We show that if the set consists entirely of downward forests, there is a polynomial-time algorithm; otherwise, it is NP-complete to decide the ...

Science.gov (United States)

... On 20 March 1995, members from the religious cult Aum Shinrikyo released sarin and VX nerve gas into the Tokyo subway system. At the height of ...

UK PubMed Central (United Kingdom)

SummaryWe consider the problem of estimating the effect of exposure on multiple continuous outcomes, when the outcomes are measured on different scales and are nested within multiple...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Looking at kriging problems with huge numbers of estimation points and measurements, computational power and storage capacities often pose heavy limitations to the maximum manageable problem size. In the past, a list of FFT-based algorithms for matrix operations have been developed. They allow extremely fast convolution, superposition and inversion of covariance matrices under certain conditions. If adequately used in kriging problems, these algorithms lead to drastic speedup and reductions in storage requirements without changing the kriging estimator. However, they require second-order stationary covariance functions, estimation on regular grids, and the measurements must also form a regular grid. In this study, we show how to alleviate these rather heavy and many times unrealistic restr...

UK PubMed Central (United Kingdom)

We consider the problem of minimal (multiplicative) complexity of polynomial multiplication and multiplication in finite extensions of fields. For infinite fields minimal complexities are known [Winograd,...Full Text Available

Science.gov (United States)

... adaptive method called Shortest Queue plus Bias ... routing problem under stochastic traffic demands have ... of permits allocated to a node or terminal ...

UK PubMed Central (United Kingdom)

AbstractA young, male miniature poodle was presented with severe neurological problems. Laboratory tests and ultrasonograph examination were consistent with extrahepatic portosystemic...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundMany difficult problems in evolutionary genomics are related to mutations that have weak effects on fitness, as the consequences of mutations with large effects are often...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The failure of receivers has been one of the main operating problems at the White Cliffs solar thermal power plant. This Technical Note reports the results of an initial investigation that identifies the cause as having been their thermal fatiguing of the tube walls. The fatigue appears to be caused by unstable heat transfer at vapor qualities below the point where critical heat flux is generally exceeded. Methods for avoiding this problem are tested.

Energy Technology Data Exchange (ETDEWEB)

A community health survey of 438 individuals was taken to detect health problems related to high voltage electrical transmission among an adjacent residential population. Results revealed no significant or consistent relationships between exposure to a high voltage DC power line and the perceived health problems that were measured. The sample was not, however, large enough to draw statistically significant conclusions regarding possible health effects with a very low incidence.

DEFF Research Database (Denmark)

Epidemiological studies of psychopathology in the first years of life are few, and the association between mental health problems in infancy and psychiatric disturbances later in life has not been systematically investigated. The aim of the present project was to study mental health problems and possibilities of intervention from infancy and onward.

International Nuclear Information System (INIS)

We present a summary of the discussions in the Exotic Collider Concepts Group. Most of the discussions were centered around the status and open problems for muon-muon and gamma-gamma colliders. In addition the group discussed some general problems and new results of accelerator physics. copyright 1995 American Institute of Physics.

CERN Document Server

We discuss the Sundman-Weierstrass theorem of total collapse in its historical context. This remarkable and relatively simple result, a type of stability criterion, is at the crossroads of some interesting developments in the gravitation Newtonian N-body problem. We use it as motivation to explore the connections to such important concepts as integrability, singularities and tyipicality in order to gain some insight on the transition from a predominantly quantitative to a novel qualitative approach to dynamical problems that took place at the end of the 19th century.

Energy Technology Data Exchange (ETDEWEB)

Room air quality and thus thermal comfort for the occupiers in closed spaces depend on several factors: temperature and humidity of the air, temperature of the surrounding surfaces, content of foreign matter of the air, acoustical perceptions, electric fields and ions as well as colours and light. Air humidification, cleaning and ionization largely contributes to improved room air quality. The article goes into problems of too dry and polluted air as well as into measures with which these problems can be solved. (BWI).

UK PubMed Central (United Kingdom)

While prior research has examined family, school, and peer factors as potential predictors of problem behavior, less attention has been given to studying when these factors are most predictive...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Solutions have been found for the problems encountered with the coil power and switching systems of the International Fusion Superconducting Magnet Test Facility (IFSMTF). The coil power system provides the filtered dc sources (+- 12 V dc; 25,000 A) for charging and discharging the coils of the IFSMTF experiment. The switching system provides the means of transferring the coil current into a dump resistor when a rapid discharge of a coil is required due to a coil failure (quench) or other system abnormalities.

