Error due to unresolved scales in estimation problems for atmospheric data assimilation

Science.gov (United States)

Janjic, Tijana

The error arising due to unresolved scales in data assimilation procedures is examined. The problem of estimating the projection of the state of a passive scalar undergoing advection at a sequence of times is considered. The projection belongs to a finite- dimensional function space and is defined on the continuum. Using the continuum projection of the state of a passive scalar, a mathematical definition is obtained for the error arising due to the presence, in the continuum system, of scales unresolved by the discrete dynamical model. This error affects the estimation procedure through point observations that include the unresolved scales. In this work, two approximate methods for taking into account the error due to unresolved scales and the resulting correlations are developed and employed in the estimation procedure. The resulting formulas resemble the Schmidt-Kalman filter and the usual discrete Kalman filter, respectively. For this reason, the newly developed filters are called the Schmidt-Kalman filter and the traditional filter. In order to test the assimilation methods, a two- dimensional advection model with nonstationary spectrum was developed for passive scalar transport in the atmosphere. An analytical solution on the sphere was found depicting the model dynamics evolution. Using this analytical solution the model error is avoided, and the error due to unresolved scales is the only error left in the estimation problem. It is demonstrated that the traditional and the Schmidt- Kalman filter work well provided the exact covariance function of the unresolved scales is known. However, this requirement is not satisfied in practice, and the covariance function must be modeled. The Schmidt-Kalman filter cannot be computed in practice without further approximations. Therefore, the traditional filter is better suited for practical use. Also, the traditional filter does not require modeling of the full covariance function of the unresolved scales, but only

On the Uniqueness of Solutions of a Nonlinear Elliptic Problem Arising in the Confinement of a Plasma in a Stellarator Device

International Nuclear Information System (INIS)

Diaz, J. I.; Galiano, G.; Padial, J. F.

1999-01-01

We study the uniqueness of solutions of a semilinear elliptic problem obtained from an inverse formulation when the nonlinear terms of the equation are prescribed in a general class of real functions. The inverse problem arises in the modeling of the magnetic confinement of a plasma in a Stellarator device. The uniqueness proof relies on an L ∞ -estimate on the solution of an auxiliary nonlocal problem formulated in terms of the relative rearrangement of a datum with respect to the solution

Projected regression method for solving Fredholm integral equations arising in the analytic continuation problem of quantum physics

International Nuclear Information System (INIS)

Arsenault, Louis-François; Millis, Andrew J; Neuberg, Richard; Hannah, Lauren A

2017-01-01

We present a supervised machine learning approach to the inversion of Fredholm integrals of the first kind as they arise, for example, in the analytic continuation problem of quantum many-body physics. The approach provides a natural regularization for the ill-conditioned inverse of the Fredholm kernel, as well as an efficient and stable treatment of constraints. The key observation is that the stability of the forward problem permits the construction of a large database of outputs for physically meaningful inputs. Applying machine learning to this database generates a regression function of controlled complexity, which returns approximate solutions for previously unseen inputs; the approximate solutions are then projected onto the subspace of functions satisfying relevant constraints. Under standard error metrics the method performs as well or better than the Maximum Entropy method for low input noise and is substantially more robust to increased input noise. We suggest that the methodology will be similarly effective for other problems involving a formally ill-conditioned inversion of an integral operator, provided that the forward problem can be efficiently solved. (paper)

Single-machine scheduling with release dates, due dates and family setup times

NARCIS (Netherlands)

Schutten, Johannes M.J.; van de Velde, S.L.; van de Velde, S.L.; Zijm, Willem H.M.

1996-01-01

We address the NP-hard problem of scheduling n independent jobs with release dates, due dates, and family setup times on a single machine to minimize the maximum lateness. This problem arises from the constant tug-of-war going on in manufacturing between efficient production and delivery

Single-machine scheduling with release dates, due dates, and family setup times

NARCIS (Netherlands)

J.M.J. Schutten (Marco); S.L. van de Velde (Steef); W.H.M. Zijm

1996-01-01

textabstractWe address the NP-hard problem of scheduling n independent jobs with release dates, due dates, and family setup times on a single machine to minimize the maximum lateness. This problem arises from the constant tug-of-war going on in manufacturing between efficient production and delivery

Boundary Value Problems Arising in Kalman Filtering

Directory of Open Access Journals (Sweden)

Sinem Ertürk

2009-01-01

Full Text Available The classic Kalman filtering equations for independent and correlated white noises are ordinary differential equations (deterministic or stochastic with the respective initial conditions. Changing the noise processes by taking them to be more realistic wide band noises or delayed white noises creates challenging partial differential equations with initial and boundary conditions. In this paper, we are aimed to give a survey of this connection between Kalman filtering and boundary value problems, bringing them into the attention of mathematicians as well as engineers dealing with Kalman filtering and boundary value problems.

Boundary Value Problems Arising in Kalman Filtering

Directory of Open Access Journals (Sweden)

Bashirov Agamirza

2008-01-01

Full Text Available The classic Kalman filtering equations for independent and correlated white noises are ordinary differential equations (deterministic or stochastic with the respective initial conditions. Changing the noise processes by taking them to be more realistic wide band noises or delayed white noises creates challenging partial differential equations with initial and boundary conditions. In this paper, we are aimed to give a survey of this connection between Kalman filtering and boundary value problems, bringing them into the attention of mathematicians as well as engineers dealing with Kalman filtering and boundary value problems.

Existence of solutions to boundary value problems arising from the fractional advection dispersion equation

Directory of Open Access Journals (Sweden)

Lingju Kong

2013-04-01

Full Text Available We study the existence of multiple solutions to the boundary value problem $$displaylines{ frac{d}{dt}Big(frac12{}_0D_t^{-eta}(u'(t+frac12{}_tD_T^{-eta}(u'(t Big+lambda abla F(t,u(t=0,quad tin [0,T],cr u(0=u(T=0, }$$ where $T>0$, $lambda>0$ is a parameter, $0leqeta<1$, ${}_0D_t^{-eta}$ and ${}_tD_T^{-eta}$ are, respectively, the left and right Riemann-Liouville fractional integrals of order $eta$, $F: [0,T]imesmathbb{R}^Nomathbb{R}$ is a given function. Our interest in the above system arises from studying the steady fractional advection dispersion equation. By applying variational methods, we obtain sufficient conditions under which the above equation has at least three solutions. Our results are new even for the special case when $eta=0$. Examples are provided to illustrate the applicability of our results.

Single-machine common/slack due window assignment problems with linear decreasing processing times

Science.gov (United States)

Zhang, Xingong; Lin, Win-Chin; Wu, Wen-Hsiang; Wu, Chin-Chia

2017-08-01

This paper studies linear non-increasing processing times and the common/slack due window assignment problems on a single machine, where the actual processing time of a job is a linear non-increasing function of its starting time. The aim is to minimize the sum of the earliness cost, tardiness cost, due window location and due window size. Some optimality results are discussed for the common/slack due window assignment problems and two O(n log n) time algorithms are presented to solve the two problems. Finally, two examples are provided to illustrate the correctness of the corresponding algorithms.

[Work days lost due to health problems in industry].

Science.gov (United States)

Yano, Sylvia Regina Trindade; Santana, Vilma Sousa

2012-05-01

This cross-sectional study estimated the prevalence of work days lost due to health problems and associated factors among industrial workers. The study population was a simple random cluster sample of 3,403 workers from 16 to 65 years of age in the city of Salvador, Bahia State, Brazil. Data were collected with individual home interviews. Among industrial workers, one-year prevalence of work days lost to health problems was 12.5%, of which 5.5% were directly work-related and 4.1% aggravated by work. There were no statistically significant differences when compared to other worker categories. Self-perceived workplace hazards, history of work-related injury, and poor self-rated health were associated with work days lost due to work-related injuries/diseases. The findings showed that work days lost are common among both industrial and non-industrial workers, thereby affecting productivity and requiring prevention programs.

Operator approximant problems arising from quantum theory

CERN Document Server

Maher, Philip J

2017-01-01

This book offers an account of a number of aspects of operator theory, mainly developed since the 1980s, whose problems have their roots in quantum theory. The research presented is in non-commutative operator approximation theory or, to use Halmos' terminology, in operator approximants. Focusing on the concept of approximants, this self-contained book is suitable for graduate courses.

Occupancy statistics arising from weighted particle rearrangements

International Nuclear Information System (INIS)

Huillet, Thierry

2007-01-01

The box-occupancy distributions arising from weighted rearrangements of a particle system are investigated. In the grand-canonical ensemble, they are characterized by determinantal joint probability generating functions. For doubly non-negative weight matrices, fractional occupancy statistics, generalizing Fermi-Dirac and Bose-Einstein statistics, can be defined. A spatially extended version of these balls-in-boxes problems is investigated

Nature Inspired Computational Technique for the Numerical Solution of Nonlinear Singular Boundary Value Problems Arising in Physiology

Directory of Open Access Journals (Sweden)

Suheel Abdullah Malik

2014-01-01

Full Text Available We present a hybrid heuristic computing method for the numerical solution of nonlinear singular boundary value problems arising in physiology. The approximate solution is deduced as a linear combination of some log sigmoid basis functions. A fitness function representing the sum of the mean square error of the given nonlinear ordinary differential equation (ODE and its boundary conditions is formulated. The optimization of the unknown adjustable parameters contained in the fitness function is performed by the hybrid heuristic computation algorithm based on genetic algorithm (GA, interior point algorithm (IPA, and active set algorithm (ASA. The efficiency and the viability of the proposed method are confirmed by solving three examples from physiology. The obtained approximate solutions are found in excellent agreement with the exact solutions as well as some conventional numerical solutions.

A fish-like robot: Mechanics of swimming due to constraints

Science.gov (United States)

Tallapragada, Phanindra; Malla, Rijan

2014-11-01

It is well known that due to reasons of symmetry, a body with one degree of actuation cannot swim in an ideal fluid. However certain velocity constraints arising in fluid-body interactions, such as the Kutta condition classically applied at the trailing cusp of a Joukowski hydrofoil break this symmetry through vortex shedding. Thus Joukowski foils that vary shape periodically can be shown to be able to swim through vortex shedding. In general it can be shown that vortex shedding due to the Kutta condition is equivalent to nonintegrable constraints arising in the mechanics of finite-dimensional mechanical systems. This equivalence allows hydrodynamic problems involving vortex shedding, especially those pertaining to swimming and related phenomena to be framed in the context of geometric mechanics on manifolds. This formal equivalence also allows the design of bio inspired robots that swim not due to shape change but due to internal moving masses and rotors. Such robots lacking articulated joints are easy to design, build and control. We present such a fish-like robot that swims due to the rotation of internal rotors.

Spectral collocation for multiparameter eigenvalue problems arising from separable boundary value problems

Science.gov (United States)

Plestenjak, Bor; Gheorghiu, Călin I.; Hochstenbach, Michiel E.

2015-10-01

In numerous science and engineering applications a partial differential equation has to be solved on some fairly regular domain that allows the use of the method of separation of variables. In several orthogonal coordinate systems separation of variables applied to the Helmholtz, Laplace, or Schrödinger equation leads to a multiparameter eigenvalue problem (MEP); important cases include Mathieu's system, Lamé's system, and a system of spheroidal wave functions. Although multiparameter approaches are exploited occasionally to solve such equations numerically, MEPs remain less well known, and the variety of available numerical methods is not wide. The classical approach of discretizing the equations using standard finite differences leads to algebraic MEPs with large matrices, which are difficult to solve efficiently. The aim of this paper is to change this perspective. We show that by combining spectral collocation methods and new efficient numerical methods for algebraic MEPs it is possible to solve such problems both very efficiently and accurately. We improve on several previous results available in the literature, and also present a MATLAB toolbox for solving a wide range of problems.

Convex solutions of systems arising from Monge-Ampere equations

Directory of Open Access Journals (Sweden)

Haiyan Wang

2009-10-01

Full Text Available We establish two criteria for the existence of convex solutions to a boundary value problem for weakly coupled systems arising from the Monge-Ampère equations. We shall use fixed point theorems in a cone.

Algorithms and ordering heuristics for distributed constraint satisfaction problems

CERN Document Server

Wahbi , Mohamed

2013-01-01

DisCSP (Distributed Constraint Satisfaction Problem) is a general framework for solving distributed problems arising in Distributed Artificial Intelligence.A wide variety of problems in artificial intelligence are solved using the constraint satisfaction problem paradigm. However, there are several applications in multi-agent coordination that are of a distributed nature. In this type of application, the knowledge about the problem, that is, variables and constraints, may be logically or geographically distributed among physical distributed agents. This distribution is mainly due to p

Visual problems in young adults due to computer use.

Science.gov (United States)

Moschos, M M; Chatziralli, I P; Siasou, G; Papazisis, L

2012-04-01

Computer use can cause visual problems. The purpose of our study was to evaluate visual problems due to computer use in young adults. Participants in our study were 87 adults, 48 male and 39 female, mean aged 31.3 years old (SD 7.6). All the participants completed a questionnaire regarding visual problems detected after computer use. The mean daily use of computers was 3.2 hours (SD 2.7). 65.5 % of the participants complained for dry eye, mainly after more than 2.5 hours of computer use. 32 persons (36.8 %) had a foreign body sensation in their eyes, while 15 participants (17.2 %) complained for blurred vision which caused difficulties in driving, after 3.25 hours of continuous computer use. 10.3 % of the participants sought medical advice for their problem. There was a statistically significant correlation between the frequency of visual problems and the duration of computer use (p = 0.021). 79.3 % of the participants use artificial tears during or after long use of computers, so as not to feel any ocular discomfort. The main symptom after computer use in young adults was dry eye. All visual problems associated with the duration of computer use. Artificial tears play an important role in the treatment of ocular discomfort after computer use. © Georg Thieme Verlag KG Stuttgart · New York.

Risk analysis for renewable energy projects due to constraints arising

Science.gov (United States)

Prostean, G.; Vasar, C.; Prostean, O.; Vartosu, A.

2016-02-01

Starting from the target of the European Union (EU) to use renewable energy in the area that aims a binding target of 20% renewable energy in final energy consumption by 2020, this article illustrates the identification of risks for implementation of wind energy projects in Romania, which could lead to complex technical implications, social and administrative. In specific projects analyzed in this paper were identified critical bottlenecks in the future wind power supply chain and reasonable time periods that may arise. Renewable energy technologies have to face a number of constraints that delayed scaling-up their production process, their transport process, the equipment reliability, etc. so implementing these types of projects requiring complex specialized team, the coordination of which also involve specific risks. The research team applied an analytical risk approach to identify major risks encountered within a wind farm project developed in Romania in isolated regions with different particularities, configured for different geographical areas (hill and mountain locations in Romania). Identification of major risks was based on the conceptual model set up for the entire project implementation process. Throughout this conceptual model there were identified specific constraints of such process. Integration risks were examined by an empirical study based on the method HAZOP (Hazard and Operability). The discussion describes the analysis of our results implementation context of renewable energy projects in Romania and creates a framework for assessing energy supply to any entity from renewable sources.

Missed Total Occlusion Due to the Occipital Artery Arising from the Internal Carotid Artery

International Nuclear Information System (INIS)

Ustunsoz, Bahri; Gumus, Burcak; Koksal, Ali; Koroglu, Mert; Akhan, Okan

2007-01-01

A 56-year-old man was referred for digital subtraction angiography (DSA) with an ultrasound diagnosis of right proximal internal carotid artery (ICA) stenosis for possible carotid artery stenting. DSA revealed total occlusion of the ICA and an occipital artery arising from the stump and simulating continuation of the ICA. An ascending pharyngeal artery also arose from the same occipital artery. This case is of interest because this is a rare variation besides being a cause of misdiagnosis at carotid ultrasound

Flow features that arise due to the interaction of a plane shock wave with concave profiles

CSIR Research Space (South Africa)

MacLucas, David A

2012-10-01

Full Text Available The focus of the author's thesis was the aerodynamic flow field that develops as a result of the interaction of a moving plane shock wave with concave profiles. In this presentation, he discusses some of the interesting flow phenomena that arise...

Stieltjes electrostatic model interpretation for bound state problems

Indian Academy of Sciences (India)

In this paper, it is shown that Stieltjes electrostatic model and quantum Hamilton Jacobi formalism are analogous to each other. This analogy allows the bound state problem to mimic as unit moving imaginary charges i ℏ , which are placed in between the two fixed imaginary charges arising due to the classical turning ...

Admissions through the emergency department due to drug-related problems

International Nuclear Information System (INIS)

Yosef H Al-Olah; Khalifa M Al Thiab

2010-01-01

Hospital admissions due to drug-related problems (DRPs) have been studied internationally, but local data are limited. Therefore, we undertook a prospective, observational study of all admissions through the emergency department (ED) at a tertiary referral hospital in Saudi Arabia to determine the incidence of admissions through the ED due to DRPs, types of DRPs, length of stay (LOS) in the hospital after ED admissions due to DRPs, and assessment of preventability of admissions due to DRPs.All admissions through the ED over a period of 28 consecutive days were evaluated to determine if they were due to definite or possible DRPs. Data was collected on a daily basis for each admission over the previous 24 hours. Each incident was assessed by three investigators Of 557 patients admitted through the ED, 82 (14.7%) admissions were due to DRP (53 definite, 29 possible). The most common types of DRP were failure to receive medication in 25 cases (47.2%), an adverse drug reaction in 13 cases (24.5%), and drug overdose in 6 cases (11.3%). In the definite DRP group, 83.0% were definitely preventable, 3.8% were possibly preventable and 13.2% were definitely non-preventable.DRPs are a serious and costly issue facing health care professionals and health care systems. Most admissions due to DRPs are avoidable (Author).

Ethical problems arising from the use of placebo in clinical trials with drugs for migraine. Their analysis by the moral deliberation method.

Science.gov (United States)

Frías, J; Pascual, J; Lahuerta, J; Gracia, D; Dal-Ré, R

2011-03-01

Migraine is characterised as episodes of headache plus a variety of accompanying symptoms. Its pharmacological control remains unsatisfactory for some patients. The use of placebo in drug clinical trials on migraine commonly leads to numerous ethical uncertainties. The purpose of this paper is to illustrate how the deliberation method helps in analysing the issues and finding solutions to selected ethical problems. Ethical decisions that try to solve conflicts arising from placebo use in clinical trials may be adopted using the moral deliberation method. Thus, the conflict is systematically assessed by identifying the following: Relevant facts; Values in conflict; Duties, or in other words, possible courses of action. Moral duty is following the optimal course of action. To identify this, it is recommended to state extreme courses of action, then intermediate courses of action, and then to proceed to the optimal course(s) of action. In this paper, the application of this method is shown in several conflicting situations arising in two placebo-controlled clinical trials with drugs under development for the prophylaxis and acute treatment of migraine. Copyright © 2010 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Absenteeism due to voice disorders in female teachers: a public health problem.

Science.gov (United States)

de Medeiros, Adriane Mesquita; Assunção, Ada Ávila; Barreto, Sandhi Maria

2012-11-01

This study estimates the prevalence of absenteeism due to voice disorders among teachers and investigates individual and contextual factors associated with it. The study involved 1,980 teachers from 76 municipal schools. The response rate was 85%. The survey was carried out between May 2004 and July 2005 using a self-administered structured questionnaire containing sociodemographic, lifestyle, health, and work-related questions. The dependent variable was obtained from answers to the following question: In the last 2 weeks, have you missed work because of voice problems? Logistic regression analysis was used to determine the associated factors. Voice-related absenteeism in the prior 2 weeks was reported by 66 teachers (3.35%). During their entire careers, approximately one-third of teachers missed work at least once due to voice problems. In the final model, factors associated with recent absenteeism were as follows: witnessing violence by students or parents one or more times (OR = 2.10; 95% CI = 1.14-3.90), presence of depression or anxiety (OR = 2.03; 95% CI = 1.09-3.78), upper respiratory problems in the prior 2 weeks (OR = 2.85; 95% CI = 1.53-5.29), and absenteeism because of voice problems during the preceding 6 months (OR = 15.79; 95% CI = 8.18-30.45). The results encourage new approaches to the problems of absenteeism in the educational sector and contribute to addressing the weaknesses of economic and administrative approaches to the phenomenon.

Decision Analysis on Survey and SOil Investigation Problem in Power Engineering Consultant

OpenAIRE

Setyaman, Amy Maulany; Sunitiyoso, Yos

2013-01-01

The study aims to gather and organize information for decision making against the problems arising in Power Engineering Consultant's survey and soil investigation product due to new policy in production cost efficiency that is implemented in 2012. The study conducted using Kepner and Tragoe's analytical process that consisted of four stages analytical process such as situation analysis, problem analysis, decision making analysis and potential problem analysis. As for the decision making analy...

Spectral inversion of an indefinite Sturm-Liouville problem due to Richardson

International Nuclear Information System (INIS)

Shanley, Paul E

2009-01-01

We study an indefinite Sturm-Liouville problem due to Richardson whose complicated eigenvalue dependence on a parameter has been a puzzle for decades. In atomic physics a process exists that inverts the usual Schroedinger situation of an energy eigenvalue depending on a coupling parameter into the so-called Sturmian problem where the coupling parameter becomes the eigenvalue which then depends on the energy. We observe that the Richardson equation is of the Sturmian type. This means that the Richardson and its related Schroedinger eigenvalue functions are inverses of each other and that the Richardson spectrum is therefore no longer a puzzle

On a Linear Equation Arising in Isometric Embedding of Torus-like Surface

Institute of Scientific and Technical Information of China (English)

Chunhe LI

2009-01-01

The solvability of a linear equation and the regularity of the solution are discussed.The equation is arising in a geometric problem which is concerned with the realization of Alexandroff's positive annul in R3.

A non-standard optimal control problem arising in an economics application

Directory of Open Access Journals (Sweden)

Alan Zinober

2013-04-01

Full Text Available A recent optimal control problem in the area of economics has mathematical properties that do not fall into the standard optimal control problem formulation. In our problem the state value at the final time the state, y(T = z, is free and unknown, and additionally the Lagrangian integrand in the functional is a piecewise constant function of the unknown value y(T. This is not a standard optimal control problem and cannot be solved using Pontryagin's Minimum Principle with the standard boundary conditions at the final time. In the standard problem a free final state y(T yields a necessary boundary condition p(T = 0, where p(t is the costate. Because the integrand is a function of y(T, the new necessary condition is that y(T should be equal to a certain integral that is a continuous function of y(T. We introduce a continuous approximation of the piecewise constant integrand function by using a hyperbolic tangent approach and solve an example using a C++ shooting algorithm with Newton iteration for solving the Two Point Boundary Value Problem (TPBVP. The minimising free value y(T is calculated in an outer loop iteration using the Golden Section or Brent algorithm. Comparative nonlinear programming (NP discrete-time results are also presented.

Problems arising in the evaluation of collective dose commitment

International Nuclear Information System (INIS)

Coulon, R.; Beau, P.

1979-01-01

In order to apply the concept of optimization it is necessary to evaluate the collective dose commitment for the population as a whole. This is found by summing the dose commitments for the different population groups involved, including persons occupationally exposed and members of the public both locally and globally. The average dose received by each of these groups can vary considerably: for occupational exposure it is about one order of magnitude below the limits, whereas for the general public it is far below, although certain local groups may be subjected to a much higher exposure than the overall average. The question arises, therefore, whether certain groups should not be weighted differently in order to take into account the heterogeneity of the distribution of exposure. As far as the validity of forecast evaluations is concerned, one may assume that for occupational exposure the dose commitment over the whole period of operation of a facility can be estimated fairly accurately. The overall collective dose commitment for the public is relatively insensitive to local variations in the environment and in the public itself but is strongly dependent on long-term developments which cannot at present be forecast. For the evaluation of dose equivalent to the critical group, local variations are of considerable importance and need to be foreseen, which is not always possible. By taking into account a period which includes the annual maximum collective dose equivalent one can make some of these difficulties less severe. (author)

Gender differences in 16-year trends in assault- and police-related problems due to drinking.

Science.gov (United States)

Timko, Christine; Moos, Bernice S; Moos, Rudolf H

2009-09-01

This study examined the frequency and predictors of physical assault and having trouble with the police due to drinking over 16 years among women and men who, at baseline, were untreated for their alcohol use disorder. Predictors examined were the personal characteristics of impulsivity, self-efficacy, and problem-solving and emotional-discharge coping, as well as outpatient treatment and Alcoholics Anonymous (AA) participation. Women and men were similar on rates of perpetrating assault due to drinking, but men were more likely to have had trouble with the police due to drinking. Respondents who, at baseline, were more impulsive and relied more on emotional discharge coping, and less on problem-solving coping, assaulted others more frequently during the first year of follow-up. Similarly, less problem-solving coping at baseline was related to having had trouble with the police more often at one and 16 years due to drinking. The association between impulsivity and more frequent assault was stronger for women, whereas associations of self-efficacy and problem-solving coping with less frequent assault and police trouble were stronger for men. Participation in AA was also associated with a lower likelihood of having trouble with the police at one year, especially for men. Interventions aimed at decreasing impulsivity and emotional discharge coping, and bolstering self-efficacy and problem-solving coping, during substance abuse treatment, and encouragement to become involved in AA, may be helpful in reducing assaultive and other illegal behaviors.

Impaired reasoning and problem-solving in individuals with language impairment due to aphasia or language delay

Science.gov (United States)

Baldo, Juliana V.; Paulraj, Selvi R.; Curran, Brian C.; Dronkers, Nina F.

2015-01-01

The precise nature of the relationship between language and thought is an intriguing and challenging area of inquiry for scientists across many disciplines. In the realm of neuropsychology, research has investigated the inter-dependence of language and thought by testing individuals with compromised language abilities and observing whether performance in other cognitive domains is diminished. One group of such individuals is patients with aphasia who have an impairment in speech and language arising from a brain injury, such as a stroke. Our previous research has shown that the degree of language impairment in these individuals is strongly associated with the degree of impairment on complex reasoning tasks, such as the Wisconsin Card Sorting Task (WCST) and Raven’s Matrices. In the current study, we present new data from a large group of individuals with aphasia that show a dissociation in performance between putatively non-verbal tasks on the Wechsler Adult Intelligence Scale (WAIS) that require differing degrees of reasoning (Picture Completion vs. Picture Arrangement tasks). We also present an update and replication of our previous findings with the WCST showing that individuals with the most profound core language deficits (i.e., impaired comprehension and disordered language output) are particularly impaired on problem-solving tasks. In the second part of the paper, we present findings from a neurologically intact individual known as “Chelsea” who was not exposed to language due to an unaddressed hearing loss that was present since birth. At the age of 32, she was fitted with hearing aids and exposed to spoken and signed language for the first time, but she was only able to acquire a limited language capacity. Chelsea was tested on a series of standardized neuropsychological measures, including reasoning and problem-solving tasks. She was able to perform well on a number of visuospatial tasks but was disproportionately impaired on tasks that required

Investigation of medical board reports of disability due to mental health problems

Directory of Open Access Journals (Sweden)

Mesut Yildiz

2016-06-01

Conclusion: We think that this report might be helpful for regulations related to disabled people, and might guide adult psychiatric services for patients who present to medical boards for disability due to mental health problems. [Cukurova Med J 2016; 41(2.000: 253-258

Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

DEFF Research Database (Denmark)

Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

2007-01-01

Over the past years, considerable high temperature corrosion problems have been encountered when firing biomass in power plants due to the high content of potassium chloride in the deposits. Therefore to combat chloride corrosion problems co-firing of biomass with a fossil fuel has been undertaken....... This results in potassium chloride being converted to potassium sulphate in the combustion chamber and it is sulphate rich deposits that are deposited on the vulnerable metallic surfaces such as high temperature superheaters. Although this removes the problem of chloride corrosion, other corrosion mechanisms...... appear such as sulphidation and hot corrosion due to sulphate deposits. At Studstrup power plant Unit 4, based on trials with exposure times of 3000 hours using 0-20% straw co-firing with coal, the plant now runs with a fuel of 10% straw + coal. After three years exposure in this environment...

SCC, Bowen's disease and BCC arising on chronic radiation dermatitis due to radiation therapy for tinea pedis

International Nuclear Information System (INIS)

Aoki, Eri; Aoki, Mikako; Ikemura, Akiko; Igarashi, Tsukasa; Suzuki, Kayano; Kawana, Seiji

2000-01-01

We reported a case who developed three different types of skin cancers: SCC, BCC, and Bowen's disease, on the chronic radiation dermatitis. He had been treated for his tinea pedis et palmaris with radiotherapy in 1940's. It is very ratre that three different types of skin cancers arise in the same patient. This is a second case reported in Japan. (author)

Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

DEFF Research Database (Denmark)

Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

2008-01-01

Over the past few years, considerable high temperature corrosion problems have been encountered when firing biomass in power plants due to the high content of potassium chloride in the deposits. Therefore, to combat chloride corrosion problems cofiring of biomass with a fossil fuel has been...... undertaken. This results in potassium chloride being converted to potassium sulphate in the combustion chamber and it is sulphate rich deposits that are deposited on the vulnerable metallic surfaces such as high temperature superheaters. Although this removes the problem of chloride corrosion, other...... corrosion mechanisms appear such as sulphidation and hot corrosion due to sulphate deposits. At Studstrup power plant Unit 4, based on trials with exposure times of 3000 h using 0–20% straw co-firing with coal, the plant now runs with a fuel mix of 10% strawþcoal. Based on results from a 3 years exposure...

The pressure equation arising in reservoir simulation. Mathematical properties, numerical methods and upscaling

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Bjoern Fredrik

1997-12-31

The main purpose of this thesis has been to analyse self-adjoint second order elliptic partial differential equations arising in reservoir simulation. It studies several mathematical and numerical problems for the pressure equation arising in models of fluid flow in porous media. The theoretical results obtained have been illustrated by a series of numerical experiments. The influence of large variations in the mobility tensor upon the solution of the pressure equation is analysed. The performance of numerical methods applied to such problems have been studied. A new upscaling technique for one-phase flow in heterogeneous reservoirs is developed. The stability of the solution of the pressure equation with respect to small perturbations of the mobility tensor is studied. The results are used to develop a new numerical method for a model of fully nonlinear water waves. 158 refs, 39 figs., 12 tabs.

The pressure equation arising in reservoir simulation. Mathematical properties, numerical methods and upscaling

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Bjoern Fredrik

1998-12-31

The main purpose of this thesis has been to analyse self-adjoint second order elliptic partial differential equations arising in reservoir simulation. It studies several mathematical and numerical problems for the pressure equation arising in models of fluid flow in porous media. The theoretical results obtained have been illustrated by a series of numerical experiments. The influence of large variations in the mobility tensor upon the solution of the pressure equation is analysed. The performance of numerical methods applied to such problems have been studied. A new upscaling technique for one-phase flow in heterogeneous reservoirs is developed. The stability of the solution of the pressure equation with respect to small perturbations of the mobility tensor is studied. The results are used to develop a new numerical method for a model of fully nonlinear water waves. 158 refs, 39 figs., 12 tabs.

On the solution of a rational matrix equation arising in G-networks

NARCIS (Netherlands)

B. Meini (Beatrice); T. Nesti (Tommaso)

2017-01-01

textabstractWe consider the problem of solving a rational matrix equation arising in the solution of G-networks. We propose and analyze two numerical methods: a fixed point iteration and the Newton–Raphson method. The fixed point iteration is shown to be globally convergent with linear convergence

On the numerical solution of coupled eigenvalue differential equations arising in molecular spectroscopy

International Nuclear Information System (INIS)

Friedman, R.S.; Jamieson, M.J.; Preston, S.C.

1990-01-01

A method for solving coupled eigenvalue differential equations is given and its relation to an existing technique is shown. Use of the Gram-Schmidt process to overcome the severe instabilities arising in molecular problems is described in detail. (orig.)

A current value Hamiltonian Approach for Discrete time Optimal Control Problems arising in Economic Growth

OpenAIRE

Naz, Rehana

2018-01-01

Pontrygin-type maximum principle is extended for the present value Hamiltonian systems and current value Hamiltonian systems of nonlinear difference equations for uniform time step $h$. A new method termed as a discrete time current value Hamiltonian method is established for the construction of first integrals for current value Hamiltonian systems of ordinary difference equations arising in Economic growth theory.

Multiple solutions for inhomogeneous nonlinear elliptic problems arising in astrophyiscs

Directory of Open Access Journals (Sweden)

Marco Calahorrano

2004-04-01

Full Text Available Using variational methods we prove the existence and multiplicity of solutions for some nonlinear inhomogeneous elliptic problems on a bounded domain in $mathbb{R}^n$, with $ngeq 2$ and a smooth boundary, and when the domain is $mathbb{R}_+^n$

Facilitating Change to a Problem-based Model

DEFF Research Database (Denmark)

Kolmos, Anette

2002-01-01

The paper presents the barriers which arise during the change process from a traditional educational system to a problem-based educational model.......The paper presents the barriers which arise during the change process from a traditional educational system to a problem-based educational model....

Hausdorff dimension of certain sets arising in Engel expansions

Science.gov (United States)

Fang, Lulu; Wu, Min

2018-05-01

The present paper is concerned with the Hausdorff dimension of certain sets arising in Engel expansions. In particular, the Hausdorff dimension of the set is completely determined, where A n (x) can stand for the digit, gap and ratio between two consecutive digits in the Engel expansion of x and ϕ is a positive function defined on natural numbers. These results significantly extend the existing results of Galambos’ open problems on the Hausdorff dimension of sets related to the growth rate of digits.

Optimal control of switched systems arising in fermentation processes

CERN Document Server

Liu, Chongyang

2014-01-01

The book presents, in a systematic manner, the optimal controls under different mathematical models in fermentation processes. Variant mathematical models – i.e., those for multistage systems; switched autonomous systems; time-dependent and state-dependent switched systems; multistage time-delay systems and switched time-delay systems – for fed-batch fermentation processes are proposed and the theories and algorithms of their optimal control problems are studied and discussed. By putting forward novel methods and innovative tools, the book provides a state-of-the-art and comprehensive systematic treatment of optimal control problems arising in fermentation processes. It not only develops nonlinear dynamical system, optimal control theory and optimization algorithms, but can also help to increase productivity and provide valuable reference material on commercial fermentation processes.

MAP estimators and their consistency in Bayesian nonparametric inverse problems

KAUST Repository

Dashti, M.; Law, K. J H; Stuart, A. M.; Voss, J.

2013-01-01

with examples from an inverse problem for the Navier-Stokes equation, motivated by problems arising in weather forecasting, and from the theory of conditioned diffusions, motivated by problems arising in molecular dynamics. © 2013 IOP Publishing Ltd.

Perfecting of shielding calculation technique against the gamma rays arising from a Tokamak with the TFR experience. Application to the conceptual design Tokamak TORE 2 SUPRA

International Nuclear Information System (INIS)

Diop, Cheikh M'Backe.

1980-09-01

The conception of the necessary shielding around a conceptual design Tokamak requires to execute an estimated calculation of the doses due to the different radiation sources arising from the machine: the thermonuclear neutron source and the gamma ray source emitted during the interaction of the runaway electrons with the diaphragm. In this study, we propose a theorical method to calculate this gamma source. We tackle also the shielding problem of the conceptual design Tokamak: TORE 2 SUPRA [fr

Measuring production loss due to health and work environment problems: construct validity and implications.

Science.gov (United States)

Karlsson, Malin Lohela; Bergström, Gunnar; Björklund, Christina; Hagberg, Jan; Jensen, Irene

2013-12-01

The aim was to validate two measures of production loss, health-related and work environment-related production loss, concerning their associations with health status and work environment factors. Validity was assessed by evaluating the construct validity. Health problems related and work environment-related problems (or factors) were included in separate analyses and evaluated regarding the significant difference in proportion of explained variation (R) of production loss. health problems production loss was not found to fulfill the criteria for convergent validity in this study; however, the measure of work environment-related production loss did fulfill the criteria that were set up. The measure of work environment-related production loss can be used to screen for production loss due to work environment problems as well as an outcome measure when evaluating the effect of organizational interventions.

Squamous Cell Carcinoma Arising in Mature Teratoma of the Ovary Masquerading as Abdominal Tuberculosis

Directory of Open Access Journals (Sweden)

Shreeya Taresh Indulkar

2018-01-01

Full Text Available Pure squamous cell carcinoma (SCC of the ovary is rare. SCC can arise in a mature teratoma (MT, ovarian endometriosis or in a Brenner tumor. SCC is the most common malignant transformation arising in MT and comprises 80% of all cases. Such neoplastic transformations are extremely difficult either to predict or detect early. The mechanism of malignant transformation has not been completely understood. Due to the rarity and the aggressive course, diagnosis and treatment constitute a big challenge. We report a case of SCC arising in MT presenting with a huge abdominopelvic mass and abundant peritoneal collections clinically masquerading as abdominal tuberculosis. A review of literature with special emphasis on prognosis and treatment modalities is also presented.

Surprises and pitfalls arising from (pseudo)symmetry

International Nuclear Information System (INIS)

Zwart, Peter H.; Grosse-Kunstleve, Ralf W.; Lebedev, Andrey A.; Murshudov, Garib N.; Adams, Paul D.

2008-01-01

The presence of pseudosymmetry can cause problems in structure determination and refinement. The relevant background and representative examples are presented. It is not uncommon for protein crystals to crystallize with more than a single molecule per asymmetric unit. When more than a single molecule is present in the asymmetric unit, various pathological situations such as twinning, modulated crystals and pseudo translational or rotational symmetry can arise. The presence of pseudosymmetry can lead to uncertainties about the correct space group, especially in the presence of twinning. The background to certain common pathologies is presented and a new notation for space groups in unusual settings is introduced. The main concepts are illustrated with several examples from the literature and the Protein Data Bank

Environmental problems attributed due to increased road traffic intensity in Hyderabad city

International Nuclear Information System (INIS)

Memon, Z.; Ansari, A.K.

2001-01-01

Hyderabad is a historical city, so roads are not so wide to cater the present intensity of traffic, hence it is facing transportation problems. No any attempt of traffic management and control has been made in this regard to solve the acute problem of city. Some of the typical problems can be stated as poor driving, encroachments, unsystematic parking on roads, improper road markings and road sings, inadequate road geometry and inadequate control system at intersections etc. This study involves measurement of vehicles flow at five sites of Hyderabad city, and assessment of health hazards on human being due to noise congestion, improper road planning coupled with old city streets converted into roads which are now insufficient for present traffic density, resulting disturbance to pedestrians and dwellers who are living near by road for smooth walk. Motor vehicles, however, play a vital role in the field of public and goods transportation and this survey shows that there are about 726 vehicles operating per hour at the five sites in the city. (author)

Constitutional Due Process and Educational Administration.

Science.gov (United States)

Uerling, Donald F.

1985-01-01

Discusses substantive and procedural due process as required by the United States Constitution and interpreted by the Supreme Court, with particular reference to situations arising in educational environments. Covers interests protected by due process requirements, the procedures required, and some special considerations that may apply. (PGD)

Statistical perspectives on inverse problems

DEFF Research Database (Denmark)

Andersen, Kim Emil

of the interior of an object from electrical boundary measurements. One part of this thesis concerns statistical approaches for solving, possibly non-linear, inverse problems. Thus inverse problems are recasted in a form suitable for statistical inference. In particular, a Bayesian approach for regularisation...... problem is given in terms of probability distributions. Posterior inference is obtained by Markov chain Monte Carlo methods and new, powerful simulation techniques based on e.g. coupled Markov chains and simulated tempering is developed to improve the computational efficiency of the overall simulation......Inverse problems arise in many scientific disciplines and pertain to situations where inference is to be made about a particular phenomenon from indirect measurements. A typical example, arising in diffusion tomography, is the inverse boundary value problem for non-invasive reconstruction...

Applying Graph Theory to Problems in Air Traffic Management

Science.gov (United States)

Farrahi, Amir H.; Goldberg, Alan T.; Bagasol, Leonard N.; Jung, Jaewoo

2017-01-01

Graph theory is used to investigate three different problems arising in air traffic management. First, using a polynomial reduction from a graph partitioning problem, it isshown that both the airspace sectorization problem and its incremental counterpart, the sector combination problem are NP-hard, in general, under several simple workload models. Second, using a polynomial time reduction from maximum independent set in graphs, it is shown that for any fixed e, the problem of finding a solution to the minimum delay scheduling problem in traffic flow management that is guaranteed to be within n1-e of the optimal, where n is the number of aircraft in the problem instance, is NP-hard. Finally, a problem arising in precision arrival scheduling is formulated and solved using graph reachability. These results demonstrate that graph theory provides a powerful framework for modeling, reasoning about, and devising algorithmic solutions to diverse problems arising in air traffic management.

Bernoulli Variational Problem and Beyond

KAUST Repository

Lorz, Alexander

2013-12-17

The question of \\'cutting the tail\\' of the solution of an elliptic equation arises naturally in several contexts and leads to a singular perturbation problem under the form of a strong cut-off. We consider both the PDE with a drift and the symmetric case where a variational problem can be stated. It is known that, in both cases, the same critical scale arises for the size of the singular perturbation. More interesting is that in both cases another critical parameter (of order one) arises that decides when the limiting behaviour is non-degenerate. We study both theoretically and numerically the values of this critical parameter and, in the symmetric case, ask if the variational solution leads to the same value as for the maximal solution of the PDE. Finally we propose a weak formulation of the limiting Bernoulli problem which incorporates both Dirichlet and Neumann boundary condition. © 2013 Springer-Verlag Berlin Heidelberg.

Multimode Preemptive Resource Investment Problem Subject to Due Dates for Activities: Formulation and Solution Procedure

Directory of Open Access Journals (Sweden)

Behrouz Afshar-Nadjafi

2014-01-01

Full Text Available The preemptive Multimode resource investment problem is investigated. The Objective is to minimize the total renewable/nonrenewable resource costs and earliness-tardiness costs by a given project deadline and due dates for activities. In this problem setting preemption is allowed with no setup cost or time. The project contains activities interrelated by finish-start type precedence relations with a time lag of zero, which require a set of renewable and nonrenewable resources. The problem formed in this way is an NP-hard. A mixed integer programming formulation is proposed for the problem and parameters tuned genetic algorithm (GA is proposed to solve it. To evaluate the performance of the proposed algorithm, 120 test problems are used. Comparative statistical results reveal that the proposed GA is efficient and effective in terms of the objective function and computational times.

An analysis of the perceived difficulties arising during the process of integrating management systems

Directory of Open Access Journals (Sweden)

Jesus Abad

2016-09-01

Originality/value: Most research emphasises the benefits of integrated management systems. By analysing the difficulties that arise during the integration process, this study contributes to fill a gap in the literature on the problems associated with processes of organisational change, in our case the integration of management systems.

Transoral videolaryngoscopic surgery for papillary carcinoma arising in lingual thyroid.

Science.gov (United States)

Mogi, Chisato; Shinomiya, Hirotaka; Fujii, Natsumi; Tsuruta, Tomoyuki; Morita, Naruhiko; Furukawa, Tatsuya; Teshima, Masanori; Kanzawa, Maki; Hirokawa, Mitsuyoshi; Otsuki, Naoki; Nibu, Ken-Ichi

2018-05-15

Carcinoma arising in lingual thyroid is an extremely rare entity accounting for only 1% of all reported ectopic thyroids. Here, we report a case of carcinoma arising in lingual thyroid, which has been successfully managed by transoral resection and bilateral neck dissections. A lingual mass 4-cm in diameter with calcification was incidentally detected by computed tomography at medical check-up. No thyroid tissue was observed in normal position. Ultrasound examination showed bilateral multiple lymphadenopathies. Fine needle aspiration biopsy from lymph node in his right neck was diagnosed as Class III and thyroglobulin level of the specimen was 459ng/ml. Due to the difficulty in performing FNA of the lingual masses, right neck dissection was performed in advance for diagnostic purpose. Pathological examination showed existence of large and small follicular thyroid tissues in several lymph nodes, suggesting lymph node metastasis from thyroid carcinoma. Two months after the initial surgery, video-assisted transoral resection of lingual thyroid with simultaneous left neck dissection was performed. Postoperative course was uneventful. Papillary carcinoma was found in the lingual thyroid and thyroid tissues were also found in left cervical lymph nodes. Video-assisted transoral resection was useful for the treatment of thyroid cancer arising in lingual thyroid. Copyright © 2018 Elsevier B.V. All rights reserved.

A comparative study of iterative solutions to linear systems arising in quantum mechanics

International Nuclear Information System (INIS)

Jing Yanfei; Huang Tingzhu; Duan Yong; Carpentieri, Bruno

2010-01-01

This study is mainly focused on iterative solutions with simple diagonal preconditioning to two complex-valued nonsymmetric systems of linear equations arising from a computational chemistry model problem proposed by Sherry Li of NERSC. Numerical experiments show the feasibility of iterative methods to some extent when applied to the problems and reveal the competitiveness of our recently proposed Lanczos biconjugate A-orthonormalization methods to other classic and popular iterative methods. By the way, experiment results also indicate that application specific preconditioners may be mandatory and required for accelerating convergence.

About the Big Graphs Arising when Forming the Diagnostic Models in a Reconfigurable Computing Field of Functional Monitoring and Diagnostics System of the Spacecraft Onboard Control Complex

Directory of Open Access Journals (Sweden)

L. V. Savkin

2015-01-01

Full Text Available One of the problems in implementation of the multipurpose complete systems based on the reconfigurable computing fields (RCF is the problem of optimum redistribution of logicalarithmetic resources in growing scope of functional tasks. Irrespective of complexity, all of them are transformed into an orgraph, which functional and topological structure is appropriately imposed on the RCF based, as a rule, on the field programmable gate array (FPGA.Due to limitation of the hardware configurations and functions realized by means of the switched logical blocks (SLB, the abovementioned problem becomes even more critical when there is a need, within the strictly allocated RCF fragment, to realize even more complex challenge in comparison with the problem which was solved during the previous computing step. In such cases it is possible to speak about graphs of big dimensions with respect to allocated RCF fragment.The article considers this problem through development of diagnostic algorithms to implement diagnostics and control of an onboard control complex of the spacecraft using RCF. It gives examples of big graphs arising with respect to allocated RCF fragment when forming the hardware levels of a diagnostic model, which, in this case, is any hardware-based algorithm of diagnostics in RCF.The article reviews examples of arising big graphs when forming the complicated diagnostic models due to drastic difference in formation of hardware levels on closely located RCF fragments. It also pays attention to big graphs emerging when the multichannel diagnostic models are formed.Three main ways to solve the problem of big graphs with respect to allocated RCF fragment are given. These are: splitting the graph into fragments, use of pop-up windows with relocating and memorizing intermediate values of functions of high hardware levels of diagnostic models, and deep adaptive update of diagnostic model.It is shown that the last of three ways is the most efficient

Work problems due to low back pain: what do GPs do? A questionnaire survey.

Science.gov (United States)

Coole, Carol; Watson, Paul J; Drummond, Avril

2010-02-01

Low back pain can affect work ability and remains a main cause of sickness absence. In the UK the GP is usually the first contact for patients seeking health care. The UK government intends that the GP will continue to be responsible for sickness certification and work advice. This role requires a considerable level of understanding of work rehabilitation, and effective communication between GPs, patients, employers and therapists. The aim of this study was to identify GPs' current practice in managing patients whose ability to work is affected by low back pain, and their perception of the support services required. A postal questionnaire of 441 GPs in the South Nottinghamshire area of the UK was carried out. Areas covered included referral patterns, sickness certification, and communication with therapists and employers. There was a 54.6% response rate. The majority of GPs (76.8%) reported that they did not take overall responsibility for managing the work problems of patients arising from low back pain. Few 'mainly agreed' that they initiated communication with employers (2.5%) and/or therapists (10.4%) regarding their patients' work. The results of this study demonstrate that most GPs do not readily engage in vocational rehabilitation and do not initiate contact with employers or other health care practitioners regarding patients' work problems. Thus the current government expectation that GPs are able to successfully manage this role may be unrealistic; considerable training and a change in the GPs' perception of their role will be required.

Current problems arising from the new law relating to franchise duties; Aktuelle Probleme des neuen Konzessionsabgabenrechts

Energy Technology Data Exchange (ETDEWEB)

Becker, P.

1996-12-31

The contribution examines the advantages and drawbacks of the new ordinance in German law relating to payment of franchise duties. The ordinance may bring about new problems if abused as a means of bringing pressure to bear in negotiations for takeover of existing electric or gas supply systems by local governments. The author analyses the legitimation of such exploitation of the franchise duty and in this context the general legal framework. (orig./CB) [Deutsch] Der Beitrag untersucht Vor- und Nachteile der neuen Verordnung im Konzessionsabgabenrecht, die im Hinblick auf Auseinandersetzungen um die ``Ubernahme von Strom- oder Gasversorgungssystemen durch Gemeinden neue Probleme mit sich bringen koennte, wenn Konzessionsabgaben als Druckmittel eingesetzt werden. Der Autor analysiert die Zulaessigkeit eines derartigen Einsatzes und in diesem Zusammenhang auch die rechtliche Basis der Konzessionsabgaben. (orig./CB)

The Problem of Time in Quantum Cosmology: A Decoherent Histories View

International Nuclear Information System (INIS)

Christodoulakis, Theodosios; Wallden, Petros

2011-01-01

The problem of time in quantum gravity arises due to the diffeomorphisms invariance of the theory and appears via the Hamiltonian constraint, in the canonical quantizations. There is a need for a description where one can ask some timeless questions that still encode some sense of temporality. The decoherent histories approach to quantum theory, already at the kinematical level admits an internal time. Several alternative proposals for resolving the problem of time via the decoherent histories, exist, and in this contribution we focus on one particular and examine how it manifests itself at some simple cosmological models.

Solving Large Scale Nonlinear Eigenvalue Problem in Next-Generation Accelerator Design

Energy Technology Data Exchange (ETDEWEB)

Liao, Ben-Shan; Bai, Zhaojun; /UC, Davis; Lee, Lie-Quan; Ko, Kwok; /SLAC

2006-09-28

A number of numerical methods, including inverse iteration, method of successive linear problem and nonlinear Arnoldi algorithm, are studied in this paper to solve a large scale nonlinear eigenvalue problem arising from finite element analysis of resonant frequencies and external Q{sub e} values of a waveguide loaded cavity in the next-generation accelerator design. They present a nonlinear Rayleigh-Ritz iterative projection algorithm, NRRIT in short and demonstrate that it is the most promising approach for a model scale cavity design. The NRRIT algorithm is an extension of the nonlinear Arnoldi algorithm due to Voss. Computational challenges of solving such a nonlinear eigenvalue problem for a full scale cavity design are outlined.

Spinal cord injury arising in anaesthesia practice.

Science.gov (United States)

Hewson, D W; Bedforth, N M; Hardman, J G

2018-01-01

Spinal cord injury arising during anaesthetic practice is a rare event, but one that carries a significant burden in terms of morbidity and mortality. In this article, we will review the pathophysiology of spinal cord injury. We will then discuss injuries relating to patient position, spinal cord hypoperfusion and neuraxial techniques. The most serious causes of spinal cord injury - vertebral canal haematoma, spinal epidural abscess, meningitis and adhesive arachnoiditis - will be discussed in turn. For each condition, we draw attention to practical, evidence-based measures clinicians can undertake to reduce their incidence, or mitigate their severity. Finally, we will discuss transient neurological symptoms. Some cases of spinal cord injury during anaesthesia can be ascribed to anaesthesia itself, arising as a direct consequence of its conduct. The injury to a spinal nerve root by inaccurate and/or incautious needling during spinal anaesthesia is an obvious example. But in many cases, spinal cord injury during anaesthesia is not caused by, related to, or even associated with, the conduct of the anaesthetic. Surgical factors, whether direct (e.g. spinal nerve root damage due to incorrect pedicle screw placement) or indirect (e.g. cord ischaemia following aortic surgery) are responsible for a significant proportion of spinal cord injuries that occur concurrently with the delivery of regional or general anaesthesia. © 2018 The Association of Anaesthetists of Great Britain and Ireland.

B-spline solution of a singularly perturbed boundary value problem arising in biology

International Nuclear Information System (INIS)

Lin Bin; Li Kaitai; Cheng Zhengxing

2009-01-01

We use B-spline functions to develop a numerical method for solving a singularly perturbed boundary value problem associated with biology science. We use B-spline collocation method, which leads to a tridiagonal linear system. The accuracy of the proposed method is demonstrated by test problems. The numerical result is found in good agreement with exact solution.

Nodular Hyperplasia Arising from the Lateral Aberrant Thyroid Tissue: A Case Report

International Nuclear Information System (INIS)

Jeong, Min Hye; Park, Jeong Seon; Lee, Young Jun

2012-01-01

The presence of aberrant thyroid tissue in the lateral neck is very rare. In addition, nodular hyperplasia in ectopic thyroid has rarely been reported. Due to the unusual location, the presence of lateral aberrant thyroid tissue could be misdiagnosed as a lymphadenopathy, neurogenic tumor, etc. We report on a case of nodular hyperplasia arising from the right lateral aberrant thyroid tissue.

A numerical solution of a singular boundary value problem arising in boundary layer theory.

Science.gov (United States)

Hu, Jiancheng

2016-01-01

In this paper, a second-order nonlinear singular boundary value problem is presented, which is equivalent to the well-known Falkner-Skan equation. And the one-dimensional third-order boundary value problem on interval [Formula: see text] is equivalently transformed into a second-order boundary value problem on finite interval [Formula: see text]. The finite difference method is utilized to solve the singular boundary value problem, in which the amount of computational effort is significantly less than the other numerical methods. The numerical solutions obtained by the finite difference method are in agreement with those obtained by previous authors.

Multimodality Imaging Approach towards Primary Aortic Sarcomas Arising after Endovascular Abdominal Aortic Aneurysm Repair: Case Series Report

Energy Technology Data Exchange (ETDEWEB)

Kamran, Mudassar, E-mail: kamranm@mir.wustl.edu; Fowler, Kathryn J., E-mail: fowlerk@mir.wustl.edu; Mellnick, Vincent M., E-mail: mellnickv@mir.wustl.edu [Washington University School of Medicine, Mallinckrodt Institute of Radiology (United States); Sicard, Gregorio A., E-mail: sicard@wudosis.wustl.edu [Washington University School of Medicine, Department of Surgery (United States); Narra, Vamsi R., E-mail: narrav@mir.wustl.edu [Washington University School of Medicine, Mallinckrodt Institute of Radiology (United States)

2016-06-15

Primary aortic neoplasms are rare. Aortic sarcoma arising after endovascular aneurysm repair (EVAR) is a scarce subset of primary aortic malignancies, reports of which are infrequent in the published literature. The diagnosis of aortic sarcoma is challenging due to its non-specific clinical presentation, and the prognosis is poor due to delayed diagnosis, rapid proliferation, and propensity for metastasis. Post-EVAR, aortic sarcomas may mimic other more common aortic processes on surveillance imaging. Radiologists are rarely knowledgeable about this rare entity for which multimodality imaging and awareness are invaluable in early diagnosis. A series of three pathologically confirmed cases are presented to display the multimodality imaging features and clinical presentations of aortic sarcoma arising after EVAR.

On the Linearized Darboux Equation Arising in Isometric Embedding of the Alexandrov Positive Annulus

Institute of Scientific and Technical Information of China (English)

Chunhe LI

2013-01-01

In the present paper,the solvability condition of the linearized Gauss-Codazzi system and the solutions to the homogenous system are given.In the meantime,the Solvability of a relevant linearized Darboux equation is given.The equations are arising in a geometric problem which is concerned with the realization of the Alexandrov's positive annulus in R3.

Iterative solution of multiple radiation and scattering problems in structural acoustics using the BL-QMR algorithm

Energy Technology Data Exchange (ETDEWEB)

Malhotra, M. [Stanford Univ., CA (United States)

1996-12-31

Finite-element discretizations of time-harmonic acoustic wave problems in exterior domains result in large sparse systems of linear equations with complex symmetric coefficient matrices. In many situations, these matrix problems need to be solved repeatedly for different right-hand sides, but with the same coefficient matrix. For instance, multiple right-hand sides arise in radiation problems due to multiple load cases, and also in scattering problems when multiple angles of incidence of an incoming plane wave need to be considered. In this talk, we discuss the iterative solution of multiple linear systems arising in radiation and scattering problems in structural acoustics by means of a complex symmetric variant of the BL-QMR method. First, we summarize the governing partial differential equations for time-harmonic structural acoustics, the finite-element discretization of these equations, and the resulting complex symmetric matrix problem. Next, we sketch the special version of BL-QMR method that exploits complex symmetry, and we describe the preconditioners we have used in conjunction with BL-QMR. Finally, we report some typical results of our extensive numerical tests to illustrate the typical convergence behavior of BL-QMR method for multiple radiation and scattering problems in structural acoustics, to identify appropriate preconditioners for these problems, and to demonstrate the importance of deflation in block Krylov-subspace methods. Our numerical results show that the multiple systems arising in structural acoustics can be solved very efficiently with the preconditioned BL-QMR method. In fact, for multiple systems with up to 40 and more different right-hand sides we get consistent and significant speed-ups over solving the systems individually.

Problems of Software Detection of Periodic Features in a Time ...

African Journals Online (AJOL)

Problems arise when attempts are made to extract automatically, visually obvious periodic features indicative of defects in a vibration time series for diagnosis using computers. Such problems may be interpretational in nature arising either from insufficient knowledge of the mechanism, or the convolution of the source signal ...

Problem specific heuristics for group scheduling problems in cellular manufacturing

OpenAIRE

Neufeld, Janis Sebastian

2016-01-01

The group scheduling problem commonly arises in cellular manufacturing systems, where parts are grouped into part families. It is characterized by a sequencing task on two levels: on the one hand, a sequence of jobs within each part family has to be identified while, on the other hand, a family sequence has to be determined. In order to solve this NP-hard problem usually heuristic solution approaches are used. In this thesis different aspects of group scheduling are discussed and problem spec...

Primary extradural meningioma arising from the calvarium

Directory of Open Access Journals (Sweden)

N Ravi

2013-06-01

Full Text Available Meningiomas are the most common intracranial tumours. Meningiomas arising at other locations are termed primary extradural meningiomas (EDM and are rare. Here we report a case of EDM arising from the calvarium – a primary calvarial meningioma (PCM.

Squamous cell carcinoma arising in an odontogenic cyst

International Nuclear Information System (INIS)

Yu, Jae Jung; Hwang, Eui Hwan; Lee, Sang Rae; Choi, Jeong Hee

2003-01-01

Squamous cell carcinoma arising in an odontogenic cyst is uncommon. The diagnosis of carcinoma arising in a cyst requires that there must be an area of microscopic transition from the benign epithelial cyst lining to the invasive squamous cell carcinoma. We report a histopathologically proven case of squamous cell carcinoma arising in a residual mandibular cyst in a 54-year-old woman.

A Spectral Multi-Domain Penalty Method for Elliptic Problems Arising From a Time-Splitting Algorithm For the Incompressible Navier-Stokes Equations

Science.gov (United States)

Diamantopoulos, Theodore; Rowe, Kristopher; Diamessis, Peter

2017-11-01

The Collocation Penalty Method (CPM) solves a PDE on the interior of a domain, while weakly enforcing boundary conditions at domain edges via penalty terms, and naturally lends itself to high-order and multi-domain discretization. Such spectral multi-domain penalty methods (SMPM) have been used to solve the Navier-Stokes equations. Bounds for penalty coefficients are typically derived using the energy method to guarantee stability for time-dependent problems. The choice of collocation points and penalty parameter can greatly affect the conditioning and accuracy of a solution. Effort has been made in recent years to relate various high-order methods on multiple elements or domains under the umbrella of the Correction Procedure via Reconstruction (CPR). Most applications of CPR have focused on solving the compressible Navier-Stokes equations using explicit time-stepping procedures. A particularly important aspect which is still missing in the context of the SMPM is a study of the Helmholtz equation arising in many popular time-splitting schemes for the incompressible Navier-Stokes equations. Stability and convergence results for the SMPM for the Helmholtz equation will be presented. Emphasis will be placed on the efficiency and accuracy of high-order methods.

Experimental bifurcation analysis—Continuation for noise-contaminated zero problems

DEFF Research Database (Denmark)

Schilder, Frank; Bureau, Emil; Santos, Ilmar Ferreira

2015-01-01

Noise contaminated zero problems involve functions that cannot be evaluated directly, but only indirectly via observations. In addition, such observations are affected by a non-deterministic observation error (noise). We investigate the application of numerical bifurcation analysis for studying...... the solution set of such noise contaminated zero problems, which is highly relevant in the context of equation-free analysis (coarse grained analysis) and bifurcation analysis in experiments, and develop specialized algorithms to address challenges that arise due to the presence of noise. As a working example......, we demonstrate and test our algorithms on a mechanical nonlinear oscillator experiment using control based continuation, which we used as a main application and test case for development of the Coco compatible Matlab toolbox Continex that implements our algorithms....

Solitary Fibrous Tumor Arising from Stomach: CT Findings

Science.gov (United States)

Park, Sung Hee; Kwon, Jieun; Park, Jong-pil; Park, Mi-Suk; Lim, Joon Seok; Kim, Joo Hee; Kim, Ki Whang

2007-01-01

Solitary fibrous tumors are spindle-cell neoplasms that usually develop in the pleura and peritoneum, and rarely arise in the stomach. To our knowledge, there is only one case reporting a solitary fibrous tumor arising from stomach in the English literature. Here we report the case of a 26-year-old man with a large solitary fibrous tumor arising from the stomach which involved the submucosa and muscular layer and resembled a gastrointestinal stromal tumor in the stomach, based on what was seen during abdominal computed tomography. A solitary fibrous tumor arising from the stomach, although rare, could be considered as a diagnostic possibility for gastric submucosal tumors. PMID:18159603

Dust in fusion devices-a multi-faceted problem connecting high- and low-temperature plasma physics

International Nuclear Information System (INIS)

Winter, J

2004-01-01

Small particles with sizes between a few nanometers and a few 10 μm (dust) are formed in fusion devices by plasma-surface interaction processes. Though it is not a major problem today, dust is considered a problem that could arise in future long pulse fusion devices. This is primarily due to its radioactivity and due to its very high chemical reactivity. Dust formation is particularly pronounced when carbonaceous wall materials are used. Dust particles can be transported in the tokamak over significant distances. Radioactivity leads to electrical charging of dust and to its interaction with plasmas and electric fields. This may cause interference with the discharge but may also result in options for particle removal. This paper discusses some of the multi-faceted problems using information both from fusion research and from low-temperature dusty plasma work

Numerical study of nonlinear singular fractional differential equations arising in biology by operational matrix of shifted Legendre polynomials

Directory of Open Access Journals (Sweden)

D. Jabari Sabeg

2016-10-01

Full Text Available In this paper, we present a new computational method for solving nonlinear singular boundary value problems of fractional order arising in biology. To this end, we apply the operational matrices of derivatives of shifted Legendre polynomials to reduce such problems to a system of nonlinear algebraic equations. To demonstrate the validity and applicability of the presented method, we present some numerical examples.

Quantum Statistics and Entanglement Problems

OpenAIRE

Trainor, L. E. H.; Lumsden, Charles J.

2002-01-01

Interpretations of quantum measurement theory have been plagued by two questions, one concerning the role of observer consciousness and the other the entanglement phenomenon arising from the superposition of quantum states. We emphasize here the remarkable role of quantum statistics in describing the entanglement problem correctly and discuss the relationship to issues arising from current discussions of intelligent observers in entangled, decohering quantum worlds.

Reinforcement learning solution for HJB equation arising in constrained optimal control problem.

Science.gov (United States)

Luo, Biao; Wu, Huai-Ning; Huang, Tingwen; Liu, Derong

2015-11-01

The constrained optimal control problem depends on the solution of the complicated Hamilton-Jacobi-Bellman equation (HJBE). In this paper, a data-based off-policy reinforcement learning (RL) method is proposed, which learns the solution of the HJBE and the optimal control policy from real system data. One important feature of the off-policy RL is that its policy evaluation can be realized with data generated by other behavior policies, not necessarily the target policy, which solves the insufficient exploration problem. The convergence of the off-policy RL is proved by demonstrating its equivalence to the successive approximation approach. Its implementation procedure is based on the actor-critic neural networks structure, where the function approximation is conducted with linearly independent basis functions. Subsequently, the convergence of the implementation procedure with function approximation is also proved. Finally, its effectiveness is verified through computer simulations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Wilms tumor arising in extracoelomic paravertebral soft tissues.

LENUS (Irish Health Repository)

Mulligan, Linda

2012-02-01

Extrarenal Wilms tumor (ERWT) is a well-established entity which most commonly arises within the genitourinary tract, including intracoelomic paranephric soft tissue. Rarely, ERWT arises within teratoma, and it tends to occur predominantly in distinct settings, such as females with spinal defects and males with testicular teratomas. We report a unique ERWT arising within an extracoelomic teratoma of the paraspinal musculature, thereby expanding the range of reported locations for this unusual tumor.

Inverse scattering problems with multi-frequencies

International Nuclear Information System (INIS)

Bao, Gang; Li, Peijun; Lin, Junshan; Triki, Faouzi

2015-01-01

This paper is concerned with computational approaches and mathematical analysis for solving inverse scattering problems in the frequency domain. The problems arise in a diverse set of scientific areas with significant industrial, medical, and military applications. In addition to nonlinearity, there are two common difficulties associated with the inverse problems: ill-posedness and limited resolution (diffraction limit). Due to the diffraction limit, for a given frequency, only a low spatial frequency part of the desired parameter can be observed from measurements in the far field. The main idea developed here is that if the reconstruction is restricted to only the observable part, then the inversion will become stable. The challenging task is how to design stable numerical methods for solving these inverse scattering problems inspired by the diffraction limit. Recently, novel recursive linearization based algorithms have been presented in an attempt to answer the above question. These methods require multi-frequency scattering data and proceed via a continuation procedure with respect to the frequency from low to high. The objective of this paper is to give a brief review of these methods, their error estimates, and the related mathematical analysis. More attention is paid to the inverse medium and inverse source problems. Numerical experiments are included to illustrate the effectiveness of these methods. (topical review)

Esophageal leiomyoma arising in an epiphrenic diverticulum

International Nuclear Information System (INIS)

Hamilton, S.

1988-01-01

A 32-year old woman was found at surgery to have an esophageal leiomyoma arising within an epiphrenic diverticulum. These uncommon conditions may rarely occur together, causing difficulty in diagnosis of the leiomyoma. Other neoplasms may also arise in an epiphrenic diverticulum and should be borne in mind in this situation. (orig.)

U(1) problem

Energy Technology Data Exchange (ETDEWEB)

McDougall, N.A. (Oxford Univ. (UK). Dept. of Theoretical Physics)

1984-08-23

The resolution of the U(1) problem requires the quark condensates to have a specific THETA dependence. We show that the required THETA dependence arises naturally upon application of the index theorem during the calculation of the dynamically generated quark mass.

Some Problems for Biolinguistics

Directory of Open Access Journals (Sweden)

Derek Bickerton

2014-03-01

Full Text Available Biolinguistics will have to face and resolve several problems before it can achieve a pivotal position in the human sciences. Its relationship to the Minimalist Program is ambiguous, creating doubts as to whether it is a genuine subdiscipline or merely another name for a particular linguistic theory. Equally ambiguous is the relationship it assumes between ‘knowledge of language’ and the neural mechanisms that actually construct sentences. The latter issue raises serious questions about the validity of covert syntactic operations. Further problems arise from the attitudes of many biolinguists towards natural selection and evo-devo: The first they misunderstand, the second they both misunderstand and overestimate. One consequence is a one-sided approach to language evolution crucially involving linguistic ‘precursors’ and the protolanguage hypothesis. Most of these problems arise through the identification of biolinguistics with internalist and essentialist approaches to language, thereby simultaneously narrowing its scope and hindering its acceptance by biologists.

An inverse problem for a semilinear parabolic equation arising from cardiac electrophysiology

Science.gov (United States)

Beretta, Elena; Cavaterra, Cecilia; Cerutti, M. Cristina; Manzoni, Andrea; Ratti, Luca

2017-10-01

In this paper we develop theoretical analysis and numerical reconstruction techniques for the solution of an inverse boundary value problem dealing with the nonlinear, time-dependent monodomain equation, which models the evolution of the electric potential in the myocardial tissue. The goal is the detection of an inhomogeneity \

Problems specific to the piping of sodium-cooled fast breeder reactors

International Nuclear Information System (INIS)

Vrillon, B.; Befre, J.; Schaller, K.

1975-01-01

A certain number of specific problems arising in connection with the sodium pipes in fast neutron reactors, especially those of large diameter, are presented. The supporting system must be designed to achieve the best compromise among stresses due to weight and various stresses of thermal origin. Large-scale experimental studies carried out on actual elements of the intermediate circuit of the Phenix reactor showed that the circuits can withstand considerable deformation collapse of the walls without danger of leakage. Protection studies against earthquakes are mentionned [fr

Climate is the real challenge, not shortage. New problems arising for global energy supply

Energy Technology Data Exchange (ETDEWEB)

Pestel, E.

1988-11-01

The author of the article is Professor E. Pestel who, as an executive member of the Club of Rome, belongs to the group of experts who first gave impetus to start thinking about the global problems of mankind. In his publications on the problems linked with CO/sub 2/ emission he explains the unavoidable dilemma created by the growing world population and the growing demand for energy on the one hand, and the resulting hazards to the global climate on the other. His analyses take away the soft cushion of hopeful make-believe still widespread in the Western World, and in his capacity as an expert and realist he decidedly calls for decisions and measures to tackle the problem.

Solitary Fibrous Tumor Arising from Stomach: CT Findings

OpenAIRE

Park, Sung Hee; Kim, Myeong-Jin; Kwon, Jieun; Park, Jong-pil; Park, Mi-Suk; Lim, Joon Seok; Kim, Joo Hee; Kim, Ki Whang

2007-01-01

Solitary fibrous tumors are spindle-cell neoplasms that usually develop in the pleura and peritoneum, and rarely arise in the stomach. To our knowledge, there is only one case reporting a solitary fibrous tumor arising from stomach in the English literature. Here we report the case of a 26-year-old man with a large solitary fibrous tumor arising from the stomach which involved the submucosa and muscular layer and resembled a gastrointestinal stromal tumor in the stomach, based on what was see...

Proxy-produced ethnographic work: what are the problems, issues, and dilemmas arising from proxy ethnography?

DEFF Research Database (Denmark)

Martinussen, Marie Louise; Højbjerg, Karin; Tamborg, Andreas Lindenskov

2018-01-01

This article addresses the implications of research-student cooperation in the production of empirical material. For the student to replace the experienced researcher and work under the researcher’s supervision, we call such work proxy-produced ethnographic work. The specific relations...... and positions arising from such a setup between the teacher/researcher and the proxy ethnographer/student are found to have implications for the ethnographies produced. This article’s main focus is to show how these relations and positions have not distorted the ethnographic work and the ethnographies but......, rather, have oriented it in certain ways. It is shown how the participating researchers – both senior and junior - have distinctive, incorporated dispositions with which they pre-consciously participate in an implicit and subtle relation that can make it very easy to overlook distortions during...

Primary extradural meningioma arising from the calvarium | Ravi ...

African Journals Online (AJOL)

Meningiomas are the most common intracranial tumours. Meningiomas arising at other locations are termed primary extradural meningiomas (EDMs) and are rare. Here we report a case of EDM arising from the calvarium – a primary calvarial meningioma (PCM).

Shilajit: A panacea for high-altitude problems.

Science.gov (United States)

Meena, Harsahay; Pandey, H K; Arya, M C; Ahmed, Zakwan

2010-01-01

High altitude problems like hypoxia, acute mountain sickness, high altitude cerebral edema, pulmonary edema, insomnia, tiredness, lethargy, lack of appetite, body pain, dementia, and depression may occur when a person or a soldier residing in a lower altitude ascends to high-altitude areas. These problems arise due to low atmospheric pressure, severe cold, high intensity of solar radiation, high wind velocity, and very high fluctuation of day and night temperatures in these regions. These problems may escalate rapidly and may sometimes become life-threatening. Shilajit is a herbomineral drug which is pale-brown to blackish-brown, is composed of a gummy exudate that oozes from the rocks of the Himalayas in the summer months. It contains humus, organic plant materials, and fulvic acid as the main carrier molecules. It actively takes part in the transportation of nutrients into deep tissues and helps to overcome tiredness, lethargy, and chronic fatigue. Shilajit improves the ability to handle high altitudinal stresses and stimulates the immune system. Thus, Shilajit can be given as a supplement to people ascending to high-altitude areas so that it can act as a "health rejuvenator" and help to overcome high-altitude related problems.

Urgent Problems in Learning the Public Administration (on the Example of Georgia

Directory of Open Access Journals (Sweden)

Shota Dogonadze

2011-12-01

Full Text Available Public management can and should be taught. Former Soviet Republics, including Georgia are facing this acute problem. Some attention is directed to management training, but public management stays in the background, although it is evident that major political and economic problems of Georgia and other countries of so-called “fledging democracies” arise due to the government theory neglect. The article considers development of administrative way of thinking starting from political doctrine to managerial approach, prospects for public management principles development, existing educational models. The epoch of classic universities is passing; with the help of textbooks students can only make courseworks. That’s why the use of innovative methods is necessary for students training.

Representation of discrete Steklov-Poincare operator arising in domain decomposition methods in wavelet basis

Energy Technology Data Exchange (ETDEWEB)

Jemcov, A.; Matovic, M.D. [Queen`s Univ., Kingston, Ontario (Canada)

1996-12-31

This paper examines the sparse representation and preconditioning of a discrete Steklov-Poincare operator which arises in domain decomposition methods. A non-overlapping domain decomposition method is applied to a second order self-adjoint elliptic operator (Poisson equation), with homogeneous boundary conditions, as a model problem. It is shown that the discrete Steklov-Poincare operator allows sparse representation with a bounded condition number in wavelet basis if the transformation is followed by thresholding and resealing. These two steps combined enable the effective use of Krylov subspace methods as an iterative solution procedure for the system of linear equations. Finding the solution of an interface problem in domain decomposition methods, known as a Schur complement problem, has been shown to be equivalent to the discrete form of Steklov-Poincare operator. A common way to obtain Schur complement matrix is by ordering the matrix of discrete differential operator in subdomain node groups then block eliminating interface nodes. The result is a dense matrix which corresponds to the interface problem. This is equivalent to reducing the original problem to several smaller differential problems and one boundary integral equation problem for the subdomain interface.

Introduction to inverse problems for differential equations

CERN Document Server

Hasanov Hasanoğlu, Alemdar

2017-01-01

This book presents a systematic exposition of the main ideas and methods in treating inverse problems for PDEs arising in basic mathematical models, though it makes no claim to being exhaustive. Mathematical models of most physical phenomena are governed by initial and boundary value problems for PDEs, and inverse problems governed by these equations arise naturally in nearly all branches of science and engineering. The book’s content, especially in the Introduction and Part I, is self-contained and is intended to also be accessible for beginning graduate students, whose mathematical background includes only basic courses in advanced calculus, PDEs and functional analysis. Further, the book can be used as the backbone for a lecture course on inverse and ill-posed problems for partial differential equations. In turn, the second part of the book consists of six nearly-independent chapters. The choice of these chapters was motivated by the fact that the inverse coefficient and source problems considered here a...

Problem-Solving during Shared Reading at Kindergarten

Science.gov (United States)

Gosen, Myrte N.; Berenst, Jan; de Glopper, Kees

2015-01-01

This paper reports on a conversation analytic study of problem-solving interactions during shared reading at three kindergartens in the Netherlands. It illustrates how teachers and pupils discuss book characters' problems that arise in the events in the picture books. A close analysis of the data demonstrates that problem-solving interactions do…

Numerical Methods for Solution of the Extended Linear Quadratic Control Problem

DEFF Research Database (Denmark)

Jørgensen, John Bagterp; Frison, Gianluca; Gade-Nielsen, Nicolai Fog

2012-01-01

In this paper we present the extended linear quadratic control problem, its efficient solution, and a discussion of how it arises in the numerical solution of nonlinear model predictive control problems. The extended linear quadratic control problem is the optimal control problem corresponding...... to the Karush-Kuhn-Tucker system that constitute the majority of computational work in constrained nonlinear and linear model predictive control problems solved by efficient MPC-tailored interior-point and active-set algorithms. We state various methods of solving the extended linear quadratic control problem...... and discuss instances in which it arises. The methods discussed in the paper have been implemented in efficient C code for both CPUs and GPUs for a number of test examples....

Fiscal Policy Problems Under Conditions Of Financial Liberalization

Directory of Open Access Journals (Sweden)

Valentina Urazayeva

2014-01-01

Full Text Available The article under the title deals with the difficulties in pursuing national fiscal policy in conditions of international financial liberalization. The author analyzes the nature of liberalization of international capital flows and its positive and negative consequences for the economies of the countries which participate in global capital movement. The author especially highlights the fact that international financial liberalization often leads to economic crises and what is even more important to their rapid spread between countries due to their growing financial interdependence. The author distinguishes two groups of fiscal policy problems in conditions of international financial liberalization. The first group includes problems arising due to quick spread of the crises due to eliminating restrictions on crossborder capital flows. These are reduction in taxes and at the same time increase in budget spending, which often happens unexpectedly and substantially impedes fiscal policy. To illustrate these points the author refers to the statistics on Spain, the USA and the OECD as a whole. Moreover countries face another range of problems regardless of the business cycle phase. In the short term it is the necessity of large scale structural economic reforms to achieve the required level of financial liberalization, which often is a heavy burden on the state budget. In the long term the attention is paid to the problem of tax competition between countries, which affects the instruments of fiscal policy. The author notes that the negative consequences of global financial liberalization are relevant not only for recipient countries but for donor countries as well and emphasizes such a burning issue as "capital flight".

FISCAL POLICY PROBLEMS UNDER CONDITIONS OF FINANCIAL LIBERALIZATION

Directory of Open Access Journals (Sweden)

Valentina Urazayeva

2014-01-01

Full Text Available The article under the title deals with the difficulties in pursuing national fiscal policy in conditions of international financial liberalization. The author analyzes the nature of liberalization of international capital flows and its positive and negative consequences for the economies of the countries which participate in global capital movement. The author especially highlights the fact that international financial liberalization often leads to economic crises and what is even more important to their rapid spread between countries due to their growing financial interdependence. The author distinguishes two groups of fiscal policy problems in conditions of international financial liberalization. The first group includes problems arising due to quick spread of the crises due to eliminating restrictions on crossborder capital flows. These are reduction in taxes and at the same time increase in budget spending, which often happens unexpectedly and substantially impedes fiscal policy. To illustrate these points the author refers to the statistics on Spain, the USA and the OECD as a whole. Moreover countries face another range of problems regardless of the business cycle phase. In the short term it is the necessity of large scale structural economic reforms to achieve the required level of financial liberalization, which often is a heavy burden on the state budget. In the long term the attention is paid to the problem of tax competition between countries, which affects the instruments of fiscal policy. The author notes that the negative consequences of global financial liberalization are relevant not only for recipient countries but for donor countries as well and emphasizes such a burning issue as "capital flight".

The Soccer-Ball Problem

Science.gov (United States)

Hossenfelder, Sabine

2014-07-01

The idea that Lorentz-symmetry in momentum space could be modified but still remain observer-independent has received quite some attention in the recent years. This modified Lorentz-symmetry, which has been argued to arise in Loop Quantum Gravity, is being used as a phenomenological model to test possibly observable effects of quantum gravity. The most pressing problem in these models is the treatment of multi-particle states, known as the 'soccer-ball problem'. This article briefly reviews the problem and the status of existing solution attempts.

Dioxins: diagnostic and prognostic challenges arising from complex mechanisms

DEFF Research Database (Denmark)

Rysavy, Noel M.; Maaetoft-Udsen, Kristina; Turner, Helen

2013-01-01

Dioxins are ubiquitous environmental challenges to humans, with a pervasiveness that arises from 200?years of rapid industrialization and mechanization of Western societies and which is now extending into the developing world. In spite of their penetrance of the human biota, these compounds...... such as cancer and diabetes, which are already multifactorial and highly complex, creates the context for the current review paper. Here, we summarize dioxin exposure paradigms and the resulting physiological effects that have been documented in animals and humans. Novel insights into potential endogenous end...... exogenous ligands, as well as the mechanisms by which these ligands impact acute and chronic cellular processes, are discussed. We develop the idea that the diagnosis of dioxin exposure, the subtleties of the cellular effects of the compounds and prognosis of the long-term effects of exposure are problems...

Customer-centered problem solving.

Science.gov (United States)

Samelson, Q B

1999-11-01

If there is no single best way to attract new customers and retain current customers, there is surely an easy way to lose them: fail to solve the problems that arise in nearly every buyer-supplier relationship, or solve them in an unsatisfactory manner. Yet, all too frequently, companies do just that. Either we deny that a problem exists, we exert all our efforts to pin the blame elsewhere, or we "Band-Aid" the problem instead of fixing it, almost guaranteeing that we will face it again and again.

Problems in Recording the Electrocardiogram.

Science.gov (United States)

Webster, John G.

The unwanted signals that arise in electrocardiography are discussed. A technical background of electrocardiography is given, along with teaching techniques that educate students of medical instrumentation to solve the problems caused by these signals. (MJH)

Endogeneously arising network allocation rules

NARCIS (Netherlands)

Slikker, M.

2006-01-01

In this paper we study endogenously arising network allocation rules. We focus on three allocation rules: the Myerson value, the position value and the component-wise egalitarian solution. For any of these three rules we provide a characterization based on component efficiency and some balanced

High intensity heat pulse problem

International Nuclear Information System (INIS)

Yalamanchili, R.

1977-01-01

The use of finite-difference methods for the solution of partial differential equations is common in both design and research and development because of the advance of computers. The numerical methods for the unsteady heat diffusion equation received most attention not only because of heat transfer problems but also happened to be the basis for any study of parabolic partial differential equations. It is common to test the heat equation first even the methods developed for complex nonlinear parabolic partial differential equations arising in fluid mechanics or convective heat transfer. It is concluded that the finite-element method is conservative in both stability and monoscillation characteristics than the finite-difference method but not as conservative as the method of weighted-residuals. Since the finite-element is unique because of Gurtin's variational principle and numerous finite-differences can be constructed, it is found that some finite-difference schemes are better than the finite-element scheme in accuracy also. Therefore, further attention is focused here on finite-difference schemes only. Various physical problems are considered in the field of heat transfer. These include: numerous problems in steady and unsteady heat conduction; heat pulse problems, such as, plasma torch; problems arising from machining operations, such as, abrasive cut-off and surface grinding. (Auth.)

Carcinoma arising in thyroglossal remnants

NARCIS (Netherlands)

van Vuuren, P. A.; Balm, A. J.; Gregor, R. T.; Hilgers, F. J.; Loftus, B. M.; Delprat, C. C.; Rutgers, E. J.

1994-01-01

Three patients with a papillary carcinoma arising in a thyroglossal duct cyst are presented and the literature is reviewed. This rare malignancy is seen mostly in women between the ages of 20 and 50 years. The distribution of carcinoma subtypes differs from that of thyroid carcinomas and

Absenteeism due to mental health problems and systems for return to work: an internet-based unmatched case-control study.

Science.gov (United States)

Doki, Shotaro; Sasahara, Shinichiro; Hirai, Yasuhito; Oi, Yuichi; Matsuzaki, Ichiyo

2016-11-01

The aim of this study was to investigate the risk factors for absenteeism due to mental health problems with regard to company characteristics and systems for return to work in Japan. This was an Internet-based unmatched case-control study. Two hundred and fifty-eight workers who experienced over 28 days of sick leave due to mental health problems (cases) and 258 workers who have not taken sick leave (controls) were recruited. Company characteristics and the awareness and presence of systems for return to work were analysed as indicators of absenteeism. A total of 501 workers were included in the analysis. Females were less likely to experience absenteeism when adjustments were made for both the awareness and presence of systems [odds ratio (OR) = 0.51 and 0.41, respectively]. Large companies showed an increased risk of having absentee workers than small companies. The awareness of a gradual resumption system and the presence of a sick pay system were related to absenteeism (OR = 2.75 and 2.40, respectively). The awareness and presence of systems for return to work are related to the long-term absenteeism. The predictors of sex and company size are also related to the experience of the long-term absenteeism. To understand the effect of systems for return to work on absenteeism due to mental problems, further studies are needed.

Semidefinite linear complementarity problems

International Nuclear Information System (INIS)

Eckhardt, U.

1978-04-01

Semidefinite linear complementarity problems arise by discretization of variational inequalities describing e.g. elastic contact problems, free boundary value problems etc. In the present paper linear complementarity problems are introduced and the theory as well as the numerical treatment of them are described. In the special case of semidefinite linear complementarity problems a numerical method is presented which combines the advantages of elimination and iteration methods without suffering from their drawbacks. This new method has very attractive properties since it has a high degree of invariance with respect to the representation of the set of all feasible solutions of a linear complementarity problem by linear inequalities. By means of some practical applications the properties of the new method are demonstrated. (orig.) [de

Adenosarcoma arising in hepatic endometriosis

International Nuclear Information System (INIS)

N'Senda, P.; Dahan, H.; Tubiana, J.M.; Arrive, L.; Wendum, D.; Balladur, P.

2000-01-01

We report a case of adenosarcoma arising in hepatic endometriosis. Both CT and MR scans demontrated a huge heterogeneous mass containing septated, thick-walled cystic lesions. After enlarged right hepatectomy, the patient was asymptomatic with no abnormalities at liver and abdominal CT scan at 2-year follow-up. (orig.)

Adenosarcoma arising in hepatic endometriosis

Energy Technology Data Exchange (ETDEWEB)

N' Senda, P.; Dahan, H.; Tubiana, J.M.; Arrive, L. [Service de Radiologie, Hopital Saint-Antoine, 75 - Paris (France); Wendum, D. [Service d' Anatomie Pathologie, Hopital Saint-Antoine, 75 - Paris (France); Balladur, P. [Service de Chirurgie Digestive et Generale, Hopital Saint-Antoine, 75 - Paris (France)

2000-08-01

We report a case of adenosarcoma arising in hepatic endometriosis. Both CT and MR scans demontrated a huge heterogeneous mass containing septated, thick-walled cystic lesions. After enlarged right hepatectomy, the patient was asymptomatic with no abnormalities at liver and abdominal CT scan at 2-year follow-up. (orig.)

Primary extraskeletal mesenchymal chondrosarcoma arising from the iliac vein

Directory of Open Access Journals (Sweden)

Hua Zhang

2017-10-01

Full Text Available The iliac vein is an extremely rare site for mesenchymal chondrosarcoma, and patients with primary extraskeletal mesenchymal chondrosarcoma arising from a vein always suffer a very poor prognosis. We report a case of a 45-year-old female who presented with a 5-month history of left leg edema in 2015. Contrast-enhanced computed tomography showed a large mass in the left iliac vein with scattered calcifications. Wide-margin resection was performed, and histopathologic and immunohistochemical analyses confirmed the presence of intraluminal mesenchymal chondrosarcoma with local invasion out of the vein wall. Due to poor patient compliance, postoperative neoadjuvant chemotherapy and radiotherapy were not started, and a bone scan performed 16 weeks postoperatively showed multiple bone metastases. The patient died on the twenty-fourth postoperative week.

Source terms for airborne radioactivity arising from uranium mill wastes

International Nuclear Information System (INIS)

O'Riordan, M.C.; Downing, A.L.

1978-01-01

One of the problems in assessing the radiological impact of uranium milling is to determine the rates of release to the air of material from the various sources of radioactivity. Such source terms are required for modelling the transport of radioactive material in the atmosphere. Activity arises from various point and area sources in the mill itself and from the mill tailings. The state of the tailings changes in time from slurry to solid. A layer of water may be maintained over the solids during the life of the mine, and the tailings may be covered with inert material on abandonment. Releases may be both gaseous and particulate. This paper indicates ways in which radon emanation and the suspension of long-lived particulate activity might be quantified, and areas requiring further exploration are identified

Visual integration dysfunction in schizophrenia arises by the first psychotic episode and worsens with illness duration

OpenAIRE

Keane, Brian P.; Paterno, Danielle; Kastner, Sabine; Silverstein, Steven M.

2016-01-01

Visual integration dysfunction characterizes schizophrenia, but prior studies have not yet established whether the problem arises by the first psychotic episode or worsens with illness duration. To investigate the issue, we compared chronic schizophrenia patients (SZs), first episode psychosis patients (FEs), and well-matched healthy controls on a brief but sensitive psychophysical task in which subjects attempted to locate an integrated shape embedded in noise. Task difficulty depended on th...

CALCULUS FROM THE PAST: MULTIPLE DELAY SYSTEMS ARISING IN CANCER CELL MODELLING

KAUST Repository

WAKE, G. C.; BYRNE, H. M.

2013-01-01

Nonlocal calculus is often overlooked in the mathematics curriculum. In this paper we present an interesting new class of nonlocal problems that arise from modelling the growth and division of cells, especially cancer cells, as they progress through the cell cycle. The cellular biomass is assumed to be unstructured in size or position, and its evolution governed by a time-dependent system of ordinary differential equations with multiple time delays. The system is linear and taken to be autonomous. As a result, it is possible to reduce its solution to that of a nonlinear matrix eigenvalue problem. This method is illustrated by considering case studies, including a model of the cell cycle developed recently by Simms, Bean and Koeber. The paper concludes by explaining how asymptotic expressions for the distribution of cells across the compartments can be determined and used to assess the impact of different chemotherapeutic agents. Copyright © 2013 Australian Mathematical Society.

Iterative method for solving a problem with mixed boundary conditions for biharmonic equation arising in fracture mechanics

Directory of Open Access Journals (Sweden)

Dang Quang A

2013-02-01

Full Text Available In this paper we consider a mixed boundary value problem for biharmonic equation of the Airy stress function which models a crack problem of a solid elastic plate. An iterative method for reducing the problem to a sequence of mixed problems for Poisson equations is proposed and investigated. The convergence of the method is established theoretically and illustrated on many numerical experiments.

Discrete and continuum links to a nonlinear coupled transport problem of interacting populations

Science.gov (United States)

Duong, M. H.; Muntean, A.; Richardson, O. M.

2017-07-01

We are interested in exploring interacting particle systems that can be seen as microscopic models for a particular structure of coupled transport flux arising when different populations are jointly evolving. The scenarios we have in mind are inspired by the dynamics of pedestrian flows in open spaces and are intimately connected to cross-diffusion and thermo-diffusion problems holding a variational structure. The tools we use include a suitable structure of the relative entropy controlling TV-norms, the construction of Lyapunov functionals and particular closed-form solutions to nonlinear transport equations, a hydrodynamics limiting procedure due to Philipowski, as well as the construction of numerical approximates to both the continuum limit problem in 2D and to the original interacting particle systems.

Cutaneous osteosarcoma arising from a burn scar

Energy Technology Data Exchange (ETDEWEB)

Lee, Min A.; Yi, Jaehyuck [Kyungpook National University, Department of Radiology, College of Medicine, Daegu (Korea, Republic of); Kyungpook National University Hospital, Department of Radiology, Daegu (Korea, Republic of); Chae, Jong Min [Kyungpook National University, Department of Pathology, College of Medicine, Daegu (Korea, Republic of)

2017-04-15

Tumors that develop in old burn scars are usually squamous cell carcinomas. Sarcomas have also been reported, albeit rarely. To our knowledge, there has been only one case report of an extraskeletal osteosarcoma arising in a prior burn scar reported in the English-language literature, mainly discussing the clinicopathological features. Herein, we present a case of cutaneous osteosarcoma visualized as a mineralized soft-tissue mass arising from the scar associated with a previous skin burn over the back. This seems to be the first report describing the imaging features of a cutaneous osteosarcoma from an old burn scar. (orig.)

The Kepler problem in the Snyder space

Indian Academy of Sciences (India)

... through a matrix that encodes the lack of commutativity between the position ... This is incompatible with Lorentz symmetry and many difficulties arise due to ... an advance of perihelion of a planet due to the deformed considerations and, ...

On the U(1) problem

International Nuclear Information System (INIS)

McDougall, N.A.

1984-01-01

The resolution of the U(1) problem requires the quark condensates to have a specific THETA dependence. We show that the required THETA dependence arises naturally upon application of the index theorem during the calculation of the dynamically generated quark mass. (orig.)

Fast multipole preconditioners for sparse matrices arising from elliptic equations

KAUST Repository

Ibeid, Huda

2017-11-09

Among optimal hierarchical algorithms for the computational solution of elliptic problems, the fast multipole method (FMM) stands out for its adaptability to emerging architectures, having high arithmetic intensity, tunable accuracy, and relaxable global synchronization requirements. We demonstrate that, beyond its traditional use as a solver in problems for which explicit free-space kernel representations are available, the FMM has applicability as a preconditioner in finite domain elliptic boundary value problems, by equipping it with boundary integral capability for satisfying conditions at finite boundaries and by wrapping it in a Krylov method for extensibility to more general operators. Here, we do not discuss the well developed applications of FMM to implement matrix-vector multiplications within Krylov solvers of boundary element methods. Instead, we propose using FMM for the volume-to-volume contribution of inhomogeneous Poisson-like problems, where the boundary integral is a small part of the overall computation. Our method may be used to precondition sparse matrices arising from finite difference/element discretizations, and can handle a broader range of scientific applications. It is capable of algebraic convergence rates down to the truncation error of the discretized PDE comparable to those of multigrid methods, and it offers potentially superior multicore and distributed memory scalability properties on commodity architecture supercomputers. Compared with other methods exploiting the low-rank character of off-diagonal blocks of the dense resolvent operator, FMM-preconditioned Krylov iteration may reduce the amount of communication because it is matrix-free and exploits the tree structure of FMM. We describe our tests in reproducible detail with freely available codes and outline directions for further extensibility.

Fast multipole preconditioners for sparse matrices arising from elliptic equations

KAUST Repository

Ibeid, Huda; Yokota, Rio; Pestana, Jennifer; Keyes, David E.

2017-01-01

Among optimal hierarchical algorithms for the computational solution of elliptic problems, the fast multipole method (FMM) stands out for its adaptability to emerging architectures, having high arithmetic intensity, tunable accuracy, and relaxable global synchronization requirements. We demonstrate that, beyond its traditional use as a solver in problems for which explicit free-space kernel representations are available, the FMM has applicability as a preconditioner in finite domain elliptic boundary value problems, by equipping it with boundary integral capability for satisfying conditions at finite boundaries and by wrapping it in a Krylov method for extensibility to more general operators. Here, we do not discuss the well developed applications of FMM to implement matrix-vector multiplications within Krylov solvers of boundary element methods. Instead, we propose using FMM for the volume-to-volume contribution of inhomogeneous Poisson-like problems, where the boundary integral is a small part of the overall computation. Our method may be used to precondition sparse matrices arising from finite difference/element discretizations, and can handle a broader range of scientific applications. It is capable of algebraic convergence rates down to the truncation error of the discretized PDE comparable to those of multigrid methods, and it offers potentially superior multicore and distributed memory scalability properties on commodity architecture supercomputers. Compared with other methods exploiting the low-rank character of off-diagonal blocks of the dense resolvent operator, FMM-preconditioned Krylov iteration may reduce the amount of communication because it is matrix-free and exploits the tree structure of FMM. We describe our tests in reproducible detail with freely available codes and outline directions for further extensibility.

Problems and Prospects for Economic Development in South ...

African Journals Online (AJOL)

The Nigerian environment today is faced with many problems of degradation arising from the impacts of human activities and natural phenomena with less prospect for economic development. Some of the problems include gully erosion; coastal erosion; flooding; drought and desertification; oil spillage and pollution; urban ...

A problem solving model for regulatory policy making

NARCIS (Netherlands)

Boer, A.; van Engers, T.; Sileno, G.; Wyner, A.; Benn, N.

2011-01-01

In this paper we discuss how the interests and field theory promoted by public administration as a stakeholder in policy argumentation, directly arise from its problem solving activities, using the framework for public administration problem solving we proposed in [1,2]. We propose that calls for

Problems due to icing of overhead lines - Part II

International Nuclear Information System (INIS)

Havard, D.G.; Pon, C.J.; Krishnasamy, S.G.