Science.gov (United States)

One of the main goals in the operation of a cupola furnace is to keep the molten iron properties within prescribed bounds while maintaining the most economical operation for the cupola. In this paper the authors present a procedure to obtain the nominal values for the manipulated process variables. The nominal values are calculated by solving a constrained nonlinear programming optimization problem. Two different optimization problems are discussed and examples for using the procedure are presented.

British Library Electronic Table of Contents (United Kingdom)

Diffraction by an impermeable scatterer in ?3 with a Dirichlet boundary condition is considered. It is shown that the null field equation is equivalent to the original diffraction problem. The general theoretical constructions are illustrated by analyzing the excitation of a sphere by a point source. The evolution of the residual of the null field equation as the scatterer surface is approached by an auxiliary surface is estimated.

Science.gov (United States)

Potential strategic missions for laser weapons, particularly those involving space-based lasers, are discussed. The functions of space-based lasers and the history of their conceptual development are summarized, and the problems of implementing such systems, including the building of a suitable laser and power source, and resolving the problem of optics, are discussed. Ongoing development programs are described, and the contrasting views of the necessity and usefulness of strategic laser systems are set forth.

International Nuclear Information System (INIS)

Certain problems of gamma-absorption method of measuring the thickness of layers in multi-layer items are analyzed. Two examples of solving the above-mentioned problems have been considered. One of them deals with a two-layer item, its integral thickness being known or measured in advance, the second example is referred to a two-layer item with unknown integral value

Energy Technology Data Exchange (ETDEWEB)

Besides industrial agglomerations suffering from excessive pollution of water, air, and soil, there are areas in the German Democratic Republic where beautiful scenery at first glance seems to be intact owing to the absence of large industries. That environmental problems exist also in the coastal regions of the German Democratic Republic is shown in this report. Some of the environmental sins mentioned, which are due to human failure, would seem to the editor to be not just GDR specific. (orig.).

International Nuclear Information System (INIS)

Beryllium has been in use in aircraft brakes for ten years. During the original design phases of the several aircraft programs using beryllium a number of problems requiring solution confronted the designers. In actual service the solution to these problems performed much better than had been anticipated. A summary is presented. (author).

Energy Technology Data Exchange (ETDEWEB)

Electric cars have long been seen as science fiction. This may be changing. As the 1990s began, several companies chose to launch publicity campaigns for electric vehicles. In California, experimental programmes are gaining momentum, in the context of LA's appalling air pollution problems and tightening clean air standards. Supporters claim that electric motive power is a key to solving several environmental problems involving atmospheric pollution. These claims are examined. (author).

Energy Technology Data Exchange (ETDEWEB)

The authors present design methodology and initial experimental results for a high power microwave switch. The switch is designed for application to the pulse compression system associated with the Next Linear Collider Test Accelerator (NLCTA). The switch is based on the excitation of a plasma layer within a silicon wafer by either a laser or an electron beam. They investigate problems associated with high power operation of such a switch. They explore solutions to the problems of thermal runaway, avalanche breakdown, photo-emission, and secondary emission.

Energy Technology Data Exchange (ETDEWEB)

This paper presents a new approach for solving multistage decision problems in power system operation by using a new fuzzy dynamic programming technique. To investigate its validity, the hydrothermal scheduling problem is used as an example problem. Within this problem, uncertainty elements exist such as load demand and natural hydraulic inflows to reservoirs exist which can be expressed by fuzzy numbers. Two new fuzzy decision making techniques for selecting the optimal operating states at each stage are introduced. Further, the hydrothermal scheduling solution obtained had an operating band defined by upper and lower bounds. To further enhance the information that this operating band provides, a midpoint operation technique that applies both forward and backward fuzzy DP is also introduced. This allows the system operator to consider current operating conditions to determine a suitable stage by stage ...

CERN Document Server

In this paper we analyze the Hilbert boundary-value problem of the theory of analytic functions for an $(N+1)$-connected circular domain. An exact series-form solution has already been derived for the case of continuous coefficients. Motivated by the study of the Hall effect in a multiply connected plate we extend these results by examining the case of discontinuous coefficients. The Hilbert problem maps into the Riemann-Hilbert problem for symmetric piece-wise meromorphic functions invariant with respect to a symmetric Schottky group. The solution to this problem is derived in terms of two analogues of the Cauchy kernel, quasiautomorphic and quasimultiplicative kernels. The former kernel is known for any symmetry Schottky group. We prove the existence theorem for the second, quasimultiplicative, kernel for any Schottky group (its series representation is known for the first class groups only). We also ...