1985-01-01

A companion paper describes uncertainties in overhead line design due to the variability of ice and wind loads. This paper reviews two other effects due to icing; conductor galloping and torsional instability, which require further study. (author)

32 CFR 537.19 - Demands arising from maritime claims.

Science.gov (United States)

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Demands arising from maritime claims. 537.19 Section 537.19 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY CLAIMS AND ACCOUNTS CLAIMS ON BEHALF OF THE UNITED STATES § 537.19 Demands arising from maritime claims. (a) It is...

Supervisory behaviour as a predictor of return to work in employees absent from work due to mental health problems

NARCIS (Netherlands)

Nieuwenhuijsen, K.; Verbeek, J.H.A.M.; Boer, A.G.E.M. de; Blonk, R.W.B.; Dijk, F.J.H. van

2004-01-01

Aims: To study supervisory behaviour as a predictive factor for return to work of employees absent due to mental health problems; and to explore the association between conditional factors and supervisory behaviour. Methods: Eighty five supervisors of employees were interviewed by telephone.

Present status and problems of radionuclide studies in emergency cases

International Nuclear Information System (INIS)

Ogawa, Kiyoshi

1983-01-01

Scintigraphy is just right for diagnosing emergency cases due to its noninvasive and simple method, but emergency radionuclide studies have not become practical as a result of difficulty problems. Recently, nuclear medical devices have become easier to use in operations. It is become of this, that I have submitted this report regarding the problems of radionuclide studies in emergency cases. There were 101 cases (1.4 %) out of 7,310 cases for the year period Sept. 1981 - Aug. 1982. The studies consisted of 12 brain imaging cases, 9 plumonary imaging cases, 22 cardiac study cases (cardio-angiography cases 8, 99m-Tc-PYP myocardium imaging cases 12, 201-Tl myocardium imaging cases 2), 12 renal study cases, 11 G.I. blood loss cases, 35 peripheral angiography cases. In the near future, we will have to be ready to perform emergency radionuclide studies if the need arises. (author)

Bernoulli Variational Problem and Beyond

KAUST Repository

Lorz, Alexander; Markowich, Peter A.; Perthame, Benoî t

2013-01-01

The question of 'cutting the tail' of the solution of an elliptic equation arises naturally in several contexts and leads to a singular perturbation problem under the form of a strong cut-off. We consider both the PDE with a drift and the symmetric

Convergence problems of Coulomb and multipole sums in crystals

International Nuclear Information System (INIS)

Kholopov, Evgenii V

2004-01-01

Different ways of calculating Coulomb and dipole sums over crystal lattices are analyzed comparatively. It is shown that the currently alleged disagreement between various approaches originates in ignoring the requirement for the self-consistency of surface conditions, which are of fundamental importance due to the long-range nature of the bulk interactions that these sums describe. This is especially true of surfaces arising when direct sums for infinite translation-invariant structures are truncated. The charge conditions for actual surfaces being self-consistently adjusted to the bulk state are formally the same as those on the truncation surface, consistent with the concept of the thermodynamic limit for the bulk-state absolute equilibrium and with the fact that the surface energy contribution in this case is, naturally, statistically small compared to the bulk contribution. Two-point multipole expansions are briefly discussed, and the problems associated with the boundary of their convergence circle are pointed out. (reviews of topical problems)

Optimal management with hybrid dynamics : The shallow lake problem

NARCIS (Netherlands)

Reddy, P.V.; Schumacher, Hans; Engwerda, Jacob; Camlibel, M.K.; Julius, A.A.; Pasumarthy, R.

2015-01-01

In this article we analyze an optimal management problem that arises in ecological economics using hybrid systems modeling. First, we introduce a discounted autonomous infinite horizon hybrid optimal control problem and develop few tools to analyze the necessary conditions for optimality. Next,

Application of spectral Lanczos decomposition method to large scale problems arising geophysics

Energy Technology Data Exchange (ETDEWEB)

Tamarchenko, T. [Western Atlas Logging Services, Houston, TX (United States)

1996-12-31

This paper presents an application of Spectral Lanczos Decomposition Method (SLDM) to numerical modeling of electromagnetic diffusion and elastic waves propagation in inhomogeneous media. SLDM approximates an action of a matrix function as a linear combination of basis vectors in Krylov subspace. I applied the method to model electromagnetic fields in three-dimensions and elastic waves in two dimensions. The finite-difference approximation of the spatial part of differential operator reduces the initial boundary-value problem to a system of ordinary differential equations with respect to time. The solution to this system requires calculating exponential and sine/cosine functions of the stiffness matrices. Large scale numerical examples are in a good agreement with the theoretical error bounds and stability estimates given by Druskin, Knizhnerman, 1987.

Four Different Tumors Arising in a Nevus Sebaceous

Directory of Open Access Journals (Sweden)

Takeshi Namiki

2016-04-01

Full Text Available Nevus sebaceous is known by its association with one or more secondary tumors, but more than three multiple tumors arising from a nevus sebaceous is extremely rare. A 67-year-old female presented with a light brown plaque on the back of her head that contained a dome-shaped black node and an erosive lesion. Histopathological examination showed atypical basaloid cells in the black node. At the periphery of that node, structures resembling follicular germs extruded from interlacing cords in the upper portion and tumor nests with sebocytes were in the lower portion. In the erosive lesion, papillated structures with an apocrine epithelium were observed. In the light brown plaque, enlargement of sebaceous lobules was noted. From those histopathological features, a diagnosis of syringocystadenoma papilliferum, sebaceoma, trichoblastoma and basal cell carcinoma arising from a nevus sebaceous was made. We discuss the rarity of multiple tumors arising from a nevus sebaceous.

Esperanto and International Language Problems: A Research Bibliography.

Science.gov (United States)

Tonkin, Humphrey R.

This bibliography is intended both for the researcher and for the occasional student of international language problems, particularly as these relate to the international language Esperanto. The book is divided into two main sections: Part One deals with problems arising from communication across national boundaries and the search for a solution…

Modeling the problem of many hands in organisations

NARCIS (Netherlands)

Lima, de T.; Royakkers, L.M.M.; Dignum, F.P.M.; Coelho, H.; Studer, R.; Woodridge, M.J.

2010-01-01

In this paper we provide a formalism to reason about the problem of many hands in organisations. This is a problem that arises whenever the organisation is responsible for some undesirable outcome but none of its members can be held responsible for the outcome. The formalism proposed here is a logic

[Chemical hazards arising from shale gas extraction].

Science.gov (United States)

Pakulska, Daria

2015-01-01

The development of the shale industry is gaining momentum and hence the analysis of chemical hazards to the environment and health of the local population is extreiely timely and important. Chemical hazards are created during the exploitation of all minerals, but in the case of shale gas production, there is much more uncertainty as regards to the effects of new technologies application. American experience suggests the increasing risk of environmental contamination, mainly groundwater. The greatest, concern is the incomplete knowledge of the composition of fluids used for fracturing shale rock and unpredictability of long-term effects of hydraulic fracturing for the environment and health of residents. High population density in the old continent causes the problem of chemical hazards which is much larger than in the USA. Despite the growing public discontent data on this subject are limited. First of all, there is no epidemiological studies to assess the relationship between risk factors, such as air and water pollution, and health effects in populations living in close proximity to gas wells. The aim of this article is to identify and discuss existing concepts on the sources of environmental contamination, an indication of the environment elements under pressure and potential health risks arising from shale gas extraction.

Sigmoid colon cancer arising in a diverticulum of the colon with involvement of the urinary bladder: a case report and review of the literature.

Science.gov (United States)

Yagi, Yasumichi; Shoji, Yasuhiro; Sasaki, Shozo; Yoshikawa, Akemi; Tsukioka, Yuji; Fukushima, Wataru; Hirosawa, Hisashi; Izumi, Ryohei; Saito, Katsuhiko

2014-05-13

Colon cancer can arise from the mucosa in a colonic diverticulum. Although colon diverticulum is a common disease, few cases have been previously reported on colon cancer associated with a diverticulum. We report a rare case of sigmoid colon cancer arising in a diverticulum with involvement of the urinary bladder, which presented characteristic radiographic images. A 73-year-old man was admitted to our hospital for macroscopic hematuria. Computed tomography and magnetic resonance imaging revealed a sigmoid colon tumor that protruded into the urinary bladder lumen. The radiographs showed a tumor with a characteristic dumbbell-shaped appearance. Colonoscopy showed a type 1 cancer and multiple diverticula in the sigmoid colon. A diagnosis of sigmoid colon cancer with involvement of the urinary bladder was made based on the pathological findings of the biopsied specimens. We performed sigmoidectomy and total resection of the urinary bladder with colostomy and urinary tract diversion. Histopathological findings showed the presence of a colovesical fistula due to extramurally growing colon cancer. Around the colon cancer, the normal colon mucosa was depressed sharply with lack of the muscular layer, suggesting that the colon cancer was arising from a colon diverticulum. The present case is the first report of sigmoid colon cancer arising in a diverticulum with involvement of the urinary bladder. Due to an accurate preoperative radiological diagnosis, we were able to successfully perform a curative resection for sigmoid colon cancer arising in a diverticulum with involvement of the urinary bladder.

Conjunctival lymphoma arising from reactive lymphoid hyperplasia

Directory of Open Access Journals (Sweden)

Fukuhara Junichi

2012-09-01

Full Text Available Abstract Extra nodal marginal zone B-cell lymphoma (EMZL of the conjunctiva typically arises in the marginal zone of mucosa-associated lymphoid tissue. The pathogenesis of conjunctival EMZL remains unknown. We describe an unusual case of EMZL arising from reactive lymphoid hyperplasia (RLH of the conjunctiva. A 35-year-old woman had fleshy salmon-pink conjunctival tumors in both eyes, oculus uterque (OU. Specimens from conjunctival tumors in the right eye, oculus dexter (OD, revealed a collection of small lymphoid cells in the stroma. Immunohistochemically, immunoglobulin (Ig light chain restriction was not detected. In contrast, diffuse atypical lymphoid cell infiltration was noted in the left eye, oculus sinister (OS, and positive for CD20, a marker for B cells OS. The tumors were histologically diagnosed as RLH OD, and EMZL OS. PCR analysis detected IgH gene rearrangement in the joining region (JH region OU. After 11 months, a re-biopsy specimen demonstrated EMZL based on compatible pathological and genetic findings OD, arising from RLH. This case suggests that even if the diagnosis of the conjunctival lymphoproliferative lesions is histologically benign, confirmation of the B-cell clonality by checking IgH gene rearrangement should be useful to predict the incidence of malignancy.

32 CFR 536.111 - Investigation of claims arising under international agreements (for those claims arising in the...

Science.gov (United States)

2010-07-01

... under international agreements (for those claims arising in the United States). Responsibility for... civilian component is attached, including the legal office of another armed force, to carry out the responsibility to investigate. The investigation will comply with the responsible Service's implementing claims...

Do experiments suggest a hierarchy problem?

International Nuclear Information System (INIS)

Vissani, F.

1997-09-01

The hierarchy problem of the scalar sector of the standard model is reformulated, emphasizing the role of experimental facts that may suggest the existence of a new physics large mass scale, for instance indications of the instability of the matter, or indications in favor of massive neutrinos. In the see-saw model for the neutrino masses a hierarchy problem arises if the mass of the right-handed neutrinos is larger than approximatively 10 7 GeV: this problem, and its possible solutions, are discussed. (author)

Biliary stricture due to neuroma after an innocent blunt abdominal trauma.

Science.gov (United States)

Katsinelos, P; Dimiropoulos, S; Galanis, I; Tsolkas, P; Paroutoglu, G; Arvaniti, M; Katsiba, D; Baltaglannis, S; Pilpilidis, I; Papagiannis, A; Vaslliadis, I

2002-10-01

A traumatic neuroma of the biliary tract is rarely associated with biliary obstruction. However, when it arises in the common bile duct (CBD) and is associated with obstructive jaundice, it is difficult to distinguish it from bile duct cancer. We describe a patient who developed obstructive jaundice and itching, due to CBD stricture, 8 years after innocent blunt abdominal trauma. The stricture was resected and hepatico-jejunal anastomosis was performed. Histological examination revealed a traumatic neuroma and a fibrous scar around the common bile duct. Symptoms disappeared following surgical removal of the lesion. Blunt abdominal injury may cause the late onset of a fibrous scar and traumatic neuroma in the common bile duct. To our knowledge, a traumatic neuroma of the biliary tract after blunt abdominal trauma has not been reported previously. We review the clinical picture of this relatively rare problem, along with its diagnosis, pathogenesis and treatment.

The co phylogeny reconstruction problem is NP-complete.

Science.gov (United States)

Ovadia, Y; Fielder, D; Conow, C; Libeskind-Hadas, R

2011-01-01

The co phylogeny reconstruction problem is that of finding minimum cost explanations of differences between historical associations. The problem arises in parasitology, molecular systematics, and biogeography. Existing software tools for this problem either have worst-case exponential time or use heuristics that do not guarantee optimal solutions. To date, no polynomial time optimal algorithms have been found for this problem. In this article, we prove that the problem is NP-complete, suggesting that future research on algorithms for this problem should seek better polynomial-time approximation algorithms and heuristics rather than optimal solutions.

Squamous cell carcinoma arising in mature cystic teratoma of ovary

Directory of Open Access Journals (Sweden)

Ranu Patni

2014-01-01

Full Text Available Squamous cell carcinoma of the ovary is a rare condition and usually arises in mature cystic teratoma (MCT or dermoid cyst of the ovary. The reported incidence of malignant transformation in MCT is approximately 2%. A case of squamous cell carcinoma arising in a dermoid cyst of the ovary presenting at an early stage is presented here. A 53-year-old postmenopausal lady, presented with the complaint of pain in right lower abdomen since one month and a large complex abdomino-pelvic mass on examination and investigations. Final histopathology was reported as squamous cell carcinoma of left ovary arising from dermoid cyst and a benign dermoid cyst in the right ovary. The patient was assigned to squamous cell carcinoma of the ovary arising in a mature cystic teratoma, surgical stage Ic2. In view of the poor prognosis, adjuvant chemotherapy was started.

Distributing Flexibility to Enhance Robustness in Task Scheduling Problems

NARCIS (Netherlands)

Wilmer, D.; Klos, T.B.; Wilson, M.

2013-01-01

Temporal scheduling problems occur naturally in many diverse application domains such as manufacturing, transportation, health and education. A scheduling problem arises if we have a set of temporal events (or variables) and some constraints on those events, and we have to find a schedule, which is

Lessons from a prototype geolocation problem

DEFF Research Database (Denmark)

Thygesen, Uffe Høgsbro; Nielsen, Anders

2009-01-01

This paper establishes simple and general expressions for the accuracy of geolocation, which may be obtained by optimal filtering of measurements front archival tags. We investigate an idealized geolocation problem where the animal performs a random walk. We derive simple closed-form expressions...... for the steady-state variance and for the characteristic time scale of the filter, i.e. the smoothing horizon. This leads to temporal and spatial scales defining the limit of resolution and explains the difference between what can be obtained for fast-moving and slow-moving animals. Using frequency......-domain methods, we consider the effect of adding additional sensors, and examine the substitution of the random walk model with anomalous diffusion, e.g. a Levy flight. We also discuss time variations in the accuracy near start and end of the time series, and due to holes in the data stream which e.g. arise...

Toward an Improved Representation of Middle Atmospheric Dynamics Thanks to the ARISE Project

Science.gov (United States)

Blanc, E.; Ceranna, L.; Hauchecorne, A.; Charlton-Perez, A.; Marchetti, E.; Evers, L. G.; Kvaerna, T.; Lastovicka, J.; Eliasson, L.; Crosby, N. B.; Blanc-Benon, P.; Le Pichon, A.; Brachet, N.; Pilger, C.; Keckhut, P.; Assink, J. D.; Smets, P. S. M.; Lee, C. F.; Kero, J.; Sindelarova, T.; Kämpfer, N.; Rüfenacht, R.; Farges, T.; Millet, C.; Näsholm, S. P.; Gibbons, S. J.; Espy, P. J.; Hibbins, R. E.; Heinrich, P.; Ripepe, M.; Khaykin, S.; Mze, N.; Chum, J.

2018-03-01

This paper reviews recent progress toward understanding the dynamics of the middle atmosphere in the framework of the Atmospheric Dynamics Research InfraStructure in Europe (ARISE) initiative. The middle atmosphere, integrating the stratosphere and mesosphere, is a crucial region which influences tropospheric weather and climate. Enhancing the understanding of middle atmosphere dynamics requires improved measurement of the propagation and breaking of planetary and gravity waves originating in the lowest levels of the atmosphere. Inter-comparison studies have shown large discrepancies between observations and models, especially during unresolved disturbances such as sudden stratospheric warmings for which model accuracy is poorer due to a lack of observational constraints. Correctly predicting the variability of the middle atmosphere can lead to improvements in tropospheric weather forecasts on timescales of weeks to season. The ARISE project integrates different station networks providing observations from ground to the lower thermosphere, including the infrasound system developed for the Comprehensive Nuclear-Test-Ban Treaty verification, the Lidar Network for the Detection of Atmospheric Composition Change, complementary meteor radars, wind radiometers, ionospheric sounders and satellites. This paper presents several examples which show how multi-instrument observations can provide a better description of the vertical dynamics structure of the middle atmosphere, especially during large disturbances such as gravity waves activity and stratospheric warming events. The paper then demonstrates the interest of ARISE data in data assimilation for weather forecasting and re-analyzes the determination of dynamics evolution with climate change and the monitoring of atmospheric extreme events which have an atmospheric signature, such as thunderstorms or volcanic eruptions.

The Cauchy problem for the Pavlov equation

International Nuclear Information System (INIS)

Grinevich, P G; Santini, P M; Wu, D

2015-01-01

Commutation of multidimensional vector fields leads to integrable nonlinear dispersionless PDEs that arise in various problems of mathematical physics and have been intensively studied in recent literature. This report aims to solve the scattering and inverse scattering problem for integrable dispersionless PDEs, recently introduced just at a formal level, concentrating on the prototypical example of the Pavlov equation, and to justify an existence theorem for global bounded solutions of the associated Cauchy problem with small data. (paper)

Blow up of solutions to ordinary differential equations arising in nonlinear dispersive problems

Directory of Open Access Journals (Sweden)

Milena Dimova

2018-03-01

Full Text Available We study a new class of ordinary differential equations with blow up solutions. Necessary and sufficient conditions for finite blow up time are proved. Based on the new differential equation, a revised version of the concavity method of Levine is proposed. As an application we investigate the non-existence of global solutions to the Cauchy problem of Klein-Gordon, and to the double dispersive equations. We obtain necessary and sufficient condition for finite time blow up with arbitrary positive energy. A very general sufficient condition for blow up is also given.

Boundary value problems on the half line in the theory of colloids

Directory of Open Access Journals (Sweden)

Ravi P. Agarwal

2002-01-01

Full Text Available We present existence results for some boundary value problems defined on infinite intervals. In particular our discussion includes a problem which arises in the theory of colloids.

A taxonomy of inductive problems.

Science.gov (United States)

Kemp, Charles; Jern, Alan

2014-02-01

Inductive inferences about objects, features, categories, and relations have been studied for many years, but there are few attempts to chart the range of inductive problems that humans are able to solve. We present a taxonomy of inductive problems that helps to clarify the relationships between familiar inductive problems such as generalization, categorization, and identification, and that introduces new inductive problems for psychological investigation. Our taxonomy is founded on the idea that semantic knowledge is organized into systems of objects, features, categories, and relations, and we attempt to characterize all of the inductive problems that can arise when these systems are partially observed. Recent studies have begun to address some of the new problems in our taxonomy, and future work should aim to develop unified theories of inductive reasoning that explain how people solve all of the problems in the taxonomy.

An unusual neonatal presentation of anomalous origin of the left coronary artery arising from the pulmonary artery.

Science.gov (United States)

Garty, Y; Guri, A; Shinwell, E S; Matitiau, A

2008-01-01

We describe a previously unreported neonatal presentation of an anomalous origin of the left coronary artery arising from the pulmonary artery. This is a full-term female infant after normal pregnancy and delivery. The baby was diagnosed at 2 days of age due to weak femoral pulses noted on the routine nursery discharge examination. The cardiac examination revealed weak pulses everywhere and mild tachypnea and tachycardia. An electrocardiogram showed clear signs of ischemia. Echocardiography demonstrated an anomalous origin of the left coronary artery arising from the pulmonary artery with bidirectional blood flow. There was a severely depressed left ventricular function and mild mitral valve regurgitation. At 4 days of age, the infant underwent complete successful surgical repair with reimplantation of the anomalous coronary artery to the aorta. She recovered slowly but well. Fifteen months later she is doing well with no cardiac residua. A neonatal presentation is very unusual due to protective high pulmonary resistance after birth, with gradual decline in pressure and gradual onset of heart failure. This case may be related to an unusually rapid drop in pulmonary vascular resistance causing very early cardiac ischemia. (c) 2007 S. Karger AG, Basel.

Tube failures due to cooling process problem and foreign materials in power plants

Energy Technology Data Exchange (ETDEWEB)

Ahmad, J. [Kapar Energy Ventures Sdn Bhd, Jalan Tok Muda, Kapar 42200 (Malaysia); Purbolaksono, J., E-mail: judha@uniten.edu.m [Department of Mechanical Engineering, Universiti Tenaga Nasional, Km 7 Jalan Kajang-Puchong, Kajang 43009, Selangor (Malaysia); Beng, L.C. [Kapar Energy Ventures Sdn Bhd, Jalan Tok Muda, Kapar 42200 (Malaysia)

2010-07-15

Cooling process which uses water for heat transfer is an essential factor in coal-fired and nuclear plants. Loss of cooling upset can force the plants to shut down. In particular, this paper reports visual inspections and metallurgical examinations on the failed SA210-A1 right-hand side (RHS) water wall tube of a coal-fired plant. The water wall tube showed the abnormal outer surface colour and has failed with wide-open ductile rupture and thin edges indicating typical signs of short-term overheating. Metallurgical examinations confirmed the failed tube experiencing higher temperature operation. Water flow starvation due to restriction inside the upstream tube is identified as the main root cause of failure. The findings are important to take failure mitigation actions in the future operation. Discussion on the typical problems related to the cooling process in nuclear power plants is also presented.

Tube failures due to cooling process problem and foreign materials in power plants

International Nuclear Information System (INIS)

Ahmad, J.; Purbolaksono, J.; Beng, L.C.

2010-01-01

Cooling process which uses water for heat transfer is an essential factor in coal-fired and nuclear plants. Loss of cooling upset can force the plants to shut down. In particular, this paper reports visual inspections and metallurgical examinations on the failed SA210-A1 right-hand side (RHS) water wall tube of a coal-fired plant. The water wall tube showed the abnormal outer surface colour and has failed with wide-open ductile rupture and thin edges indicating typical signs of short-term overheating. Metallurgical examinations confirmed the failed tube experiencing higher temperature operation. Water flow starvation due to restriction inside the upstream tube is identified as the main root cause of failure. The findings are important to take failure mitigation actions in the future operation. Discussion on the typical problems related to the cooling process in nuclear power plants is also presented.

An Integrated Approach to the Ground Crew Rostering Problem with Work Patterns

DEFF Research Database (Denmark)

Lusby, Richard Martin; Hansen, Anders Dohn; Range, Troels Martin

This paper addresses the Ground Crew Rostering Problem with Work Patterns, an important manpower planning problem arising in the ground operations of airline companies. We present a cutting stock based integer programming formulation of the problem and describe a powerful decomposition approach...

The global warming problem

International Nuclear Information System (INIS)

Anon.

1990-01-01

In this chapter, a discussion is presented of the global warming problem and activities contributing to the formation of acid rain, urban smog and to the depletion of the ozone layer. Globally, about two-thirds of anthropogenic carbon dioxide emissions arise from fossil-fuel burning; the rest arise primarily from deforestation. Chlorofluorocarbons are the second largest contributor to global warming, accounting for about 20% of the total. The third largest contributor is methane, followed by ozone and nitrous oxide. A study of current activities in the US that contribute to global warming shows the following: electric power plants account for about 33% of carbon dioxide emissions; motor vehicles, planes and ships (31%); industrial plants (24%); commercial and residential buildings (11%)

Frequency response as a surrogate eigenvalue problem in topology optimization

DEFF Research Database (Denmark)

Andreassen, Erik; Ferrari, Federico; Sigmund, Ole

2018-01-01

This article discusses the use of frequency response surrogates for eigenvalue optimization problems in topology optimization that may be used to avoid solving the eigenvalue problem. The motivation is to avoid complications that arise from multiple eigenvalues and the computational complexity as...

ARISE: American renaissance in science education

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-09-14

The national standards and state derivatives must be reinforced by models of curricular reform. In this paper, ARISE presents one model based on a set of principles--coherence, integration of the sciences, movement from concrete ideas to abstract ones, inquiry, connection and application, sequencing that is responsive to how people learn.

Vanishing viscosity limits of mixed hyperbolic–elliptic systems arising in multilayer channel flows

International Nuclear Information System (INIS)

Papaefthymiou, E S; Papageorgiou, D T

2015-01-01

This study considers the spatially periodic initial value problem of 2 × 2 quasi-linear parabolic systems in one space dimension having quadratic polynomial flux functions. These systems arise physically in the interfacial dynamics of viscous immiscible multilayer channel flows. The equations describe the spatiotemporal evolution of phase-separating interfaces with dissipation arising from surface tension (fourth-order) and/or stable stratification effects (second-order). A crucial mathematical aspect of these systems is the presence of mixed hyperbolic–elliptic flux functions that provide the only source of instability. The study concentrates on scaled spatially 2π-periodic solutions as the dissipation vanishes, and in particular the behaviour of such limits when generalized dissipation operators (spanning second to fourth-order) are considered. Extensive numerical computations and asymptotic analysis suggest that the existence (or not) of bounded vanishing viscosity solutions depends crucially on the structure of the flux function. In the absence of linear terms (i.e. homogeneous flux functions) the vanishing viscosity limit does not exist in the L ∞ -norm. On the other hand, if linear terms in the flux function are present the computations strongly suggest that the solutions exist and are bounded in the L ∞ -norm as the dissipation vanishes. It is found that the key mechanism that provides such boundedness centres on persistent spatiotemporal hyperbolic–elliptic transitions. Strikingly, as the dissipation decreases, the flux function becomes almost everywhere hyperbolic except on a fractal set of elliptic regions, whose dimension depends on the order of the regularized operator. Furthermore, the spatial structures of the emerging weak solutions are found to support an increasing number of discontinuities (measure-valued solutions) located in the vicinity of the fractally distributed elliptic regions. For the unscaled problem, such spatially

Issues arising in applying the BSS concepts

International Nuclear Information System (INIS)

Linsley, G.

1997-01-01

The following issues are discussed arising in applying the basic safety standard concepts: terminology, naturally occurring radionuclides, the exemption and clearance levels, management of very low level wastes, transboundary movements, the waste convention

The general linear thermoelastic end problem for solid and hollow cylinders

International Nuclear Information System (INIS)

Thompson, J.J.; Chen, P.Y.P.

1977-01-01

This paper reports on three topics arising from work in progress on theoretical and computational aspects of the utilization of self equilibrating and load stress systems, to solve thermoelastic problems of finite, or semi-infinite, solid or hollow circular cylinders, with particular reference to the pellets, rods, tubes and shells with arbitrary internal heat generation encountered in Nuclear Reactor Technology. Specifically the work is aimed at the evaluation of stress intensification factors in the end elastic boundary layer region, due to various thermal and mechanical end load conditions, in relation to the external, exact stress solutions, which satisfy conditions on the curved surfaces only and are valid over the remainder of the cylindrical body. More generally, it is possible, at least for symmetric thermoelastic problems, to derive exact external solutions, using self equilibrating end load systems, which describe the stress/displacement state completely as a combination of a simple local plane strain solution and a correction dependent on the magnitude of axial thermal gradients. Thus plane strain, and self equilibrating end load systems are sufficient for the complete external and boundary layer solution of a finite cylindrical body. This formulation is capable of further extension, e.g., to concentric multi-region problems, and provides a useful approach to the study of local stress intensification factors due to thermal perturbations

Dresses problems arising from hot-plant operation and their solution (1961)

International Nuclear Information System (INIS)

Rodier, J.; Bouzigues, H.; Boutot, P.

1961-01-01

This article deals with effective methods to struggle radioactive contamination using rationally designed working clothes. The choice of the cloth is important and cotton, because of its absorbent properties constitutes an effective barrier to radioelements failing on its surface. Clothing the personnel of large nuclear industrial concerns is a big problem which can only be solved by carefully studied methods. The decontamination and washing of large amounts of clothes whose flow increases during periods of radio-active incidents have to be treated as are those operations in hospital laundering. Linen washing by the German counter-current method (the Sulzman system) is of great value because of the volume which can be treated and, more important, because of the small amount of liquid waste produced. Dry cleaning is certainly a method of the future and is even more economic than the preceding one. In 'active' laundries, the control of clothing for residual contamination can constitute a serious bottleneck in the production of clean clothing if automatic high-speed machines are not used. The risk to the operating personnel comes solely from contamination of the atmosphere and of the surfaces. Because of this, the plant must be considered as an active zone in which are handled several tens of millicuries of dangerous emitters and several micro- curies of plutonium daily. (authors) [fr

Meta-heuristic algorithms for parallel identical machines scheduling problem with weighted late work criterion and common due date.

Science.gov (United States)

Xu, Zhenzhen; Zou, Yongxing; Kong, Xiangjie

2015-01-01

To our knowledge, this paper investigates the first application of meta-heuristic algorithms to tackle the parallel machines scheduling problem with weighted late work criterion and common due date ([Formula: see text]). Late work criterion is one of the performance measures of scheduling problems which considers the length of late parts of particular jobs when evaluating the quality of scheduling. Since this problem is known to be NP-hard, three meta-heuristic algorithms, namely ant colony system, genetic algorithm, and simulated annealing are designed and implemented, respectively. We also propose a novel algorithm named LDF (largest density first) which is improved from LPT (longest processing time first). The computational experiments compared these meta-heuristic algorithms with LDF, LPT and LS (list scheduling), and the experimental results show that SA performs the best in most cases. However, LDF is better than SA in some conditions, moreover, the running time of LDF is much shorter than SA.

Incidental Finding of a Neuroendocrine Tumor Arising from Meckel Diverticulum During Hernia Repair - A Case Report and Literature Review.

Science.gov (United States)

Bacalbasa, Nicolae; Costin, Radu; Orban, Carmen; Iliescu, Laura; Hurjui, Ioan; Hurjui, Marcela; Niculescu, Nicoleta; Cristea, Mirela; Balescu, Irina

2016-04-01

Meckel diverticulum is the most common abnormality of the gastrointestinal tract arising from an incomplete obliteration of the vitelline duct during the intrauterine life. Although tumor development in Meckel diverticulum is not a common situation, it can occur due to the persistence of cellular islets with gastric, pancreatic or intestinal origin. The presence of a neuroendocrine tumor arising from Meckel diverticulum is even scarcer. We present the case of a 59-year-old patient in whom a Meckel diverticulum was found during surgery for inguinal hernia; the histopathological and immunohistochemical studies revealed the presence of a well-differentiated neuroendocrine tumor with low mitotic index. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Electric reaction arising in bone subjected to mechanical loadings

Science.gov (United States)

Murasawa, Go; Cho, Hideo; Ogawa, Kazuma

2006-03-01

The aim of present study is the investigation of the electric reaction arising in bone subjected to mechanical loadings. Firstly, specimen was fabricated from femur of cow, and ultrasonic propagation in bone was measured by ultrasonic technique. Secondary, 4-point bending test was conducted up to fracture, and electric reaction arising in bone was measured during loading. Thirdly, cyclic 4-point bending test was conducted to investigate the effect of applied displacement speed on electric reaction.

Chemical hazards arising from shale gas extraction

Directory of Open Access Journals (Sweden)

Daria Pakulska

2015-02-01

Full Text Available The development of the shale industry is gaining momentum and hence the analysis of chemical hazards to the environment and health of the local population is extremely timely and important. Chemical hazards are created during the exploitation of all minerals, but in the case of shale gas production, there is much more uncertainty as regards to the effects of new technologies application. American experience suggests the increasing risk of environmental contamination, mainly groundwater. The greatest concern is the incomplete knowledge of the composition of fluids used for fracturing shale rock and unpredictability of long-term effects of hydraulic fracturing for the environment and health of residents. High population density in the old continent causes the problem of chemical hazards which is much larger than in the USA. Despite the growing public discontent data on this subject are limited. First of all, there is no epidemiological studies to assess the relationship between risk factors, such as air and water pollution, and health effects in populations living in close proximity to gas wells. The aim of this article is to identify and discuss existing concepts on the sources of environmental contamination, an indication of the environment elements under pressure and potential health risks arising from shale gas extraction. Med Pr 2015;66(1:99–117

Environmental problems due to mining in Jharia Coalfield

Energy Technology Data Exchange (ETDEWEB)

Banerjee, S.P.

1985-06-01

The Jharia coalfield to the NW of Calcutta, India is the most important source of coking coal in the country. Coal mining started in 1890; in 1971-3 the coking coal mines were nationalised, the remainder being operated by the Bharat Coking Coal Ltd., TISCO and IISCO. Intensive mining has resulted in major environmental problems - land damage, water pollution, air pollution and overpopulation - which a major reconstruction programme started in 1976 hopes to solve. 2 references.

Polyomino Problems to Confuse Computers

Science.gov (United States)

Coffin, Stewart

2009-01-01

Computers are very good at solving certain types combinatorial problems, such as fitting sets of polyomino pieces into square or rectangular trays of a given size. However, most puzzle-solving programs now in use assume orthogonal arrangements. When one departs from the usual square grid layout, complications arise. The author--using a computer,…

Robust Consumption-Investment Problem on Infinite Horizon

Energy Technology Data Exchange (ETDEWEB)

Zawisza, Dariusz, E-mail: dariusz.zawisza@im.uj.edu.pl [Jagiellonian University in Krakow, Institute of Mathematics, Faculty of Mathematics and Computer Science (Poland)

2015-12-15

In our paper we consider an infinite horizon consumption-investment problem under a model misspecification in a general stochastic factor model. We formulate the problem as a stochastic game and finally characterize the saddle point and the value function of that game using an ODE of semilinear type, for which we provide a proof of an existence and uniqueness theorem for its solution. Such equation is interested on its own right, since it generalizes many other equations arising in various infinite horizon optimization problems.

Riemann–Hilbert problem approach for two-dimensional flow inverse scattering

Energy Technology Data Exchange (ETDEWEB)

Agaltsov, A. D., E-mail: agalets@gmail.com [Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Novikov, R. G., E-mail: novikov@cmap.polytechnique.fr [CNRS (UMR 7641), Centre de Mathématiques Appliquées, Ecole Polytechnique, 91128 Palaiseau (France); IEPT RAS, 117997 Moscow (Russian Federation); Moscow Institute of Physics and Technology, Dolgoprudny (Russian Federation)

2014-10-15

We consider inverse scattering for the time-harmonic wave equation with first-order perturbation in two dimensions. This problem arises in particular in the acoustic tomography of moving fluid. We consider linearized and nonlinearized reconstruction algorithms for this problem of inverse scattering. Our nonlinearized reconstruction algorithm is based on the non-local Riemann–Hilbert problem approach. Comparisons with preceding results are given.

Riemann–Hilbert problem approach for two-dimensional flow inverse scattering

International Nuclear Information System (INIS)

Agaltsov, A. D.; Novikov, R. G.

2014-01-01

We consider inverse scattering for the time-harmonic wave equation with first-order perturbation in two dimensions. This problem arises in particular in the acoustic tomography of moving fluid. We consider linearized and nonlinearized reconstruction algorithms for this problem of inverse scattering. Our nonlinearized reconstruction algorithm is based on the non-local Riemann–Hilbert problem approach. Comparisons with preceding results are given

Non-Gaussian signatures arising from warm inflation driven by geometric tachyon

International Nuclear Information System (INIS)

Bhattacharjee, Anindita; Deshamukhya, Atri

2014-01-01

In a warm inflationary scenario, the initial seeds of density perturbation arise from thermal fluctuations of the inflaton field. These fluctuations in principle have Gaussian distribution. In a Gaussian distribution the density perturbation can be expressed as the two point correlation function. Thus if in an inflationary model the density perturbation is expressed as correlation function of order higher than two, these fluctuations are non-Gaussian in nature. A simple inflationary model containing single scalar field, slow roll, canonical kinetic term and vacuum initial state can produce a tiny amount of non-Gaussianity which are very small to be detected by any experiment. Non-Gaussianity can also arise in inflationary models containing multiple scalar fields. For an inflationary scenario with single scalar field, non-Gaussianity can be expressed in terms of bi-spectrum however for multi field Inflation, it is expressed in terms of trispectrum etc. In this piece of work, the warm inflationary scenario, driven by a D3 brane due to the presence of a stack of k coincident NS 5 branes is considered and the non-Gaussian effects in such an inflationary scenario has been analysed by measuring the bispectrum of the gravitational field fluctuations generated during the warm inflation in strong dissipative regime. The bi-spectrum of the Inflation is expressed in terms of the parameter f NL and it is seen that the value of f NL parameter lies well within the limit observed by WMAP7

Primitive neuroectodermal tumor arising 8 years after chemotherapy and radiotherapy for acute lymphoblastic leukemia. Case report

International Nuclear Information System (INIS)

Yoshida, Yuya; Toma, Yasuo; Arai, Masayuki; Higashi, Ryo; Kashihara, Kengo; Kaizaki, Yasuharu

2005-01-01

We report a case of primitive neuroectodermal tumor (PNET) arising 8 years after chemotherapy and radiotherapy for acute lymphoblastic leukemia. A 15-year-old boy with a history of acute lymphoblastic leukemia, at the age of 7, underwent chemotherapy and 14 Gy of radiotherapy to the whole brain. He was admitted to our department due to the development of aphasia, right hemiparesis and generalized convulsive seizure. MRI showed an irregularly enhanced mass in the left frontal lobe. A gross total removal of the tumor was performed and histological examination showed it to be PNET. Postoperatively, the patient underwent 20 Gy of radiotherapy to the whole brain and 42 Gy of local radiotherapy. Follow-up MRI showed no evidence of recurrent tumor 4 months after the radiotherapy. This tumor was thought to be a secondary brain tumor arising in this survivor of childhood acute lymphoblastic leukemia and it is a rare complication of successful leukemia treatment. (author)

Attention problems and pathological gaming: resolving the 'chicken and egg' in a prospective analysis.

Science.gov (United States)

Ferguson, Christopher J; Ceranoglu, T Atilla

2014-03-01

Pathological gaming (PG) behaviors are behaviors which interfere with other life responsibilities. Continued debate exists regarding whether symptoms of PG behaviors are a unique phenomenon or arise from other mental health problems, including attention problems. Development of attention problems and occurrence of pathological gaming in 144 adolescents were followed during a 1-year prospective analysis. Teens and their parents reported on pathological gaming behaviors, attention problems, and current grade point average, as well as several social variables. Results were analyzed using regression and path analysis. Attention problems tended to precede pathological gaming behaviors, but the inverse was not true. Attention problems but not pathological gaming predicted lower GPA 1 year later. Current results suggest that pathological gaming arises from attention problems, but not the inverse. These results suggest that pathological gaming behaviors are symptomatic of underlying attention related mental health issues, rather than a unique phenomenon.

Balance Problems

Science.gov (United States)

... often, it could be a sign of a balance problem. Balance problems can make you feel unsteady. You may ... related injuries, such as a hip fracture. Some balance problems are due to problems in the inner ...

Earliness-tardiness scheduling around almost equal due dates

NARCIS (Netherlands)

Hoogeveen, J.A.; Velde, van de S.L.

1997-01-01

The just-in-time concept in manufacturing has aroused interest in machine scheduling problems with earliness-tardiness penalties. In particular, common due date problems, which are structurally less complicated than problems with general due dates, have emerged as an interesting and fruitful field

Health problems due to long working hours in Japan: working hours, workers' compensation (Karoshi), and preventive measures.

Science.gov (United States)

Iwasaki, Kenji; Takahashi, Masaya; Nakata, Akinori

2006-10-01

Late in the 1970s, serious social concern over health problems due to long working hours has arisen in Japan. This report briefly summarizes the Japanese circumstances about long working hours and what the Government has achieved so far. The national statistics show that more than 6 million people worked for 60 h or more per week during years 2000 and 2004. Approximately three hundred cases of brain and heart diseases were recognized as labour accidents resulting from overwork (Karoshi) by the Ministry of Health, Labour and Welfare (MHLW) between 2002 and 2005. Consequently, the MHLW has been working to establish a more appropriate compensation system for Karoshi, as well as preventive measures for overwork related health problems. In 2001, the MHLW set the standards for clearly recognizing Karoshi in association with the amount of overtime working hours. These standards were based on the results of a literature review and medical examinations indicating a relationship between overwork and brain and heart diseases. In 2002, the MHLW launched the program for the prevention of health impairment due to overwork, and in 2005 the health guidance through an interview by a doctor for overworked workers has been enacted as law. Long working hours are controversial issues because of conflicts between health, safety, work-life balance, and productivity. It is obvious that we need to continue research regarding the impact on worker health and the management of long working hours.

Expansion of capacity of spent fuel pools and associated problems

International Nuclear Information System (INIS)

Francisco, J.L. De; Lopez-Cotarelo, J.; Ramos, J.M.

1978-01-01

Expanding the spent fuel storage pool capacity is a good solution for utilities facing the current shortage in fuel reprocessing capacity. The problems more likely to be found when expanding a spent fuel storage facility by using high density storage racks are reviewed. Basically three types of problems arise: 1) Problems related with the characteristics of the new facility. 2) Problems related with the works of expansion. 3) Problems related with the long term storage of large quantities of spent fuel. (author)

Software problems in library automation in India

OpenAIRE

Francis, A. T.

1998-01-01

Important software problems faced by the library professionals in India are analysed and points out various compatibility and suitability issues in the selection of a library software. The paper also hints that these problems has affected the progress of computerisation of libraries. Upto date and detailed information on softwares available in India can prevent several issues that may arise in the course of computerisation. An agency/mechanism to continuously evaluate the softwares may be ...

Anomalous Posterior Intercostal Arterial Trunk Arising From the Abdominal Aorta

Energy Technology Data Exchange (ETDEWEB)

Jie, Bing, E-mail: jbshh@163.com; Yu, Dong, E-mail: yudong-mail@126.com; Jiang, Sen, E-mail: jasfly77@vip.163.com [Tongji University School of Medicine, Department of Radiology, Shanghai Pulmonary Hospital (China)

2016-04-15

A common trunk of the ipsilateral posterior intercostal artery (PIA) arising from the thoracic aorta is usually an anatomical variation. However, a common trunk of bilateral posterior intercostal arterial trunk (PIAT) arising from the abdominal aorta is rare. It is important to recognize this anatomical variation of PIA when performing interventional radiological procedures. We present a rare case of an anomalous PIAT that originated from the abdominal aorta in a patient with hemoptysis caused by tuberculosis sequelae. Bilateral 4th to 11th PIAs arose from a common trunk and the trunk arising from the posterior aspect of the abdominal aorta at the level of T12/L1 intervertebral space. The pathological right 4th and 5th PIAs and bronchial arteries were embolized. Hemoptysis has been controlled for 3 months.

A game theoretic approach to assignment problems

NARCIS (Netherlands)

Klijn, F.

2000-01-01

Game theory deals with the mathematical modeling and analysis of conflict and cooperation in the interaction of multiple decision makers. This thesis adopts two game theoretic methods to analyze a range of assignment problems that arise in various economic situations. The first method has as

Rotastenting in an anomalously arising right coronary artery after an ugly dissection

Directory of Open Access Journals (Sweden)

Ashwin B. Mehta

2013-07-01

Full Text Available Rotational atherectomy is contraindicated in dissected coronary arteries since it can lead to progression of the dissection or perforation. In our case, the right coronary artery (RCA arose anomalously from the left coronary sinus. The lesion in the RCA was an undilatable calcified one. There was a dissection in the RCA due to high pressure balloon dilatation. Since the patient was hemodynamically unstable and there were no options besides rotablation, we proceeded with caution. Rotablation and stenting were successfully done. Our case report highlights the importance of the need for good guide catheter support even in the presence of anomalously arising arteries and the rotablation option for unyielding calcified coronary lesions, even in the setting of a dissection.

MAP estimators and their consistency in Bayesian nonparametric inverse problems

KAUST Repository

Dashti, M.

2013-09-01

We consider the inverse problem of estimating an unknown function u from noisy measurements y of a known, possibly nonlinear, map applied to u. We adopt a Bayesian approach to the problem and work in a setting where the prior measure is specified as a Gaussian random field μ0. We work under a natural set of conditions on the likelihood which implies the existence of a well-posed posterior measure, μy. Under these conditions, we show that the maximum a posteriori (MAP) estimator is well defined as the minimizer of an Onsager-Machlup functional defined on the Cameron-Martin space of the prior; thus, we link a problem in probability with a problem in the calculus of variations. We then consider the case where the observational noise vanishes and establish a form of Bayesian posterior consistency for the MAP estimator. We also prove a similar result for the case where the observation of can be repeated as many times as desired with independent identically distributed noise. The theory is illustrated with examples from an inverse problem for the Navier-Stokes equation, motivated by problems arising in weather forecasting, and from the theory of conditioned diffusions, motivated by problems arising in molecular dynamics. © 2013 IOP Publishing Ltd.

MAP estimators and their consistency in Bayesian nonparametric inverse problems

International Nuclear Information System (INIS)

Dashti, M; Law, K J H; Stuart, A M; Voss, J

2013-01-01

We consider the inverse problem of estimating an unknown function u from noisy measurements y of a known, possibly nonlinear, map G applied to u. We adopt a Bayesian approach to the problem and work in a setting where the prior measure is specified as a Gaussian random field μ 0 . We work under a natural set of conditions on the likelihood which implies the existence of a well-posed posterior measure, μ y . Under these conditions, we show that the maximum a posteriori (MAP) estimator is well defined as the minimizer of an Onsager–Machlup functional defined on the Cameron–Martin space of the prior; thus, we link a problem in probability with a problem in the calculus of variations. We then consider the case where the observational noise vanishes and establish a form of Bayesian posterior consistency for the MAP estimator. We also prove a similar result for the case where the observation of G(u) can be repeated as many times as desired with independent identically distributed noise. The theory is illustrated with examples from an inverse problem for the Navier–Stokes equation, motivated by problems arising in weather forecasting, and from the theory of conditioned diffusions, motivated by problems arising in molecular dynamics. (paper)

MYC Amplification in Angiosarcoma Arising from an Arteriovenous Graft Site

Directory of Open Access Journals (Sweden)

Kristen M. Paral

2015-01-01

Full Text Available Angiosarcoma arising in association with an arteriovenous graft (AVG or fistula is a unique clinicopathologic scenario that appears to be gaining recognition in the literature. Among reported cases, none has described high-level MYC gene amplification, a genetic aberration that is increasingly unifying the various clinicopathologic subdivisions of angiosarcoma. We therefore report the MYC gene status in a case of angiosarcoma arising at an AVG site.

On the Combinatorics of SAT and the Complexity of Planar Problems

DEFF Research Database (Denmark)

Talebanfard, Navid

In this thesis we study several problems arising in Boolean satisfiability ranging from lower bounds for SAT algorithms and proof systems to extremal properties of formulas. The first problem is about construction of hard instances for k-SAT algorithms. For PPSZ algorithm [40] we give the first...

Optimal Stopping Problems Driven by Lévy Processes and Pasting Principles

NARCIS (Netherlands)

Surya, B.A.

2007-01-01

Solving optimal stopping problems driven by Lévy processes has been a challenging task and has found many applications in modern theory of mathematical finance. For example situations in which optimal stopping typically arise include the problem of finding the arbitrage-free price of the American

Periodic solutions of an indefinite singular equation arising from the Kepler problem on the sphere

Czech Academy of Sciences Publication Activity Database

Hakl, Robert; Zamora, M.

2018-01-01

Roč. 70, č. 1 (2018), s. 173-190 ISSN 0008-414X Institutional support: RVO:67985840 Keywords : indefinite singularity * periodic solution * Kepler problem on S^1 Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics Impact factor: 0.963, year: 2016 https://cms.math.ca/10.4153/CJM-2016-050-1

Sustainable Development and Spatial Planning: Some considerations arising from the Greek case

Directory of Open Access Journals (Sweden)

Pavlos Marinos Delladetsima

2012-03-01

Full Text Available The paper aims to elaborate on the notion of sustainable development in relation to spatial planning and to question its applicability based on the experience arising from the distinct socio-economic situation in Greece. Experience accumulated in the country with the adoption of sustainable development as a spatial policy concept proves to be in contradiction with perceptions that consider it as a basis for improving the plan making process and the planning system as whole. In this respect, it is argued that sustainable development is not a feasible proposition for planning in Greece and offers little to alleviate urban development and sprawl problems. Further, the paper highlights how a globalised approach to sustainable development and planning in Greece has made a negligible contribution to reinvigorating a weak and disjointed system, while also creating significant adverse effects in spatial policymaking.

A case of malignant fibrous histiocytoma arising in the irradiated maxilla

International Nuclear Information System (INIS)

Fukuta, Yoshiyasu; Yamada, Kazumi; Ohmura, Hiromi; Kudo, Keigo; Takeda, Yasunori

1994-01-01

A malignant fibrous histiocytoma (MFH) arising in the irradiated maxilla is reported. The patient was a 59-year-old Japanese female who was referred to us for a relatively well defined and lobulated tumor extending from the right buccal mucosa to left hard palate. Her past medical history revealed that she had had a squamous cell carcinoma of the right buccal mucosa treated by 145 Gy of radiotherapy 3 years previously. Although the patient underwent a bilateral partial maxillectomy, she died due to extensive local recurrence 14 months postoperatively. Histopathologically, proliferation of atypical tumor cells of non-epithelial origin, i.e., spindle-shaped fibroblastic cells, histiocytic cells and bizarre multinucleated giant cells, were noted. Furthermore, a storiform pattern was also seen in part of the lesion. These features suggested that this care was a postirradiation malignant fibrous histiocytoma. (author)

A case of malignant fibrous histiocytoma arising in the irradiated maxilla

Energy Technology Data Exchange (ETDEWEB)

Fukuta, Yoshiyasu; Yamada, Kazumi; Ohmura, Hiromi; Kudo, Keigo; Takeda, Yasunori (Iwate Medical Univ., Morioka (Japan). School of Dentistry)

1994-03-01

A malignant fibrous histiocytoma (MFH) arising in the irradiated maxilla is reported. The patient was a 59-year-old Japanese female who was referred to us for a relatively well defined and lobulated tumor extending from the right buccal mucosa to left hard palate. Her past medical history revealed that she had had a squamous cell carcinoma of the right buccal mucosa treated by 145 Gy of radiotherapy 3 years previously. Although the patient underwent a bilateral partial maxillectomy, she died due to extensive local recurrence 14 months postoperatively. Histopathologically, proliferation of atypical tumor cells of non-epithelial origin, i.e., spindle-shaped fibroblastic cells, histiocytic cells and bizarre multinucleated giant cells, were noted. Furthermore, a storiform pattern was also seen in part of the lesion. These features suggested that this care was a postirradiation malignant fibrous histiocytoma. (author).

Estimates of the eigenvalues of operator arising in swelling pressure model

International Nuclear Information System (INIS)

Kanguzhin, Baltabek; Zhapsarbayeva, Lyailya

2016-01-01

Swelling pressures from materials confined by structures can cause structural deformations and instability. Due to the complexity of interactions between expansive solid and solid-liquid equilibrium, the forces exerting on retaining structures from swelling are highly nonlinear. This work is our initial attempt to study a simplistic spectral problem based on the Euler-elastic beam theory and some simplistic swelling pressure model. In this work estimates of the eigenvalues of some initial/boundary value problem for nonlinear Euler-elastic beam equation are obtained.

Defect Shape Recovering by Parameter Estimation Arising in Eddy Current Testing

International Nuclear Information System (INIS)

Kojima, Fumio

2003-01-01

This paper is concerned with a computational method for recovering a crack shape of steam generator tubes of nuclear plants. Problems on the shape identification are discussed arising in the characterization of a structural defect in a conductor using data of eddy current inspection. A surface defect on the generator tube ran be detected as a probe impedance trajectory by scanning a pancake type coil. First, a mathematical model of the inspection process is derived from the Maxwell's equation. Second, the input and output relation is given by the approximate model by virtue of the hybrid use of the finite element and boundary element method. In that model, the crack shape is characterized by the unknown coefficients of the B-spline function which approximates the crack shape geometry. Finally, a parameter estimation technique is proposed for recovering the crack shape using data from the probe coil. The computational experiments were successfully tested with the laboratory data

Empiricism Verses Rationalism: Matters Arising in Medical Practice ...

African Journals Online (AJOL)

Empiricism Verses Rationalism: Matters Arising in Medical Practice. ... AFRREV STECH: An International Journal of Science and Technology ... entirely antagonistic to one another, one favoring the senses and the other favoring the mind.

Substantive law problems in jurisdiction

International Nuclear Information System (INIS)

Sternberg, D.

1977-01-01

Substantive law problems in nuclear licensing procedure jurisdiction are discussed. Preconditions for the right to file a suit pursuant to section 42, sub-section 2 VwGO are investigated, in the context of which the necessity is pointed out to differentiate between normal operation and possible accidents. Furthermore, comments are made on the definition of 'facility' in terms of nuclear law, the understanding of which is rather decisive for the substantial scope of the nuclear licensing procedures. Also, legal problems are examined which arise from special forms of financing for nuclear power plant projects, in particular in connection with leasing financing. (HP) [de

The Cauchy problem for the Pavlov equation with large data

Science.gov (United States)

Wu, Derchyi

2017-08-01

We prove a local solvability of the Cauchy problem for the Pavlov equation with large initial data by the inverse scattering method. The Pavlov equation arises in studies Einstein-Weyl geometries and dispersionless integrable models. Our theory yields a local solvability of Cauchy problems for a quasi-linear wave equation with a characteristic initial hypersurface.

A theory of intelligence: networked problem solving in animal societies

OpenAIRE

Shour, Robert

2009-01-01

A society's single emergent, increasing intelligence arises partly from the thermodynamic advantages of networking the innate intelligence of different individuals, and partly from the accumulation of solved problems. Economic growth is proportional to the square of the network entropy of a society's population times the network entropy of the number of the society's solved problems.

Requirements Elicitation Problems: A Literature Analysis

Directory of Open Access Journals (Sweden)

Bill Davey

2015-06-01

Full Text Available Requirements elicitation is the process through which analysts determine the software requirements of stakeholders. Requirements elicitation is seldom well done, and an inaccurate or incomplete understanding of user requirements has led to the downfall of many software projects. This paper proposes a classification of problem types that occur in requirements elicitation. The classification has been derived from a literature analysis. Papers reporting on techniques for improving requirements elicitation practice were examined for the problem the technique was designed to address. In each classification the most recent or prominent techniques for ameliorating the problems are presented. The classification allows the requirements engineer to be sensitive to problems as they arise and the educator to structure delivery of requirements elicitation training.

Nonlinear programming for classification problems in machine learning

Science.gov (United States)

Astorino, Annabella; Fuduli, Antonio; Gaudioso, Manlio

2016-10-01

We survey some nonlinear models for classification problems arising in machine learning. In the last years this field has become more and more relevant due to a lot of practical applications, such as text and web classification, object recognition in machine vision, gene expression profile analysis, DNA and protein analysis, medical diagnosis, customer profiling etc. Classification deals with separation of sets by means of appropriate separation surfaces, which is generally obtained by solving a numerical optimization model. While linear separability is the basis of the most popular approach to classification, the Support Vector Machine (SVM), in the recent years using nonlinear separating surfaces has received some attention. The objective of this work is to recall some of such proposals, mainly in terms of the numerical optimization models. In particular we tackle the polyhedral, ellipsoidal, spherical and conical separation approaches and, for some of them, we also consider the semisupervised versions.

Non-epiphyseal chondroblastoma arising in the iliac bone, and complicated by an aneurysmal bone cyst: a case report and review of the literature

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin; Kumar, Rajendra [The University of Texas MD Anderson Cancer Center, Department of Diagnostic Radiology, Houston, TX (United States); Raymond, A.K. [Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX (United States); Ayala, Alberto G. [The Methodist Hospital, Department of Pathology, Houston, TX (United States)

2010-06-15

Chondroblastoma is a benign bone tumor that typically arises in the epiphysis of a long bone. However, when it occurs in non-epiphyseal location in flat bones, it may create a diagnostic problem. We describe such a case of chondroblastoma arising in the iliac bone. A 29-year-old man was incidentally found to have a bony pelvic lesion while undergoing evaluation for Crohn's disease. The radiographs and CT revealed an expansile lytic lesion in the right iliac bone. A core biopsy of the lesion was performed. The histopathology revealed the lesion to be a chondroblastoma with secondary features of aneurysmal bone cyst. An en bloc surgical resection of the tumor was performed. (orig.)

Cellular schwannoma arising from sigmoid mesocolon presenting ...

African Journals Online (AJOL)

Schwannomas are a type of peripheral nerve sheath tumors with clinically indolent behavior. Though, they can occur anywhere in body, the incidence in retroperitoneum, mediastinum, and pelvis is exceedingly rare. We present a case of a 58‑year‑old female with a massive twisted tumor arising from sigmoid mesocolon.

Cellular Schwannoma Arising from Sigmoid Mesocolon Presenting ...

African Journals Online (AJOL)

Schwannomas are a type of peripheral nerve sheath tumors with clinically indolent behavior. Though, they can occur anywhere in body, the incidence in retroperitoneum, mediastinum, and pelvis is exceedingly rare. We present a case of a 58‑year‑old female with a massive twisted tumor arising from sigmoid mesocolon.

A quadratic approximation-based algorithm for the solution of multiparametric mixed-integer nonlinear programming problems

KAUST Repository

Domí nguez, Luis F.; Pistikopoulos, Efstratios N.

2012-01-01

An algorithm for the solution of convex multiparametric mixed-integer nonlinear programming problems arising in process engineering problems under uncertainty is introduced. The proposed algorithm iterates between a multiparametric nonlinear

The Analysis of English and Lithuanian Idioms and the Problems of Their Translation

Directory of Open Access Journals (Sweden)

Jelena Suchanova

2013-12-01

Full Text Available The paper considers the problems associated with comprehension and translation of idioms within the framework of the theory of linguistic relativity and the translation theories. The main statements of these theories used for explaining the difficulties of idioms’ translation from/into the English or Lithuanian language are presented. The considered problems are analysed from various perspectives. Case studies, demonstrating different nomination principles used in English and Lithuanian due to different approaches of the native speakers of these languages to the same objects or ‘pieces’ of reality are provided. The comparative analysis of English and Lithuanian idioms as the most interesting and peculiar expressions of a language, showing its unique character, is performed and the arising difficulties and the available techniques of idioms’ translation are demonstrated, taking into account the main statements of the theories of linguistic relativity and translation. Special attention is paid to idioms, whose main ideas are expressed differently in the considered languages and, therefore, present many difficulties to non-native speakers. The influence of traditions, culture, the environment and other factors on the form and contents of the idioms in each of the considered languages is also shown. The analysis performed demonstrates the effectiveness of the theory of linguistic relativity in explaining the nature and causes of the arising comprehension and translation problems, as well as its possibilities to give a translator a native speaker’s insight and help him\\her avoid some typical errors. The recommendations of how to make a translation of idioms more accurate and authentic by using the appropriate translation techniques are also given.

Primary chondroid chordoma arising from the petrous temporal bone: a case report

Energy Technology Data Exchange (ETDEWEB)

Lee, Young Uk; Youn, Eun Kyung [Koryo General Hospital, Seoul (Korea, Republic of)

1991-01-15

Chordomas are uncommon tumors which arise from remnants of the primitive notochord. They are situated chiefly in the anterior spinal axis with a predilection for the sacrococcygeal region and the basiocciput. About 50% of chordomas are sacrococcygeal, 35% are intracranial, and 15% arise from a vertebral body. As a histologic variant of chordoma, /chondroid chordoma' was first described by Heffelfinger et al. We present a rare case of primary chondroid chordoma arising from the petrous temporal bone. To our knowledge, only two other cases of this type have been reported earlier.

Primary chondroid chordoma arising from the petrous temporal bone: a case report

International Nuclear Information System (INIS)

Lee, Young Uk; Youn, Eun Kyung

1991-01-01

Chordomas are uncommon tumors which arise from remnants of the primitive notochord. They are situated chiefly in the anterior spinal axis with a predilection for the sacrococcygeal region and the basiocciput. About 50% of chordomas are sacrococcygeal, 35% are intracranial, and 15% arise from a vertebral body. As a histologic variant of chordoma, /chondroid chordoma' was first described by Heffelfinger et al. We present a rare case of primary chondroid chordoma arising from the petrous temporal bone. To our knowledge, only two other cases of this type have been reported earlier

Challenges, problems and possible solutions in wind generator systems from the aspect of forecast, planning and delivery of wind energy

International Nuclear Information System (INIS)

Giovski, Nikola

2014-01-01

The fundamental difficulties of integrating wind energy into the power system arise from its large temporal variability and limited predictability. That's why the integration of wind power presents major challenge for today's operating and planning practices of the power system operators. Accurate predictions of the possible wind power output, in time intervals relevant for creating schedules for production and exchange capacity, allows to system operators and dispatching personnel more efficient power system management. Despite the challenges and problems that arise due to integration of wind power into power systems, which need to be solved or reduced, wind power has its advantages that should be utilized. The effective integration of wind power plants into the transmission grid should allow them to represent the backbone of future energy systems. Modern wind generators represent production units that have the ability to participate in the management of energy systems e.g. in the regulation of frequency, voltage and other network operating requirements. This paper provides a brief overview of global experiences with the challenges, problems and possible solutions that appear in wind generator systems from the aspect of forecasting, planning and delivery of wind energy. (author)

Uncertainty in soil-structure interaction analysis arising from differences in analytical techniques

International Nuclear Information System (INIS)

Maslenikov, O.R.; Chen, J.C.; Johnson, J.J.

1982-07-01

This study addresses uncertainties arising from variations in different modeling approaches to soil-structure interaction of massive structures at a nuclear power plant. To perform a comprehensive systems analysis, it is necessary to quantify, for each phase of the traditional analysis procedure, both the realistic seismic response and the uncertainties associated with them. In this study two linear soil-structure interaction techniques were used to analyze the Zion, Illinois nuclear power plant: a direct method using the FLUSH computer program and a substructure approach using the CLASSI family of computer programs. In-structure response from two earthquakes, one real and one synthetic, was compared. Structure configurations from relatively simple to complicated multi-structure cases were analyzed. The resulting variations help quantify uncertainty in structure response due to analysis procedures

Solution of adsorption problems involving steep moving profiles

DEFF Research Database (Denmark)

Kiil, Søren; Bhatia, Suresh K.

1998-01-01

The moving finite element collocation method proposed by Kiil et al. (1995) for solution of problems with steep gradients is further developed to solve transient problems arising in the field of adsorption. The technique is applied to a model of adsorption in solids with bidisperse pore structures....... Numerical solutions were found to match the analytical solution when it exists (i.e. when the adsorption isotherm is linear). Results of this application study show that the method is simple yet sufficiently accurate for use in adsorption problems with steep moving gradients, where global collocation...

Parallel algorithms for network routing problems and recurrences

International Nuclear Information System (INIS)

Wisniewski, J.A.; Sameh, A.H.

1982-01-01

In this paper, we consider the parallel solution of recurrences, and linear systems in the regular algebra of Carre. These problems are equivalent to solving the shortest path problem in graph theory, and they also arise in the analysis of Fortran programs. Our methods for solving linear systems in the regular algebra are analogues of well-known methods for solving systems of linear algebraic equations. A parallel version of Dijkstra's method, which has no linear algebraic analogue, is presented. Considerations for choosing an algorithm when the problem is large and sparse are also discussed

Selection bias in population-based cancer case-control studies due to incomplete sampling frame coverage.

Science.gov (United States)

Walsh, Matthew C; Trentham-Dietz, Amy; Gangnon, Ronald E; Nieto, F Javier; Newcomb, Polly A; Palta, Mari

2012-06-01

Increasing numbers of individuals are choosing to opt out of population-based sampling frames due to privacy concerns. This is especially a problem in the selection of controls for case-control studies, as the cases often arise from relatively complete population-based registries, whereas control selection requires a sampling frame. If opt out is also related to risk factors, bias can arise. We linked breast cancer cases who reported having a valid driver's license from the 2004-2008 Wisconsin women's health study (N = 2,988) with a master list of licensed drivers from the Wisconsin Department of Transportation (WDOT). This master list excludes Wisconsin drivers that requested their information not be sold by the state. Multivariate-adjusted selection probability ratios (SPR) were calculated to estimate potential bias when using this driver's license sampling frame to select controls. A total of 962 cases (32%) had opted out of the WDOT sampling frame. Cases age <40 (SPR = 0.90), income either unreported (SPR = 0.89) or greater than $50,000 (SPR = 0.94), lower parity (SPR = 0.96 per one-child decrease), and hormone use (SPR = 0.93) were significantly less likely to be covered by the WDOT sampling frame (α = 0.05 level). Our results indicate the potential for selection bias due to differential opt out between various demographic and behavioral subgroups of controls. As selection bias may differ by exposure and study base, the assessment of potential bias needs to be ongoing. SPRs can be used to predict the direction of bias when cases and controls stem from different sampling frames in population-based case-control studies.

Nonlinear diffusion problem arising in plasma physics

International Nuclear Information System (INIS)

Berryman, J.G.; Holland, C.J.

1978-01-01

In earlier studies of plasma diffusion with Okuda-Dawson scaling (D approx. n/sup -1/2/), perturbation theory indicated that arbitrary initial data should evolve rapidly toward the separation solution of the relevant nonlinear diffusion equation. Now a Lyapunov functional has been found which is strictly decreasing in time and bounded below. The rigorous proof that arbitrary initial data evolve toeard the separable solution is summarized. Rigorous bounds on the decay time are also presented

Elasto-plastic torsion problem as an infinity Laplace's equation

Directory of Open Access Journals (Sweden)

Ahmed Addou

2006-12-01

Full Text Available In this paper, we study a perturbed infinity Laplace's equation, the perturbation corresponds to an Leray-Lions operator with no coercivity assumption. We consider the case where data are distributions or $L^{1}$ elements. We show that this problem has an unique solution which is the solution to the variational inequality arising in the elasto-plastic torsion problem, associated with an operator $A$.

A parameter identification problem arising from a two-dimensional airfoil section model

International Nuclear Information System (INIS)

Cerezo, G.M.

1994-01-01

The development of state space models for aeroelastic systems, including unsteady aerodynamics, is particularly important for the design of highly maneuverable aircraft. In this work we present a state space formulation for a special class of singular neutral functional differential equations (SNFDE) with initial data in C(-1, 0). This work is motivated by the two-dimensional airfoil model presented by Burns, Cliff and Herdman in. In the same authors discuss the validity of the assumptions under which the model was formulated. They pay special attention to the derivation of the evolution equation for the circulation on the airfoil. This equation was coupled to the rigid-body dynamics of the airfoil in order to obtain a complete set of functional differential equations that describes the composite system. The resulting mathematical model for the aeroelastic system has a weakly singular component. In this work we consider a finite delay approximation to the model presented in. We work with a scalar model in which we consider the weak singularity appearing in the original problem. The main goal of this work is to develop numerical techniques for the identification of the parameters appearing in the kernel of the associated scalar integral equation. Clearly this is the first step in the study of parameter identification for the original model and the corresponding validation of this model for the aeroelastic system

The CANDU-PHW generating system waste arisings

International Nuclear Information System (INIS)

Simmons, G.R.

1979-03-01

In this report, the volume of material and level of contained radioactive nuclides are tabulated for wastes arising from four fuel cycles which might be operated in CANDU-PHW (CANada Deuterium Uranium - Pressurized Heavy Water) reactors. The data presented, based on Canadian experience and/or studies, cover the range of conditioned waste volumes which could be expected from steady-state (no growth), CANDU-PHW-powered electrical generating systems. The wastes arising from operation and decommissioning of facilities in each phase of each fuel cycle are estimated. Each fuel cycle is considered to operate in isolation with the data given in terms of quantities per gigawatt-year of electricity produced. Three of the fuel cycles for which data are presented, the natural uranium once-through cycle, the plutonium-enriched uranium cycle (plutonium recycle) and the low-burnup uranium-enriched thorium cycle (thorium and uranium recycle), were studied by INFCE WG.7 (the International Nuclear Fuel Cycle Evaluation, Working Group 7) as fuel cycles 4, 5 and 6. The high-burnup uranium-enriched thorium cycle is included for comparison. INFCE WG.7 selected many common reference parameters which are applied uniformly to all seven INFCE WG.7 reference fuel cycles in determining waste arisings. Where these parameters differ from the data of Canadian origin given in the body of this report, the INFCE WG.7 data are given in an appendix. The waste management costs associated with operation of each INFCE WG.7 reference fuel cycle were calculated and compared by the working group. An arbitrary set of costing parameters and disposal technologies was selected by the working group for application to each of the reference fuel cycles. The waste management and disposal costs for the PHW reactor fuel cycles based on these arbitrary cost parameters are given in an appendix. (author)

Squamous cell carcinoma arising within a maxillary odontogenic keratocyst: A rare occurrence

International Nuclear Information System (INIS)

Jalali, Elnaz; Tadinada, Aditya; Rengasamy, Kandasamy; Ferneini, Elie M.

2017-01-01

Squamous cell carcinoma (SCC) arising within the lining of an odontogenic keratocyst (OKC) is a rare occurrence. Although potentially locally destructive, OKC is a benign odontogenic process that typically presents with clinical and radiographic features characteristic of a benign intraosseous neoplasm. We present the clinical and radiographic features of a maxillary mass that demonstrated SCC arising from the lining of an OKC. Although the initial clinical and radiographic presentation suggested an infection or malignant neoplasm, biopsies revealed an infiltrative well-differentiated SCC contiguous with and arising from the focus of a pre-existing OKC. The patient subsequently underwent a type II hemi-maxillectomy with neoadjuvant chemoradiation. This report discusses the clinical and radiographic features associated with intraosseous malignancies, especially those arising from an otherwise benign odontogenic lesion. While the majority of OKCs are benign, the current report illustrates the potential for carcinomatous transformation within the lining of an OKC

Squamous cell carcinoma arising within a maxillary odontogenic keratocyst: A rare occurrence

Energy Technology Data Exchange (ETDEWEB)

Jalali, Elnaz [Eliray Oral and Maxillofacial Radiology Consulting Services, Miami (United States); Tadinada, Aditya; Rengasamy, Kandasamy; Ferneini, Elie M. [University of Connecticut, School of Dental Medicine, Farmington (United States)

2017-06-15

Squamous cell carcinoma (SCC) arising within the lining of an odontogenic keratocyst (OKC) is a rare occurrence. Although potentially locally destructive, OKC is a benign odontogenic process that typically presents with clinical and radiographic features characteristic of a benign intraosseous neoplasm. We present the clinical and radiographic features of a maxillary mass that demonstrated SCC arising from the lining of an OKC. Although the initial clinical and radiographic presentation suggested an infection or malignant neoplasm, biopsies revealed an infiltrative well-differentiated SCC contiguous with and arising from the focus of a pre-existing OKC. The patient subsequently underwent a type II hemi-maxillectomy with neoadjuvant chemoradiation. This report discusses the clinical and radiographic features associated with intraosseous malignancies, especially those arising from an otherwise benign odontogenic lesion. While the majority of OKCs are benign, the current report illustrates the potential for carcinomatous transformation within the lining of an OKC.

Chemistry and the Internal Combustion Engine II: Pollution Problems.

Science.gov (United States)

Hunt, C. B.

1979-01-01

Discusses pollution problems which arise from the use of internal combustion (IC) engines in the United Kingdom (UK). The IC engine exhaust emissions, controlling IC engine pollution in the UK, and some future developments are also included. (HM)

Definition of the risk grounding fatalities due to unintentional airplane crashes by calculates

Directory of Open Access Journals (Sweden)

І.Л. Государська

2005-04-01

Full Text Available  Estimates of the expected number of grounding fatalities, are given which probably will arise due to accident of air carriers, air taxi and general aviation. Measures regulation of the risk is considered.

Density perturbations due to the inhomogeneous discrete spatial structure of space-time

International Nuclear Information System (INIS)

Wolf, C.

1998-01-01

For the case that space-time permits an inhomogeneous discrete spatial structure due to varying gravitational fields or a foam-like structure of space-time, it is demonstrated that thermodynamic reasoning implies that matter-density perturbations will arise in the early universe

Computing the full spectrum of large sparse palindromic quadratic eigenvalue problems arising from surface Green's function calculations

Science.gov (United States)

Huang, Tsung-Ming; Lin, Wen-Wei; Tian, Heng; Chen, Guan-Hua

2018-03-01

Full spectrum of a large sparse ⊤-palindromic quadratic eigenvalue problem (⊤-PQEP) is considered arguably for the first time in this article. Such a problem is posed by calculation of surface Green's functions (SGFs) of mesoscopic transistors with a tremendous non-periodic cross-section. For this problem, general purpose eigensolvers are not efficient, nor is advisable to resort to the decimation method etc. to obtain the Wiener-Hopf factorization. After reviewing some rigorous understanding of SGF calculation from the perspective of ⊤-PQEP and nonlinear matrix equation, we present our new approach to this problem. In a nutshell, the unit disk where the spectrum of interest lies is broken down adaptively into pieces small enough that they each can be locally tackled by the generalized ⊤-skew-Hamiltonian implicitly restarted shift-and-invert Arnoldi (G⊤SHIRA) algorithm with suitable shifts and other parameters, and the eigenvalues missed by this divide-and-conquer strategy can be recovered thanks to the accurate estimation provided by our newly developed scheme. Notably the novel non-equivalence deflation is proposed to avoid as much as possible duplication of nearby known eigenvalues when a new shift of G⊤SHIRA is determined. We demonstrate our new approach by calculating the SGF of a realistic nanowire whose unit cell is described by a matrix of size 4000 × 4000 at the density functional tight binding level, corresponding to a 8 × 8nm2 cross-section. We believe that quantum transport simulation of realistic nano-devices in the mesoscopic regime will greatly benefit from this work.

Single machine scheduling with slack due dates assignment

Science.gov (United States)

Liu, Weiguo; Hu, Xiangpei; Wang, Xuyin

2017-04-01

This paper considers a single machine scheduling problem in which each job is assigned an individual due date based on a common flow allowance (i.e. all jobs have slack due date). The goal is to find a sequence for jobs, together with a due date assignment, that minimizes a non-regular criterion comprising the total weighted absolute lateness value and common flow allowance cost, where the weight is a position-dependent weight. In order to solve this problem, an ? time algorithm is proposed. Some extensions of the problem are also shown.

Satellite communications: possibilities and problems

International Nuclear Information System (INIS)

Hine, M.

1986-01-01

Communication links via satellites are becoming available in Europe, both as part of the development of the telephone system and as special services aimed at data traffic. They offer the possibility of speeds between 50 kb/s and 2 Mb/s, without the problems and long term commitments of long distance land lines. Such links are provided by the PTT's as circuits which can be booked for variable periods, and have error rates which can be very low and well controlled. Problems in networking can arise from the satellite delay, particularly if errors occur in the local connections, and from the leased circuit and tariff philosophies of the PTT's. (Auth.)

Convergence of Cell Based Finite Volume Discretizations for Problems of Control in the Conduction Coefficients

DEFF Research Database (Denmark)

Evgrafov, Anton; Gregersen, Misha Marie; Sørensen, Mads Peter

2011-01-01

We present a convergence analysis of a cell-based finite volume (FV) discretization scheme applied to a problem of control in the coefficients of a generalized Laplace equation modelling, for example, a steady state heat conduction. Such problems arise in applications dealing with geometric optimal......, whereas the convergence of the coefficients happens only with respect to the "volumetric" Lebesgue measure. Additionally, depending on whether the stationarity conditions are stated for the discretized or the original continuous problem, two distinct concepts of stationarity at a discrete level arise. We...... provide characterizations of limit points, with respect to FV mesh size, of globally optimal solutions and two types of stationary points to the discretized problems. We illustrate the practical behaviour of our cell-based FV discretization algorithm on a numerical example....

An efficient heuristic for the multi-compartment vehicle routing problem

OpenAIRE

Paulo Vitor Silvestrin

2016-01-01

We study a variant of the vehicle routing problem that allows vehicles with multiple compartments. The need for multiple compartments frequently arises in practical applications when there are several products of different quality or type, that must be kept or handled separately. The resulting problem is called the multi-compartment vehicle routing problem (MCVRP). We propose a tabu search heuristic and embed it into an iterated local search to solve the MCVRP. In several experiments we analy...

Nuclear energy centers: Economic and environmental problems

International Nuclear Information System (INIS)

Dollezhal', N.A.; Bobolovich, V.N.; Emel'yanov, I.Ya.; Kochenov, A.S.; Koryakin, Yu.I.; Stolyarevskij, A.Ya.; Chernyaev, V.A.; Ponomarev-Stepnoj, N.N.; Protsenko, A.M.

1977-01-01

The report deals with qualitative and quantitative analysis of factors and problems, which may arise in the nearest future with the dispersion of sites of nuclear and fuel cycle plants. These problems arise with a large increase in the transportation of radioactive nuclear fuel, the necessity in valuable land and water resources, delay in construction and scheduled commercial operation of nuclear power plant, increase in the cost of labour and other economic and environmental factors and limitations. The report has an analysis of one of the ways of decreasing these difficulties, connected with the construction of large nuclear energy centres, consisting of a cluster of reactors on a single reactor site with the combined capacity of 40,000-50,000 MWe. The centres may consist, for example, of a cluster of conventional nuclear power plants that mainly consist of fast breeders and fuel cycle plants. They should be located in regions with a low density population and low value and deficiency of land and water resources. Electricity will be transmitted to consumers. The social-economic functions of such centres as factors that give birth to industrial regions are considered. Also given is the comparative estimate of benefits and problems of these two ways of further development of nuclear power system [ru

The Cauchy problem for the Pavlov equation

Science.gov (United States)

Grinevich, P. G.; Santini, P. M.; Wu, D.

2015-10-01

Commutation of multidimensional vector fields leads to integrable nonlinear dispersionless PDEs that arise in various problems of mathematical physics and have been intensively studied in recent literature. This report aims to solve the scattering and inverse scattering problem for integrable dispersionless PDEs, recently introduced just at a formal level, concentrating on the prototypical example of the Pavlov equation, and to justify an existence theorem for global bounded solutions of the associated Cauchy problem with small data. An essential part of this work was made during the visit of the three authors to the Centro Internacional de Ciencias in Cuernavaca, Mexico in November-December 2012.

Combined algorithms in nonlinear problems of magnetostatics

International Nuclear Information System (INIS)

Gregus, M.; Khoromskij, B.N.; Mazurkevich, G.E.; Zhidkov, E.P.

1988-01-01

To solve boundary problems of magnetostatics in unbounded two- and three-dimensional regions, we construct combined algorithms based on a combination of the method of boundary integral equations with the grid methods. We study the question of substantiation of the combined method of nonlinear magnetostatic problem without the preliminary discretization of equations and give some results on the convergence of iterative processes that arise in non-linear cases. We also discuss economical iterative processes and algorithms that solve boundary integral equations on certain surfaces. Finally, examples of numerical solutions of magnetostatic problems that arose when modelling the fields of electrophysical installations are given too. 14 refs.; 2 figs.; 1 tab

On Helmholtz Problem for Plane Periodical Structures

International Nuclear Information System (INIS)

Akishin, P.G.; Vinitskij, S.I.

1994-01-01

The plane Helmholtz problem of the periodical disc structures with the phase shifts conditions of the solutions along the basis lattice vectors and the Dirichlet conditions on the basic boundaries is considered. The Green function satisfying the quasi periodical conditions on the lattice is constructed. The Helmholtz problem is reduced to the boundary integral equations for the simple layer potentials of this Green function. The methods of the discretization of the arising integral equations are proposed. The procedures of calculation of the matrix elements are discussed. The reality of the spectral parameter of the nonlinear continuous and discretized problems is shown. 8 refs., 2 figs

Help-seeking for early childhood mental health problems

OpenAIRE

Oh, Elizabeth

2017-01-01

Children's mental health has significant implications for functioning across home, school, and community settings. The infant to preschool years has been found to be a crucial stage in a child’s development. As such, problems that arise during these years are likely to impact a child’s social and emotional development if no treatment is sought. Childhood mental health problems affect up to almost one quarter of children globally (Belfer, 2008; Canino, Bird, Rubio-Stipec, & Bravo, 1995; Egger ...

Malignancy arising within cutaneous tattoos: case of dermatofibrosarcoma protuberans and review of literature.

Science.gov (United States)

Reddy, Kavitha K; Hanke, C William; Tierney, Emily P

2011-08-01

Dermatofibrosarcoma protuberans (DFSP) is an uncommon tumor of the skin with high rates of local recurrence. Several reports describe a frequent history of local trauma. In one prior case, a DFSP arising in a tattoo site has been reported. Mohs micrographic surgery (MMS) has been used successfully for treatment. To present a case of dermatofibrosarcoma protuberans arising in the site of a prior and current tattoo, and treated with Mohs micrographic surgery. We present findings of a case of a DFSP arising in a tattoo and a review of Medline literature on the association between tattoos and cutaneous malignancy, and treatment of DFSP with MMS. Review of the literature confirms multiple reports of DFSP arising in sites of local trauma, as well as malignancies arising in sites of tattoos. The recurrence rate for MMS treatment of DFSP (0-6.6%) was found to be significantly lower than that for patients treated with wide local excision (13% to 95%). DFSP should be considered in the differential diagnosis of neoplasms arising within areas of tattoos. Sites of local trauma and tattoos may show predilection for benign and malignant changes and should be evaluated during regular skin exams. Review of the literature confirms MMS is an ideal treatment modality for DFSP as the tumor often extends far beyond clinical margins.

An Inventory-Routing Problem with Pickups and Deliveries Arising in the Replenishment of Automated Teller Machines

NARCIS (Netherlands)

van Anholt, Roel G.; Coelho, Leandro C.; Laporte, Gilbert; Vis, Iris F. A.

The purpose of this paper is to introduce, model, and solve a rich multiperiod inventory-routing problem with pickups and deliveries motivated by the replenishment of automated teller machines in the Netherlands. Commodities can be brought to and from the depot, as well as being exchanged among

An inventory-routing problem with pickups and deliveries arising in the replenishment of automated teller machines

NARCIS (Netherlands)

Van Anholt, Roel G.; Coelho, Leandro C.; Laporte, Gilbert; Vis, Iris F.A.

2016-01-01

The purpose of this paper is to introduce, model, and solve a rich multiperiod inventory-routing problem with pickups and deliveries motivated by the replenishment of automated teller machines in the Netherlands. Commodities can be brought to and from the depot, as well as being exchanged among

Psychosocial problems of children whose parents visit the emergency department due to intimate partner violence, substance abuse or a suicide attempt.

Science.gov (United States)

Hoytema van Konijnenburg, E M M; van der Lee, J H; Teeuw, A H; Lindeboom, R; Brilleslijper-Kater, S N; Sieswerda-Hoogendoorn, T; van Goudoever, J B; Lindauer, R J L

2017-05-01

High levels of maltreatment are found in children who are identified because their parents visit the emergency department due to partner violence, substance abuse or suicide attempt. However, it is unknown if these children experience psychosocial problems. This study aims to assess their levels of post-traumatic stress, anxiety, depression, behavioural problems and health-related quality of life. A cross-sectional study was conducted in six hospitals. All consecutive families of which a parent visited the emergency department due to partner violence, substance abuse or suicide attempt between 1 July 2012 and 1 March 2014 with children aged 1.5-17 years were approached for participation. Parents and children aged 8 years and older filled out questionnaires measuring post-traumatic stress [13-item version of Children's Revised Impact of Event Scale (CRIES-13)], anxiety, depression (Revised Child Anxiety and Depression Scale), behavioural problems [Child Behavior Checklist (CBCL) and Youth Self-Report (YSR)] and health-related quality of life (PedsQL). Scores of participants were compared with reference data obtained in children in similar age ranges from representative Dutch community samples (CRIES-13, Revised Child Anxiety and Depression Scale, PedsQL and CBCL) and to a normed cutoff score (CRIES-13). Of 195 eligible families, 89 (46%) participated in the study. Participating children did not score different from community children, both on child-reported and parent-reported instruments. Standardized mean differences of total sum scores were 0 (CRIES-13 and CBCL 1.5-5), 0.1 (YSR), 0.2 (CBCL 6-18) and -0.3 (PedsQL) and not statistically different from community children. Thirty-five percent of the participating children scored above the cutoff score on the CRIES-13, indicating post-traumatic stress disorder, but this difference was not statistically significant from community children (mean difference 8%; 95% CI -4-22%). We found no differences in psychosocial

Atomic policies: history, problems

International Nuclear Information System (INIS)

Galvan, Cesare Giuseppe.

1993-01-01

Two kinds of problems follow from the development of nuclear technology: its use in (diversion to) armaments, and its dangers for the population. Both arise as social phenomena: technology can be diverted to military aims; and installations require specific measures in order not to expose human life to danger. The diffusion of this technology required a series of tentative solutions for such problems. Its history constitutes our first part. The second part aims at understanding the dynamics, which led to the diffusion of such a technology in the capitalist world. The concept of subsumption (especially of its realization) is suited to interpret the meanings of the social interests, which led content ro this diffusion. Subsumption is found between labor and capital, but also between society and state. At both levels, it shows that there was some social meaning in the diffusion of nuclear technology notwithstanding its problems. 590 refs

Two cases of basal cell carcinoma arising from chronic radiation dermatitis

International Nuclear Information System (INIS)

Wakamori, Takeshi; Takenaka, Hideya; Ueda, Eiichiro; Katoh, Norito; Kishimoto, Saburo

2003-01-01

A 48-year-old female and a 51-year-old male with basal cell carcinoma (BCC) arising from chronic radiation dermatitis are reviewed. They are treated with radiotherapy for hemangioma on their right cheek in their childhood. Review in the literature showed high incidence of the histological diagnosis of malignant skin tumors arising from chronic radiation dermatitis are follows: squamous cell carcinoma (SCC), BCC, sarcoma, and Bowen's disease. (author)

To the development of numerical methods in problems of radiation transport

International Nuclear Information System (INIS)

Germogenova, T.A.

1990-01-01

Review of studies on the development of numerical methods and the discrete ordinate method in particular, used for solution of radiation protection physics problems is given. Consideration is given to the problems, which arise when calculating fields of penetrating radiation and when studying processes of charged-particle transport and cascade processes, generated by high-energy primary radiation

Assessment by human research ethics committees of potential conflicts of interest arising from pharmaceutical sponsorship of clinical research.

Science.gov (United States)

Newcombe, J P; Kerridge, I H

2007-01-01

Conflicts of interest arising from pharmaceutical industry sponsorship of clinical research have the potential to bias research outcomes and ultimately prejudice patient care. It is unknown how Australian Human Research Ethics Committees (HREC) assess and manage such conflicts of interest. We aimed to gain an understanding of how HREC approach the problem of potential conflicts of interest arising from pharmaceutical sponsorship of clinical research. We conducted a survey of HREC chairpersons in New South Wales. HREC vary widely in their approaches to conflicts of interest, including in their use of National Health and Medical Research Council guidelines, which were often misinterpreted or overlooked. Many committees rely primarily on researchers disclosing potential conflicts of interest, whereas a majority of HREC use disclosure to research participants as the primary tool for preventing and managing conflicts of interest. Almost no HREC place limitations on researcher relationships with pharmaceutical companies. These findings suggest reluctance on the part of HREC to regulate many potential conflicts of interest between researchers and pharmaceutical sponsors, which may arise from uncertainty regarding the meaning or significance of conflicts of interest in research, from ambiguity surrounding the role of HREC in assessing and managing conflicts of interest in research or from misinterpretation or ignorance of current National Health and Medical Research Council guidelines. Further review of policies and practices in this important area may prove beneficial in safeguarding clinical research and patient care while promoting continuing constructive engagement with the pharmaceutical industry.

Use of dispersion modelling for Environmental Impact Assessment of biological air pollution from composting: Progress, problems and prospects.

Science.gov (United States)

Douglas, P; Hayes, E T; Williams, W B; Tyrrel, S F; Kinnersley, R P; Walsh, K; O'Driscoll, M; Longhurst, P J; Pollard, S J T; Drew, G H

2017-12-01

With the increase in composting asa sustainable waste management option, biological air pollution (bioaerosols) from composting facilities have become a cause of increasing concern due to their potential health impacts. Estimating community exposure to bioaerosols is problematic due to limitations in current monitoring methods. Atmospheric dispersion modelling can be used to estimate exposure concentrations, however several issues arise from the lack of appropriate bioaerosol data to use as inputs into models, and the complexity of the emission sources at composting facilities. This paper analyses current progress in using dispersion models for bioaerosols, examines the remaining problems and provides recommendations for future prospects in this area. A key finding is the urgent need for guidance for model users to ensure consistent bioaerosol modelling practices. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Classical limit of the quantum inverse scattering problem

International Nuclear Information System (INIS)

Bogdanov, I.V.

1986-01-01

This paper studies the passage to the limit of classical mechanics which is realized in the formalism of Marchenko's method for a spherically symmetric inverse problem of quantum scattering for fixed angular momentum. The limit is considered for the general case of partial waves with arbitrary values of the orbital number 1>0 in the lowest order of perturbation theory. It is shown how in the limit h→0 in the quantum inverse problem the integral Able transformation characteristic of classical inverse problems arises. The classical inversion formula with delay time is derived from the Marchenko equation

Closed nuclear facilities in Estonia: developments and problems

International Nuclear Information System (INIS)

Realo, E.; Realo, K.

2000-01-01

At present Estonia has no operating nuclear or a radioactive material production facility. As a legacy of the past the country has become responsible for the decommissioning of two large nuclear cycle facilities of the former USSR. Besides limited funding, major problems arise from deficiencies in legislation, expertise, training and research. International co-operation has been of immense importance to overcome the problems, to establish the national radiation protection and radioactive waste management infrastructure and to launch decommissioning and remediation activities. An overview is given on the status and problems. Copyright (2000) Australasian Radiation Protection Society Inc

Injury done to vegetation by gases arising from certain manufacturing processes

Energy Technology Data Exchange (ETDEWEB)

Hamburger, S

1884-04-29

The question of damage done to vegetation by smoke and acid gases escaping from the chimneys of manufacturing establishments is comparatively of recent date, and complaints seem to have increased with the progress which industry has made in the last decades. Such complaints have principally been brought forward in districts where many manufactures were carried on, and the blame was always laid at the doors of chemical manufacturers, and especially the alkali makers, of whose works it was known that they gave rise to large quantities of acid gases. Lately this subject has been taken up by several unprejudiced investigators, and great credit is due to them for having shown that gases arising from other manufactures maybe equally noxious, and even more so. Much, however, still remains to be done in that direction. People somehow cling to their old belief, and every endeavor ought to be made to dispel that erroneous notion. That is the object of this paper.

A fast nonlinear conjugate gradient based method for 3D frictional contact problems

NARCIS (Netherlands)

Zhao, J.; Vollebregt, E.A.H.; Oosterlee, C.W.

2014-01-01

This paper presents a fast numerical solver for a nonlinear constrained optimization problem, arising from a 3D frictional contact problem. It incorporates an active set strategy with a nonlinear conjugate gradient method. One novelty is to consider the tractions of each slip element in a polar

Optimal recombination in genetic algorithms for combinatorial optimization problems: Part II

Directory of Open Access Journals (Sweden)

Eremeev Anton V.

2014-01-01

Full Text Available This paper surveys results on complexity of the optimal recombination problem (ORP, which consists in finding the best possible offspring as a result of a recombination operator in a genetic algorithm, given two parent solutions. In Part II, we consider the computational complexity of ORPs arising in genetic algorithms for problems on permutations: the Travelling Salesman Problem, the Shortest Hamilton Path Problem and the Makespan Minimization on Single Machine and some other related problems. The analysis indicates that the corresponding ORPs are NP-hard, but solvable by faster algorithms, compared to the problems they are derived from.

Problems in diagnosis and treatment of tuberculosis infection.

Science.gov (United States)

Tsara, V; Serasli, E; Christaki, P

2009-01-01

Tuberculosis is still a major health problem in industrialized countries due to specific socioeconomic factors and there is the growing need of new rapid and accurate diagnostic methods, in order to achieve higher sensitivity and specificity compared to traditional methods of microscopic sputum examination and culture. Such methods, recently introduced, are nucleic acid amplification (NAA) tests, used directly on clinical specimens and blood tests (QuantiFERON-TB, T-SPOT.TB test), measuring the IFN-gamma released by stimulated T cells. Furthermore, new drugs for the disease need to be developed, aiming to better treatment results and to prevention of Multiple Drug Resistance (MDR) cases. Critical aspects in the management of drug resistance cases should be the careful choices of drugs combination, the close follow up of the patients alongside with the patients adherence to therapy. The role of national and international tuberculosis programs is invaluable in TB control and therapy, as well as the collaboration of all the health system departments. However, most of the clinical problems that may arise are addressed by the International Standards for Tuberculosis Care-ISTC and these guidelines should be taken into consideration, at least until future research provides more promising diagnostic and therapeutic modalities for control of the disease.

A fast nonlinear conjugate gradient based method for 3D concentrated frictional contact problems

NARCIS (Netherlands)

J. Zhao (Jing); E.A.H. Vollebregt (Edwin); C.W. Oosterlee (Cornelis)

2015-01-01

htmlabstractThis paper presents a fast numerical solver for a nonlinear constrained optimization problem, arising from 3D concentrated frictional shift and rolling contact problems with dry Coulomb friction. The solver combines an active set strategy with a nonlinear conjugate gradient method. One

Applying Cooperative Techniques in Teaching Problem Solving

Directory of Open Access Journals (Sweden)

Krisztina Barczi

2013-12-01

Full Text Available Teaching how to solve problems – from solving simple equations to solving difficult competition tasks – has been one of the greatest challenges for mathematics education for many years. Trying to find an effective method is an important educational task. Among others, the question arises as to whether a method in which students help each other might be useful. The present article describes part of an experiment that was designed to determine the effects of cooperative teaching techniques on the development of problem-solving skills.

Advanced Research Workshop on Nonlinear Hyperbolic Problems

CERN Document Server

Serre, Denis; Raviart, Pierre-Arnaud

1987-01-01

The field of nonlinear hyperbolic problems has been expanding very fast over the past few years, and has applications - actual and potential - in aerodynamics, multifluid flows, combustion, detonics amongst other. The difficulties that arise in application are of theoretical as well as numerical nature. In fact, the papers in this volume of proceedings deal to a greater extent with theoretical problems emerging in the resolution of nonlinear hyperbolic systems than with numerical methods. The volume provides an excellent up-to-date review of the current research trends in this area.

Reflections on the surface energy imbalance problem

Science.gov (United States)

Ray Leuning; Eva van Gorsela; William J. Massman; Peter R. Isaac

2012-01-01

The 'energy imbalance problem' in micrometeorology arises because at most flux measurement sites the sum of eddy fluxes of sensible and latent heat (H + λE) is less than the available energy (A). Either eddy fluxes are underestimated or A is overestimated. Reasons for the imbalance are: (1) a failure to satisfy the fundamental assumption of one-...

A natural solution to the μ-problem in supergravity theories

International Nuclear Information System (INIS)

Giudice, G.F.; Masiero, A.

1988-01-01

We propose a 'natural' way to avoid the introduction by hand of a small mass scale μ in the observable sector of N=1 supergravity theories. In our approach, μ automatically arises from the general couplings of broken supergravity. In this way, all low energy mass parameters arise only from supergravity breaking and, in particular, SU(2)xU(1) is left unbroken in the limit of exact supersymmetry. Our solution of the μ-problem presents interesting connections with the strong CP puzzle through the implementation of symmetries a la Peccei and Quinn. (orig.)

Solving Large Scale Crew Scheduling Problems in Practice

NARCIS (Netherlands)

E.J.W. Abbink (Erwin); L. Albino; T.A.B. Dollevoet (Twan); D. Huisman (Dennis); J. Roussado; R.L. Saldanha

2010-01-01

textabstractThis paper deals with large-scale crew scheduling problems arising at the Dutch railway operator, Netherlands Railways (NS). NS operates about 30,000 trains a week. All these trains need a driver and a certain number of guards. Some labor rules restrict the duties of a certain crew base

Problems in quantum cosmology

International Nuclear Information System (INIS)

Amsterdamski, P.