CERN Document Server

In Internet Routing, the static shortest path (SP) problem has been addressed using well known intelligent optimization techniques like artificial neural networks, genetic algorithms (GAs) and particle swarm optimization. Advancement in wireless communication lead more and more mobile wireless networks, such as mobile networks [mobile ad hoc networks (MANETs)] and wireless sensor networks. Dynamic nature of the network is the main characteristic of MANET. Therefore, the SP routing problem in MANET turns into dynamic optimization problem (DOP). Here the nodes ae made aware of the environmental condition, thereby making it intelligent, which goes as the input for GA. The implementation then uses GAs with immigrants and memory schemes to solve the dynamic SP routing problem (DSPRP) in MANETS. In our paper, once the network topology changes, the optimal solutions in the new environment can be searched using ...

Energy Technology Data Exchange (ETDEWEB)

The authors are developing MP-TOUGH2 for exploiting massively parallel computers. The goals of this effort are to (1) create a data-parallel subsurface transport code for solving larger problems than currently practical on workstations, (2) write portable code that can take advantage of scalability to run on machines with more processors, and (3) minimize the necessity for additional validation and verification of the resulting code. The initial strategy they have followed is to focus on optimizing the generic and time-consuming task of linear equation solution while leaving the bulk of TOUGH2 unmodified. In so doing, they have implemented a massively parallel direct solver (MPDS) that takes advantage of the banded structure of TOUGH2 Jacobian matrices. The authors have compared timings of the iterative conjugate gradient solvers DSLUBC, DSLUCS, and DSLUGM written in Fortran77 for the front end with the MPDS which uses the data parallel unit. The MPDS shows good ...

CERN Document Server

This research will be helpful for people to display the 2-dimensiona projective models of 4-variable actual problems in many fields, in order to investigate deeply those actual problems. By using the theory of N-dimensional finite rotation group of the regular polytopes, the author established the 2-dimensional projective model of 4-dimensional rectangular coordinate system, and deduced a transformation matrix, and adopt it to display successfully the 2-dimensional overall shapes of two most complicated regular polytopes 120-Cell and 600-Cell. In the meantime, the author calculated all the vertex coordinates and determine the joint relationships between adjacent vertices of the regular polytopes 120-Cell and 600-Cell. Also, this provided a pattern for displaying the 2-dimensional projective model of 4-variable actual problem.

British Library Electronic Table of Contents (United Kingdom)

Some of the most important problems facing the United States and China, indeed facing our entire planet, require approaches that are fundamentally multidisciplinary in nature. Many of those require skills in computer science (CS), basic understanding of another discipline, and the ability to apply the skills in one discipline to the problems of another. Modern training in computer science needs to prepare students to work in other disciplines or to work on multidisciplinary problems. What do we do to prepare them for a multidisciplinary world when there are already too many things we want to teach them about computer science? This paper describes successful examples of multidisciplinary education at the interface between CS and the biological sciences, as well as other examples involving C...

Energy Technology Data Exchange (ETDEWEB)

In the world of pipeline maintenance, there are pigs and there are intelligent pigs. Intelligent pigs, when launched into a pipeline, carry instrumentation onboard which enables them to gather and record information about problems such as denting, corrosion, and cracking. More basic pigs, on the other hand, look after the routine internal maintenance chores such as cleaning and swabbing, or else perform operational duties such as batching different types of product along the line. The harsh environment in which pigs often operate is described. Aside from the mechanical shocks they undergo when passing welds, bends, and other fittings, they may have to contend with hostile conditions such as hydrogen sulfide environments. High pressure is another factor to consider. In crude oil lines, significant paraffin deposits also can cause problems if they affect the sensors ability to maintain good contact with the pipe wall. In spite of these ...

International Nuclear Information System (INIS)

This paper reviews the state of the art of silicon-germanium technology and assesses the problems of building thermoelectric modules in Europe, based upon silicon-germanium alloys, for use in multihundred watt radio-isotope thermoelectric generator. The generator developed in the United States for the International Solar Polar mission has been used as a reference system. The essential features of an alternative system, which employs thermocouples fabricated from improved silicon-germanium alloys based upon a design by the Fairchild Space and Electronics Company, is also described. It is concluded that although the fabrication of reliable electrical contacts will present a major problem, the technology is available in Europe to build thermoelectric modules similar to those developed for the International Solar Polar mission. (orig.).