1986-01-01

The standard cosmological model is reviewed and shown not to be self-sufficient in that it requires initial conditions most likely to be supplied by quantum cosmology. The possible approaches to the issue of initial conditions for cosmology are then discussed. In this thesis, the author considers three separate problems related to this issue. First, the possibility of inflation is investigated in detail by analyzing the evolution of metric perturbations and fluctuations in the expectation value of a scalar field prior to a phase transition; finite temperature effects are also included. Since the inhomogeneities were damped well before the onset of a phase transition. It is concluded that an inflation was possible. Next, the effective action of neutrino and photon fields is calculated for homogeneous spacetimes with small anisotropy; it is shown that quantum corrections to the action due to these fields influence the evolution of an early Universe in the Same way as do the analogous correction terms arising from a conformally invariant scalar which has been previously studied. Finally, the question of an early anisotropy is also discussed in a framework of Hartle-Hawking wave function of the Universe. A wave function of a Bianchi IX type Universe is calculated in a semiclassical approximation

About some types of constraints in problems of routing

Science.gov (United States)

Petunin, A. A.; Polishuk, E. G.; Chentsov, A. G.; Chentsov, P. A.; Ukolov, S. S.

2016-12-01

Many routing problems arising in different applications can be interpreted as a discrete optimization problem with additional constraints. The latter include generalized travelling salesman problem (GTSP), to which task of tool routing for CNC thermal cutting machines is sometimes reduced. Technological requirements bound to thermal fields distribution during cutting process are of great importance when developing algorithms for this task solution. These requirements give rise to some specific constraints for GTSP. This paper provides a mathematical formulation for the problem of thermal fields calculating during metal sheet thermal cutting. Corresponding algorithm with its programmatic implementation is considered. The mathematical model allowing taking such constraints into account considering other routing problems is discussed either.

Clinical outcomes of patients with clear cell and endometrioid ovarian cancer arising from endometriosis.

Science.gov (United States)

Paik, E Sun; Kim, Tae Joong; Choi, Chel Hun; Kim, Byoung Gie; Bae, Duk Soo; Lee, Jeong Won

2018-03-01

The aim of this investigation is to compare outcomes of patients according to the presence of cancer arising from endometriosis in ovarian clear cell carcinoma (CCC) and endometrioid carcinoma (EC). This study retrospectively investigated 224 CCC and EC patients treated in Samsung Medical Center from 2001 to 2015 to identify cancer arising from endometriosis according to Sampson and Scott criteria. Propensity score matching was performed to compare patients arising from endometriosis to patients without endometriosis (ratio 1:1) according to stage, age, lymph node metastasis (LNM), cancer antigen (CA)-125 level, and residual status after debulking surgery. Forty-five cases arising from endometriosis were compared with 179 cases without endometriosis. CCC and EC arising from endometriosis tended to present with early age (mean, 45.2 vs. 49.2 years; p=0.003), early-stage (stages I and II, 92.7% vs. 62.3%; p<0.001), lower CA-125 level (mean, 307.1 vs. 556.7; p=0.041), higher percentages of no gross residual disease after surgery (87.8% vs.56.8%; p=0.001), and higher percentages of negative LNM (82.9% vs. 59.0%; p=0.008) compared to cases without endometriosis. Kaplan-Meier curves for progression-free survival (PFS) and overall survival (OS) showed better outcomes for groups with cancer arising from endometriosis (p=0.014 for PFS; and p=0.010 for OS). However, the association with endometriosis was not significant in multivariate analysis. Also, after propensity score matching, survival differences between the 2 groups were not significant. CCC and EC arising from endometriosis are diagnosed at an earlier age and stage. However, cancer arising from endometriosis was not a significant prognostic factor. Copyright © 2018. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology

The Australasian Resuscitation in Sepsis Evaluation (ARISE) trial statistical analysis plan.

Science.gov (United States)

Delaney, Anthony P; Peake, Sandra L; Bellomo, Rinaldo; Cameron, Peter; Holdgate, Anna; Howe, Belinda; Higgins, Alisa; Presneill, Jeffrey; Webb, Steve

2013-09-01

The Australasian Resuscitation in Sepsis Evaluation (ARISE) study is an international, multicentre, randomised, controlled trial designed to evaluate the effectiveness of early goal-directed therapy compared with standard care for patients presenting to the emergency department with severe sepsis. In keeping with current practice, and considering aspects of trial design and reporting specific to non-pharmacological interventions, our plan outlines the principles and methods for analysing and reporting the trial results. The document is prepared before completion of recruitment into the ARISE study, without knowledge of the results of the interim analysis conducted by the data safety and monitoring committee and before completion of the two related international studies. Our statistical analysis plan was designed by the ARISE chief investigators, and reviewed and approved by the ARISE steering committee. We reviewed the data collected by the research team as specified in the study protocol and detailed in the study case report form. We describe information related to baseline characteristics, characteristics of delivery of the trial interventions, details of resuscitation, other related therapies and other relevant data with appropriate comparisons between groups. We define the primary, secondary and tertiary outcomes for the study, with description of the planned statistical analyses. We have developed a statistical analysis plan with a trial profile, mock-up tables and figures. We describe a plan for presenting baseline characteristics, microbiological and antibiotic therapy, details of the interventions, processes of care and concomitant therapies and adverse events. We describe the primary, secondary and tertiary outcomes with identification of subgroups to be analysed. We have developed a statistical analysis plan for the ARISE study, available in the public domain, before the completion of recruitment into the study. This will minimise analytical bias and

Lower Limb Injuries Arising From Motorcycle Crashes | Kortor ...

African Journals Online (AJOL)

Background: Motorcycle accidents are the second most common cause of road traffic accidents in both developing and developed countries. In this study we aim to look at the pattern and characteristics of lower limb injuries arising from motorcycle accidents and evaluate early outcome of treatment. Methods: All the patients ...

On time-dependent diffusion coefficients arising from stochastic processes with memory

Science.gov (United States)

Carpio-Bernido, M. Victoria; Barredo, Wilson I.; Bernido, Christopher C.

2017-08-01

Time-dependent diffusion coefficients arise from anomalous diffusion encountered in many physical systems such as protein transport in cells. We compare these coefficients with those arising from analysis of stochastic processes with memory that go beyond fractional Brownian motion. Facilitated by the Hida white noise functional integral approach, diffusion propagators or probability density functions (pdf) are obtained and shown to be solutions of modified diffusion equations with time-dependent diffusion coefficients. This should be useful in the study of complex transport processes.

Counting in Lattices: Combinatorial Problems from Statistical Mechanics.

Science.gov (United States)

Randall, Dana Jill

In this thesis we consider two classical combinatorial problems arising in statistical mechanics: counting matchings and self-avoiding walks in lattice graphs. The first problem arises in the study of the thermodynamical properties of monomers and dimers (diatomic molecules) in crystals. Fisher, Kasteleyn and Temperley discovered an elegant technique to exactly count the number of perfect matchings in two dimensional lattices, but it is not applicable for matchings of arbitrary size, or in higher dimensional lattices. We present the first efficient approximation algorithm for computing the number of matchings of any size in any periodic lattice in arbitrary dimension. The algorithm is based on Monte Carlo simulation of a suitable Markov chain and has rigorously derived performance guarantees that do not rely on any assumptions. In addition, we show that these results generalize to counting matchings in any graph which is the Cayley graph of a finite group. The second problem is counting self-avoiding walks in lattices. This problem arises in the study of the thermodynamics of long polymer chains in dilute solution. While there are a number of Monte Carlo algorithms used to count self -avoiding walks in practice, these are heuristic and their correctness relies on unproven conjectures. In contrast, we present an efficient algorithm which relies on a single, widely-believed conjecture that is simpler than preceding assumptions and, more importantly, is one which the algorithm itself can test. Thus our algorithm is reliable, in the sense that it either outputs answers that are guaranteed, with high probability, to be correct, or finds a counterexample to the conjecture. In either case we know we can trust our results and the algorithm is guaranteed to run in polynomial time. This is the first algorithm for counting self-avoiding walks in which the error bounds are rigorously controlled. This work was supported in part by an AT&T graduate fellowship, a University of

Squamous cell carcinoma arising in previously burned or irradiated skin

International Nuclear Information System (INIS)

Edwards, M.J.; Hirsch, R.M.; Broadwater, J.R.; Netscher, D.T.; Ames, F.C.

1989-01-01

Squamous cell carcinoma (SCC) arising in previously burned or irradiated skin was reviewed in 66 patients treated between 1944 and 1986. Healing of the initial injury was complicated in 70% of patients. Mean interval from initial injury to diagnosis of SCC was 37 years. The overwhelming majority of patients presented with a chronic intractable ulcer in previously injured skin. The regional relapse rate after surgical excision was very high, 58% of all patients. Predominant patterns of recurrence were in local skin and regional lymph nodes (93% of recurrences). Survival rates at 5, 10, and 20 years were 52%, 34%, and 23%, respectively. Five-year survival rates in previously burned and irradiated patients were not significantly different (53% and 50%, respectively). This review, one of the largest reported series, better defines SCC arising in previously burned or irradiated skin as a locally aggressive disease that is distinct from SCC arising in sunlight-damaged skin. An increased awareness of the significance of chronic ulceration in scar tissue may allow earlier diagnosis. Regional disease control and survival depend on surgical resection of all known disease and may require radical lymph node dissection or amputation

A problem of finding an acceptable variant in generalized project networks

Directory of Open Access Journals (Sweden)

David Blokh

2005-01-01

Full Text Available A project network often has some activities or groups of activities which can be performed at different stages of the project. Then, the problem of finding an optimal/acceptable time or/and optimal/acceptable order of such an activity or a group of activities arises. Such a problem emerges, in particular, in house-building management when the beginnings of some activities may vary in time or/and order. We consider a mathematical formulation of the problem, show its computational complexity, and describe an algorithm for solving the problem.

The single-sink fixed-charge transportation problem: Applications and solution methods

DEFF Research Database (Denmark)

Goertz, Simon; Klose, Andreas

2007-01-01

The single-sink fixed-charge transportation problem (SSFCTP) consists in finding a minimum cost flow from a number of supplier nodes to a single demand node. Shipping costs comprise costs proportional to the amount shipped as well as a fixed-charge. Although the SSFCTP is an important special case...... of the well-known fixed-charge transportation problem, just a few methods for solving this problem have been proposed in the literature. After summarising some applications of this problem arising in manufacturing and transportation, we give an overview on approximation algorithms and worst-case results...

Trade Credit Insurance and Asymmetric Information Problem

Directory of Open Access Journals (Sweden)

Sokolovska Olena

2017-03-01

Full Text Available The presence of different risk factors in international trade gives evidence of the necessity of support in gaps that may affect exporters’ activity. To maximize the trade volumes and in the same time to minimize the exporters’ risks the stakeholders use trade credit insurance. The paper provides analysis of conceptual background of the trade credit insurance in the world. We analyzed briefly the problems, arising in insurance markets due to asymmetric information, such as adverse selection and moral hazard. Also we discuss the main stages of development of trade credit insurance in countries worldwide. Using comparative and graphical analysis we provide a brief evaluation of the dynamics of claims and recoveries for different forms of trade credit insurance. We found that the claims related to the commercial risk for medium and long trade credits in recent years exceed the recoveries, while with the political risk the reverse trend holds. And we originally consider these findings in terms of information asymmetry in the trade credit insurance differentiated by type of risk.

Bayesian inverse problems for functions and applications to fluid mechanics

International Nuclear Information System (INIS)

Cotter, S L; Dashti, M; Robinson, J C; Stuart, A M

2009-01-01

In this paper we establish a mathematical framework for a range of inverse problems for functions, given a finite set of noisy observations. The problems are hence underdetermined and are often ill-posed. We study these problems from the viewpoint of Bayesian statistics, with the resulting posterior probability measure being defined on a space of functions. We develop an abstract framework for such problems which facilitates application of an infinite-dimensional version of Bayes theorem, leads to a well-posedness result for the posterior measure (continuity in a suitable probability metric with respect to changes in data), and also leads to a theory for the existence of maximizing the posterior probability (MAP) estimators for such Bayesian inverse problems on function space. A central idea underlying these results is that continuity properties and bounds on the forward model guide the choice of the prior measure for the inverse problem, leading to the desired results on well-posedness and MAP estimators; the PDE analysis and probability theory required are thus clearly dileneated, allowing a straightforward derivation of results. We show that the abstract theory applies to some concrete applications of interest by studying problems arising from data assimilation in fluid mechanics. The objective is to make inference about the underlying velocity field, on the basis of either Eulerian or Lagrangian observations. We study problems without model error, in which case the inference is on the initial condition, and problems with model error in which case the inference is on the initial condition and on the driving noise process or, equivalently, on the entire time-dependent velocity field. In order to undertake a relatively uncluttered mathematical analysis we consider the two-dimensional Navier–Stokes equation on a torus. The case of Eulerian observations—direct observations of the velocity field itself—is then a model for weather forecasting. The case of

Solitary osteochondroma arising in lumbar spinous process: Case report

Directory of Open Access Journals (Sweden)

Khaled Hadhri

2016-12-01

Full Text Available Solitary osteochondromas rarely occur in the axial skeleton. Those tumors mostly arise on the posterior elements of the cervical column causing various symptoms especially when developing within the spinal canal. Exophytic lumbar variety is uncommon presenting with palpable mass or spinal deformity. We report a 20-year-old man presenting with a solid painless mass at the lower lumbar region. Radiological examinations revealed an exophytic lesion arising in the third lumbar spinous process appearing to be a solitary osteochondroma. The lesion was treated by en-bloc resection; histopathological examination confirmed the diagnosis of osteochondroma with no evidence of recurrence at the end of 2-year follow up.

Optimization methods for the Train Unit Shunting Problem

DEFF Research Database (Denmark)

Haahr, Jørgen Thorlund; Lusby, Richard Martin; Wagenaar, Joris Camiel

2017-01-01

We consider the Train Unit Shunting Problem, an important planning problem for passenger railway operators. This problem entails assigning train units from shunting yards to scheduled train services in such a way that the resulting operations are without conflicts. The problem arises at every...... shunting yard in the railway network and involves matching train units to arriving and departing train services as well as assigning the selected matchings to appropriate shunting yard tracks. We present an extensive comparison benchmark of multiple solution approaches for this problem, some of which...... are novel. In particular, we develop a constraint programming formulation, a column generation approach, and a randomized greedy heuristic. We compare and benchmark these approaches with two existing methods, a mixed integer linear program and a two-stage heuristic. The benchmark contains multiple real...

An efficient iterative method for the generalized Stokes problem

Energy Technology Data Exchange (ETDEWEB)

Sameh, A. [Univ. of Minnesota, Twin Cities, MN (United States); Sarin, V. [Univ. of Illinois, Urbana, IL (United States)

1996-12-31

This paper presents an efficient iterative scheme for the generalized Stokes problem, which arises frequently in the simulation of time-dependent Navier-Stokes equations for incompressible fluid flow. The general form of the linear system is where A = {alpha}M + vT is an n x n symmetric positive definite matrix, in which M is the mass matrix, T is the discrete Laplace operator, {alpha} and {nu} are positive constants proportional to the inverses of the time-step {Delta}t and the Reynolds number Re respectively, and B is the discrete gradient operator of size n x k (k < n). Even though the matrix A is symmetric and positive definite, the system is indefinite due to the incompressibility constraint (B{sup T}u = 0). This causes difficulties both for iterative methods and commonly used preconditioners. Moreover, depending on the ratio {alpha}/{nu}, A behaves like the mass matrix M at one extreme and the Laplace operator T at the other, thus complicating the issue of preconditioning.

Post-transplant Lymphoproliferative Disorder Arising from Renal Allograft Parenchyma: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Park, Byung Kwan; Kim, Chan Kyo; Kwon, Ghee Young [Samsung Medical Center, Sungkyunkwan University College of Medicine, Seoul (Korea, Republic of)

2010-06-15

Post-transplant lymphoproliferative disorder (PTLD) is a rare but serious complication that occurs in patients undergoing kidney transplantation. PTLD usually manifests as a renal hilar mass comprised of histologically B-lymphocytes. We report our experience of managing a patient with PTLD arising from renal parenchyma. Ultrasonographic and MR imaging features of this unusual PTLD suggested differentiated renal cell carcinoma arising from the renal allograft

What is physics problem solving competency?

DEFF Research Database (Denmark)

Niss, Martin

2018-01-01

on the nature of physics problem- solving competency. The first, Sommerfeld’s, is a “theory first, phenomenon second” approach. Here the relevant problems originate in one of the theories of physics and the job goal of the problem- solver is to make a mathematical analysis of the suitable equation......A central goal of physics education is to teach problem-solving competency, but the nature of this competency is not well-described in the literature. The present paperarticle uses recent historical scholarship on Arnold Sommerfeld and Enrico Fermi to identify and characterize two positions......(s) and then give a qualitative analysis of the phenomenon that arise from these mathematical results. Fermi’s position is a “phenomenon first, theory second” approach, where the starting point is a physical phenomenon that is analyzed and then brought into the realm of a physics theory. The two positions...

Closed solutions to a differential-difference equation and an associated plate solidification problem.

Science.gov (United States)

Layeni, Olawanle P; Akinola, Adegbola P; Johnson, Jesse V

2016-01-01

Two distinct and novel formalisms for deriving exact closed solutions of a class of variable-coefficient differential-difference equations arising from a plate solidification problem are introduced. Thereupon, exact closed traveling wave and similarity solutions to the plate solidification problem are obtained for some special cases of time-varying plate surface temperature.

Security risks arising from portable storage devices

CSIR Research Space (South Africa)

Molotsi, K

2012-10-01

Full Text Available of the security risks arising from the use of PSDs, and further provides possible security countermeasures to help organisations and users to protect their digital assets. APPROACH Literature review: ? To investigate security risks posed by PSDs... technology in the workplace. International Journal of Electronic Security and Digital Forensics. 3(1): 73?81 [3] Kim, K., Kim, E. & Hong S. (2009). Privacy information protection in portable device. Proceedings of International Conference on Convergence...

The indeterminate rate problem for birth-death processes

NARCIS (Netherlands)

van Doorn, Erik A.

1987-01-01

A birth-death process is completely determined by its set of rates if and only if this set satisfies a certain condition C, say. If for a set of rates R the condition C is not fulfilled, then the problem arises of characterizing all birth-death processes which have rate set R (the indeterminate rate

Philosophy of river problems: local to regional, static to mobile

International Nuclear Information System (INIS)

Jansky, L.

1997-01-01

According to the statistics, thirteen of the twenty-five major river basins in Europe are basins of transboundary rivers. The Danube river basin is largest transboundary river basin in Europe. Almost in each case the local and regional problems arise, like division of fishing rights (or rights on river beds), right to claim tolls on navigation, how to adjust boundaries if the channel moves, or rights to claim duty on crossing the river, or to build bridges, weirs, etc. All the above problems on a larger scale include also rights of non-contiguous lands (i.e. not fronting on the river) to use the river for navigation, for passage of migrating fish, to exploit river (e.g. bed sediments) without damage by one country or society to another below. Similarly, pollution and large-scale removal of water, are problems on regional or national levels. Disputes usually arise from the above, more or less exacerbated by their superimposition or other non-river problems, e.g. religion, politics, historical issues, recent aggression, relative prosperity, expanding economy vs. contrasting economy. May be cause or consequence of many of these. And somewhere here is likely the case of Gabcikovo on Danube between Slovakia and Hungary, as well. (author)

Adaptive neck support for wellbeing adaptive neck support for wellbeing

NARCIS (Netherlands)

Tan, C.F.; Chen, W.; Rauterberg, G.W.M.; Augusto, J.C.; Huch, M.; Kameas, A.; Maitland, J.; McCullagh, P.; Roberts, J.; Sixsmith, A.; Wichert, R.

2012-01-01

Air travel is becoming increasingly more accessible to people both through the availability of low cost flights. Health problems may arise due to anxiety and unfamiliarity with airport departure procedures prior to flying, whilst during the air travel, problems may arise as a result of the food

Mathematical problems in meteorological modelling

CERN Document Server

Csomós, Petra; Faragó, István; Horányi, András; Szépszó, Gabriella

2016-01-01

This book deals with mathematical problems arising in the context of meteorological modelling. It gathers and presents some of the most interesting and important issues from the interaction of mathematics and meteorology. It is unique in that it features contributions on topics like data assimilation, ensemble prediction, numerical methods, and transport modelling, from both mathematical and meteorological perspectives. The derivation and solution of all kinds of numerical prediction models require the application of results from various mathematical fields. The present volume is divided into three parts, moving from mathematical and numerical problems through air quality modelling, to advanced applications in data assimilation and probabilistic forecasting. The book arose from the workshop “Mathematical Problems in Meteorological Modelling” held in Budapest in May 2014 and organized by the ECMI Special Interest Group on Numerical Weather Prediction. Its main objective is to highlight the beauty of the de...

Effects arising from charged particles overcoming of the light velocity barrier

International Nuclear Information System (INIS)

Afanas'ev, G.N.; Eliseev, S.M.; Stepanovskij, Yu.P.

1997-01-01

The effects arising from accelerated and decelerated motion of the charged point particle inside the medium are studied. It is shown explicitly that in addition to the Bremsstrahlung and Cherenkov shock wave, the electromagnetic shock wave arising from the charge overcoming the light velocity in the medium should be observed. This shock wave has the same singularity as the Cherenkov one and, therefore, it is more singular than the Bremsstrahlung shock wave. The space-time regions where these shock waves exist and conditions under which they appear are determined

Adenocarcinomas arising from primary retroperitoneal mature teratomas: CT and MR imaging

International Nuclear Information System (INIS)

Wang, Li-Jen; Wong, Yon-Cheong; Chu, Sheng-Hsien; Ng, Kwai-Fong

2002-01-01

An adenocarcinoma arising from mature teratoma is one form of teratoma with malignant transformation. It is extremely rare but highly malignant. The authors report two patients with adenocarcinomas arising from primary retroperitoneal teratomas. The CT and MRI findings of the tumors are presented with emphasis on imaging features implying the presence of malignant transformation and differing from those of pure benign mature teratoma. Correct diagnosis of the presence of malignant transformation from a benign mature teratoma can be made as early as possible by awareness of the imaging features. (orig.)

Ecknomic benefits arising from the Canadian nuclear industry

International Nuclear Information System (INIS)

1982-03-01

This document is a collection of surveys of the Canadian nuclear industry, with forecasts covering a number of possible scenarios. Topics covered include uranium mining and processing; economic benefits arising from the design, manufacture and construction of CANDU generating stations; employment and economic activity in the Canadian nqclear industry; and an overview of the remainder of the industry

Similarities of discrete and continuous Sturm-Liouville problems

Directory of Open Access Journals (Sweden)

Kazem Ghanbari

2007-12-01

Full Text Available In this paper we present a study on the analogous properties of discrete and continuous Sturm-Liouville problems arising in matrix analysis and differential equations, respectively. Green's functions in both cases have analogous expressions in terms of the spectral data. Most of the results associated to inverse problems in both cases are identical. In particular, in both cases Weyl's m-function determines the Sturm-Liouville operators uniquely. Moreover, the well known Rayleigh-Ritz Theorem in linear algebra can be proved by using the concept of Green's function in discrete case.

Joint Optimization of Star P-hub Median Problem and Seat Inventory Control Decisions Considering a Hybrid Routing Transportation System

Directory of Open Access Journals (Sweden)

Hamid Tikani

2016-11-01

Full Text Available In this paper, we study the problem of integrated capacitated hub location problem and seat inventory control considering concept and techniques of revenue management. We consider an airline company maximizes its revenue by utilizing the best network topology and providing proper booking limits for all itineraries and fare classes. The transportation system arises in the form of a star/star network and includes both hub-stop and non-stop flights. This problem is formulated as a two-stage stochastic integer program with mixed-integer recourse. We solve various instances carried out from the Turkish network data set. Due to the NP-hardness of the problem, we propose a hybrid optimization method, consisting of an evolutionary algorithm based on genetic algorithm and exact solution. The quality of the solutions found by the proposed meta-heuristic is compared with the original version of GA and the mathematical programming model. The results obtained by the proposed model imply that integrating hub location and seat inventory control problem would help to increase the total revenue of airline companies. Also, in the case of serving non-stop flights, the model can provide more profit by employing less number of hubs.

Mucinous adenocarcinoma arising at the anastomotic site after operation for hirschsprung's disease: case report

International Nuclear Information System (INIS)

Kim, Hyung Soo; Yoon, Kwon Ha

2004-01-01

To our knowledge, rectal cancer arising at the anastomotic site after surgery for Hirschsprung's disease has not been reported. We report a case of mucinous adenocarcinoma arising at the anastomotic site after Soave operation 26 years ago

Some open problems in the physics of disordered systems

Indian Academy of Sciences (India)

Some problems in the physics of disordered systems are pointed out; most of these arise from experiments. Keywords. Disordered systems; electron localization; metal insulator transitions. PACS Nos 71.55. .... overlapping the free electron Fermi sphere, the Fermi surface is cut up into a large number of small electron and ...

An update on the big bang nucleosynthesis prediction for 7Li: the problem worsens

International Nuclear Information System (INIS)

Cyburt, Richard H; Fields, Brian D; Olive, Keith A

2008-01-01

The lithium problem arises from the significant discrepancy between the primordial 7 Li abundance as predicted by big bang nucleosynthesis (BBN) theory and the Wilkinson Microwave Anisotropy Probe (WMAP) baryon density, and the pre-Galactic lithium abundance inferred from observations of metal-poor (Population II) stars. This problem has loomed for the past decade, with a persistent discrepancy of a factor of 2–3 in 7 Li/H. Recent developments have sharpened all aspects of the Li problem. Namely: (1) BBN theory predictions have sharpened due to new nuclear data; in particular, the uncertainty on the reaction rate for 3 He(α,γ) 7 Be has reduced to 7.4%, nearly a factor of 2 tighter than previous determinations. (2) The WMAP five-year data set now yields a cosmic baryon density with an uncertainty reduced to 2.7%. (3) Observations of metal-poor stars have tested for systematic effects. With these, we now find that the BBN+WMAP predicts 7 Li/H = (5.24 −0.67 +0.71 ) × 10 −10 . The central value represents an increase by 23%, most of which is due to the upward shift in the 3 He(α,γ) 7 Be rate. More significant is the reduction in the 7 Li/H uncertainty by almost a factor of 2, tracking the reduction in the 3 He(α,γ) 7 Be error bar. These changes exacerbate the Li problem; the discrepancy is now a factor 2.4 or 4.2σ (from globular cluster stars) to 4.3 or 5.3σ (from halo field stars). Possible resolutions to the lithium problem are briefly reviewed, and key experimental and astronomical measurements highlighted

Infinite-horizon optimal control problems in economics

International Nuclear Information System (INIS)

Aseev, Sergei M; Besov, Konstantin O; Kryazhimskii, Arkadii V

2012-01-01

This paper extends optimal control theory to a class of infinite-horizon problems that arise in studying models of optimal dynamic allocation of economic resources. In a typical problem of this sort the initial state is fixed, no constraints are imposed on the behaviour of the admissible trajectories at large times, and the objective functional is given by a discounted improper integral. We develop the method of finite-horizon approximations in a broad context and use it to derive complete versions of the Pontryagin maximum principle for such problems. We provide sufficient conditions for the normality of infinite-horizon optimal control problems and for the validity of the 'standard' limit transversality conditions with time going to infinity. As a meaningful example, we consider a new two-sector model of optimal economic growth subject to a random jump in prices. Bibliography: 53 titles.

Radiologic findings of malignant tumors arising from ovarian endometriosis

International Nuclear Information System (INIS)

Lee, Eun Ju; Joo, Hee Jae; Kim, Bo Hyun

1999-01-01

To determine the radiologic characteristics of malignant tumors arising from ovarian endometriosis. The radiologic findings of eleven patients with pelvic masses histologically confirmed as malignant ovarian tumors arising from endometriosis were retrospectively reviewed. All patients underwent MR, and six underwent ultrasonography. The findings were evaluated with regard to tumor size and shape, locularity, thickness and enhancement of the wall and septa, the presence of papillary nodule or solid portion, signal intensity of the locule, the presence of mass in contralateral ovary, ascites, local invasion, distant metastases, and the Pathologic diagnosis included clear cell carcinoma in six cases, endometrioid carcinoma in three, and mucinous cystadenocarcinoma of borderline malignancy and endometrial stromal sarcoma in one case each. Tumor size ranged from 8 to 20 (mean, 12.7)cm. The tumors were mixed in four cases, entirely cystic in three, predominantly cystic in three, and predominantly solid in one. Six cases were unilocular and five were multilocular. The wall and septa varied in thickness and regularity and were well enhanced in all but one case. In all cases papillary nodules or solid portions with similar enhancement to uterine myometrium were seen. On T1WI, the signal intensity of fluid was seen to be high in eight cases, low or intermediate in two, and of differing intensity in one. Ten cases showed high signal intensity on T2WI, whereas in one case in which high signal intensity was seen on T1WI, there was low signal intensity(shading). In three cases the contralateral ovary contained an endometrioma. Other features included ascites in seven cases and peritoneal seeding in one. Malignant ovarian tumors arising from endometriosis showed radiologic features of malignancy:they were larger than 10cm, there was enhancement of the wall and septa, and a papillary nodule or solid portion was present. However, the presence of hyperintense fluid, as seen on T1WI

Radiologic findings of malignant tumors arising from ovarian endometriosis

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun Ju; Joo, Hee Jae [Ajou Univ. College of Medicine, Suwon (Korea, Republic of); Kim, Bo Hyun [SungkyunKwan Univ. College of Medicine, Seoul (Korea, Republic of)

1999-11-01

To determine the radiologic characteristics of malignant tumors arising from ovarian endometriosis. The radiologic findings of eleven patients with pelvic masses histologically confirmed as malignant ovarian tumors arising from endometriosis were retrospectively reviewed. All patients underwent MR, and six underwent ultrasonography. The findings were evaluated with regard to tumor size and shape, locularity, thickness and enhancement of the wall and septa, the presence of papillary nodule or solid portion, signal intensity of the locule, the presence of mass in contralateral ovary, ascites, local invasion, distant metastases, and the Pathologic diagnosis included clear cell carcinoma in six cases, endometrioid carcinoma in three, and mucinous cystadenocarcinoma of borderline malignancy and endometrial stromal sarcoma in one case each. Tumor size ranged from 8 to 20 (mean, 12.7)cm. The tumors were mixed in four cases, entirely cystic in three, predominantly cystic in three, and predominantly solid in one. Six cases were unilocular and five were multilocular. The wall and septa varied in thickness and regularity and were well enhanced in all but one case. In all cases papillary nodules or solid portions with similar enhancement to uterine myometrium were seen. On T1WI, the signal intensity of fluid was seen to be high in eight cases, low or intermediate in two, and of differing intensity in one. Ten cases showed high signal intensity on T2WI, whereas in one case in which high signal intensity was seen on T1WI, there was low signal intensity(shading). In three cases the contralateral ovary contained an endometrioma. Other features included ascites in seven cases and peritoneal seeding in one. Malignant ovarian tumors arising from endometriosis showed radiologic features of malignancy:they were larger than 10cm, there was enhancement of the wall and septa, and a papillary nodule or solid portion was present. However, the presence of hyperintense fluid, as seen on T1WI

Existence and nonexistence results for a singular boundary value problem arising in the theory of epitaxial growth

Czech Academy of Sciences Publication Activity Database

Escudero, C.; Hakl, Robert; Peral, I.; Torres, P.J.

2014-01-01

Roč. 37, č. 6 (2014), s. 793-807 ISSN 0170-4214 Institutional support: RVO:67985840 Keywords : singular boundary value problem * epitaxial growth * radial solution Subject RIV: BA - General Mathematics Impact factor: 0.918, year: 2014 http://onlinelibrary.wiley.com/doi/10.1002/mma.2836/full

34 CFR 300.508 - Due process complaint.

Science.gov (United States)

2010-07-01

... attending; (5) A description of the nature of the problem of the child relating to the proposed or refused initiation or change, including facts relating to the problem; and (6) A proposed resolution of the problem... section, the hearing officer must make a determination on the face of the due process complaint of whether...

Vragov’s boundary value problem for an implicit equation of mixed type

Science.gov (United States)

Egorov, I. E.

2017-10-01

We study a Vragov boundary value problem for a third-order implicit equation of mixed type with an arbitrary manifold of type switch. These Sobolev-type equations arise in many important applied problems. Given certain constraints on the coefficients and the right-hand side of the equation, we demonstrate, using nonstationary Galerkin method and regularization method, the unique regular solvability of the boundary value problem. We also obtain an error estimate for approximate solutions of the boundary value problem in terms of the regularization parameter and the eigenvalues of the Dirichlet spectral problem for the Laplace operator.

Giant Cell Tumor of Rib Arising Anteriorly as a Large Inframammary Mass: A Case Report and Review of the Literature

Directory of Open Access Journals (Sweden)

Amit Sharma

2012-01-01

posteriorly. The rarity of this tumor poses diagnostic and therapeutic problems for physicians, especially when it is located in the anterior arc of the rib in close proximity to the breasts in female patients. Case Presentation. We report the case of a 32-year-old Asian female with a giant cell tumor of her anterior rib, presenting as a large inframammary mass. Computed tomography showed a tumor arising from the 7th rib anteriorly with marginal sclerosis, cortical destruction, and a soft tissue mass. She was treated with surgical resection, and the defect was reconstructed primarily. The surgical specimen measured 28.0 × 24.0 cm. The microscopic examination showed a large number of multinucleate giant cells scattered over the parenchyma. Patient recovered uneventfully and continues to be recurrence-free six years after surgical resection. Conclusion. We report the largest known case of giant cell tumor arising from the anterior aspect of a rib. We recommend including giant cell tumor in the differential diagnosis of chest wall masses especially in female patients, regardless of the size on clinical examination.

Paradox in a non-linear capacitated transportation problem

Directory of Open Access Journals (Sweden)

Dahiya Kalpana

2006-01-01

Full Text Available This paper discusses a paradox in fixed charge capacitated transportation problem where the objective function is the sum of two linear fractional functions consisting of variables costs and fixed charges respectively. A paradox arises when the transportation problem admits of an objective function value which is lower than the optimal objective function value, by transporting larger quantities of goods over the same route. A sufficient condition for the existence of a paradox is established. Paradoxical range of flow is obtained for any given flow in which the corresponding objective function value is less than the optimum value of the given transportation problem. Numerical illustration is included in support of theory.

Solitary osteochondroma arising in lumbar spinous process: Case report.

Science.gov (United States)

Hadhri, Khaled; Tebourbi, Anis; Saidi, Mehdi; Kooli, Mondher

2016-12-01

Solitary osteochondromas rarely occur in the axial skeleton. Those tumors mostly arise on the posterior elements of the cervical column causing various symptoms especially when developing within the spinal canal. Exophytic lumbar variety is uncommon presenting with palpable mass or spinal deformity. We report a 20-year-old man presenting with a solid painless mass at the lower lumbar region. Radiological examinations revealed an exophytic lesion arising in the third lumbar spinous process appearing to be a solitary osteochondroma. The lesion was treated by en-bloc resection; histopathological examination confirmed the diagnosis of osteochondroma with no evidence of recurrence at the end of 2-year follow up. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

Myoepithelial carcinoma arising within an adenomyoepithelioma of the breast: A case report

Energy Technology Data Exchange (ETDEWEB)

Kim, You Yeon; Cho, Kyu Ran; Song, Sung Eun [Dept. of Radiology, Anam Hospital, Korea University College of Medicine, Seoul (Korea, Republic of); Seo, Bo Kyoung [Dept. of Radiology, Ansan Hospital, Korea University College of Medicine, Ansan (Korea, Republic of); Woo, Ok Hee [Dept. of Radiology, Guro Hospital, Korea University College of Medicine, Seoul (Korea, Republic of); Lee, Jeong Hyun [Dept. of Radiology, Anam Hospital, Korea University College of Medicine, Seoul (Korea, Republic of)

2017-07-15

Adenomyoepithelioma of the breast is a rare tumor. A myoepithelial carcinoma arising within an adenomyoepithelioma is even more unusual. There are a limited number of reports discussing myoepithelial carcinoma; most of them describe pathological findings, but not imaging findings. We present a case of a 55-year-old woman who had a screen-detected myoepithelial carcinoma arising within an adenomyoepithelioma in her right breast. Upon the completion of a mammography and sonography an oval shaped mass with an indistinct margin in the upper portion of the right breast had been seen. It as appeared to be a spiculated, irregular-shaped, peripheral-enhancing mass on an MRI. On sonography-guided biopsy, an epithelial-myothelial tumor was confirmed, and the possibility of myoepithelial carcinoma was suggested. Breast-conserving surgery with a sentinel lymph node dissection was performed, and a pathological examination revealed a myoepithelial carcinoma arising within an adenomyoepithelioma.

A matrix problem over a discrete valuation ring

International Nuclear Information System (INIS)

Zavadskii, A G; Revitskaya, U S

1999-01-01

A flat matrix problem of mixed type (over a discrete valuation ring and its skew field of fractions) is considered which naturally arises in connection with several problems in the theory of integer-valued representations and in ring theory. For this problem, a criterion for module boundedness is proved, which is stated in terms of a pair of partially ordered sets (P(A),P(B)) associated with the pair of transforming algebras (A,B) defining the problem. The corresponding statement coincides in effect with the formulation of Kleiner's well-known finite-type criterion for representations of pairs of partially ordered sets over a field. The proof is based on a reduction (which uses the techniques of differentiation) to representations of semimaximal rings (tiled orders) and partially ordered sets

Integrating packing and distribution problems and optimization through mathematical programming

Directory of Open Access Journals (Sweden)

Fabio Miguel

2016-06-01

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

Detecting Internal Control Problems Based on COSO and Islamic Perspective: Case on SMEs

Directory of Open Access Journals (Sweden)

Yuniarti Hidayah Suyoso Putra

2014-03-01

Full Text Available Objective – The presence of Small Medium Enterprises (SMEs has been able to be livelihoods sources and absorb more labor, even though it has a relative smaller contribution of additional value compared to the Large-scale Enterprises. The number of economic actors of SMEs spread across area from urban to rural. However, SMEs have faced several serious problems. These problems are caused by the unique characteristics of SMEs itself. First, lack of managerial skills due to limited human resources and lack of monitoring which it is rarely conducted by the manager or the owner. Second, lack of information and technology to carry out operations. Both problems have great impacts in lack of internal controls. Third, SMEs also face problems in developing business scale, limited access to capital to the banks and financial institutions due to the lack of transparency. Therefore, this research aimed to detect to what extent of the problems arising in the application and assessment of internal controls performed by SMEs.Method – The research employs descriptive qualitative research method through direct observation, interview and business documentation owned by the company. Research materials are 29 SMEs consisting of 19 trading SMEs and 10 service SMEs. All SMEs are located in Malang city. Detection of application and assessment of internal controls in this study is based on the COSO framework and the Islamic perspective.Result – Internal control activities indicators apply the five principles of COSO framework which focused on three layers. First layer is self-assessment control area. Second layer is environment control area and the third layer is independent control area. While the Islamic perspective is focused on the internal control of business activities based on the Qur'an and Hadith. The results derive from application and assessment based on COSO framework and Islamic perspectives are complementary in improving the practice of internal

PROBLEMS OF IT DEPARTMENT IN A MEDICAL UNIVERSITY

Directory of Open Access Journals (Sweden)

V. Ya Gelman

2017-01-01

Full Text Available The aim of the study is the analysis of the problems faced by heads and staff of IT departments in medical universities. Methodology and research methods. The methods involve expert estimation, analysis and generalization of practical work experience of IT departments. Results and scientific novelty. The main aspects and specifics of professional activity of IT departments of modern medical schools are designated. The approaches to the definition of the hierarchy of goals in the professional activities of the department, as well as quantitative and qualitative indicators that assess the effectiveness of their achievements are analyzed. The contradictions arising between long-term and short-term goals of the IT department are highlighted. The main challenges which heads of IT departments can deal with in the course of day-to-day management work planning are described. The problems arising in educational, educational-methodical and scientific work of department, in its economic activity, solution of personnel affairs, and aspects of material support are considered. The possible solutions to these problems are proposed. Practical significance. The results of the analysis, proposed approaches and practical recommendations will enable to better organize the work of the IT department in a medical school. The advantage of the proposed approaches consists in their versatility: with some adjustment, they can be used by other departments, regardless of the specifics and the type of educational institution.

Severe lower urinary tract symptoms due to anteriorly located midline prostatic cyst arising from the bladder neck in a young male: case report

Energy Technology Data Exchange (ETDEWEB)

Guragac, Ali; Demirer, Zafer; Alp, Bilal Firat; Aydur, Emin, E-mail: zaferdemirer@mynet.com, E-mail: zaferdemirer1903@gmail.com [Department of Urology, School of Medicine, Gulhane Military Medical Academy, Ankara (Turkey)

2016-09-15

Context: Prostatic cysts are uncommon. These cysts are usually asymptomatic and are diagnosed incidentally during ultrasonographic examination. On rare occasions, they may cause drastic symptoms. Case Report: We report on a case of severely symptomatic anteriorly located prostatic cyst arising from the bladder neck in a 30-year-old man presenting with lower urinary tract symptoms, without clinical evidence of benign prostatic hyperplasia. Transrectal ultrasonography (TRUS), computed tomography (CT) and cystourethroscopy demonstrated a projecting prostatic cyst that occupied the bladder neck at the precise twelve o’clock position. It was acting as a ball-valve, such that it obstructed the bladder outlet. Transurethral unroofing of the cyst was performed and the patient’s obstructive symptoms were successfully resolved. Histopathological examination indicated a retention cyst. Conclusions: It should be borne in mind that midline prostate cysts can be a reason for bladder outlet obstruction in a young male. Such patients may have tremendous improvement in symptoms through transurethral unroofing of the cyst wall. (author)

Finite Element Modeling of Perturbation Fields due to Colonies of Stress Corrosion Cracks(SCCs) in a Gas Transmission Pipeline

International Nuclear Information System (INIS)

Yang, Sun Ho

2001-01-01

The detection of axial cracks using conventional MFL pig is a significant challenge in the gas pipeline inspection. In this study, a technique using interaction of circumferentially induced torrents with axial stress corrosion crack is presented. The feasibility of this technique is investigated using finite element modeling. Finite element analysis of such interaction is a difficult problem in terms of both computation time and memory requirements. The challenges arise due to the nonlinearity of material properties, the small sire of tight cracks relative to that of the magnetizer, and also time stepping involved in modeling velocity effects. This paper presents an approach based on perturbation methods. The overall analysis procedure is divided into 4 simple steps that can be performed sequentially. Modeling results show that this technique can effectively detect colonies of SCC as well as single SCC

Poorly Differentiated Squamous Cell Carcinoma Arising in Tattooed Skin

Science.gov (United States)

Sarma, Deba P.; Dentlinger, Renee B.; Forystek, Amanda M.; Stevens, Todd; Huerter, Christopher

2010-01-01

Introduction. Tattoos have increasingly become accepted by mainstream Western society. As a result, the incidence of tattoo-associated dermatoses is on the rise. The presence of a poorly differentiated squamous cell carcinoma in an old tattooed skin is of interest as it has not been previously documented. Case Presentation. A 79-year-old white homeless man of European descent presented to the dermatology clinic with a painless raised nodule on his left forearm arising in a tattooed area. A biopsy of the lesion revealed a poorly differentiated squamous cell carcinoma infiltrating into a tattoo. The lesion was completely excised and the patient remains disease-free one year later. Conclusion. All previous reports of squamous cell carcinomas arising in tattoos have been well-differentiated low-grade type or keratoacanthoma-type and are considered to be coincidental rather than related to any carcinogenic effect of the tattoo pigments. Tattoo-associated poorly differentiated invasive carcinoma appears to be extremely rare. PMID:21274289

Poorly Differentiated Squamous Cell Carcinoma Arising in Tattooed Skin

Directory of Open Access Journals (Sweden)

Deba P. Sarma

2010-01-01

Full Text Available Introduction. Tattoos have increasingly become accepted by mainstream Western society. As a result, the incidence of tattoo-associated dermatoses is on the rise. The presence of a poorly differentiated squamous cell carcinoma in an old tattooed skin is of interest as it has not been previously documented. Case Presentation. A 79-year-old white homeless man of European descent presented to the dermatology clinic with a painless raised nodule on his left forearm arising in a tattooed area. A biopsy of the lesion revealed a poorly differentiated squamous cell carcinoma infiltrating into a tattoo. The lesion was completely excised and the patient remains disease-free one year later. Conclusion. All previous reports of squamous cell carcinomas arising in tattoos have been well-differentiated low-grade type or keratoacanthoma-type and are considered to be coincidental rather than related to any carcinogenic effect of the tattoo pigments. Tattoo-associated poorly differentiated invasive carcinoma appears to be extremely rare.

Basal Cell Carcinoma Arising in a Breast Augmentation Scar.

Science.gov (United States)

Edwards, Lisa R; Cresce, Nicole D; Russell, Mark A

2017-04-01

We report a case of a 46-year-old female who presented with a persistent lesion on the inferior right breast. The lesion was located within the scar from a breast augmentation procedure 12 years ago. The lesion had been treated as several conditions with no improvement. Biopsy revealed a superficial and nodular basal cell carcinoma, and the lesion was successfully removed with Mohs micrographic surgery. Basal cell carcinoma arising in a surgical scar is exceedingly rare with only 13 reported cases to date. This is the first reported case of basal cell carcinoma arising in a breast augmentation scar. We emphasize the importance of biopsy for suspicious lesions or those refractory to treatment, particularly those lesions that form within a scar. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Measuring impairment when diagnosing adolescent ADHD: Differentiating problems due to ADHD versus other sources.

Science.gov (United States)

Vazquez, Alejandro L; H Sibley, Margaret; Campez, Mileini

2018-04-13

The DSM-5 requires clinicians to link ADHD symptoms to clinically meaningful impairments in daily life functioning. Measuring impairment during ADHD assessments may be particularly challenging in adolescence, when ADHD is often not the sole source of a youth's difficulties. Existing impairment rating scales are criticized for not specifying ADHD as the source of impairment in their instructions, leading to potential problems with rating scale specificity. The current study utilized a within subjects design (N = 107) to compare parent report of impairment on two versions of a global impairment measure: one that specified ADHD as the source of impairment (Impairment Rating Scale-ADHD) and a standard version that did not (Impairment Rating Scale). On the standard family impairment item, parents endorsed greater impairment as compared to the IRS-ADHD. This finding was particularly pronounced when parents reported high levels of parenting stress. More severe ADHD symptoms were associated with greater concordance between the two versions. Findings indicate that adolescent family related impairments reported during ADHD assessments may be due to sources other than ADHD symptoms, such as developmental maladjustment. To prevent false positive diagnoses, symptom-specific wording may optimize impairment measures when assessing family functioning in diagnostic assessments for adolescents with ADHD. Copyright © 2018 Elsevier B.V. All rights reserved.

How are things adding up? Neural differences between arithmetic operations are due to general problem solving strategies.

Science.gov (United States)

Tschentscher, Nadja; Hauk, Olaf

2014-05-15

A number of previous studies have interpreted differences in brain activation between arithmetic operation types (e.g. addition and multiplication) as evidence in favor of distinct cortical representations, processes or neural systems. It is still not clear how differences in general task complexity contribute to these neural differences. Here, we used a mental arithmetic paradigm to disentangle brain areas related to general problem solving from those involved in operation type specific processes (addition versus multiplication). We orthogonally varied operation type and complexity. Importantly, complexity was defined not only based on surface criteria (for example number size), but also on the basis of individual participants' strategy ratings, which were validated in a detailed behavioral analysis. We replicated previously reported operation type effects in our analyses based on surface criteria. However, these effects vanished when controlling for individual strategies. Instead, procedural strategies contrasted with memory retrieval reliably activated fronto-parietal and motor regions, while retrieval strategies activated parietal cortices. This challenges views that operation types rely on partially different neural systems, and suggests that previously reported differences between operation types may have emerged due to invalid measures of complexity. We conclude that mental arithmetic is a powerful paradigm to study brain networks of abstract problem solving, as long as individual participants' strategies are taken into account. Copyright © 2014 Elsevier Inc. All rights reserved.

RAMs: the problem of transient errors due to alpha radiation

International Nuclear Information System (INIS)

Goujon, Pierre.

1980-01-01

Errors that remained unexplained for a long time have occurred with dynamic random access memories. It has been known since 1978 that they are due to stray alpha radiation. A good understanding of this phenomenon enables its effects to be neutralized and the reliability of the products to be guarantied [fr

Radiological field survey problems and solutions

International Nuclear Information System (INIS)

Deming, E.J.; Boerner, A.J.

1986-01-01

Situations often arise during radiological field surveys which require the health physicist to improvise and/or make spot decisions. At times these situations can be humorous, but they can also present hazards more serious than normal radiological considerations. This presentation will depict various problematic situations encountered by Oak Ridge Associated Universities Radiological Site Assessment Program in the course of performing field environmental surveys. Detailing these potential hazards can alert other field survey groups to problems they may encounter

Infinite-horizon optimal control problems in economics

Energy Technology Data Exchange (ETDEWEB)

Aseev, Sergei M; Besov, Konstantin O; Kryazhimskii, Arkadii V

2012-04-30

This paper extends optimal control theory to a class of infinite-horizon problems that arise in studying models of optimal dynamic allocation of economic resources. In a typical problem of this sort the initial state is fixed, no constraints are imposed on the behaviour of the admissible trajectories at large times, and the objective functional is given by a discounted improper integral. We develop the method of finite-horizon approximations in a broad context and use it to derive complete versions of the Pontryagin maximum principle for such problems. We provide sufficient conditions for the normality of infinite-horizon optimal control problems and for the validity of the 'standard' limit transversality conditions with time going to infinity. As a meaningful example, we consider a new two-sector model of optimal economic growth subject to a random jump in prices. Bibliography: 53 titles.

Divorce Rate in the Slovak Republic as a Social and Educational Problem

Directory of Open Access Journals (Sweden)

Gežová Katarína Cimprichová

2016-08-01

Full Text Available Divorce is considered an unwanted phenomenon in the society, although the divorce rate increases. There are many problems for both sides - parents and their children - coming along with divorce. The legal adjustment of divorce may violently strike not only the lives of children influenced by divorce but also the lives of other persons, whose existence is seriously endangered or complicated by establishing new life conditions. Family break-up and the loss of one parent leaves lifelong consequences on the child. The decision for divorce should be therefore thoroughly considered, because it is the point, where the source of loss of personal and family safety arises. Our aim is to point out the problems arising from divorce not only for the divorcing couple, but also for their children, above all, because divorce should not mean hostility for sensible people, particularly if they have children. It is necessary to find a way how to talk together before and during divorce and to do best in solving problems in the possibly shortest time.

A New Approach to the Container Positioning Problem

DEFF Research Database (Denmark)

Ahmt, Jonas; Sigtenbjerggaard, Jonas Skott; Lusby, Richard Martin

Programming model that not only improves on earlier attempts at this problem, but also better reflects reality. In particular, the proposed model adopts a preference to reshuffle containers in line with a just-in-time concept, as it is assumed that data is more accurate the closer to a container’s scheduled...... for solving larger instances of the problem. We show that this new formulation drastically outperforms previous attempts at the problem through a direct comparison on instances available in the literature. Furthermore, we also show that the rolling horizon based heuristic can further reduce the solution time......In this paper the Container Positioning Problem is revisited. This problem arises at busy container terminals and requires one to minimize the use of block cranes in handling the containers that must wait at the terminal until their next means of transportation. We propose a new Mixed Integer...

Simulating Arctic clouds during Arctic Radiation- IceBridge Sea and Ice Experiment (ARISE)

Science.gov (United States)

Bromwich, D. H.; Hines, K. M.; Wang, S. H.

2015-12-01

The representation within global and regional models of the extensive low-level cloud cover over polar oceans remains a critical challenge for quantitative studies and forecasts of polar climate. In response, the polar-optimized version of the Weather Research and Forecasting model (Polar WRF) is used to simulate the meteorology, boundary layer, and Arctic clouds during the September-October 2014 Arctic Radiation- IceBridge Sea and Ice Experiment (ARISE) project. Polar WRF was developed with several adjustments to the sea ice thermodynamics in WRF. ARISE was based out of Eielson Air Force Base near Fairbanks, Alaska and included multiple instrumented C-130 aircraft flights over open water and sea ice of the Beaufort Sea. Arctic boundary layer clouds were frequently observed within cold northeasterly flow over the open ocean and ice. Preliminary results indicate these clouds were primarily liquid water, with characteristics differing between open water and sea ice surfaces. Simulated clouds are compared to ARISE observations. Furthermore, Polar WRF simulations are run for the August-September 2008 Arctic Summer Cloud Ocean Study (ASCOS) for comparison to the ARISE. Preliminary analysis shows that simulated low-level water clouds over the sea ice are too extensive during the the second half of the ASCOS field program. Alternatives and improvements to the Polar WRF cloud schemes are considered. The goal is to use the ARISE and ASCOS observations to achieve an improved polar supplement to the WRF code for open water and sea ice that can be provided to the Polar WRF community.

Solving the Selective Multi-Category Parallel-Servicing Problem

DEFF Research Database (Denmark)

Range, Troels Martin; Lusby, Richard Martin; Larsen, Jesper

In this paper we present a new scheduling problem and describe a shortest path based heuristic as well as a dynamic programming based exact optimization algorithm to solve it. The Selective Multi-Category Parallel-Servicing Problem (SMCPSP) arises when a set of jobs has to be scheduled on a server...... (machine) with limited capacity. Each job requests service in a prespecified time window and belongs to a certain category. Jobs may be serviced partially, incurring a penalty; however, only jobs of the same category can be processed simultaneously. One must identify the best subset of jobs to process...

Solving the selective multi-category parallel-servicing problem

DEFF Research Database (Denmark)

Range, Troels Martin; Lusby, Richard Martin; Larsen, Jesper

2015-01-01

In this paper, we present a new scheduling problem and describe a shortest path-based heuristic as well as a dynamic programming-based exact optimization algorithm to solve it. The selective multi-category parallel-servicing problem arises when a set of jobs has to be scheduled on a server (machine......) with limited capacity. Each job requests service in a prespecified time window and belongs to a certain category. Jobs may be serviced partially, incurring a penalty; however, only jobs of the same category can be processed simultaneously. One must identify the best subset of jobs to process in each time...

High grade angiosarcoma arising in fibroadenoma

Science.gov (United States)

2011-01-01

Primary angiosarcoma of the breast is a rare tumour that account for fewer than 0.05% of all malignant mammary tumours. Angiosarcoma may have an perfidious clinical onset. Radiologic findings are often nonspecific and may appear completely normal in one-third of cases with primary angiosarcoma. The prognosis is usually poor because of the high rates of local recurrence and early development of metastases. Aggressive surgical resection is the mainstay of treatment. The role of adjuvant therapy has not yet been well established. Here we present a case of a 53 year old, postmenopausal women with primary angiosarcoma arising in fibroadenoma. To our knowledge, this is the first case described in the literature to date. PMID:22185665

Periorbital nodular fasciitis arising during pregnancy

Directory of Open Access Journals (Sweden)

Brandon N Phillips

2014-01-01

Full Text Available Nodular fasciitis (NF is a benign proliferation of fibroblasts and myofibroblasts that rarely occurs in the periorbital region. We report what we believe to be the first case of periorbital NF associated with pregnancy. A case of intravascular fasciitis, a NF variant, has been reported during pregnancy, but it was not located in the periorbital region. A weak presence of estrogen receptors has been reported in NF. This may make it more susceptible to the hormone-related changes during pregnancy and contribute to the development of the lesion by stimulating fibroblasts and smooth muscle cell types. Although rare, NF should be considered in the differential diagnosis of periorbital soft-tissue masses arising during pregnancy.

Small cell carcinoma arising in Barrett's esophagus: a case report and review of the literature

Directory of Open Access Journals (Sweden)

Markogiannakis Haridimos

2008-01-01

Full Text Available Abstract Introduction Gastrointestinal tract small cell carcinoma is an infrequent and aggressive neoplasm that represents 0.1–1% of gastrointestinal malignancies. Very few cases of small cell esophageal carcinoma arising in Barrett's esophagus have been reported in the literature. An extremely rare case of primary small cell carcinoma of the distal third of the esophagus arising from dysplastic Barrett's esophagus is herein presented. Case presentation A 62-year-old man with gastroesophageal reflux history presented with epigastric pain, epigastric fullness, dysphagia, anorexia, and weight loss. Esophagogastroscopy revealed an ulceroproliferative, intraluminar mass in the distal esophagus obstructing the esophageal lumen. Biopsy showed small cell esophageal carcinoma. Contrast-enhanced chest and abdominal computed tomography demonstrated a large tumor of the distal third of the esophagus without any lymphadenopathy or distant metastasis. Preoperative chemotherapy with cisplatine and etoposide for 3 months resulted in a significant reduction of the tumor. After en block esophagectomy with two field lymph node dissection, proximal gastrectomy, and cervical esophagogastric anastomosis, the patient was discharged on the 14th postoperative day. Histopathology revealed a primary small cell carcinoma of the distal third of the esophagus arising from dysplastic Barrett's esophagus. The patient received another 3 month course of postoperative chemotherapy with the same agents and remained free of disease at 12 month review. Conclusion Although small cell esophageal carcinoma is rare and its association with dysplastic Barrett's esophagus is extremely infrequent, the high carcinogenic risk of Barrett's epithelium should be kept in mind. Prognosis is quite unfavorable; a better prognosis might be possible with early diagnosis and treatment strategies incorporating chemotherapy along with oncological radical surgery and/or radiotherapy as part of a

Sound radiation quantities arising from a resilient circular radiator

NARCIS (Netherlands)

Aarts, R.M.; Janssen, A.J.E.M.

2009-01-01

Power series expansions in ka are derived for the pressure at the edge of a radiator, the reaction force on the radiator, and the total radiated power arising from a harmonically excited, resilient, flat, circular radiator of radius a in an infinite baffle. The velocity profiles on the radiator are

Symmetry of the Adiabatic Condition in the Piston Problem

Science.gov (United States)

Anacleto, Joaquim; Ferreira, J. M.

2011-01-01

This study addresses a controversial issue in the adiabatic piston problem, namely that of the piston being adiabatic when it is fixed but no longer so when it can move freely. It is shown that this apparent contradiction arises from the usual definition of adiabatic condition. The issue is addressed here by requiring the adiabatic condition to be…

Basal Cell Carcinoma Arising in a Tattooed Eyebrow

Science.gov (United States)

Lee, Jong-Sun; Park, Jin; Kim, Seong-Min; Kim, Han-Uk

2009-01-01

Malignant skin tumors, including squamous cell carcinoma and malignant melanoma, have occurred in tattoos. Seven documented cases of basal cell carcinoma associated with tattoos have also been reported in the medical literature. We encountered a patient with basal cell carcinoma in a tattooed eyebrow. We report on this case as the eighth reported case of a patient with basal cell carcinoma arising in a tattooed area. PMID:20523804

On Newton-Raphson formulation and algorithm for displacement based structural dynamics problem with quadratic damping nonlinearity

Directory of Open Access Journals (Sweden)

Koh Kim Jie

2017-01-01

Full Text Available Quadratic damping nonlinearity is challenging for displacement based structural dynamics problem as the problem is nonlinear in time derivative of the primitive variable. For such nonlinearity, the formulation of tangent stiffness matrix is not lucid in the literature. Consequently, ambiguity related to kinematics update arises when implementing the time integration-iterative algorithm. In present work, an Euler-Bernoulli beam vibration problem with quadratic damping nonlinearity is addressed as the main source of quadratic damping nonlinearity arises from drag force estimation, which is generally valid only for slender structures. Employing Newton-Raphson formulation, tangent stiffness components associated with quadratic damping nonlinearity requires velocity input for evaluation purpose. For this reason, two mathematically equivalent algorithm structures with different kinematics arrangement are tested. Both algorithm structures result in the same accuracy and convergence characteristic of solution.

The impact of alternate weekly collections on waste arisings

Energy Technology Data Exchange (ETDEWEB)

Williams, I.D., E-mail: idw@soton.ac.uk [Waste Management Research Group, Faculty of Engineering and the Environment, Lanchester Building, University of Southampton, University Rd, Highfield, SOUTHAMPTON, Hampshire, SO17 1BJ (United Kingdom); Cole, C. [Centre for Innovative and Collaborative Construction Engineering, School of Civil and Building Engineering, Loughborough University, Epinal Way, Loughborough, LE11 3TU (United Kingdom)

2013-02-15

Residual waste is commonly collected separately from recyclable and organic materials. Different forms of collection and disposal are used internationally since regional or municipal authorities have to adapt to their own circumstances. Many authorities have adopted an alternate weekly collection (AWC) of residual waste and recyclables to force/encourage householders to recycle; however, the degree to which they achieve waste reduction has yet to be reliably quantified. This study reports on how the introduction of AWCs affects household waste arisings. The paper evaluates single and dual stream collection methods and compares their performance with the previous system. Household waste collection trials were conducted between March and June 2009 in England (Lichfield). The trials examined changes to frequency of collection, type of container issued, amounts of sorting required of residents, household participation and productivity levels. A survey of households was completed before any changes were implemented. The quantity of recyclates collected was examined for 2008/2009 and 2009/2010. The study showed that the AWC scheme positively impacted on recycling rates and household behaviour, with no adverse impacts on public participation, household waste arisings or the local environment. No public health problems were reported. Both trials saw an increase in the quantities of recyclates collected per household during the trial period compared to the same period of time in the previous year. The dual stream performed better than the single stream, collecting an average of 5.94 kg/hh/week compared to an average of 5.63 kg/hh/week. The single stream system showed a greater increase in the weight of material collected (0.53 kg/hh/week vs. 0.48 kg/hh/week). Participation and set-out rates showed an increase during the trial period. The single stream option (comingled materials in one container) outperformed the dual stream service. The reduction in costs and improved

The impact of alternate weekly collections on waste arisings

International Nuclear Information System (INIS)

Williams, I.D.; Cole, C.

2013-01-01

Residual waste is commonly collected separately from recyclable and organic materials. Different forms of collection and disposal are used internationally since regional or municipal authorities have to adapt to their own circumstances. Many authorities have adopted an alternate weekly collection (AWC) of residual waste and recyclables to force/encourage householders to recycle; however, the degree to which they achieve waste reduction has yet to be reliably quantified. This study reports on how the introduction of AWCs affects household waste arisings. The paper evaluates single and dual stream collection methods and compares their performance with the previous system. Household waste collection trials were conducted between March and June 2009 in England (Lichfield). The trials examined changes to frequency of collection, type of container issued, amounts of sorting required of residents, household participation and productivity levels. A survey of households was completed before any changes were implemented. The quantity of recyclates collected was examined for 2008/2009 and 2009/2010. The study showed that the AWC scheme positively impacted on recycling rates and household behaviour, with no adverse impacts on public participation, household waste arisings or the local environment. No public health problems were reported. Both trials saw an increase in the quantities of recyclates collected per household during the trial period compared to the same period of time in the previous year. The dual stream performed better than the single stream, collecting an average of 5.94 kg/hh/week compared to an average of 5.63 kg/hh/week. The single stream system showed a greater increase in the weight of material collected (0.53 kg/hh/week vs. 0.48 kg/hh/week). Participation and set-out rates showed an increase during the trial period. The single stream option (comingled materials in one container) outperformed the dual stream service. The reduction in costs and improved

Squamous cell carcinoma arising in a mature cystic teratoma

Directory of Open Access Journals (Sweden)

Gupta Vishwanath

2009-04-01

Full Text Available Two cases of squamous cell carcinoma (SCC arising in a mature cystic teratoma (MCT are being discussed for their rarity and pattern of infiltration of tumor cells in the stroma (alpha mode, beta mode and gamma mode, which is a key factor in deciding the prognosis and patient survival.

Vibration due to non-circularity of a rotating ring having discrete radial supports - With application to thin-walled rotor/magnetic bearing systems

Science.gov (United States)

Fakkaew, Wichaphon; Cole, Matthew O. T.

2018-06-01

This paper investigates the vibration arising in a thin-walled cylindrical rotor subject to small non-circularity and coupled to discrete space-fixed radial bearing supports. A Fourier series description of rotor non-circularity is incorporated within a mathematical model for vibration of a rotating annulus. This model predicts the multi-harmonic excitation of the rotor wall due to bearing interactions. For each non-circularity harmonic there is a set of distinct critical speeds at which resonance can potentially arise due to flexural mode excitation within the rotor wall. It is shown that whether each potential resonance occurs depends on the multiplicity and symmetry of the bearing supports. Also, a sufficient number of evenly spaced identical supports will eliminate low order resonances. The considered problem is pertinent to the design and operation of thin-walled rotors with active magnetic bearing (AMB) supports, for which small clearances exist between the rotor and bearing and so vibration excitation must be limited to avoid contacts. With this motivation, the mathematical model is further developed for the case of a distributed array of electromagnetic actuators controlled by feedback of measured rotor wall displacements. A case study involving an experimental system with short cylindrical rotor and a single radial AMB support is presented. The results show that flexural mode resonance is largely avoided for the considered design topology. Moreover, numerical predictions based on measured non-circularity show good agreement with measurements of rotor wall vibration, thereby confirming the validity and utility of the theoretical model.

Dynamics of the middle atmosphere as observed by the ARISE project

Science.gov (United States)

Blanc, E.

2015-12-01

It has been strongly demonstrated that variations in the circulation of the middle atmosphere influence weather and climate all the way to the Earth's surface. A key part of this coupling occurs through the propagation and breaking of planetary and gravity waves. However, limited observations prevent to faithfully reproduce the dynamics of the middle atmosphere in numerical weather prediction and climate models. The main challenge of the ARISE (Atmospheric dynamics InfraStructure in Europe) project is to combine existing national and international observation networks including: the International infrasound monitoring system developed for the CTBT (Comprehensive nuclear-Test-Ban Treaty) verification, the NDACC (Network for the Detection of Atmospheric Composition Changes) lidar network, European observation infrastructures at mid latitudes (OHP observatory), tropics (Maïdo observatory), high latitudes (ALOMAR and EISCAT), infrasound stations which form a dense European network and satellites. The ARISE network is unique by its coverage (polar to equatorial regions in the European longitude sector), its altitude range (from troposphere to mesosphere and ionosphere) and the involved scales both in time (from seconds to tens of years) and space (from tens of meters to thousands of kilometers). Advanced data products are produced with the scope to assimilate data in the Weather Prediction models to improve future forecasts over weeks and seasonal time scales. ARISE observations are especially relevant for the monitoring of extreme events such as thunderstorms, volcanoes, meteors and at larger scales, deep convection and stratospheric warming events for physical processes description and study of long term evolution with climate change. Among the applications, ARISE fosters integration of innovative methods for remote detection of non-instrumented volcanoes including distant eruption characterization to provide notifications with reliable confidence indices to the

Improving Teaching Quality and Problem Solving Ability through Contextual Teaching and Learning in Differential Equations: A Lesson Study Approach

Science.gov (United States)

Khotimah, Rita Pramujiyanti; Masduki

2016-01-01

Differential equations is a branch of mathematics which is closely related to mathematical modeling that arises in real-world problems. Problem solving ability is an essential component to solve contextual problem of differential equations properly. The purposes of this study are to describe contextual teaching and learning (CTL) model in…

Intraosseous verrucous carcinoma arising from an orthokeratinized odontogenic keratocyst: A report of a rarest entity

Directory of Open Access Journals (Sweden)

Nagaraju Kamarthi

2016-01-01

Full Text Available Intraosseous verrucous carcinomas (VCs arising from odontogenic cysts are a rare entity. An unusual case of a VC arising from the orthokeratinized odontogenic cyst is described for the first time. The microscopic features of the lesion are presented.

Plagiarism Due to Misunderstanding: Online Instructor Perceptions

Science.gov (United States)

Greenberger, Scott; Holbeck, Rick; Steele, John; Dyer, Thomas

2016-01-01

Plagiarism is an ongoing problem in higher education. This problem exists in both online and face-to-face modalities. The literature indicates that there are three ways higher education institutions define plagiarism, which includes theft, deception, and misunderstanding. Plagiarism due to misunderstanding has received less attention in the…

Problems and paradoxes of the Lifshitz theory

International Nuclear Information System (INIS)

Klimchitskaya, G L

2009-01-01

The problems and paradoxes of the Lifshitz theory in application to real dielectric and semiconductor materials are reviewed. It is shown that the inclusion of drift current of conduction electrons into the model of dielectric response results in contradictions with both thermodynamics and experimental data of different experimental groups. Physical reasons why the problems and paradoxes arise are analyzed and found to be connected with the violation of basic applicability condition of the Lifshitz theory, the thermal equilibrium. A recent alternative approach to the resolution of the problems based on the inclusion of screening effects and diffusion current is considered and demonstrated to be thermodynamically and experimentally inconsistent. It is argued that the inclusion of the diffusion current leads to an even deeper violation of thermal equilibrium. Phenomenologically, the Lifshitz theory with role of drift and diffusion currents neglected is shown to be free of problems and in agreement with both thermodynamics and all available experimental data.

Entanglement witnesses arising from exposed positive linear maps

OpenAIRE

Ha, Kil-Chan; Kye, Seung-Hyeok

2011-01-01

We consider entanglement witnesses arising from positive linear maps which generate exposed extremal rays. We show that every entanglement can be detected by one of these witnesses, and this witness detects a unique set of entanglement among those. Therefore, they provide a minimal set of witnesses to detect all entanglement in a sense. Furthermore, if those maps are indecomposable then they detect large classes of entanglement with positive partial transposes which have nonempty relative int...

High-Grade Leiomyosarcoma Arising in a Previously Replanted Limb

Directory of Open Access Journals (Sweden)

Tiffany J. Pan

2015-01-01

Full Text Available Sarcoma development has been associated with genetics, irradiation, viral infections, and immunodeficiency. Reports of sarcomas arising in the setting of prior trauma, as in burn scars or fracture sites, are rare. We report a case of a leiomyosarcoma arising in an arm that had previously been replanted at the level of the elbow joint following traumatic amputation when the patient was eight years old. He presented twenty-four years later with a 10.8 cm mass in the replanted arm located on the volar forearm. The tumor was completely resected and pathology examination showed a high-grade, subfascial spindle cell sarcoma diagnosed as a grade 3 leiomyosarcoma with stage pT2bNxMx. The patient underwent treatment with brachytherapy, reconstruction with a free flap, and subsequently chemotherapy. To the best of our knowledge, this is the first case report of leiomyosarcoma developing in a replanted extremity. Development of leiomyosarcoma in this case could be related to revascularization, scar formation, or chronic injury after replantation. The patient remains healthy without signs of recurrence at three-year follow-up.

Multiple Ectopic Hepatocellular Carcinomas Arising in the Abdominal Cavity

Directory of Open Access Journals (Sweden)

Toru Miyake

2012-09-01

Full Text Available Ectopic hepatocellular carcinoma (HCC is a very rare clinical entity that is defined as HCC arising from extrahepatic liver tissue. This report presents a case of ectopic multiple HCC arising in the abdominal cavity. A 42-year-old otherwise healthy male presented with liver dysfunction at a general health checkup. Both HCV antibody and hepatitis B surface antigen were negative. Laboratory examination showed elevations in serum alpha-fetoprotein and PIVKA-II. Ultrasonography and computed tomography revealed multiple nodular lesions in the abdominal cavity with ascites without a possible primary tumor. Exploratory laparoscopy was performed, which revealed bloody ascites and multiple brown nodular tumors measuring approximately 10 mm in size that were disseminated on the perineum and mesentery. A postoperative PET-CT scan was performed but it did not reveal any evidence of a tumor in the liver. The tumors resected from the peritoneum were diagnosed as HCC. The present case of HCC was thought to have possibly developed from ectopic liver on the peritoneum or mesentery.

Minimal surfaces, stratified multivarifolds, and the plateau problem

CERN Document Server

Thi, Dao Trong; Primrose, E J F; Silver, Ben

1991-01-01

Plateau's problem is a scientific trend in modern mathematics that unites several different problems connected with the study of minimal surfaces. In its simplest version, Plateau's problem is concerned with finding a surface of least area that spans a given fixed one-dimensional contour in three-dimensional space--perhaps the best-known example of such surfaces is provided by soap films. From the mathematical point of view, such films are described as solutions of a second-order partial differential equation, so their behavior is quite complicated and has still not been thoroughly studied. Soap films, or, more generally, interfaces between physical media in equilibrium, arise in many applied problems in chemistry, physics, and also in nature. In applications, one finds not only two-dimensional but also multidimensional minimal surfaces that span fixed closed "contours" in some multidimensional Riemannian space. An exact mathematical statement of the problem of finding a surface of least area or volume requir...

Survival of mutations arising during invasions.

Science.gov (United States)

Miller, Judith R

2010-03-01

When a neutral mutation arises in an invading population, it quickly either dies out or 'surfs', i.e. it comes to occupy almost all the habitat available at its time of origin. Beneficial mutations can also surf, as can deleterious mutations over finite time spans. We develop descriptive statistical models that quantify the relationship between the probability that a mutation will surf and demographic parameters for a cellular automaton model of surfing. We also provide a simple analytic model that performs well at predicting the probability of surfing for neutral and beneficial mutations in one dimension. The results suggest that factors - possibly including even abiotic factors - that promote invasion success may also increase the probability of surfing and associated adaptive genetic change, conditioned on such success.

[A case of carcinoma arising in a diverticulum of the transverse colon].

Science.gov (United States)

Nomi, Masako; Umemoto, Satoshi; Kikutake, Takashi; Hosaka, Seiji; Mase, Takahiro; Kawamoto, Shunji; Yoshida, Takahisa

2014-11-01

A 64 year-old woman presented with advanced, transverse colon cancer arising in the diverticulum. Tumor invasion extended beyond the serosa to the anal side of the colon. Anemia and fatigue progressed after 6 months of iron administration. The hemoglobin value was 5.3 g/dL and carcinoembryonic antigen (CEA) level was elevated to 44.2 ng/mL. A palpable and tender fist-sized mass was found in the right upper abdomen. Computed tomography (CT) revealed a low-density mass in the transverse colon invading beyond the serosa to the anal side of the colon. Right hemi-colectomy with lymph node dissection was performed. The resected specimen contained multiple diverticula including the one from which the tumor arose. Histological examination revealed a well-differentiated, tubular adenocarcinoma (UICC TNM T4bN0M0) arising in a transverse colon diverticulum. There has been no recurrence for 2 years. Colon cancer arising in a diverticulum may expand to the extra-serosa and easily invade to the adjacent organ. In such cases, malignancy should be considered.

Addressing Cultural Diversity: Effects of a Problem-Based Intercultural Learning Unit

Science.gov (United States)

Busse, Vera; Krause, Ulrike-Marie

2015-01-01

This article explores to what extent a problem-based learning unit in combination with cooperative learning and affectively oriented teaching methods facilitates intercultural learning. As part of the study, students reflected on critical incidents, which display misunderstandings or conflicts that arise as a result of cultural differences. In…

A perspective on problems and prospects for academic publishing in Geography

NARCIS (Netherlands)

Meadow, M.; Dietz, A.J.; Vandermotten, C.

2016-01-01

This commentary highlights problems of inequity in academic publishing in geography that arise from the increasing use of metrics as a measure of research quality. In so doing, we examine patterns in the ranking of geographical journals in the major global databases (e.g. Web of Science, Scopus) and

Integrating routing decisions in public transportation problems

CERN Document Server

Schmidt, Marie E

2014-01-01

This book treats three planning problems arising in public railway transportation planning: line planning, timetabling, and delay management, with the objective to minimize passengers’ travel time. While many optimization approaches simplify these problems by assuming that passengers’ route choice is independent of the solution, this book focuses on models which take into account that passengers will adapt their travel route to the implemented planning solution. That is, a planning solution and passengers’ routes are determined and evaluated simultaneously. This work is technically deep, with insightful findings regarding complexity and algorithmic approaches to public transportation problems with integrated passenger routing. It is intended for researchers in the fields of mathematics, computer science, or operations research, working in the field of public transportation from an optimization standpoint. It is also ideal for students who want to gain intuition and experience in doing complexity proofs ...

Refrigerators with chlorofluorohydrocarbon - always a problem. Why chlorofluorohydrocarbons are still an issue; Kuehlgeraete mit FCKW immer ein Problem. Warum Fluorchlorkohlenwasserstoffe noch ein Thema sind

Energy Technology Data Exchange (ETDEWEB)

Schnepel, Christiane

2009-05-15

The report discusses the following questions: What are CFCs and what is the environmental impact? Why is there still a CFCs problem in spite of the prohibition? Why is it so important to dispose old refrigerators in an appropriate way? What is the appropriate way for refrigerator disposal? What are the cost for refrigerator disposal and who is paying? What is the mass throughput balance and why is this value not suitable as control instrument? Which problems arise during disposal? What is the solution: where are we and what is the future?.

The new framework for resolving the energy problem and its application to the utilization of nuclear technology

International Nuclear Information System (INIS)

Kurata, Kenji

2002-01-01

Until recently, the energy problem in Japan had been the problem of how enough energy could be supplied to various sectors in society under Japan's conditions of only a few energy resources existing within its territory. However, recently new environmental and social conditions are arising. These new conditions strongly affect not only concrete measures for solving the energy problem but also the characteristics of the energy problem itself. Nowadays, it seems to be impossible to resolve the energy problem without taking these conditions into consideration. For this reason, a new framework, which enables various social values to be reflected in concrete measures, is urgently needed to resolve the energy problem. This thesis uses the ISO14001 framework to consider a possible solution over the energy problem. In the first part of this thesis, an examination shows that the ISO14001 framework should be generalized beyond the original objective of dealing with environmental problems to accommodate any kind of problems caused by newly arising social values. This generalized framework is defined as a 'Social measure' and expected to enhance the resolution of the problem in socially appropriate manner. In the second part, this paper uses the idea of the Social measure to consider a possible solution to recover public trust on the utilization of nuclear technology, which is regarded as a typical energy problem under the social condition. (author)

Chemical contaminants in the 81Rb→/sup 81m/Kr generator arising from target deterioration

International Nuclear Information System (INIS)

Finn, R.D.; Vora, M.; Boothe, T.; Kothari, P.; Emran, A.

1985-01-01

A cyclotron adjunct to a large medical center is an extremely useful tool in the armamentarium for basic biomedical research and clinical applications. However, specific quality assurances must be applied to diagnostic radionuclides that are routinely prepared. The lack of data on the toxicity of a variety of fabrication materials used for the preparation of an automated cyclotron processing system, such as the 81 Rb→/sup 81m/Kr generator system, should be of concern. Of paramount importance is the design of an efficient and reproducible system requiring minimal maintenance. The stability of various components toward their surroundings, resistance to radiation damage, and temperature considerations must be addressed. In spite of conscientious planning, problems arise when unanticipated chemical moieties formed either from electrolytic and/or radiolytic processes appear. The authors experience with these unexpected species, as well as a hypothetical explanation of their origin, are presented

Radioactive wastes: present problems and future prospects

International Nuclear Information System (INIS)

Gauvenet, Andre

1975-01-01

The main characteristics of radioactive wastes are described and the present problems arising from liquid or gas effluents are considered. It is concluded that nuclear power stations are considerably less pollutant, at equal capacity, than conventional power stations. Programs of investigation are now being developed to meet with the foreseeable increase of activity. The problem is: first, to maintain absorbed doses at their present level and second, to study the problem of long-lived elements the storage of which would, in the long run create a nuisance on a world scale. The different waste storage techniques now in use are described and current investigations and works are exposed some of which, like vitrification, have already begun to be put into application. After having noted that the problem of wastes constitutes doubtless a difficulty in the technical field and, maybe even more so in the psychological field, the conditions are defined which will have to be met in order that this problem should not hinder the short- and long-term development of nuclear energy [fr

Bricolage Programming and Problem Solving Ability in Young Children : an Exploratory Study

OpenAIRE

Rose, Simon

2016-01-01

Visual programming environments, such as Scratch, are increasingly being used by schools to teach problem solving and computational thinking skills. However, academic research is divided on the effect that visual programming has on problem solving in a computational context. This paper focuses on the role of bricolage programming in this debate; a bottom-up programming approach that arises when using block-style programming interfaces. Bricolage programming was a term originally used to descr...

[Specific problems posed by carbohydrate utilization in the rainbow trout].

Science.gov (United States)

Bergot, F

1979-01-01

Carbohydrate incorporation in trout diets arises problems both at digestive and metabolic levels. Digestive utilization of carbohydrate closely depends on their molecular weight. In addition, in the case of complex carbohydrates (starches), different factors such as the level of incorporation, the amount consumed and the physical state of starch influence the digestibility. The measurement of digestibility in itself is confronted with methodological difficulties. The way the feces are collected can affect the digestion coefficient. Dietary carbohydrates actually serve as a source of energy. Nevertheless, above a certain level in the diet, intolerance phenomena may appear. The question that arises now is to establish the optimal part that carbohydrates can take in the metabolizable energy of a given diet.

Mind over matter? I: philosophical aspects of the mind-brain problem.

Science.gov (United States)

Schimmel, P

2001-08-01

To conceptualize the essence of the mind-body or mind-brain problem as one of metaphysics rather than science, and to propose a formulation of the problem in the context of current scientific knowledge and its limitations. The background and conceptual parameters of the mind-body problem are delineated, and the limitations of brain research in formulating a solution identified. The problem is reformulated and stated in terms of two propositions. These constitute a 'double aspect theory'. The problem appears to arise as a consequence of the conceptual limitations of the human mind, and hence remains essentially a metaphysical one. A 'double aspect theory' recognizes the essential unity of mind and brain, while remaining consistent with the dualism inherent in human experience.

Ombud’s Corner: due credit!

CERN Multimedia

Sudeshna Datta-Cockerill

2016-01-01

Patents, copyrights, trademarks… there are many ways to protect intellectual property and yet, despite these precautionary measures, it seems that colleagues sometimes still slip up: plots done by one person are used in another’s presentation without being appropriately credited, citations are wrongly assigned, references are inaccurate…   Plagiarism and misappropriation do not only happen in the worlds of art, music and literature. Often in our world, during the preparation phase of a scientific paper or even just in their daily work, scientists are required to share the work of many contributors and sometimes they do not keep track of who did what. No-one minds as long as this stays within the limits of teamwork, in which credits are distributed evenly and nobody’s contribution gets forgotten. Problems arise however, when one person’s work ends up being presented by another without the correct credit, or indeed when someone is held back from p...

Relative locality and the soccer ball problem

International Nuclear Information System (INIS)

Amelino-Camelia, Giovanni; Freidel, Laurent; Smolin, Lee; Kowalski-Glikman, Jerzy

2011-01-01

We consider the behavior of macroscopic bodies within the framework of relative locality [G. Amelino-Camelia, L. Freidel, J. Kowalski-Glikman, and L. Smolin, arXiv:1101.0931]. This is a recent proposal for Planck scale modifications of the relativistic dynamics of particles which are described as arising from deformations in the geometry of momentum space. We consider and resolve a common objection against such proposals, which is that, even if the corrections are small for elementary particles in current experiments, they are huge when applied to composite systems such as soccer balls, planets, and stars, with energies E macro much larger than M P . We show that this soccer ball problem does not arise within the framework of relative locality because the nonlinear effects for the dynamics of a composite system with N elementary particles appear at most of order E macro /N·M P .

Functioning and Participation Problems of Students with ADHD in Higher Education: Which Reasonable Accommodations Are Effective?

Science.gov (United States)

Jansen, Dorien; Petry, Katja; Ceulemans, Eva; van der Oord, Saskia; Noens, Ilse; Baeyens, Dieter

2017-01-01

Students with ADHD struggle in higher education as a result of various functioning and participation problems. However, there are remaining gaps in the literature. First, it remains unclear how often and during which teaching and evaluation methods problems arise. Second, we do not yet know which reasonable accommodations are most effective to…

Statistical optimisation techniques in fatigue signal editing problem

International Nuclear Information System (INIS)

Nopiah, Z. M.; Osman, M. H.; Baharin, N.; Abdullah, S.

2015-01-01

Success in fatigue signal editing is determined by the level of length reduction without compromising statistical constraints. A great reduction rate can be achieved by removing small amplitude cycles from the recorded signal. The long recorded signal sometimes renders the cycle-to-cycle editing process daunting. This has encouraged researchers to focus on the segment-based approach. This paper discusses joint application of the Running Damage Extraction (RDE) technique and single constrained Genetic Algorithm (GA) in fatigue signal editing optimisation.. In the first section, the RDE technique is used to restructure and summarise the fatigue strain. This technique combines the overlapping window and fatigue strain-life models. It is designed to identify and isolate the fatigue events that exist in the variable amplitude strain data into different segments whereby the retention of statistical parameters and the vibration energy are considered. In the second section, the fatigue data editing problem is formulated as a constrained single optimisation problem that can be solved using GA method. The GA produces the shortest edited fatigue signal by selecting appropriate segments from a pool of labelling segments. Challenges arise due to constraints on the segment selection by deviation level over three signal properties, namely cumulative fatigue damage, root mean square and kurtosis values. Experimental results over several case studies show that the idea of solving fatigue signal editing within a framework of optimisation is effective and automatic, and that the GA is robust for constrained segment selection

Statistical optimisation techniques in fatigue signal editing problem

Energy Technology Data Exchange (ETDEWEB)

Nopiah, Z. M.; Osman, M. H. [Fundamental Engineering Studies Unit Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM (Malaysia); Baharin, N.; Abdullah, S. [Department of Mechanical and Materials Engineering Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM (Malaysia)

2015-02-03

Success in fatigue signal editing is determined by the level of length reduction without compromising statistical constraints. A great reduction rate can be achieved by removing small amplitude cycles from the recorded signal. The long recorded signal sometimes renders the cycle-to-cycle editing process daunting. This has encouraged researchers to focus on the segment-based approach. This paper discusses joint application of the Running Damage Extraction (RDE) technique and single constrained Genetic Algorithm (GA) in fatigue signal editing optimisation.. In the first section, the RDE technique is used to restructure and summarise the fatigue strain. This technique combines the overlapping window and fatigue strain-life models. It is designed to identify and isolate the fatigue events that exist in the variable amplitude strain data into different segments whereby the retention of statistical parameters and the vibration energy are considered. In the second section, the fatigue data editing problem is formulated as a constrained single optimisation problem that can be solved using GA method. The GA produces the shortest edited fatigue signal by selecting appropriate segments from a pool of labelling segments. Challenges arise due to constraints on the segment selection by deviation level over three signal properties, namely cumulative fatigue damage, root mean square and kurtosis values. Experimental results over several case studies show that the idea of solving fatigue signal editing within a framework of optimisation is effective and automatic, and that the GA is robust for constrained segment selection.

The use of Adomian decomposition method for solving problems in calculus of variations

Directory of Open Access Journals (Sweden)

Mehdi Dehghan

2006-01-01

Full Text Available In this paper, a numerical method is presented for finding the solution of some variational problems. The main objective is to find the solution of an ordinary differential equation which arises from the variational problem. This work is done using Adomian decomposition method which is a powerful tool for solving large amount of problems. In this approach, the solution is found in the form of a convergent power series with easily computed components. To show the efficiency of the method, numerical results are presented.

Some dynamic resource allocation problems in wireless networks

Science.gov (United States)

Berry, Randall

2001-07-01

We consider dynamic resource allocation problems that arise in wireless networking. Specifically transmission scheduling problems are studied in cases where a user can dynamically allocate communication resources such as transmission rate and power based on current channel knowledge as well as traffic variations. We assume that arriving data is stored in a transmission buffer, and investigate the trade-off between average transmission power and average buffer delay. A general characterization of this trade-off is given and the behavior of this trade-off in the regime of asymptotically large buffer delays is explored. An extension to a more general utility based quality of service definition is also discussed.

Cuticular characteristics in the detection of plant stress due to air pollution - new problems in the use of these cuticular characteristics

International Nuclear Information System (INIS)

Garrec, J.P.

1994-01-01

The foliar surface, and particularly the cuticle, is the first zone of impact of air pollutants on leaves. At the level of the cuticle, it is mainly studies on the modifications of the physico-chemical properties of the waxes that allow us to detect and estimate plant stress. However, during recent years, with modifications in the nature and level of air pollution (decrease of primary pollutants: SO 2 , HF; increase of secondary pollutants: O 2 , acid deposits; increase of nitrogen deposits; increase of organic micropollutants; appearence of global environmental problems: CO 2 , climatic change), the physiological impact on plants and in particular on the cuticle is different. For this reason, new problems have appeared and use of cuticular characteristics in the detection of plant stress due to air pollutants has recently evolved. Some examples are given, but much remains to be done to understand the effects on the cuticle of these new modifications of the atmospheric environment of plants. (orig.)

THE MULTIPLE CHOICE PROBLEM WITH INTERACTIONS BETWEEN CRITERIA

Directory of Open Access Journals (Sweden)

Luiz Flavio Autran Monteiro Gomes

2015-12-01

Full Text Available ABSTRACT An important problem in Multi-Criteria Decision Analysis arises when one must select at least two alternatives at the same time. This can be denoted as a multiple choice problem. In other words, instead of evaluating each of the alternatives separately, they must be combined into groups of n alternatives, where n = 2. When the multiple choice problem must be solved under multiple criteria, the result is a multi-criteria, multiple choice problem. In this paper, it is shown through examples how this problemcan be tackled on a bipolar scale. The Choquet integral is used in this paper to take care of interactions between criteria. A numerical application example is conducted using data from SEBRAE-RJ, a non-profit private organization that has the mission of promoting competitiveness, sustainable developmentand entrepreneurship in the state of Rio de Janeiro, Brazil. The paper closes with suggestions for future research.

Methods of using the quadratic assignment problem solution

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Izabela Kudelska

2012-09-01

Full Text Available Background: Quadratic assignment problem (QAP is one of the most interesting of combinatorial optimization. Was presented by Koopman and Beckamanna in 1957, as a mathematical model of the location of indivisible tasks. This problem belongs to the class NP-hard issues. This forces the application to the solution already approximate methods for tasks with a small size (over 30. Even though it is much harder than other combinatorial optimization problems, it enjoys wide interest because it models the important class of decision problems. Material and methods: The discussion was an artificial intelligence tool that allowed to solve the problem QAP, among others are: genetic algorithms, Tabu Search, Branch and Bound. Results and conclusions: QAP did not arise directly as a model for certain actions, but he found its application in many areas. Examples of applications of the problem is: arrangement of buildings on the campus of the university, layout design of electronic components in systems with large scale integration (VLSI, design a hospital, arrangement of keys on the keyboard.

Characterization of Rayleigh backscattering arising in various two-mode fibers

NARCIS (Netherlands)

Yu, Dawei; Fu, Songnian; Cao, Zizheng; Tang, Ming; Deng, Lei; Liu, Deming; Giles, I.; Koonen, T.; Okonkwo, C.

2016-01-01

We experimentally characterize the mode dependent characteristics of Rayleigh backscattering (RB) arising in various two-mode fibers (TMFs). With the help of an all-fiber photonic lantern, we are able to measure the RB power at individual modes. Consequently, mode dependent power distribution of RB

An Empirical Investigation into the Matching Problems among Game Theoretically Coordinating Parties in a Virtual Organization

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Muhammad Yasir

2010-09-01

Full Text Available Virtual organization emerged as a highly flexible structure in response to the rapidly changing environment of 20th century. This organization consists of independently working parties that combine their best possible resources to exploit the emerging market opportunities. There are no formal control and coordination mechanisms employed by the classical hierarchical structures. Parties, therefore, manage their dependencies on each other through mutual understanding and trust.Mathematician John Nash, having significant contributions in Game Theory suggests that in every non-cooperative game there is at least one equilibrium point. At this point, according to him, every strategy of the player represents a response to the others’ strategies. Such equilibria could exist in a virtual organization, at which parties coordinate which each other to optimize their performance.Coordination/Matching problems are likely to arise among game theoretically coordinating parties in a virtual organization, mainly due to lack of binding agreements. By identifying and resolving these matching problems, virtual organizations could achieve efficiency and better coordination among parties.  

Contributions to thermal and fluid dynamic problems in nuclear technology

International Nuclear Information System (INIS)

Mueller, U.; Krebs, L.; Rust, K.

1984-02-01

The majority of contributions compiled in this report deals with thermal and fluid dynamic problems in nuclear engineering. Especially problems of heat transfer and cooling are represented which may arise during and afer a loss-of-coolant accident both in light water reactors and in liquid metal cooled fast breeder reactors. Papers on the mass transfer in pressurized water, tribological problems in sodium cooled reactors, the fluid dynamics of pulsed column, and fundamental investigations of convective flows supplement these contributions on problems connected with accidents. Furthermore, a keynote paper presents the individual activities relating to the reliability of reactor components, a field recently included in our research program. Technical solutions to special problems are closely connected to the investigations based on experiments. Therefore, several contributions deal with new developments in technology and measuring techniques. (orig.) [de

Endometrial Stromal Sarcoma Arising in Colorectal Endometriosis: A Case Report and Review of the Literature

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Qiao Wang

2015-01-01

Full Text Available Extrauterine endometrial stromal sarcoma (ESS arising in endometriosis is extremely rare, particularly in the colorectum. It should always be included in the differential diagnosis of primary tumors originating from gastrointestinal tract in females, given that preoperative endoscopical biopsy may reveal no specific changes. We reported a case of ESS arising in colorectal endometriosis and reviewed the previous 7 cases reported in the English literature. Our patient, who was unavailable for tumor resection and refused further adjuvant therapy, played a role in representing the natural history of low-grade extragenital ESS. This case was the only death from ESS arising in colorectal endometriosis.

Multi-Objective Flexible Flow Shop Scheduling Problem Considering Variable Processing Time due to Renewable Energy

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Xiuli Wu

2018-03-01

Full Text Available Renewable energy is an alternative to non-renewable energy to reduce the carbon footprint of manufacturing systems. Finding out how to make an alternative energy-efficient scheduling solution when renewable and non-renewable energy drives production is of great importance. In this paper, a multi-objective flexible flow shop scheduling problem that considers variable processing time due to renewable energy (MFFSP-VPTRE is studied. First, the optimization model of the MFFSP-VPTRE is formulated considering the periodicity of renewable energy and the limitations of energy storage capacity. Then, a hybrid non-dominated sorting genetic algorithm with variable local search (HNSGA-II is proposed to solve the MFFSP-VPTRE. An operation and machine-based encoding method is employed. A low-carbon scheduling algorithm is presented. Besides the crossover and mutation, a variable local search is used to improve the offspring’s Pareto set. The offspring and the parents are combined and those that dominate more are selected to continue evolving. Finally, two groups of experiments are carried out. The results show that the low-carbon scheduling algorithm can effectively reduce the carbon footprint under the premise of makespan optimization and the HNSGA-II outperforms the traditional NSGA-II and can solve the MFFSP-VPTRE effectively and efficiently.

Chondrosarcoma arising within a radiation-induced osteochondroma several years following childhood total body irradiation: Case report

Energy Technology Data Exchange (ETDEWEB)

Nagata, Shuji [Kurume University Hospital, Department of Radiology, Fukuoka (Japan); Shen, Robert K. [Mayo Clinic, Department of Surgery, Rochester, MN (United States); Laack, Nadia N. [Mayo Clinic, Department of Radiation Oncology, Rochester, MN (United States); Inwards, Carrie Y. [Mayo Clinic, Department of Pathology, Rochester, MN (United States); Wenger, Doris E.; Amrami, Kimberly K. [Mayo Clinic, Department of Radiology, Rochester, MN (United States)

2013-08-15

Malignant degeneration arising in radiation-induced osteochondromas is extremely rare. We report a case of a 34-year-old man with a chondrosarcoma arising from an osteochondroma of the left posterior eighth rib that developed following total body irradiation received as part of the conditioning regimen prior to bone marrow transplantation at age 8. To our knowledge, this is only the fourth reported case of a chondrosarcoma arising within a radiation-induced osteochondroma and the first case occurring following childhood total body irradiation. (orig.)