International Nuclear Information System (INIS)

A numerical analysis method for melting/solidification phenomena has been developed to evaluate a feasibility of several candidate techniques in the nuclear fuel cycle. Our method is based on the eXtended Finite Element Method (X-FEM) which has been used for moving boundary problems. Key technique of the X-FEM is to incorporate signed distance function into finite element interpolation to represent a discontinuous gradient of the temperature at a moving solid-liquid interface. Construction of the finite element equation, the technique of quadrature and the method to solve the equation are reported here. The numerical solutions of the one-dimensional Stefan problem, solidification in a two-dimensional square corner and melting of pure gallium are compared to the exact solutions or to the experimental data. Through these analyses, validity of the newly developed numerical analysis method has been demonstrated. (author)

Energy Technology Data Exchange (ETDEWEB)

Magnetic refrigeration uses the temperature- and field-dependence of the entropy of some magnetic materials to accomplish cooling. Because of the intrinsically high efficiency of the magnetization and demagnetization process and because of the potential for excellent heat transfer between solids and fluids, magnetic refrigerators promise to have higher efficiency than existing gas-cycle refrigerators. Many ground-based and space-based applications could benefit significantly from the cost savings implied by higher efficiency. Other attributes of these devices are high reliability and low volume and mass per unit cooling power. The development of these refrigerators is underway at several places around the world, including the Los Alamos National Laboratory. The progress to date has been encouraging but some problems have been clearly identified. The arguments for high efficiency and the problems that will need to be solved to achieve this goal ...

CERN Document Server

After mathematicians and physicists had learned that the structure of physical space was not necessarily Euclidean, it became conceivable that the global topological structure of space was non-trivial. In the context of the late 19th century debates on physical space this speculation gave rise to the problem of classifying spaces of constant curvature from a topological point of view. William Kingdon Clifford, Felix Klein and Wilhelm Killing, the latter of whom devoted a substantial amount of work to the topic in the early 1890s, clearly perceived this problem as relevant for both mathematics and natural philosophy (i.e., physics or cosmology). To some extent, a cosmological interest may even be found among those authors who restated the space form problem in more modern terms in the early 20th century, such as Heinz Hopf.

CERN Document Server

In a recent paper [4], Duarte and Jutten investigated the Blind Source Separation (BSS) problem, for the nonlinear mixing model that they introduced in that paper. They proposed to solve this problem by using information-theoretic tools, more precisely by minimizing the mutual information (MI) of the outputs of the separating structure. When applying the MI approach to BSS problems, one usually determines the analytical expressions of the derivatives of the MI with respect to the parameters of the considered separating model. In the literature, these calculations were mainly reported for linear mixtures up to now. They are more complex for nonlinear mixtures, due to dependencies between the considered quantities. Moreover, the notations commonly employed by the BSS community in such calculations may become misleading when using them for nonlinear mixtures, due to the above-mentioned dependencies. We claim that the ...

International Nuclear Information System (INIS)

Problems are discussed of heat exchange tubes of Westinghouse type vertical steam generators exhibiting corrosion damage such as point corrosion, planar corrosion, tube denting, corrosion stress cracking, crevice corrosion, fretting corrosion and intergranular corrosion. Attention is also paid to problems of WWER-440 type horizontal steam generators, where the level fluctuation area is critical; noncompact porous deposits of the corrosion products give rise to crevice effects and cause significant concentration of chloride ions and other additions. This problem can be partly resolved by a modification of the collector design at the level variation area. An additional measure is the production of steel 08Kh18N10T with a very low level of harmful elements and inclusions. (Z.M.). 3 figs., 11 refs.

British Library Electronic Table of Contents (United Kingdom)

The (simplified) Backus? Problem (BP) consists in finding a harmonic function u on the domain exterior to the three dimensional unit sphere S, such that u tends to zero at infinity and the norm of the gradient of u takes prescribed values g on S. Except for a change of sign, the solution is not unique in general. However, there is uniqueness of solutions in the class of functions with the additional property that the radial component of the gradient of u on S is nonpositive. This is the geodetically relevant case. If a solution u with this property exists, then u is the maximal solution of the problem (and -u the minimal one). In this paper we propose a method of successive approximations to get this particular solution of BP and prove the convergence for functions g close to a constant fu...