Chondrosarcoma arising within a radiation-induced osteochondroma several years following childhood total body irradiation: Case report

International Nuclear Information System (INIS)

Nagata, Shuji; Shen, Robert K.; Laack, Nadia N.; Inwards, Carrie Y.; Wenger, Doris E.; Amrami, Kimberly K.

2013-01-01

Malignant degeneration arising in radiation-induced osteochondromas is extremely rare. We report a case of a 34-year-old man with a chondrosarcoma arising from an osteochondroma of the left posterior eighth rib that developed following total body irradiation received as part of the conditioning regimen prior to bone marrow transplantation at age 8. To our knowledge, this is only the fourth reported case of a chondrosarcoma arising within a radiation-induced osteochondroma and the first case occurring following childhood total body irradiation. (orig.)

Stability Estimates for h-p Spectral Element Methods for Elliptic Problems

NARCIS (Netherlands)

Dutt, Pravir; Tomar, S.K.; Kumar, B.V. Rathish

2002-01-01

In a series of papers of which this is the first we study how to solve elliptic problems on polygonal domains using spectral methods on parallel computers. To overcome the singularities that arise in a neighborhood of the corners we use a geometrical mesh. With this mesh we seek a solution which

Giant lipoma arising from deep lobe of the parotid gland

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Hsu Ying-Che

2006-06-01

Full Text Available Abstract Background Lipomas are common benign soft tissue neoplasms but they are found very rarely in the deep lobe of parotid gland. Surgical intervention in these tumors is challenging because of the proximity of the facial nerve, and thus knowledge of the anatomy and meticulous surgical technique are essential. Case presentation A 71-year-old female presented with a large asymptomatic mass, which had occupied the left facial area for over the past fifteen years, and she requested surgical excision for a cosmetically better facial appearance. The computed tomography (CT scan showed a well-defined giant lipoma arising from the left deep parotid gland. The lipoma was successfully enucleated after full exposure and mobilization of the overlying facial nerve branches. The surgical specimen measured 9 × 6 cm in size, and histopathology revealed fibrolipoma. The patient experienced an uneventful recovery, with a satisfying facial contour and intact facial nerve function. Conclusion Giant lipomas involving the deep parotid lobe are extremely rare. The high-resolution CT scan provides an accurate and cost-effective preoperative investigative method. Surgical management of deep lobe lipoma should be performed by experienced surgeons due to the need for meticulous dissection of the facial nerve branches. Superficial parotidectomy before deep lobe lipoma removal may be unnecessary in selected cases because preservation of the superficial lobe may contribute to a better aesthetic and functional result.

Analytic approximations to nonlinear boundary value problems modeling beam-type nano-electromechanical systems

Energy Technology Data Exchange (ETDEWEB)

Zou, Li [Dalian Univ. of Technology, Dalian City (China). State Key Lab. of Structural Analysis for Industrial Equipment; Liang, Songxin; Li, Yawei [Dalian Univ. of Technology, Dalian City (China). School of Mathematical Sciences; Jeffrey, David J. [Univ. of Western Ontario, London (Canada). Dept. of Applied Mathematics

2017-06-01

Nonlinear boundary value problems arise frequently in physical and mechanical sciences. An effective analytic approach with two parameters is first proposed for solving nonlinear boundary value problems. It is demonstrated that solutions given by the two-parameter method are more accurate than solutions given by the Adomian decomposition method (ADM). It is further demonstrated that solutions given by the ADM can also be recovered from the solutions given by the two-parameter method. The effectiveness of this method is demonstrated by solving some nonlinear boundary value problems modeling beam-type nano-electromechanical systems.

A possible solution of the flavor problem and radiative neutrino masses

International Nuclear Information System (INIS)

Adulpravitchai, Adisorn

2010-01-01

In this thesis, we discuss two important problems of the Standard Model of Particle Physics (SM), namely the flavor problem and the reason for the smallness of neutrino masses. The first one might be related to the origin of non-abelian discrete flavor symmetries. We discuss the possibility of obtaining them from an underlying continuous flavor symmetry, i.e. SU(2) or SU(3) through spontaneous symmetry breaking. Moreover, we investigate their possible origin from an orbifold compactification. We discuss all non-abelian discrete symmetries, which can arise from an orbifold T 2 /Z N . They are A 4 , S 4 , D 4 , D 3 , and D 6 . We present the idea of combining the breaking of an orbifold GUT and the flavor symmetry arising from the orbifold. We demonstrate the construction in a 6d SUSY SO(10) x S 4 . For the second problem, we propose a one-loop neutrino mass model in the left-right symmetric framework. We observe the transmitted hierarchy from the charged lepton masses to the right-handed neutrino masses, which we call ''Radiative Transmission of Lepton Flavor Hierarchy''. Finally, we study the phenomenological aspects of the model such as lepton flavor violation (LFV), flavor number violation (FNV), and flavor changing neutral currents (FCNCs). (orig.)

Visual integration dysfunction in schizophrenia arises by the first psychotic episode and worsens with illness duration.

Science.gov (United States)

Keane, Brian P; Paterno, Danielle; Kastner, Sabine; Silverstein, Steven M

2016-05-01

Visual integration dysfunction characterizes schizophrenia, but prior studies have not yet established whether the problem arises by the first psychotic episode or worsens with illness duration. To investigate the issue, we compared chronic schizophrenia patients (SZs), first episode psychosis patients (FEs), and well-matched healthy controls on a brief but sensitive psychophysical task in which subjects attempted to locate an integrated shape embedded in noise. Task difficulty depended on the number of noise elements co-presented with the shape. For half of the experiment, the entire display was scaled down in size to produce a high spatial frequency (HSF) condition, which has been shown to worsen patient integration deficits. Catch trials-in which the circular target appeared without noise-were also added so as to confirm that subjects were paying adequate attention. We found that controls integrated contours under noisier conditions than FEs, who, in turn, integrated better than SZs. These differences, which were at times large in magnitude (d = 1.7), clearly emerged only for HSF displays. Catch trial accuracy was above 95% for each group and could not explain the foregoing differences. Prolonged illness duration predicted poorer HSF integration across patients, but age had little effect on controls, indicating that the former factor was driving the effect in patients. Taken together, a brief psychophysical task efficiently demonstrates large visual integration impairments in schizophrenia. The deficit arises by the first psychotic episode, worsens with illness duration, and may serve as a biomarker of illness progression. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

How Do They Solve It? An Insight into the Learner's Approach to the Mechanism of Physics Problem Solving

Science.gov (United States)

Hegde, Balasubrahmanya; Meera, B. N.

2012-01-01

A perceived difficulty is associated with physics problem solving from a learner's viewpoint, arising out of a multitude of reasons. In this paper, we have examined the microstructure of students' thought processes during physics problem solving by combining the analysis of responses to multiple-choice questions and semistructured student…

Performance of mixed formulations for the particle finite element method in soil mechanics problems

Science.gov (United States)

Monforte, Lluís; Carbonell, Josep Maria; Arroyo, Marcos; Gens, Antonio

2017-07-01

This paper presents a computational framework for the numerical analysis of fluid-saturated porous media at large strains. The proposal relies, on one hand, on the particle finite element method (PFEM), known for its capability to tackle large deformations and rapid changing boundaries, and, on the other hand, on constitutive descriptions well established in current geotechnical analyses (Darcy's law; Modified Cam Clay; Houlsby hyperelasticity). An important feature of this kind of problem is that incompressibility may arise either from undrained conditions or as a consequence of material behaviour; incompressibility may lead to volumetric locking of the low-order elements that are typically used in PFEM. In this work, two different three-field mixed formulations for the coupled hydromechanical problem are presented, in which either the effective pressure or the Jacobian are considered as nodal variables, in addition to the solid skeleton displacement and water pressure. Additionally, several mixed formulations are described for the simplified single-phase problem due to its formal similitude to the poromechanical case and its relevance in geotechnics, since it may approximate the saturated soil behaviour under undrained conditions. In order to use equal-order interpolants in displacements and scalar fields, stabilization techniques are used in the mass conservation equation of the biphasic medium and in the rest of scalar equations. Finally, all mixed formulations are assessed in some benchmark problems and their performances are compared. It is found that mixed formulations that have the Jacobian as a nodal variable perform better.

Multi-focal lobular carcinoma in situ arising in benign phylodes tumor: A case report

International Nuclear Information System (INIS)

Lee, Taeg Ki; Choi, Chang Hwan; Kim, Youn Jeong; Kim, Mi Young; Lee, Kyung Hee; Cho, Soon Gu

2015-01-01

Coexistent breast malignancy arising in phyllodes tumor is extremely rare, and most of them are incidental reports after surgical excision. Coexistent malignancy in phyllodes tumor can vary from in-situ to invasive carcinoma. Lobular neoplasia is separated into atypical lobular hyperplasia and lobular carcinoma in situ (LCIS). LCIS is known to have a higher risk of developing invasive cancer. We reported imaging findings of multifocal LCIS arising in benign phyllodes tumor

Multi-focal lobular carcinoma in situ arising in benign phylodes tumor: A case report

Energy Technology Data Exchange (ETDEWEB)

Lee, Taeg Ki; Choi, Chang Hwan; Kim, Youn Jeong; Kim, Mi Young; Lee, Kyung Hee; Cho, Soon Gu [Inha University Hospital, Incheon (Korea, Republic of)

2015-08-15

Coexistent breast malignancy arising in phyllodes tumor is extremely rare, and most of them are incidental reports after surgical excision. Coexistent malignancy in phyllodes tumor can vary from in-situ to invasive carcinoma. Lobular neoplasia is separated into atypical lobular hyperplasia and lobular carcinoma in situ (LCIS). LCIS is known to have a higher risk of developing invasive cancer. We reported imaging findings of multifocal LCIS arising in benign phyllodes tumor.

Radiation-induced squamous carcinoma arising within a seborrhoeic keratosis

Energy Technology Data Exchange (ETDEWEB)

Suvarna, S.K.; Bagary, M.; Glazer, G. (Saint Mary' s Hospital, London (United Kingdom))

1993-04-01

Seborrhoeic keratoses (SK) are common skin tumours. They are benign, and present little difficulty in management. However, rare malignant transformation is recognized. The authors report a case of a squamous cell carcinoma arising from dysplastic changes within a long-standing SK on the chest wall of a 75-year-old retired radiologist, and consider the role of radiation in inducing malignant change within SKs. (author).

Radiation-induced squamous carcinoma arising within a seborrhoeic keratosis

International Nuclear Information System (INIS)

Suvarna, S.K.; Bagary, M.; Glazer, G.

1993-01-01

Seborrhoeic keratoses (SK) are common skin tumours. They are benign, and present little difficulty in management. However, rare malignant transformation is recognized. The authors report a case of a squamous cell carcinoma arising from dysplastic changes within a long-standing SK on the chest wall of a 75-year-old retired radiologist, and consider the role of radiation in inducing malignant change within SKs. (author)

Mucinous adenocarcinoma arising at the anastomotic site after operation for hirschsprung's disease: case report

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyung Soo; Yoon, Kwon Ha [College of Medicine, Wonkwang Univ., Iksan (Korea, Republic of)

2004-02-01

To our knowledge, rectal cancer arising at the anastomotic site after surgery for Hirschsprung's disease has not been reported. We report a case of mucinous adenocarcinoma arising at the anastomotic site after Soave operation 26 years ago.

On a Mixed Nonlinear One Point Boundary Value Problem for an Integrodifferential Equation

Directory of Open Access Journals (Sweden)

Mesloub Said

2008-01-01

Full Text Available This paper is devoted to the study of a mixed problem for a nonlinear parabolic integro-differential equation which mainly arise from a one dimensional quasistatic contact problem. We prove the existence and uniqueness of solutions in a weighted Sobolev space. Proofs are based on some a priori estimates and on the Schauder fixed point theorem. we also give a result which helps to establish the regularity of a solution.

Incentive Problems in Banking Supervision: The European Case

OpenAIRE

Schüler, Martin

2003-01-01

This paper discusses the incentive conflicts that arise in banking supervision in the EU in a principal-agent framework, where the regulator is the agent and the taxpayers is the principal. The regulatory agent in addition to maintaining financial stability (the objective of the principal) may pursue private interests. Incomplete information, insufficient accountability of the agent and lack of enforceability of compliance result in an incentive problem. A reform of the European supervisory s...

Computerized systems of NPP operators support. (Psychological problems)

International Nuclear Information System (INIS)

Mashin, V.A.

1995-01-01

Operator psychological problems arising in the work with NPP operators support computerized systems (OSCS) are considered. The conclusion is made that the OSCS intellectual application will bring the operator into dangerous dependence on his computerized assistant. To avoid this danger it is necessary by creation of the OSCS to divide specially the tasks areas of the operator and OSCS in order to assure the active role of the operator in the NPP control

Solving network design problems via decomposition, aggregation and approximation

CERN Document Server

Bärmann, Andreas

2016-01-01

Andreas Bärmann develops novel approaches for the solution of network design problems as they arise in various contexts of applied optimization. At the example of an optimal expansion of the German railway network until 2030, the author derives a tailor-made decomposition technique for multi-period network design problems. Next, he develops a general framework for the solution of network design problems via aggregation of the underlying graph structure. This approach is shown to save much computation time as compared to standard techniques. Finally, the author devises a modelling framework for the approximation of the robust counterpart under ellipsoidal uncertainty, an often-studied case in the literature. Each of these three approaches opens up a fascinating branch of research which promises a better theoretical understanding of the problem and an increasing range of solvable application settings at the same time. Contents Decomposition for Multi-Period Network Design Solving Network Design Problems via Ag...

Toward an Improved Representation of Middle Atmospheric Dynamics Thanks to the ARISE Project

Czech Academy of Sciences Publication Activity Database

Blanc, E.; Ceranna, L.; Hauchecorne, A.; Charlton-Perez, A.; Marchetti, E.; Evers, L.G.; Kvaerna, T.; Laštovička, Jan; Eliasson, L.; Crosby, N. B.; Blanc-Benon, P.; Le Pichon, A.; Brachet, N.; Pilger, C.; Keckhut, P.; Assink, J.D.; Smets, P. S. M.; Lee, C. F.; Kero, J.; Šindelářová, Tereza; Kämpfer, N.; Rüfenacht, R.; Farges, T.; Millet, C.; Näsholm, S. P.; Gibbons, S. J.; Espy, P. J.; Hibbins, R. E.; Heinrich, P.; Ripepe, M.; Khaykin, S.; Mze, N.; Chum, Jaroslav

2018-01-01

Roč. 39, č. 2 (2018), s. 171-225 ISSN 0169-3298 EU Projects: European Commission(XE) 284387 - ARISE; European Commission(XE) 653980 - ARISE2 Institutional support: RVO:68378289 Keywords : Atmospheric dynamics * Middle atmosphere * Infrasound * Gravity waves * Volcanoes * Atmospheric disturbances * Extreme events * stratospheric temperature trends * total solar eclipse * wave momentum flux * natural infrasound * acoustic-waves * polar-low * model simulations * sudden warmings * Doppler lidar Subject RIV: DG - Athmosphere Sciences, Meteorology OBOR OECD: Meteorology and atmospheric sciences Impact factor: 4.413, year: 2016 https://link.springer.com/article/10.1007/s10712-017-9444-0

Adenocarcinoma arising in female urethral diverticulum

International Nuclear Information System (INIS)

Patanaphan, V.; Prempree, T.; Sewchand, W.; Hafiz, M.A.; Jaiwatana, J.

1983-01-01

Cancer arising from a female urethral diverticulum is rare, and because of its rarity, a review of the medical literature reveals significant nonuniformity in its management. We report an additional 2 cases of this disease, one of which has an even rarer feature of being mucin-producing. The management of our 2 cases is presented in detail and in line with the management of female urethral cancer. From our extensive literature search, diverticulectomy alone showed poor results with the highest rate of recurrence (67%). Extensive surgery, either in the form of cystourethrectomy or anterior exenteration, offered results comparable with those of combined therapy (diverticulectomy and full course of irradiation for early cases; preoperative irradiation followed by cystourethrectomy for late cases). Individualization of radiation treatment and cooperative effort between urologist and radiation oncologist are essential if best results are to be achieved

Primary diffuse large B cell lymphoma arising from a leiomyoma of the uterine corpus.

Science.gov (United States)

Zhao, Lianhua; Ma, Qiang; Wang, Qiushi; Zeng, Ying; Luo, Qingya; Xiao, Hualiang

2016-01-20

Primary diffuse large B cell lymphoma (DLBCL) of the uterus is rare, and primary DLBCL arising from a uterine leiomyoma (collision tumor) has not been reported in the literature. We describe the clinical, histological, immunohistochemical, and molecular features of primary DLBCL arising from a leiomyoma in the uterine corpus. A 73-year-old female patient had a uterine mass for 23 years. An ultrasound scan revealed marked enlargement of the uterus, measuring 18.2 × 13 × 16.3 cm, with a 17.6 × 10.9 × 11.6 cm hypoechoic mass in the uterine corpus. The tumors consisted of medium- to large-sized cells exhibiting a diffuse pattern of growth with a well-circumscribed leiomyoma. The neoplastic cells strongly expressed CD79α, CD20 and PAX5. Molecular analyses indicated clonal B-cell receptor gene rearrangement. To the best of our knowledge, no previous cases of primary DLBCL arising from a leiomyoma have been reported. It is necessary to differentiate a diagnosis of primary DLBCL arising from a leiomyoma from that of leiomyoma with florid reactive lymphocytic infiltration (lymphoma-like lesion). Careful analysis of clinical, histological, immunophenotypic, and genetic features is required to establish the correct diagnosis.

Sumudu transform series expansion method for solving the local fractional Laplace equation in fractal thermal problems

Directory of Open Access Journals (Sweden)

Guo Zheng-Hong

2016-01-01

Full Text Available In this article, the Sumudu transform series expansion method is used to handle the local fractional Laplace equation arising in the steady fractal heat-transfer problem via local fractional calculus.

Difficulties of Secondary school teachers implicating in the reading, innovation and research in science education (II: the problem of “hands-on”

Directory of Open Access Journals (Sweden)

Oliva Martínez, José María

2012-04-01

Full Text Available This work is a continuation of another recent article in these pages (Oliva, 2011, which dealt with the difficulties of high school teachers to start in the dynamics of innovation and research in science education. In another study that examined the views expressed by a sample of 16 secondary science teachers around the obstacles to immersion in these tasks, as well as comments, expressed doubts and obstacles they face the task write a short article in the context of an introductory training course on this subject. From the same source, in this other paper the intrinsic difficulties that arise once the teachers decide to engage in this type of work and faces the tasks associated with these processes. The problems identified in this case are due, among other reasons, lack of trust in teachers' own possibilities, difficulties in the formulating of the problem object of research, lack of theoretical and problems in drafting written work. From the above results makes some conclusions and implications for teacher training in this field.

Return to Work after sick leave due to mental health problems

NARCIS (Netherlands)

Lagerveld, S.; Houtman, I.L.D.

2014-01-01

The article will describe factors of influence on return to work RTW and evidence-based interventions that enhance return to work (RTW) after sick leave due to common mental health disorders (CMD). First the concepts of both RTW and CMD are outlined. Second, the sense of urgency for effective RTW

The Topical Problems of Reengineering of Production Enterprises

Directory of Open Access Journals (Sweden)

Chumak Larysa F.

2018-01-01

Full Text Available The article is aimed at researching the problems of reengineering of industrial enterprises and determining the efficient ways of their solution. The essence of process of reengineering, conditions and expediency of carrying out reengineering were researched. Elements of the system of principles of reengineering, its stages, problems of implementation, and typical errors arising during reengineering, have been defined. It has been determined that reengineering should be closely connected with the strategies of industrial enterprise in order to achieve maximum efficiency of the enterprise’s activity and to prevent additional costs. Reengineering of an industrial enterprise should be supported by an appropriate organizational structure, sound information technology, and contemporary strategic considerations.

HOSPITALIZATIONS DUE TO RESPIRATORY PROBLEMS DURING DIWALI FESTIVAL IN A TERTIARY CARE HOSPITAL IN SOUTH INDIA

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Raghu

2016-02-01

Full Text Available BACKGROUND The burning of firecrackers during Diwali festival produces an adverse respiratory outcome. However, there are no published articles on the impact of fireworks on hospital admission due to acute respiratory issues, hospital stay, and respiratory mortality during Diwali in India. MATERIALS AND METHODS This was a prospective, open label, observational study. It was conducted in patients admitted to the pulmonary emergency unit with respiratory symptoms 15 days before and after Diwali. It was conducted after the approval of ethics committee and written informed consent. RESULTS The number of admissions post-Diwali were significantly more compared to pre-Diwali from both rural and urban locations (p<0.001. The mean duration of hospital stay was significantly less pre-Diwali (7.59±0.74 days compared to post-Diwali (9.46±0.44 days. Also, significantly increased number of patients required ventilator support post Diwali. CONCLUSION The findings from the present study validate the deterioration of respiratory health during Diwali festival in India. There should be more awareness campaigns about the harmful effects of fire-crackers. Patients suffering from respiratory problems should be advised to avoid heavy exposure to fireworks

Hypokalemic paralysis due to primary hyperaldosteronism simulating gitelman′s syndrome

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Kasifoglu Timucin

2009-01-01

Full Text Available Some diseases, such as Gitelman′s syndrome, Bartter′s syndrome, and primary hyperaldosteronism (Conn′s syndrome, may bear some similar clinical and laboratory findings. Their treatment modalities being different from one another, the need for a scrupulous diagnostic evaluation arises as far as clinical practice is concerned. In this report, we present a patient with Conn′s syndrome who was initially considered to have Gitelman′s syndrome due to displaying a few overlapping features of both diseases. We also give an account of the hardships encountered during the diagnostic evaluation.

Testicular artery arising from an aberrant right renal artery | Suluba ...

African Journals Online (AJOL)

This case report we discovered the rare variation of the origin of the right testicular artery arising from the right aberrant renal artery with double renal artery irrigating both left and right kidneys. These variations in the testicular arteries and renal arteries have implication to surgical procedures such as orchidopexy repair for ...

Three-body ΛNN force due to Λ-Σ coupling

International Nuclear Information System (INIS)

Myint, Khin Swe; Akaishi, Yoshinori

2003-01-01

The ΛNN three - body force due to coherent Λ - Σ Coupling effect was derived from realistic Nijmegen model D potential. Repulsive and attractive three - body ΛNN forces were reconcilably accounted. For 5 He, within one - channel description, ΛNN force is largely repulsive and its origin comes from Pauli forbidden terms. Within two - channel description, attractive Pauli allowed terms exist and resulting three - body force is always attractive. Large attractive ΛNN force effect due to coherent Λ - Σ coupling effect is predicted in neutron - rich nuclei. The attractive coherent Λ - Σ coupling effect is largely enhanced at high density neutron matter. The attractive three - body ΛNN force effect is essential dynamics of Λ - Σ coupling while the repulsive Nogami three - body effect arises from Pauli forbidden diagrams. (Y. Kazumata)

Steel heat treating: mathematical modelling and numerical simulation of a problem arising in the automotive industry

Directory of Open Access Journals (Sweden)

Jose Manuel Diaz Moreno

2017-12-01

Full Text Available We describe a mathematical model for the industrial heating and cooling processes of a steel workpiece representing the steering rack of an automobile. The goal of steel heat treating is to provide a hardened surface on critical parts of the workpiece while keeping the rest soft and ductile in order to reduce fatigue. The high hardness is due to the phase transformation of steel accompanying the rapid cooling. This work takes into account both heating-cooling stage and viscoplastic model. Once the general mathematical formulation is derived, we can perform some numerical simulations.

To the problem of foreign experience application for power generation management

International Nuclear Information System (INIS)

Barinov, V.A.

1993-01-01

The structure and organization of the United Power System in the former USSR and problems arised later in connection with its reorganization are discussed. It is shown that the model, in which the Russian power system operation efficiency is achieved via the mechanism of coordination and competition, but not via the marketing force actions, is the most advantageous one

Mental health problems due to community violence exposure in a small urban setting

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Faraz Ahmad

2017-10-01

Full Text Available Objective: Studies conducted in large metropolitan inner-city communities with high violent crime rates have demonstrated an association between exposure to violence and mental health problems; therefore the purpose of this study was to determine if similar trends exist in smaller inner-city communities with substantially lower violent crime rates. Methods: One hundred twenty-six children and young adults living in inner-city Omaha, Nebraska, were screened for posttraumatic stress disorder (PTSD, depression, and anxiety symptoms and assessed for community violence exposure (CVE. Pearson’s correlation and analysis of variance were used to determine the relationship between PTSD, depression, and anxiety symptoms and CVE. Results: A statistically significant relationship was found between CVE and PTSD and anxiety symptoms among participants despite their having lower rates of exposure to violent events in comparison with other studies. No association was found between violence and depression symptoms. Additionally, the presence of anxiety and depression, as well as increased age of participants, was associated with higher rates of PTSD symptoms. Conclusion: We recommend that health care providers in smaller cities, where the effects of violent crime may be underestimated or overlooked, be informed of the existence of this public health problem within their community and that they screen at-risk patients for mental health problems.

Competitive Benchmarking: An IS Research Approach to Address Wicked Problems with Big Data and Analytics

NARCIS (Netherlands)

W. Ketter (Wolfgang); M. Peters (Markus); J. Collins (John); A. Gupta (Alok)

2015-01-01

textabstractWicked problems like sustainable energy and financial market stability are societal challenges that arise from complex socio-technical systems in which numerous social, economic, political, and technical factors interact. Understanding and mitigating them requires research methods that

Constraint-Based Local Search for Constrained Optimum Paths Problems

Science.gov (United States)

Pham, Quang Dung; Deville, Yves; van Hentenryck, Pascal

Constrained Optimum Path (COP) problems arise in many real-life applications and are ubiquitous in communication networks. They have been traditionally approached by dedicated algorithms, which are often hard to extend with side constraints and to apply widely. This paper proposes a constraint-based local search (CBLS) framework for COP applications, bringing the compositionality, reuse, and extensibility at the core of CBLS and CP systems. The modeling contribution is the ability to express compositional models for various COP applications at a high level of abstraction, while cleanly separating the model and the search procedure. The main technical contribution is a connected neighborhood based on rooted spanning trees to find high-quality solutions to COP problems. The framework, implemented in COMET, is applied to Resource Constrained Shortest Path (RCSP) problems (with and without side constraints) and to the edge-disjoint paths problem (EDP). Computational results show the potential significance of the approach.

2-Sensor Problem

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Michael Segal

2004-11-01

Full Text Available Abstract: Ad-hoc networks of sensor nodes are in general semi-permanently deployed. However, the topology of such networks continuously changes over time, due to the power of some sensors wearing out to new sensors being inserted into the network, or even due to designers moving sensors around during a network re-design phase (for example, in response to a change in the requirements of the network. In this paper, we address the problem of covering a given path by a limited number of sensors — in our case to two, and show its relation to the well-studied matrix multiplication problem.

Primary intraosseous carcinoma arising from odontogenic keratocyst with parotid lymph node metastasis. A case report

Directory of Open Access Journals (Sweden)

Siddesh Shenoy

2007-01-01

Full Text Available Squamous cell carcinoma (SCC arising from odontogenic cyst lining is rare. The exact incidence of carcinoma arising in odontogenic cyst is unknown, but it is estimated to vary between 1 and 2/1000. The pathogenesis is unknown, but a long-standing inflammation and continuous intracystic pressure have been suggested as possible causative factors. Metastasis from these lesions is not common (< 20%, and most of the carcinomas are moderately to well differentiated. To qualify as a primary intraosseous carcinoma, there must be no initial connection with the oral mucosa, overlying skin, or antral or nasal mucosa. This paper presents a case of primary intraosseous carcinoma arising from odontogenic keratocyst in the anterior mandible with metastasis to left parotid lymph nodes.

Ethnic Problems in Sociological Work in Market Conditions

OpenAIRE

N E Aimautova; Leniungo ZhB Onzimba; O A Trykina

2013-01-01

The article considers some problems arising when a sociologist renders services to the customer; a general description of a modern sociologist's activities is given where their results can be seen as “goods”. The work of a sociologist fulfilled to order, is seen as something providing for managerial activities. At the same time, the sociologist taking the order either defines his individual position, or he does not. There may exist different limitations for the sociologist's self-identificati...

Microbial diversity arising from thermodynamic constraints

Science.gov (United States)

Großkopf, Tobias; Soyer, Orkun S

2016-01-01

The microbial world displays an immense taxonomic diversity. This diversity is manifested also in a multitude of metabolic pathways that can utilise different substrates and produce different products. Here, we propose that these observations directly link to thermodynamic constraints that inherently arise from the metabolic basis of microbial growth. We show that thermodynamic constraints can enable coexistence of microbes that utilise the same substrate but produce different end products. We find that this thermodynamics-driven emergence of diversity is most relevant for metabolic conversions with low free energy as seen for example under anaerobic conditions, where population dynamics is governed by thermodynamic effects rather than kinetic factors such as substrate uptake rates. These findings provide a general understanding of the microbial diversity based on the first principles of thermodynamics. As such they provide a thermodynamics-based framework for explaining the observed microbial diversity in different natural and synthetic environments. PMID:27035705

Microbial diversity arising from thermodynamic constraints.

Science.gov (United States)

Großkopf, Tobias; Soyer, Orkun S

2016-11-01

The microbial world displays an immense taxonomic diversity. This diversity is manifested also in a multitude of metabolic pathways that can utilise different substrates and produce different products. Here, we propose that these observations directly link to thermodynamic constraints that inherently arise from the metabolic basis of microbial growth. We show that thermodynamic constraints can enable coexistence of microbes that utilise the same substrate but produce different end products. We find that this thermodynamics-driven emergence of diversity is most relevant for metabolic conversions with low free energy as seen for example under anaerobic conditions, where population dynamics is governed by thermodynamic effects rather than kinetic factors such as substrate uptake rates. These findings provide a general understanding of the microbial diversity based on the first principles of thermodynamics. As such they provide a thermodynamics-based framework for explaining the observed microbial diversity in different natural and synthetic environments.

Il problema dei debiti internazionali nel periodo tra le due guerre mondiali. (The international debt problem in the interwar period

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M. DE CECCO

2013-12-01

Full Text Available Grande attenzione è stata recentemente dedicata al problema attuale del debito del terzo mondo e le sue implicazioni per il sistema bancario internazionale . Una rassegna di eventi simili a volte precedenti in passato dimostra che gli operatori dei mercati finanziari internazionali hanno la memoria corta , poiché la maggior parte degli aspetti della crisi si sono verificati in passato. Questo è confermato dal considerare il problema del debito internazionale tra la prima e la seconda guerra mondiale . La principale differenza tra allora e adesso è che il periodo tra le due guerre fu un periodo di transizione da un sistema di commercio dominato daòòa sterlina ad uno dominato  dal dollaro statunitense . Molti dei problemi di oggi derivano da questa continua dominazione dollaroConsiderable attention has recently been paid to the current problem of third world debt and its implications for the international banking system. A review of similar events at previous times in the past shows that operators in international financial markets have very short memories, since most of the aspects of the current crisis have occurred in the past. This is borne out by considering the international debt problem between the first and second world wars. The major difference between then and now is that the interwar period was a time of transition from a sterling-dominated trading system to one dominated by the US dollar. Many of today's problems stem from this continuing dollar domination.JEL: N24

Inverse problems with Poisson data: statistical regularization theory, applications and algorithms

International Nuclear Information System (INIS)

Hohage, Thorsten; Werner, Frank

2016-01-01

Inverse problems with Poisson data arise in many photonic imaging modalities in medicine, engineering and astronomy. The design of regularization methods and estimators for such problems has been studied intensively over the last two decades. In this review we give an overview of statistical regularization theory for such problems, the most important applications, and the most widely used algorithms. The focus is on variational regularization methods in the form of penalized maximum likelihood estimators, which can be analyzed in a general setup. Complementing a number of recent convergence rate results we will establish consistency results. Moreover, we discuss estimators based on a wavelet-vaguelette decomposition of the (necessarily linear) forward operator. As most prominent applications we briefly introduce Positron emission tomography, inverse problems in fluorescence microscopy, and phase retrieval problems. The computation of a penalized maximum likelihood estimator involves the solution of a (typically convex) minimization problem. We also review several efficient algorithms which have been proposed for such problems over the last five years. (topical review)

Shiftwork-Mediated Disruptions of Circadian Rhythms and Sleep Homeostasis Cause Serious Health Problems

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Suliman Khan

2018-01-01

Full Text Available Shiftwork became common during the last few decades with the growing demands of human life. Despite the social inactivity and irregularity in habits, working in continuous irregular shifts causes serious health issues including sleep disorders, psychiatric disorders, cancer, and metabolic disorders. These health problems arise due to the disruption in circadian clock system, which is associated with alterations in genetic expressions. Alteration in clock controlling genes further affects genes linked with disorders including major depression disorder, bipolar disorder, phase delay and phase advance sleep syndromes, breast cancer, and colon cancer. A diverse research work is needed focusing on broad spectrum changes caused by jet lag in brain and neuronal system. This review is an attempt to motivate the researchers to conduct advanced studies in this area to identify the risk factors and mechanisms. Its goal is extended to make the shift workers aware about the risks associated with shiftwork.

Adenocarcinoma arising in rectal duplication cyst: case report and review of the literature.

Science.gov (United States)

Shivnani, Anand T; Small, William; Benson, Al; Rao, Sambasiva; Talamonti, Mark S

2004-11-01

Duplication cyst of the gastrointestinal (GI) tract is a rare congenital anomaly, and rectal duplication cysts comprise a small fraction these cases. Most patients present for the first time in adulthood, and the origin of rectal duplication cysts is unclear. Prior series document malignant transformation in approximately 20 per cent of cases. The following case report describes a carcinoma arising in a rectal duplication cyst. Given the lack of data demonstrating adequate control for patients with adenocarcinoma arising in a rectal duplication cyst and our experience with this patient, we recommend all patients undergo multidisciplinary evaluation prior to any therapy.

Eletromagnetic radiation and the mechanical reactions arising from it

CERN Document Server

Schott, G A

1912-01-01

Fundamental equations of the electron theory ; transformation of the potentials ; other types of solution ; physical interpretation of the solutions obtained ; illustrative examples ; remarks on the solutions obtained and on the methods of calculating the potentials in general ; periodic motions ; on the distant field due to a moving charge ; pseudo-periodic and aperiodic motions ; on the field near the orbit of a moving charge or group ; the mechanical forces acting on electric charges in motion ; the motion of groups of electric charges ; on the Doppler effect ; on the disturbed motion of a ring of electrons ; on the field close to a point charge in motion ; the mechanical force exterted by an electron on itself ; the mechanical explanation of the electron ; the mechanics of the Lorentz electron ; problems illustrative of the motion of the Lorentz electron.

Problems of linguistic discrimination in the communicative space of Tajikistan: legal, sociolinguistic and educational aspects

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Diloro Iskandarova

2017-11-01

Full Text Available Although it is disregarded and banned, a person can be discriminated in the society according to various attributes – due to the person's language, religion, nationality, social background. The problem touches upon not only individuals but minorities as well. Almost all states have one or several groups – minorities – that differ from the main population in ethnic, linguistic or religious lines. Most international treaties on human rights contain anti-discriminatory provisions. In addition to the main rights of the freedom of conscience, thought and associations, the principal legal guarantees for each representative of minorities consist in being treated equally by the law and courts and in equal protection of laws. The paper studies the problems of legal, sociolinguistic and educational basis of linguistic discrimination in the communicative space of Tajikistan. Linguistic discrimination and political correctness are closely connected with the language policy of the state. With exoglossic linguistic situation being characteristic for Tajikistan arises a need to study the questions related to linguistic discrimination. This will allow making certain adjustments to language building and harmonizing the ethnic and interethnic interests on the basis of a balanced and scientifically justified language policy.

Inverse problems in systems biology

International Nuclear Information System (INIS)

Engl, Heinz W; Lu, James; Müller, Stefan; Flamm, Christoph; Schuster, Peter; Kügler, Philipp

2009-01-01

Systems biology is a new discipline built upon the premise that an understanding of how cells and organisms carry out their functions cannot be gained by looking at cellular components in isolation. Instead, consideration of the interplay between the parts of systems is indispensable for analyzing, modeling, and predicting systems' behavior. Studying biological processes under this premise, systems biology combines experimental techniques and computational methods in order to construct predictive models. Both in building and utilizing models of biological systems, inverse problems arise at several occasions, for example, (i) when experimental time series and steady state data are used to construct biochemical reaction networks, (ii) when model parameters are identified that capture underlying mechanisms or (iii) when desired qualitative behavior such as bistability or limit cycle oscillations is engineered by proper choices of parameter combinations. In this paper we review principles of the modeling process in systems biology and illustrate the ill-posedness and regularization of parameter identification problems in that context. Furthermore, we discuss the methodology of qualitative inverse problems and demonstrate how sparsity enforcing regularization allows the determination of key reaction mechanisms underlying the qualitative behavior. (topical review)

Contract Design: The problem of information asymmetry

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Axel C. Mühlbacher

2018-01-01

Full Text Available Introduction: Integrated care systems are advocated as an effective method of improving the performance of healthcare systems. These systems outline a payment and care delivery model that intends to tie provider reimbursements to predefined quality metrics. Little is known about the contractual design and the main challenges of delegating “accountability” to these new kinds of organisations and/or contracts. The research question in this article focuses on how healthcare contracts can look like and which possible problems arise in designing such contracts. In this a special interest is placed on information asymmetries.  Methods: A comprehensive literature review on methods of designing contracts in Integrated Care was conducted. This article is the first in a row of three that all contribute to a specific issue in designing healthcare contracts. Starting with the organisation of contracts and information asymmetries, part 2 focusses on financial options and risks and part 3 finally concludes with the question of risk management and evaluation.  Results: Healthcare contracting between providers and payers will have a major impact on the overall design of future healthcare systems. If Integrated care systems or any other similar concept of care delivery are to be contracted directly by payers to manage the continuum of care the costs of market utilisation play an essential role. Transaction costs also arise in the course of the negotiation and implementation of contracts. These costs are the reason why it is generally not possible to conclude perfect (complete contracts. Problems with asymmetric distribution of information can relate to the situation before a contract is concluded (adverse selection and after conclusion of a contract (moral hazard.  Discussion and Conclusions: Information asymmetries are seen as a major obstacle to the efficient operation of integrated care programmes. Coordination and motivation problems cannot be solved

Contract Design: The problem of information asymmetry.

Science.gov (United States)

Mühlbacher, Axel C; Amelung, Volker E; Juhnke, Christin

2018-01-12

Integrated care systems are advocated as an effective method of improving the performance of healthcare systems. These systems outline a payment and care delivery model that intends to tie provider reimbursements to predefined quality metrics. Little is known about the contractual design and the main challenges of delegating "accountability" to these new kinds of organisations and/or contracts. The research question in this article focuses on how healthcare contracts can look like and which possible problems arise in designing such contracts. In this a special interest is placed on information asymmetries. A comprehensive literature review on methods of designing contracts in Integrated Care was conducted. This article is the first in a row of three that all contribute to a specific issue in designing healthcare contracts. Starting with the organisation of contracts and information asymmetries, part 2 focusses on financial options and risks and part 3 finally concludes with the question of risk management and evaluation. Healthcare contracting between providers and payers will have a major impact on the overall design of future healthcare systems. If Integrated care systems or any other similar concept of care delivery are to be contracted directly by payers to manage the continuum of care the costs of market utilisation play an essential role. Transaction costs also arise in the course of the negotiation and implementation of contracts. These costs are the reason why it is generally not possible to conclude perfect (complete) contracts. Problems with asymmetric distribution of information can relate to the situation before a contract is concluded (adverse selection) and after conclusion of a contract (moral hazard). Information asymmetries are seen as a major obstacle to the efficient operation of integrated care programmes. Coordination and motivation problems cannot be solved at no-costs. The presented problems in the design of selective individual contracts

Sequential Inverse Problems Bayesian Principles and the Logistic Map Example

Science.gov (United States)

Duan, Lian; Farmer, Chris L.; Moroz, Irene M.

2010-09-01

Bayesian statistics provides a general framework for solving inverse problems, but is not without interpretation and implementation problems. This paper discusses difficulties arising from the fact that forward models are always in error to some extent. Using a simple example based on the one-dimensional logistic map, we argue that, when implementation problems are minimal, the Bayesian framework is quite adequate. In this paper the Bayesian Filter is shown to be able to recover excellent state estimates in the perfect model scenario (PMS) and to distinguish the PMS from the imperfect model scenario (IMS). Through a quantitative comparison of the way in which the observations are assimilated in both the PMS and the IMS scenarios, we suggest that one can, sometimes, measure the degree of imperfection.

A comment on the infra-red problem in the AdS/CFT correspondence

International Nuclear Information System (INIS)

Gottschalk, Hanno; Thaler, Horst

2008-01-01

In this note we report on some recent progress in proving the AdS/CFT correspondence for quantum fields using rigorously defined Euclidean path integrals. We also comment on the infra-red problem in the AdS/CFT correspondence and argue that it is different from the usual IR problem in constructive quantum field theory. To illustrate this, a triviality proof based on hypercontractivity estimates is given for the case of an ultraviolet regularized potential of type: φ 4 :. We also give a brief discussion on possible renormalization strategies and the specific problems that arise in this context. (orig.)

A comment on the infra-red problem in the AdS/CFT correspondence

Energy Technology Data Exchange (ETDEWEB)

Gottschalk, Hanno; Thaler, Horst

2008-03-15

In this note we report on some recent progress in proving the AdS/CFT correspondence for quantum fields using rigorously defined Euclidean path integrals. We also comment on the infra-red problem in the AdS/CFT correspondence and argue that it is different from the usual IR problem in constructive quantum field theory. To illustrate this, a triviality proof based on hypercontractivity estimates is given for the case of an ultraviolet regularized potential of type: {phi}{sup 4}:. We also give a brief discussion on possible renormalization strategies and the specific problems that arise in this context. (orig.)

28 CFR 45.2 - Disqualification arising from personal or political relationship.

Science.gov (United States)

2010-07-01

... political relationship. 45.2 Section 45.2 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMPLOYEE RESPONSIBILITIES § 45.2 Disqualification arising from personal or political relationship. (a) Unless authorized under paragraph (b) of this section, no employee shall participate in a criminal investigation or...

Ecological and human health risks arising from exposure to metals in urban soils under different land use in Nigeria.

Science.gov (United States)

Iwegbue, Chukwujindu M A; Martincigh, Bice S

2018-05-01

The concentrations of eight metals (Cd, Pb, Cr, Ni, Cu, Mn, Zn and Fe) were measured in soils under different land use in an urban environment of the Niger Delta in Nigeria. The aim was to provide information on the potential ecological and human health risks associated with human exposure to metals in these soils. The potential ecological risk due to metals in soils of these land use types falls in the range of low to moderate ecological risk with a significant contribution from Cd. The severity of the individual metals to ecological risk in these land use types followed the order Cd > Pb > Zn > Cu > Ni > Cr > Mn. The non-carcinogenic risk, expressed in terms of the hazard index (HI), arising through exposure to metals through oral, dermal and inhalation pathways, was greater than 1 for children in the majority of the land use types and less than 1 for adults for all land use types. This indicated that there are considerable non-cancer risks arising from childhood exposure to metals in soils of these land use types. The cancer risk values were within acceptable threshold values indicating a negligible cancer risk for both children and adults exposed to metals in these urban soils.

Shape functions for separable solutions to cross-field diffusion problems

International Nuclear Information System (INIS)

Luning, C.D.; Perry, W.L.

1984-01-01

The shape function S(x), which arises in the study of nonlinear diffusion for cross-field diffusion in plasmas, satisfies the equation S''(x)+lambdaa(x)S/sup α/(x) = 0, 0 0. In the cases of physical interest a(x) possesses an integrable singularity at some point in (0,1) but is otherwise continuous. Existence of a positive solution to this problem is established

Problems and challenges in social marketing.

Science.gov (United States)

Bloom, P N; Novelli, W D

1981-01-01

This article reviews the problems that arise when general marketing principles are applied to social programs. Social marketing is conceptualized as the design, implementation, and control of programs seeking to increase the acceptability of a social ideal or practice in a target group. These problems can occur in 8 basic decision-making areas: market analysis, market segmentation, product strategy development, pricing strategy development, channel strategy development, communications strategy development, organizational design and planning, and evaluation. Social marketers find that they have less good secondary data about their consumers, more problems obtaining valid and reliable measures of relevant variables, more difficulty sorting out the relative influence of determinants of consumer behavior, and more problems getting consumer research funded than marketers in the commercial sector. They tend to have less flexibility in shaping their products and more difficulty formulating product concepts. Problems associated with establishing, utilizing, and controlling distribution channels comprise another major difference between social and more conventional forms of marketing. Social marketers also find that their communications options are somewhat limited as a result of problems associated with use of paid advertisements, pressures not to use certain types of appeals in their messages, and the need to communicate large amounts of information in their messages. Moreover, social marketers must function in organizations where marketing activities are poorly understood, underappreciated, and inappropriately located. Finally, they face problems trying to define effectiveness measures or estimating the contribution their program has made toward the achievement of certain objectives. If all these problems are anticipated and handled creatively, social marketing efforts can succeed.

Medical and economic impact of extraintestinal infections due to Escherichia coli: focus on an increasingly important endemic problem.

Science.gov (United States)

Russo, Thomas A; Johnson, James R

2003-04-01

Escherichia coli is probably the best-known bacterial species and one of the most frequently isolated organisms from clinical specimens. Despite this, underappreciation and misunderstandings exist among medical professionals and the lay public alike regarding E. coli as an extraintestinal pathogen. Underappreciated features include (i) the wide variety of extraintestinal infections E. coli can cause, (ii) the high incidence and associated morbidity, mortality, and costs of these diverse clinical syndromes, (iii) the pathogenic potential of different groups of E. coli strains for causing intestinal versus extraintestinal disease, and (iv) increasing antimicrobial resistance. In this era in which health news often sensationalizes uncommon infection syndromes or pathogens, the strains of E. coli that cause extraintestinal infection are an increasingly important endemic problem and underappreciated "killers". Billions of health care dollars, millions of work days, and hundreds of thousands of lives are lost each year to extraintestinal infections due to E. coli. New treatments and prevention measures will be needed for improved outcomes and a diminished disease burden.

A possible solution of the flavor problem and radiative neutrino masses

Energy Technology Data Exchange (ETDEWEB)

Adulpravitchai, Adisorn

2010-06-23

In this thesis, we discuss two important problems of the Standard Model of Particle Physics (SM), namely the flavor problem and the reason for the smallness of neutrino masses. The first one might be related to the origin of non-abelian discrete flavor symmetries. We discuss the possibility of obtaining them from an underlying continuous flavor symmetry, i.e. SU(2) or SU(3) through spontaneous symmetry breaking. Moreover, we investigate their possible origin from an orbifold compactification. We discuss all non-abelian discrete symmetries, which can arise from an orbifold T{sup 2}/Z{sub N}. They are A{sub 4}, S{sub 4}, D{sub 4}, D{sub 3}, and D{sub 6}. We present the idea of combining the breaking of an orbifold GUT and the flavor symmetry arising from the orbifold. We demonstrate the construction in a 6d SUSY SO(10) x S{sub 4}. For the second problem, we propose a one-loop neutrino mass model in the left-right symmetric framework. We observe the transmitted hierarchy from the charged lepton masses to the right-handed neutrino masses, which we call ''Radiative Transmission of Lepton Flavor Hierarchy''. Finally, we study the phenomenological aspects of the model such as lepton flavor violation (LFV), flavor number violation (FNV), and flavor changing neutral currents (FCNCs). (orig.)

Statistical problems in nuclear regulation: introduction and overview

International Nuclear Information System (INIS)

Moore, R.H.; Easterling, R.G.

1978-01-01

The U.S. Nuclear Regulatory Commission (NRC) was organized formally in January 1975. The Commission's responsibilities can be categorized into four broad areas involving the licensing and use of nuclear materials and facilities: protecting public health and safety; protecting the environment; safeguarding nuclear materials and facilities; and assuring conformity with antitrust laws. A large variety of statistical problems are related to these basic responsibilities. They arise from the data-based nature of many of the issues to be resolved in making regulatory decisions. Hence, they are reflected in interactions among the NRC staff and licensees, vendors, and the public. This paper identifies and outlines some of these problems, providing a spectrum for comparison with the other presentations in this session. These problems are linked by the need for clear and objective treatment of data; their articulation and solution will benefit from insights and contributions from an informed statistical community

Thermodynamic and chemical engineering problems arising with hybride processes

International Nuclear Information System (INIS)

Hunsaenger, K.

1981-01-01

Marginal parameters and definitions are set up for the NaK-NaKH cyclic process, the vapour-phase electrolysis on the basis of carbonates, high-temperature electrolysis using borax, the HCl/NaLiNO 3 cyclic process and the methane/methanol cyclic process. Such parameters and definitions are to create uniform conditions for the process design. (DG) [de

A heuristics-based solution to the continuous berth allocation and crane assignment problem

Directory of Open Access Journals (Sweden)

Mohammad Hamdy Elwany

2013-12-01

Full Text Available Effective utilization plans for various resources at a container terminal are essential to reducing the turnaround time of cargo vessels. Among the scarcest resources are the berth and its associated cranes. Thus, two important optimization problems arise, which are the berth allocation and quay crane assignment problems. The berth allocation problem deals with the generation of a berth plan, which determines where and when a ship has to berth alongside the quay. The quay crane assignment problem addresses the problem of determining how many and which quay crane(s will serve each vessel. In this paper, an integrated heuristics-based solution methodology is proposed that tackles both problems simultaneously. The preliminary experimental results show that the proposed approach yields high quality solutions to such an NP-hard problem in a reasonable computational time suggesting its suitability for practical use.

28 CFR 68.53 - Review of an interlocutory order of an Administrative Law Judge in cases arising under section...

Science.gov (United States)

2010-07-01

... Administrative Law Judge in cases arising under section 274A or 274C. 68.53 Section 68.53 Judicial Administration... ADMINISTRATIVE LAW JUDGES IN CASES INVOLVING ALLEGATIONS OF UNLAWFUL EMPLOYMENT OF ALIENS, UNFAIR IMMIGRATION... Administrative Law Judge in cases arising under section 274A or 274C. (a) Authority. In a case arising under...

Solitary fibrous tumor arising in an intrathoracic goiter

DEFF Research Database (Denmark)

Larsen, Stine Rosenkilde; Godballe, Christian; Krogdahl, Annelise

2010-01-01

. CONCLUSION: The histological appearance and immunohistochemical reaction pattern of SFT is characteristic. The entity should be considered when dealing with a spindle cell lesion in the thyroid gland. All cases of this site of origin reported have had a benign clinical course. As only a small number of cases......BACKGROUND: Solitary fibrous tumor (SFT) is a rare spindle cell tumor most often found in the mediastinal pleura. Nineteen cases of SFT arising in the thyroid gland have been reported. We report a case of SFT of the thyroid gland with immunohistochemical and cytogenetic investigation. SUMMARY: A 58...

Convergence problems and energetic regions in π excited states of certain conjugated molecules

International Nuclear Information System (INIS)

Giambiagi, M.S. de; Giambiagi, M.; Barros, H.G. de P.L. de.

1980-01-01

When calculating π bond orders of excited and superexcited states of conjugated molecules, difficulties arise in applying the variation method; besides, the convergence problems involved are well known. For pyridazine, chosen for discussion, 27 states are considered; the convergence problem is envisaged through two criteria in the choice of a parameter introduced in the compromise Hamiltonian. This convergence parameter is related to the variation method. There exist three particular solutions for bond orders, which divide the 27 states into energetical regions. (Author) [pt

The problems inherent in teaching technical writing and report writing to native Americans

Science.gov (United States)

Zukowski/faust, J.

1981-01-01

Teaching technical writing to Native Americans contending with a second language and culture is addressed. Learning difficulties arising from differences between native and acquired language and cultural systems are examined. Compartmentalized teaching, which presents the ideals of technical writing in minimal units, and skills development are considered. Rhetorical problems treated include logic of arrangement, selection of support and scope of detail, and time and space. Specific problems selected include the concept of promptness, the contextualization of purpose, interpersonal relationships, wordiness, mixture of registers, and the problem of abstracting. Four inductive procedures for students having writing and perception problems are included. Four sample exercises and a bibliography of 13 references are also included.

Hepatocellular carcinoma arising from hepatocellular adenoma in a hepatitis B virus-associated cirrhotic liver

International Nuclear Information System (INIS)

Seo, J.M.; Lee, S.J.; Kim, S.H.; Park, C.K.; Ha, S.Y.

2012-01-01

Hepatocellular adenoma (HCA) is a rare, benign proliferation of hepatocytes that occurs mostly in a normal liver and in extreme rare cases, occurs in a cirrhotic liver. Hepatocellular carcinomas (HCC) arising within HCA through malignant transformation is rare. The specific incidence and mechanism of malignant transformation has not been established, but the long term use of oral contraceptives is considered a causative agent. We report a case of HCC arising from HCA detected in a hepatitis B-related cirrhotic liver with serial radiologic images.

Hepatocellular carcinoma arising from hepatocellular adenoma in a hepatitis B virus-associated cirrhotic liver

Energy Technology Data Exchange (ETDEWEB)

Seo, J.M. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Lee, S.J., E-mail: lucia@skku.edu [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, S.H. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Park, C.K.; Ha, S.Y. [Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2012-04-15

Hepatocellular adenoma (HCA) is a rare, benign proliferation of hepatocytes that occurs mostly in a normal liver and in extreme rare cases, occurs in a cirrhotic liver. Hepatocellular carcinomas (HCC) arising within HCA through malignant transformation is rare. The specific incidence and mechanism of malignant transformation has not been established, but the long term use of oral contraceptives is considered a causative agent. We report a case of HCC arising from HCA detected in a hepatitis B-related cirrhotic liver with serial radiologic images.

Analysis of multimedian problems on time dependent networks

OpenAIRE

Salman, F Sibel

1994-01-01

Ankara : The Department of Industrial Engineering and the Institute of Enginering and Science of Bilkent Univ., 1994. Thesis (Master's) -- Bilkent University, 1994. Includes bibliographical references leaves 81-85. Time dependency arises in transportation and computer-communication networks due to factors such as time varying demand, traffic intensity, and road conditions. This necessitates a locational decision to be based on an analysis involving a time horizon. In this st...

Diabetes mellitus type 1 as a health, nutriotial and social problem for children up to 18 years of age.

OpenAIRE

FRIDRICHOVSKÁ, Pavlína

2011-01-01

Work specifies the problems of children with diabetes mellitus type 1 - of site for health, in nutrition and social problems. The theoretical part is characterized by diabetes mellitus type 1, its causes, symptoms, treatment with diet and takes into account the specific problems arising from this condition for age. The practical part comprises the results of the questionnaire survey, which focuses on the problems of diabetes mellitus type 1 in childhood, and the level of knowledge about diabe...

Melanotic paraganglioma arising in the temporal horn following Langerhans cell histiocytosis

International Nuclear Information System (INIS)

Yoo, Jeong Hyun; Rivera, Andreana; Naeini, Ramin M.; Yedururi, Sireesha; Megahead, Hatem; Bayindir, Petek; Fuller, Gregory N.; Suh, Jeong Soo; Adesina, Adekunle M.; Hunter, Jill V.

2008-01-01

Intracerebral paragangliomas are rare because of the lack of paraganglial cells in the cerebral tissue. We report a rare case of melanotic paraganglioma arising from the temporal horn of the lateral ventricle in a patient with prior Langerhans cell histiocytosis (LCH) treated with chemotherapy and radiation. (orig.)

Concerning the problem of polygraphic wire calculation: theoretical aspects, software, practical implementation

Directory of Open Access Journals (Sweden)

Selkina A. V.

2016-05-01

Full Text Available the article analyzes the problems arising while organizing the workflow in printing companies. We suggest to address these problems by means of implementing computer-based accounting systems. Online and offline calculators used by printing enterprises for accounting are discussed. The author outlined the functional and specified requirements to such software. They were considered in the calculation module of accounting polygraphic wire used for block bonding. The software allows to increase the calculation process speed, to reduce the amount of errors in calculation and to decrease the labour intensity of the accounting process.

Malignant mixed mullerian tumor arising from the uterine cervix: A case report

International Nuclear Information System (INIS)

Shim, Jong Joon; Shim, Jae Chan; Lee, Kyoung Eun; Lee, Ghi Jai; Kim, Ho Kyun; Suh, Jung Ho; Lee, Hye Kyung

2012-01-01

Malignant mixed mullerian tumors (MMMTs) are a rare uterine tumor and contribute to approximately 1-3% of all corpus malignant tumors. MMMTs are usually in the uterine corpus, but can also arise from the uterine cervix, vagina, ovaries and fallofian tubes. MMMTs of the uterine cervix are extremely rare. MMMTs are highly malignant and tend to maintain a rapid growth and exhibit a high rate of recurrence. Therefore, the prognosis of patients diagnosed with these types of tumors is extremely poor. We report a rare case of a malignant mixed mullerian tumor arising from the uterine cervix and introduce CT and MRI findings. CT and magnetic resonance findings of the uterine cervical MMMT in our case show highly aggressive features, such as parametrial involvement, pelvic and paraaortic lymphadenopathy, and distant metastasis and high enhancement

Statistical physics of hard optimization problems

International Nuclear Information System (INIS)

Zdeborova, L.

2009-01-01

Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the non-deterministic polynomial (NP)-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an NP-complete problem the practically arising instances might, in fact, be easy to solve. The principal question we address in this article is: How to recognize if an NP-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfy ability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named ”locked” constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfy ability.

Statistical physics of hard optimization problems

International Nuclear Information System (INIS)

Zdeborova, L.

2009-01-01

Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the non-deterministic polynomial-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an non-deterministic polynomial-complete problem the practically arising instances might, in fact, be easy to solve. The principal the question we address in the article is: How to recognize if an non-deterministic polynomial-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfiability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named 'locked' constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfiability (Authors)

Statistical physics of hard optimization problems

Science.gov (United States)

Zdeborová, Lenka

2009-06-01

Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the non-deterministic polynomial (NP)-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an NP-complete problem the practically arising instances might, in fact, be easy to solve. The principal question we address in this article is: How to recognize if an NP-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfiability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named "locked" constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfiability.

Integrable equations, addition theorems, and the Riemann-Schottky problem

International Nuclear Information System (INIS)

Buchstaber, Viktor M; Krichever, I M

2006-01-01

The classical Weierstrass theorem claims that, among the analytic functions, the only functions admitting an algebraic addition theorem are the elliptic functions and their degenerations. This survey is devoted to far-reaching generalizations of this result that are motivated by the theory of integrable systems. The authors discovered a strong form of the addition theorem for theta functions of Jacobian varieties, and this form led to new approaches to known problems in the geometry of Abelian varieties. It is shown that strong forms of addition theorems arise naturally in the theory of the so-called trilinear functional equations. Diverse aspects of the approaches suggested here are discussed, and some important open problems are formulated.

How do they solve it? An insight into the learner’s approach to the mechanism of physics problem solving

OpenAIRE

Balasubrahmanya Hegde; B. N. Meera

2012-01-01

A perceived difficulty is associated with physics problem solving from a learner’s viewpoint, arising out of a multitude of reasons. In this paper, we have examined the microstructure of students’ thought processes during physics problem solving by combining the analysis of responses to multiple-choice questions and semistructured student interviews. Design of appropriate scaffoldings serves as pointers to the identification of student problem solving difficulties. An analysis of the results ...

Defining transmedia narrative: problems and questions. Dialogue with Mary-Laure Ryan

Directory of Open Access Journals (Sweden)

Franco Passalacqua

2011-07-01

Full Text Available In this interview Mary-Laure Ryan faces some problems that arise from her definition of «transmedia narrative». Can every semiotic system tell stories? How can we elaborate a definition of «narrative» which accounts both for cognitive and semantic aspects? How can we dispense with the syntactic level if we need a definition of «narrativity» that suits every semiotic system? Answering these questions, Ryan deals with other proposals developed around the same theoretical problems, and points out a thought-provoking argument against Meir Sternberg’s functionalist definition of narrative.

Nipple adenoma arising from axillary accessory breast: a case report

Directory of Open Access Journals (Sweden)

Shioi Yoshihiro

2012-11-01

Full Text Available Abstract Nipple adenoma is a relatively rare benign breast neoplasm, and cases of the disease arising from the axillary accessory breast have very seldom been reported in the English literature. We report a case of nipple adenoma arising from axillary accessory breast including clinical and pathological findings. An 82-year-old woman presented with the complaint of a small painful mass in the right axilla. Physical examination confirmed a well-defined eczematous crusted mass that was 8 mm in size. The diagnosis of nipple adenoma was made from an excisional specimen on the basis of characteristic histological findings. Microscopic structural features included a compact proliferation of small tubules lined by epithelial and myoepithelial cells, and the merging of glandular epithelial cells of the adenoma into squamous epithelial cells in the superficial epidermal layer. Because clinically nipple adenoma may resemble Paget’s disease and pathologically can be misinterpreted as tubular carcinoma, the correct identification of nipple adenoma is an important factor in the differential diagnosis for axillary tumor neoplasms. Virtual slides The virtual slide(s for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1186821489769063

The Perceived Benefits and Problems Associated with Teaching Activities Undertaken by Doctoral Students

Science.gov (United States)

Jordan, Katy; Howe, Christine

2018-01-01

Postgraduate students involved in delivering undergraduate teaching while working toward a research degree are known as graduate teaching assistants (GTAs). This study focused upon the problems and benefits arising from this dual role as researchers and teachers, as perceived by GTAs at the University of Cambridge. To this end, GTAs at Cambridge…

Minimization of Linear Functionals Defined on| Solutions of Large-Scale Discrete Ill-Posed Problems

DEFF Research Database (Denmark)

Elden, Lars; Hansen, Per Christian; Rojas, Marielba

2003-01-01

The minimization of linear functionals de ned on the solutions of discrete ill-posed problems arises, e.g., in the computation of con dence intervals for these solutions. In 1990, Elden proposed an algorithm for this minimization problem based on a parametric-programming reformulation involving...... the solution of a sequence of trust-region problems, and using matrix factorizations. In this paper, we describe MLFIP, a large-scale version of this algorithm where a limited-memory trust-region solver is used on the subproblems. We illustrate the use of our algorithm in connection with an inverse heat...

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

Science.gov (United States)

Savoye, Philippe

2009-01-01

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

Apocrine carcinoma arising in a complex fibroadenoma: a case report.

Science.gov (United States)

Mele, Marco; Vahl, Pernille; Funder, Jonas Amstrup; Sorensen, Anne Schmidt; Jensen, Vibeke

2014-01-01

A carcinoma arising in a fibroadenoma is a rare event, which often entails a diagnostic challenge. The most common type is the lobular carcinoma and secondary a ductal carcinoma. We present an extremely rare case of malignant development of an invasive apocrine carcinoma in a complex fibroadenoma and underline the importance for clinicians to recognize the possibility of benign and malignant co-existence especially in older women.

Airborne iodine-125 arising from surface contamination

International Nuclear Information System (INIS)

Kwok, C.S.; Hilditch, T.E.

1982-01-01

Measurements of airborne 125 I were made during the subdivision of 740 MBq stocks of 125 I iodide solution in a hospital dispensary. Within the fume cupboard the mean airborne 125 I concentration was 3.5 +- 2.9 kBqm -3 . No airborne concentration contamination was found outside the fume cupboard during these dispensing sessions. The airborne 125 I concentration arising from deliberate surface contamination (50 μl, 3.7-6.3 MBq) of the top of a lead pot was measured at a height simulating face level at an open work bench. There was a progressive fall in airborne concentration over seven days but even then the level was still significantly above background. Measurements made with the extraction system of the fume cupboard in operation were 2-3 times lower. (U.K.)

Faltas ao trabalho por problemas de saúde na indústria Work days lost due to health problems in industry

Directory of Open Access Journals (Sweden)

Sylvia Regina Trindade Yano

2012-05-01

Full Text Available Neste estudo transversal, estima-se a prevalência de episódios de faltas ao trabalho por motivo de saúde (FTS, e fatores associados, focalizando o trabalho na indústria. A população do estudo foi uma amostra aleatória por conglomerado de 3.403 trabalhadores de 16 a 65 anos residentes em Salvador, Bahia, Brasil. Dados foram obtidos em entrevistas domiciliares. Entre os trabalhadores da indústria, a prevalência em um ano de FTS em geral, foi 12,5%, 5,5% para FTS relacionados ao trabalho, e 4,1% para FTS agravados pelo trabalho. Não houve diferenças estatisticamente significantes em relação aos demais trabalhadores. Fatores associados à FTS foram percepção de perigo no trabalho, história de acidente de trabalho, e saúde autopercebida como ruim. Os resultados indicam que a ocorrência de faltas ao trabalho é comum, tanto na indústria como nos demais ramos de atividade, podem afetar a produtividade, o que requer programas de prevenção de agentes de risco em locais de trabalho.This cross-sectional study estimated the prevalence of work days lost due to health problems and associated factors among industrial workers. The study population was a simple random cluster sample of 3,403 workers from 16 to 65 years of age in the city of Salvador, Bahia State, Brazil. Data were collected with individual home interviews. Among industrial workers, one-year prevalence of work days lost to health problems was 12.5%, of which 5.5% were directly work-related and 4.1% aggravated by work. There were no statistically significant differences when compared to other worker categories. Self-perceived workplace hazards, history of work-related injury, and poor self-rated health were associated with work days lost due to work-related injuries/diseases. The findings showed that work days lost are common among both industrial and non-industrial workers, thereby affecting productivity and requiring prevention programs.

Fuzzy mathematics method for theoretical analysis of ground movements due to underground excavation

Energy Technology Data Exchange (ETDEWEB)

Li Wenxiu (Changsa Research Institute of Mining and Metallurgy, Changsa (China))

1991-07-01

The analysis of the rock mass movements due to excavation operations is one of the many important problems of rock mass mechanics. It is difficult to calculate the ground movements due to underground excavation accurately because of the complexity of the problem. In this paper, the application is described of the fuzzy probability measures to the analysis of ground movements. Based on the definition of the fuzzy probability measure, the theories for both the two-dimensional and three-dimensional problems are developed and are applied to the analysis of ground movements due to underground excavation. 31 refs., 5 figs.

On the calculation of lattice sums arising in Bose-Einstein statistics of quasiparticle excitations

International Nuclear Information System (INIS)

Millev, Y.; Faehnle, M.

1994-05-01

A new method for the calculations of the average occupation number of bosonic quasi-particle excitations valid for any type of lattice is proposed. The method is based on the recognition of the connection with lattice Green's functions and generalized Watson integrals, on one hand, and on a very simple differentiation technique which renders unnecessary and artificial to this problem more sophisticated Laplace transform summation procedures. The mean-field approximation to Green's function theories of ferromagnetism arises naturally as the zeroth term in the obtained summation formulae. The results have been specified completely for the three cubic lattices. They are new for the simple cubic and face-centred cases, whereas certain redundancy is removed form the known body-centred cubic results. Applications of the method to more complex sums as, for instance, the thermodynamic sum for the total energy of the quasiparticles, are straightforward. There has also been found a new three-position recursion relation for the calculation of frequently occurring triple geometric integrals in the face-centred cubic case. It originates form a corresponding relation for a relevant Heun function. (author). 29 refs, 1 tab

Insight Is Not in the Problem: Investigating Insight in Problem Solving across Task Types.

Science.gov (United States)

Webb, Margaret E; Little, Daniel R; Cropper, Simon J

2016-01-01

The feeling of insight in problem solving is typically associated with the sudden realization of a solution that appears obviously correct (Kounios et al., 2006). Salvi et al. (2016) found that a solution accompanied with sudden insight is more likely to be correct than a problem solved through conscious and incremental steps. However, Metcalfe (1986) indicated that participants would often present an inelegant but plausible (wrong) answer as correct with a high feeling of warmth (a subjective measure of closeness to solution). This discrepancy may be due to the use of different tasks or due to different methods in the measurement of insight (i.e., using a binary vs. continuous scale). In three experiments, we investigated both findings, using many different problem tasks (e.g., Compound Remote Associates, so-called classic insight problems, and non-insight problems). Participants rated insight-related affect (feelings of Aha-experience, confidence, surprise, impasse, and pleasure) on continuous scales. As expected we found that, for problems designed to elicit insight, correct solutions elicited higher proportions of reported insight in the solution compared to non-insight solutions; further, correct solutions elicited stronger feelings of insight compared to incorrect solutions.

Focus point in gaugino mediation — Reconsideration of the fine-tuning problem

Energy Technology Data Exchange (ETDEWEB)

Yanagida, Tsutomu T.; Yokozaki, Norimi, E-mail: n.yokozaki@gmail.com

2013-05-24

We reconsider the fine-tuning problem in SUSY models, motivated by the recent observation of the relatively heavy Higgs boson and non-observation of the SUSY particles at the LHC. Based on this thought, we demonstrate a focus point-like behavior in a gaugino mediation model, and show that the fine-tuning is indeed reduced to about 2% level if the ratio of the gluino mass to wino mass is about 0.4 at the GUT scale. We show that such a mass ratio may arise naturally in a product group unification model without the doublet–triplet splitting problem. This fact suggests that the fine-tuning problem crucially depends on the physics at the high energy scale.

Dealing with uncertainty arising out of probabilistic risk assessment

International Nuclear Information System (INIS)

Solomon, K.A.; Kastenberg, W.E.; Nelson, P.F.

1984-03-01

In addressing the area of safety goal implementation, the question of uncertainty arises. This report suggests that the Nuclear Regulatory Commission (NRC) should examine how other regulatory organizations have addressed the issue. Several examples are given from the chemical industry, and comparisons are made to nuclear power risks. Recommendations are made as to various considerations that the NRC should require in probabilistic risk assessments in order to properly treat uncertainties in the implementation of the safety goal policy. 40 references, 7 figures, 5 tables

Language Problems and the Final Act. Esperanto Documents, New Series No. 11A.

Science.gov (United States)

Universal Esperanto Association, Rotterdam (Netherlands).

The Final Act of the Conference on Security and Co-operation in Europe, linguistic problems in the way of cooperation, language differences and the potential for discriminatory practice, and the need for a new linguistic order are discussed. It is suggested that misunderstandings arising from differences of language reduce the ability of the 35…

An Investigation of Starting Point Preferences in Human Performance on Traveling Salesman Problems

Science.gov (United States)

MacGregor, James N.

2014-01-01

Previous studies have shown that people start traveling sales problem tours significantly more often from boundary than from interior nodes. There are a number of possible reasons for such a tendency: first, it may arise as a direct result of the processes involved in tour construction; second, boundary points may be perceptually more salient than…

Effectively Tackling Reinsurance Problems by Using Evolutionary and Swarm Intelligence Algorithms

Directory of Open Access Journals (Sweden)

Sancho Salcedo-Sanz

2014-04-01

Full Text Available This paper is focused on solving different hard optimization problems that arise in the field of insurance and, more specifically, in reinsurance problems. In this area, the complexity of the models and assumptions considered in the definition of the reinsurance rules and conditions produces hard black-box optimization problems (problems in which the objective function does not have an algebraic expression, but it is the output of a system (usually a computer program, which must be solved in order to obtain the optimal output of the reinsurance. The application of traditional optimization approaches is not possible in this kind of mathematical problem, so new computational paradigms must be applied to solve these problems. In this paper, we show the performance of two evolutionary and swarm intelligence techniques (evolutionary programming and particle swarm optimization. We provide an analysis in three black-box optimization problems in reinsurance, where the proposed approaches exhibit an excellent behavior, finding the optimal solution within a fraction of the computational cost used by inspection or enumeration methods.

Dealing with sickness certification – a survey of problems and strategies among general practitioners and orthopaedic surgeons

Directory of Open Access Journals (Sweden)

Nilsson Gunnar

2007-10-01

Full Text Available Abstract Background In order to get sickness benefit a sick-listed person need a medical certificate issued by a physician; in Sweden after one week of self-certification. Physicians experience sick-listing tasks as problematic and conflicts may arise when patients regard themselves unable to work due to complaints that are hard to objectively verify for the physician. Most GPs and orthopaedic surgeons (OS deal regularly with sick-listing issues in their daily practice. The aim of this study was to explore perceived problems and coping strategies related to tasks of sickness certification among general practitioners (GP and orthopaedic surgeons (OS. Methods A cross-sectional study about sickness certification in two Swedish counties, with 673 participating GPs and 149 OSs, who answered a comprehensive questionnaire. Frequencies together with crude and adjusted (gender and working years Odds ratios were calculated. Results A majority of the GPs and OSs experienced problems in sickness certification every week. To assess the patient's work ability, to handle situations when they and the patient had different opinions about the need for sickness absence, and to issue prolongation certificates when the previous was issued by another physician were reported as problematic by a majority in both groups. Both GPs and OSs prolonged sickness certifications due to waiting times in health care or at Social Insurance Office (SIO. To handle experienced problems they used different strategies; OSs issued sickness certificates without personal appointment more often than the GPs, who on the other hand reported having contact with SIO more often than the OSs. A higher rate of GPs experienced support from management and had a common strategy for handling sickness certification at the clinic than the OSs. Conclusion Most GPs and OSs handled sickness certification weekly and reported a variety of problems in relation to this task, generally GPs to a higher extent

Rival framings: A framework for discovering how problem formulation uncertainties shape risk management trade-offs in water resources systems

Science.gov (United States)

Quinn, J. D.; Reed, P. M.; Giuliani, M.; Castelletti, A.

2017-08-01

Managing water resources systems requires coordinated operation of system infrastructure to mitigate the impacts of hydrologic extremes while balancing conflicting multisectoral demands. Traditionally, recommended management strategies are derived by optimizing system operations under a single problem framing that is assumed to accurately represent the system objectives, tacitly ignoring the myriad of effects that could arise from simplifications and mathematical assumptions made when formulating the problem. This study illustrates the benefits of a rival framings framework in which analysts instead interrogate multiple competing hypotheses of how complex water management problems should be formulated. Analyzing rival framings helps discover unintended consequences resulting from inherent biases of alternative problem formulations. We illustrate this on the monsoonal Red River basin in Vietnam by optimizing operations of the system's four largest reservoirs under several different multiobjective problem framings. In each rival framing, we specify different quantitative representations of the system's objectives related to hydropower production, agricultural water supply, and flood protection of the capital city of Hanoi. We find that some formulations result in counterintuitive behavior. In particular, policies designed to minimize expected flood damages inadvertently increase the risk of catastrophic flood events in favor of hydropower production, while min-max objectives commonly used in robust optimization provide poor representations of system tradeoffs due to their instability. This study highlights the importance of carefully formulating and evaluating alternative mathematical abstractions of stakeholder objectives describing the multisectoral water demands and risks associated with hydrologic extremes.

A classical Perron method for existence of smooth solutions to boundary value and obstacle problems for degenerate-elliptic operators via holomorphic maps

Science.gov (United States)

Feehan, Paul M. N.

2017-09-01

We prove existence of solutions to boundary value problems and obstacle problems for degenerate-elliptic, linear, second-order partial differential operators with partial Dirichlet boundary conditions using a new version of the Perron method. The elliptic operators considered have a degeneracy along a portion of the domain boundary which is similar to the degeneracy of a model linear operator identified by Daskalopoulos and Hamilton [9] in their study of the porous medium equation or the degeneracy of the Heston operator [21] in mathematical finance. Existence of a solution to the partial Dirichlet problem on a half-ball, where the operator becomes degenerate on the flat boundary and a Dirichlet condition is only imposed on the spherical boundary, provides the key additional ingredient required for our Perron method. Surprisingly, proving existence of a solution to this partial Dirichlet problem with ;mixed; boundary conditions on a half-ball is more challenging than one might expect. Due to the difficulty in developing a global Schauder estimate and due to compatibility conditions arising where the ;degenerate; and ;non-degenerate boundaries; touch, one cannot directly apply the continuity or approximate solution methods. However, in dimension two, there is a holomorphic map from the half-disk onto the infinite strip in the complex plane and one can extend this definition to higher dimensions to give a diffeomorphism from the half-ball onto the infinite ;slab;. The solution to the partial Dirichlet problem on the half-ball can thus be converted to a partial Dirichlet problem on the slab, albeit for an operator which now has exponentially growing coefficients. The required Schauder regularity theory and existence of a solution to the partial Dirichlet problem on the slab can nevertheless be obtained using previous work of the author and C. Pop [16]. Our Perron method relies on weak and strong maximum principles for degenerate-elliptic operators, concepts of

Where Cognitive Conflict Arises from?: The Structure of Creating Cognitive Conflict

Science.gov (United States)

Lee, Gyoungho; Yi, Jinseog

2013-01-01

In this study, our basic contention was that it is essential for researchers to answer the question, "Where does cognitive conflict really arise from?" with more precision than has heretofore been attempted. First, we examined how the term "cognitive conflict" has been treated in the existing literature and try to pinpoint some difficulties,…

Analysis of disability indicators due to occupational diseases in the Lviv region: problems and perspectives of the decision.

Directory of Open Access Journals (Sweden)

I. Borisova

2018-04-01

Full Text Available Disability is a social phenomenon that can not be ruled out by any society. The potential of society in combating the growth of disability – as a social evil – is determined not only by the degree of understanding of this problem but mainly by economic resources. The risk of developing oc­cupational diseases in the coal industry is 5-10 times higher than in other branches of industry. In Ukraine, about 3 million people work under the harmful conditions of production, 60.0% of them are miners. The study analyzed the dy­namics of disability as a result of occupational diseases in the Lviv region for the period 2015-2017. The results of the study prove that the disability indicators due to occupational diseases tend to grow. The ways to overcome this unfa­vorable tendency should be state measures on improvement of normative and legal documents, coherence between dif­ferent state institutions and strengthening effective state control over hygiene norms in industries with harmful factors.

Facial Cellulitis Arising from Dens Evaginatus: A Case Report

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Chun-Ming Chen

2005-07-01

Full Text Available Dens evaginatus is a developmental anomaly that produces a tubercle on the occlusal surface of a tooth. It is found most frequently in the mandibular premolars. The occlusal tubercle easily causes occlusal interferences. Attrition or fracture of the tubercle can lead to pulpitis, pulp necrosis, periapical pathosis, and periapical infection. This case report illustrates the treatment of facial cellulitis arising from dens evaginatus with open apex. Calcium hydroxide was used for the apexification procedure. One year after canal obturation, radiography revealed no apical pathosis and the apical seal was evident.

Building Language Through Conflict Resolution: Discussing Problems Enriches Language While Leading to Solutions

Science.gov (United States)

Church, Ellen Booth

2005-01-01

This brief article describes how classroom group time can be "talk central" for children to discuss problems, imagine solutions, even role-play hypothetical situations. It is often in the safety and support of the large group that children develop the tools they need to learn how to resolve the inevitable conflicts that arise throughout life.…

Uniqueness in some higher order elliptic boundary value problems in n dimensional domains

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C.-P. Danet

2011-07-01

Full Text Available We develop maximum principles for several P functions which are defined on solutions to equations of fourth and sixth order (including a equation which arises in plate theory and bending of cylindrical shells. As a consequence, we obtain uniqueness results for fourth and sixth order boundary value problems in arbitrary n dimensional domains.

The Settlement of Litigations Arising from the Interpretation and Enforcement of Administrative Contracts

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Vasilica NEGRUŢ

2015-03-01

Full Text Available Regarded nowadays as an instrument of strategy implementation of government policy and establishment mechanism of public administration, the administrative contract raises many debates on its applicable regime, but also on the jurisdiction, to solve litigations arising from their interpretation and execution. In this paper we proposed, based on the analysis of the laws in force, doctrine, jurisprudence, and previous research results related to the subject, using the comparative method, to clarify the mentioned issues. The conclusions of this paper will strengthen the practice on the referral of courts competent to solve litigations arising from the implementation of the administrative contracts in the context where the administrative contract has profound implications in the administrative, economic and social field.

An Open Challenge Problem Repository for Systems Supporting Binders

OpenAIRE

Felty, A.; Momigliano, A.; Pientka, B.

2015-01-01

A variety of logical frameworks support the use of higher-order abstract syntax in representing formal systems; however, each system has its own set of benchmarks. Even worse, general proof assistants that provide special libraries for dealing with binders offer a very limited evaluation of such libraries, and the examples given often do not exercise and stress-test key aspects that arise in the presence of binders. In this paper we design an open repository ORBI (Open challenge problem Repo...

Modeling of problems of projection: A non-countercyclic approach

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Jason Ginsburg

2016-06-01

Full Text Available This paper describes a computational implementation of the recent Problems of Projection (POP approach to the study of language (Chomsky 2013; 2015. While adopting the basic proposals of POP, notably with respect to how labeling occurs, we a attempt to formalize the basic proposals of POP, and b develop new proposals that overcome some problems with POP that arise with respect to cyclicity, labeling, and wh-movement operations. We show how this approach accounts for simple declarative sentences, ECM constructions, and constructions that involve long-distance movement of a wh-phrase (including the that-trace effect. We implemented these proposals with a computer model that automatically constructs step-by-step derivations of target sentences, thus making it possible to verify that these proposals work.

A Riemann-Hilbert approach to the inverse problem for the Stark operator on the line

Science.gov (United States)

Its, A.; Sukhanov, V.

2016-05-01

The paper is concerned with the inverse scattering problem for the Stark operator on the line with a potential from the Schwartz class. In our study of the inverse problem, we use the Riemann-Hilbert formalism. This allows us to overcome the principal technical difficulties which arise in the more traditional approaches based on the Gel’fand-Levitan-Marchenko equations, and indeed solve the problem. We also produce a complete description of the relevant scattering data (which have not been obtained in the previous works on the Stark operator) and establish the bijection between the Schwartz class potentials and the scattering data.

Existence theorem and optimality conditions for a class of convex semi-infinite problems with noncompact index sets

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Olga Kostyukova

2017-11-01

Full Text Available The paper is devoted to study of a special class of semi-infinite problems arising in nonlinear parametric Semi-infinite Programming, when the differential properties of the solutions are being studied. These problems are convex and possess noncompact index sets. In the paper, we present conditions guaranteeing the existence of optimal solutions, and prove new optimality criterion. An example illustrating the obtained results is presented.

Epithelioid sarcoma and squamous cell carcinoma arising in a burn scar

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Kusum D Jashnani

2011-01-01

Full Text Available Development of a malignant tumor is a well known complication of a chronic burn scar. Most of these tumors are squamous cell carcinomas and only 28 cases of burn scar sarcomas have been reported in literature. We report the first occurrence of the combination of squamous cell carcinoma and epithelioid sarcoma arising in a burn scar.

Aberrant ovarian artery arising from the common Iliac artery: Case report

Energy Technology Data Exchange (ETDEWEB)

Kim, Won Kyung [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Yang, Seung Boo; Lee, Jae Myeong [Dept. of Radiology, Soonchunhyang University Gumi Hospital, Soonchunhyang University College of Medicine, Gumi (Korea, Republic of); Goo, Dong Erk; Kim, Yong Jae; Chang, Yun Woo [Dept. of Radiology, Soonchunhyang University Seoul Hospital, Soonchunhyang University College of Medicine, Seoul (Korea, Republic of)

2013-01-15

A 46-year-old Vietnamese woman received embolization therapy in order to control postpartum hemorrhage. Angiography revealed an aberrant ovarian artery arising from the right common iliac artery. Superselective catheterization and subsequent embolization of the aberrant ovarian artery and bilateral uterine arteries were performed. Precise knowledge of the anatomic variations of the ovarian artery is important for successful embolization.

Aberrant ovarian artery arising from the common Iliac artery: Case report

International Nuclear Information System (INIS)

Kim, Won Kyung; Yang, Seung Boo; Lee, Jae Myeong; Goo, Dong Erk; Kim, Yong Jae; Chang, Yun Woo

2013-01-01

A 46-year-old Vietnamese woman received embolization therapy in order to control postpartum hemorrhage. Angiography revealed an aberrant ovarian artery arising from the right common iliac artery. Superselective catheterization and subsequent embolization of the aberrant ovarian artery and bilateral uterine arteries were performed. Precise knowledge of the anatomic variations of the ovarian artery is important for successful embolization.

Clear Cell Adenocarcinoma Arising from Abdominal Wall Endometriosis

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Thouraya Achach

2008-01-01

Full Text Available Endometriosis is a frequent benign disorder. Malignancy arising in extraovarian endometriosis is a rare event. A 49-year-old woman is presented with a large painful abdominal wall mass. She underwent a myomectomy, 20 years before, for uterus leiomyoma. Computed tomography suggested that this was a desmoid tumor and she underwent surgery. Histological examination showed a clear cell adenocarcinoma associated with endometriosis foci. Pelvic ultrasound, computed tomography, and endometrial curettage did not show any malignancy or endometriosis in the uterus and ovaries. Adjuvant chemotherapy was recommended, but the patient was lost to follow up. Six months later, she returned with a recurrence of the abdominal wall mass. She was given chemotherapy and then she was reoperated.

Some nonlinear problems in the manipulation of beams

International Nuclear Information System (INIS)

Sessler, A.M.

1990-01-01

An overview is given of nonlinear problems that arise in the manipulation of beams. Beams can be made of material particles or photons, can be intense or dilute, can be energetic or not, and they can be propagating in vacuum or in a medium. The nonlinear aspects of the motion are different in each case, and this diversity of behavior is categorized. Many examples are given, which serves to illustrate the categorization and, furthermore, display the richness of behavior encountered in the physics of beams. 25 refs., 5 figs

Nonlinear electric reaction arising in dry bone subjected to 4-point bending

Science.gov (United States)

Murasawa, Go; Cho, Hideo; Ogawa, Kazuma

2007-04-01

Bone is a smart, self-adaptive and also partly self-repairing tissue. In recent years, many researchers seek to find how to give the effective mechanical stimulation to bone, because it is the predominant loading that determines the bone shape and macroscopic structure. However, the trial of regeneration of bone is still under way. On the other hand, it has been known that electrical potential generates from bone by mechanical stimulation (Yasuda, 1977; Williams, 1982; Starkebaum, 1979; Cochran, 1968; Lanyon, 1977; Salzstein, 1987a,b; Friedenberg, 1966). This is called "stress-generated potential (SGP)". The process of information transfer between "strain" and "cells" is not still clear. But, there is some possibility that SGP has something to do with the process of information transfer. If the electrical potential is more clear under some mechanical loadings, we will be able to regenerate bone artificially and freely. Therefore, it is important to investigate SGP in detail. The aim of present study is to investigate the electric reaction arising in dry bone subjected to mechanical loadings at high amplitude and low frequency strain. Firstly, specimen is fabricated from femur of cow. Next, the speeds of wave propagation in bone are tried to measure by laser ultra sonic technique and wavelet transform, because these have relationship with bone density. Secondary, 4-point bending test is conducted up to fracture. Then, electric reaction arising in bone is measured during loading. Finally, cyclic 4-point bending tests are conducted to investigate the electric reaction arising in bone at low frequency strain.

Fundamental problem in the relativistic approach to atomic structure theory

International Nuclear Information System (INIS)

Kagawa, Takashi

1987-01-01

It is known that the relativistic atomic structure theory contains a serious fundamental problem, so-called the Brown-Ravenhall (BR) problem or variational collapse. This problem arises from the fact that the energy spectrum of the relativistic Hamiltonian for many-electron systems is not bounded from below because the negative-energy solutions as well as the positive-energy ones are obtained from the relativistic equation. This report outlines two methods to avoid the BR problem in the relativistic calculation, that is, the projection operator method and the general variation method. The former method is described first. The use of a modified Hamiltonian containing a projection operator which projects the positive-energy solutions in the relativistic wave equation has been proposed to remove the BR difficulty. The problem in the use of the projection operator method is that the projection operator for the system cannot be determined uniquely. The final part of this report outlines the general variation method. This method can be applied to any system, such as relativistic ones whose Hamiltonian is not bounded from below. (Nogami, K.)

Associations among everyday stress, critical life events, and sexual problems.

Science.gov (United States)

Bodenmann, Guy; Ledermann, Thomas; Blattner, Denise; Galluzzo, Claudia

2006-07-01

This study addresses the question of how stress is linked to sexual problems among women and men in close relationships. Psychological symptoms, relationship quality, internal daily stress (i.e., originating within the couple such as conflicts, worry for the partner), external daily stress (i.e., stress arising outside the couple such as job stress, stressful relatives, and so forth), and critical life events were examined with regard to their association with different sexual problems. The results support the hypotheses that (1) there is an incremental effect of stress on sexual problems after controlling for psychological symptoms and relationship quality, and that (2) it is primarily internal daily stress and in some cases critical life events rather than external daily stress that are related to sexual problems, particularly hypoactive sexual desire in women and men, sexual aversion in women, vaginismus in women, and premature ejaculation in men. Our findings indicate that the treatment of these sexual problems should address relationship issues and include a focus on helping individuals improve their stress management skills within their couple relationship.

Laplace transform homotopy perturbation method for the approximation of variational problems.

Science.gov (United States)

Filobello-Nino, U; Vazquez-Leal, H; Rashidi, M M; Sedighi, H M; Perez-Sesma, A; Sandoval-Hernandez, M; Sarmiento-Reyes, A; Contreras-Hernandez, A D; Pereyra-Diaz, D; Hoyos-Reyes, C; Jimenez-Fernandez, V M; Huerta-Chua, J; Castro-Gonzalez, F; Laguna-Camacho, J R

2016-01-01

This article proposes the application of Laplace Transform-Homotopy Perturbation Method and some of its modifications in order to find analytical approximate solutions for the linear and nonlinear differential equations which arise from some variational problems. As case study we will solve four ordinary differential equations, and we will show that the proposed solutions have good accuracy, even we will obtain an exact solution. In the sequel, we will see that the square residual error for the approximate solutions, belongs to the interval [0.001918936920, 0.06334882582], which confirms the accuracy of the proposed methods, taking into account the complexity and difficulty of variational problems.

Usefulness and problems of film dosimetry in high energy radiotherapy

International Nuclear Information System (INIS)

Hirabayashi, Hisae

1995-01-01

Film dosimetry is a convenient and quick method of obtaining a set of high energy radiation isodose curves in the plane of the film, but it is an empirical method which presents some problems. Many authors have reported on film dosimetry for industrial films. Recently, the development of computerized densitometer systems, ready-pack films for radiotherapy and automatic film processors has helped improve the procedure. This paper reports our experiences regarding film dosimetry using the new materials, its usefulness in radiotherapy and some of technical problems encountered. The optical density value corresponding to a given dose depends upon the processing conditions, for XV-2 film, variation is about 4% when an automatic processor is used under controlled conditions. The Off-axis-ratios and the PDD in the perpendicular film plane agree well with the ion-chamber for photon and electron beams; by contrast, the PDD in the parallel film plane is significantly affected by variations in the phantom thickness, the type of film package and misalignment in phantom. But, bare films inserted into a cassette made of phantom material agree well for electron beams. Film dosimetry is effective and accurate at the edges of the field and for small fields, due to its high spatial resolution and rapid method. In addition, it is useful for electron beams OCR beam data input; for evaluating the input parameters for treatment planning systems; for quality assurance of the treatment equipment; and for preliminary clinical studies. Even when modern materials are used for film dosimetry, some technical problems will arise. Thus, to ensure the accuracy, certain precautions are required when setting conditions of film exposure and for quality control of the film processor. (author)

Discrete quintic spline for boundary value problem in plate deflation theory

Science.gov (United States)

Wong, Patricia J. Y.

2017-07-01

We propose a numerical scheme for a fourth-order boundary value problem arising from plate deflation theory. The scheme involves a discrete quintic spline, and it is of order 4 if a parameter takes a specific value, else it is of order 2. We also present a well known numerical example to illustrate the efficiency of our method as well as to compare with other numerical methods proposed in the literature.

Iterative Methods for Solving Nonlinear Parabolic Problem in Pension Saving Management

Science.gov (United States)

Koleva, M. N.

2011-11-01

In this work we consider a nonlinear parabolic equation, obtained from Riccati like transformation of the Hamilton-Jacobi-Bellman equation, arising in pension saving management. We discuss two numerical iterative methods for solving the model problem—fully implicit Picard method and mixed Picard-Newton method, which preserves the parabolic characteristics of the differential problem. Numerical experiments for comparison the accuracy and effectiveness of the algorithms are discussed. Finally, observations are given.

Legal problems connected with irradiated fuel reprocessing and its waste storage

International Nuclear Information System (INIS)

Nercy, B. de.

1981-10-01

In view of its nature, an irradiated nuclear fuel reprocessing operation -and the contracts implementing it between the reprocessor and the customer- raises certain difficult legal problems. This paper analyses this question from the legal viewpoint, in particular as regards nuclear fuel and material ownership and products or waste arising therefrom, as well as in the context of rules of international trade and non-proliferation standards. (NEA) [fr

Mesenchymal chondrosarcoma arising from the intrascrotal extratesicular soft tissue;a case report

International Nuclear Information System (INIS)

Lim, Jong-Uk; Koo, Bong-Sik; Park, Byeong-Ho; Park, Chang-Sook; Nam, Kyung-Jin; Kweon, Heon-Young

2000-01-01

Intrascrotal extratesticular malignancies are rare, and the radiologic findings of extraskeletal chondrosarcoma have not been reported. We describe the radiologic findings of a case of mesenchymal chondrosarcoma arising from intrascrotal extratesticular soft tissue and represented by a complex, cystic, solid mass containing calcifications and hematoma

Geometric phase due to orbit-orbit interaction: rotating LP11 modes in a two-mode fiber

Science.gov (United States)

Pradeep Chakravarthy, T.; Naik, Dinesh N.; Viswanathan, Nirmal K.

2017-10-01

Accumulation of geometric phase due to non-coplanar propagation of higher-order modes in an optical fiber is experimentally demonstrated. Vertically-polarized LP11 fiber mode, excited in a horizontally-held, torsion-free, step-index, two-mode optical fiber, rotates due to asymmetry in the propagating k-vectors, arising due to off-centered beam location at the fiber input. Perceiving the process as due to rotation of the fiber about the off-axis launch position, the orbital Berry phase accumulation upon scanning the launch position in a closed-loop around the fiber axis manifests as rotational Doppler effect, a consequence of orbit-orbit interaction. The anticipated phase accumulation as a function of the input launch position, observed through interferometry is connected to the mode rotation angle, quantified using the autocorrelation method.

A problem with problem solving: motivational traits, but not cognition, predict success on novel operant foraging tasks.

Science.gov (United States)

van Horik, Jayden O; Madden, Joah R

2016-04-01

Rates of innovative foraging behaviours and success on problem-solving tasks are often used to assay differences in cognition, both within and across species. Yet the cognitive features of some problem-solving tasks can be unclear. As such, explanations that attribute cognitive mechanisms to individual variation in problem-solving performance have revealed conflicting results. We investigated individual consistency in problem-solving performances in captive-reared pheasant chicks, Phasianus colchicus , and addressed whether success depends on cognitive processes, such as trial-and-error associative learning, or whether performances may be driven solely via noncognitive motivational mechanisms, revealed through subjects' willingness to approach, engage with and persist in their interactions with an apparatus, or via physiological traits such as body condition. While subjects' participation and success were consistent within the same problems and across similar tasks, their performances were inconsistent across different types of task. Moreover, subjects' latencies to approach each test apparatus and their attempts to access the reward were not repeatable across trials. Successful individuals did not improve their performances with experience, nor were they consistent in their techniques in repeated presentations of a task. However, individuals that were highly motivated to enter the experimental chamber were more likely to participate. Successful individuals were also faster to approach each test apparatus and more persistent in their attempts to solve the tasks than unsuccessful individuals. Our findings therefore suggest that individual differences in problem-solving success can arise from inherent motivational differences alone and hence be achieved without inferring more complex cognitive processes.

Relationships between Problem Behaviors and Academic Achievement in Adolescents: The Unique Role of Attention Problems.

Science.gov (United States)

Barriga, Alvaro Q.; Doran, Jeffrey W.; Newell, Stephanie B.; Morrison, Elizabeth M.; Barbetti, Victor; Robbins, Brent Dean

2002-01-01

This study examined relationships among eight teacher-reported problem behavior syndromes and standardized measures of academic achievement among 58 adolescents in an alternative school. Analysis suggested association between attention problems and academic achievement was primarily due to inattention component of the syndrome rather than the…