CERN Document Server

Real-time object detection is one of the core problems in computer vision. The cascade boosting framework proposed by Viola and Jones has become the standard for this problem. In this framework, the learning goal for each node is asymmetric, which is required to achieve a high detection rate and a moderate false positive rate. We develop new boosting algorithms to address this asymmetric learning problem. We show that our methods explicitly optimize asymmetric loss objectives in a totally corrective fashion. The methods are totally corrective in the sense that the coefficients of all selected weak classifiers are updated at each iteration. In contract, conventional boosting like AdaBoost is stage-wise in that only the current weak classifier's coefficient is updated. At the heart of the totally corrective boosting is the column generation technique. Experiments on face detection show that our methods outperform the ...

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Bloodstream infection by highly antibiotic-resistant bacteria, such as vancomycin-resistant Enterococcus (VRE), is a growing clinical problem that increasingly defies medical intervention....Full Text Available

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eling of the Stefan Problem, AIAA J., vol. 22, Nov. 1984, pp. 1685-1690. Schlichting, H., Boundary-Layer Theory. F. J. Cerra, ED. ...

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Accessory cusp present on the occlusal surface may seldom pose problems. While its presence may not be a cause for alarm in most instances, it can sometimes lead to serious consequences if it is damaged....Full Text Available

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... Tschantz, Performance Evaluation of Constructed Urban Stormwater Detention Ponds in the Knoxville Area, proceedings and presentation to International Conference on Decision Making in Urban and Civil Engineering, Lyon, France, November 22, 2000. B.A. Tschanz, Current Problems, Practices, and ...

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The classical Stefan theory for the melting of a solid or the freezing of a liquid is too simplistic to describe phenomena such as supercooling, in which a liquid supports temperatures below its freezing point, or superheating, the analog for solids, or d...

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Investigations of superdense compression touch on such problems as ultrahigh-frequency oscillations of matter in the generation of gravitational waves, the powerful pumping of hard coherent radiation, and the laboratory simulation of stellar interiors. This paper reviews the theory of supercompression and discusses some experiments involving multifoil collision supercompression.

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The phase space of quantized systems that contain tachyons has been investigated. Interpretation difficulties and unexpected divergences are found when it is considered the volume of Lorentz-invariant phase space. These problems can be overcome, however, at the expense of Lorentz invariance.

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A community health survey of 438 individuals was taken to detect health problems related to high voltage electrical transmission among an adjacent residential population. Results revealed no significant...Full Text Available

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What do we mean when we say that a mental condition is a medical disorder rather than a normal form of human suffering or a problem in living? The status of psychiatry as a medical discipline depends...Full Text Available

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ObjectivesModernising Medical Careers (MMC) emerged in response to acknowledged problems in training in the Senior House Officer grade. The objective of this study was to assess...Full Text Available

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BackgroundHepatitis B (HBV) and C (HCV) infections are a serious global and national public health problem. Earlier studies have reported increasing rates of hepatitis infection...Full Text Available

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Petroleum contamination of groundwater is widely recognized as a serious environmental problem. Toluene (methylbenzene) occurs naturally in crude oil and is commonly found as a contaminant in the subsurface as a result of waste disposal and storage activities. Biological transf...

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BackgroundPublic information about prevention of zoonoses should be based on the perceived problem by the public and should be adapted to regional circumstances. Growing fox populations...Full Text Available

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High blood pressure (BP) is a major public health problem in India and its prevalence is rapidly increasing among urban and rural populations. Reducing systolic and diastolic BP can decrease cardiovascular...Full Text Available

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The likelihood that past experience will produce correct guides to current practice depends on the signal-to-noise ratio for the clinical problem of interest. If the signal-to-noise ratio is high, the...Full Text Available

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Experiments were carried out to clarify problems encountered in measuring metabolic and storage pool sizes of nitrate in wheat leaf sections with an in vivo nitrate reductase assay....Full Text Available

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Solid molecular orthohydrogen exhibits orientational order at low temperatures. The orthohydrogen molecules, which are quadrupoles, order in the Pa3 structure. We have simulated this ordering, and explored the behaviour under dilution by spherical parahydrogen molecules.

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Sexually transmitted diseases (STDs) represent a major public health problem in the country, cause patients enormous suffering, and cost the nation billions of dollars annually. Demographic, sociological,...Full Text Available

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Semiclassical analysis of heavy ion induced transfer reactions are discussed for the quasielastic region. Some unique aspects of these reactions are shown, the variety of features which can be understood semiclassically is demonstrated, and some open problems are indicated. 28 refs., 16 figs. (LEW)

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The erosion phenomena of coastal regions in Italy and in the world is remarkable from the environmental point of view. Are showed activities of mechanical defense and numerical models to solve complex problem.

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Zoonotic visceral leishmaniasis (ZVL) is a serious public health problem in several Brazilian cities. Although the proximity of chicken houses is often cited as a risk factor in studies of urban ZVL,...Full Text Available

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Our group has developed a physician-operated inpatient order-entry system (BICS-OE). Mindful of the problems inherent in bringing a radical cultural change such as this to the hospital, we conducted...Full Text Available

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Relativistic mean field (RMF) theory is applied to modern problems of nuclear structure, such as the description of rotating bands in super-deformed nuclei or the investigation of neutron halos in light exotic nuclei. (orig.)

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ORDINARY HUMAN REASONING MAY LEAD PATIENTS to provide an unreliable history of past experiences because of errors in comprehension, recall, evaluation and expression. Comprehension of a question may...Full Text Available

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A patient’s electronic medical record contains a large amount of unstructured textual information. As patient records become increasingly dense owing to an aging population and increased occurrence...Full Text Available

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The global problem concerning contamination of the environment because of human activities is increasing. Most of the environmental contaminants are chemical by-products and heavy metals such as lead (Pb). Lead released into the environment makes its way into the air, soil and water. Lead contribute...

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The phase space of quantized systems that contain tachyons has been investigated. Interpretation difficulties and unexpected divergences are found when we consider the volume of Lorentz-invariant phase space. These problems can be overcome, however, at the expense of Lorentz invariance.

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Transport of negative ion beams through plasma is reviewed. The effect of space charge on beam stability and beam emittance is discussed. The approaches to the beam transport problem developed at Los Alamos, Berkeley, Oak Ridge and Culham Laboratory are intercompared. (AIP)

International Nuclear Information System (INIS)

The NATO Advanced Research Workshop on Nuclear Submarine Decommissioning and Related Problems was held in Moscow June 19--22, 1995. It was preceded by a visit to the Zvezdotchka Shipyard at Severodvinsk, a repair and maintenance yard for Russian nuclear submarines, for a subgroup of the workshop attendees. Most of the material in this paper is drawn directly form the workshop proceedings. Slightly less than 500 nuclear ships and submarines (the vast majority are submarines) have been constructed by the countries with nuclear navies. This includes approximately 250 by Russia, 195 by the United States, 23 by the United Kingdom, 11 by France and 6 by China. By the year 2000 it is expected that approximately one-half of these nuclear vessels will be removed from service and in various states of decommissioning. A newspaper account in June 1997 indicated that 156 Russian nuclear submarines had been removed from service. In August 1996 it was reported that 55 reactor ...

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The paper is concerned with the economic operation of power systems comprising pumped storage and thermal plants. In power systems, pumped storage plants may receive the energy required for pumping water either from the system in which they are integrated or from a neighbouring system. Therefore, two mathematical formulations of the problem are presented depending on the source of energy during pumping. In both cases, the problem is reduced to a non linear optimization problem. Two numerical techniques are suggested for the solution of this optimization problem, namely the Lagrangian Multipliers technique and the Rosen Gradient Projection technique. Numerical examples are presented to demonstrate the techniques. Although the Lagrangian Multipliers technique has the advantage of being a well known technique, however, computer wise, the Rosen Gradient Projection technique proves to be more efficient. The ...

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Rapid changes in China over the past two decades have led to significant problems associated with population migration and changing social attitudes, including a growing sex industry and concurrent...Full Text Available

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The evolution of drug resistant bacteria is a severe public health problem, both in hospitals and in the community. Currently, some countries aim at concentrating highly specialized services in large...Full Text Available

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This chapter provides an overview of the problem of response to a nuclear weapon accident, the fundamentals of response to an accident, and a summary of the NARP Manual. The manual provides a summary of procedural guidance, technical information, and DoD responsibilities, to assist DoD forces in preparing a response to a nuclear weapon accident.

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Arriving at a firm diagnosis of neurosarcoidosis continues to pose serious problems, particularly when evidence of granulomatous disease outside the nervous system is lacking. The commonest mode of...Full Text Available

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Motivation: The identification of gene regulatory modules is an important yet challenging problem in computational biology. While many computational methods have been proposed to identify...Full Text Available

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Specific criteria have been developed based on computerized dynamic posturography (CDP) to assist clinicians in identifying patients with psychogenic balance problems (Cyr and Cevette, Full Text Available

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To elucidate problems with microfungal infestation in indoor environments, a multidisciplinary collaborative pilot study, supported by a grant from the Danish Ministry of Housing and Urban Affairs,...Full Text Available