bluuebunny/crossref_metadata_2025 huggingface dataset:
From Haystacks to Hospitals: An Evolving Understanding of Mental Disorder and Firesetting
Authors: Nanayakkara Vindya , Ogloff James R. P. , Thomas Stuart D. M.
Published: April 2015

Early literature regarding firesetting almost exclusively assumed this behavior to occur as a result of mental illness, specifically pyromania. However, over time, the etiology and nature of firesetting has been acknowledged as being highly varied. This article reviews the literature on pathological firesetting, focusing on the mental disorders that have been empirically associated with the behavior. The diagnostic and treatment dilemmas, which hinge on improved understanding about the motives for firesetting, are also considered. Following the recent publication of the DSM-5, and the retention of the pyromania diagnosis, this review provides mental health practitioners an opportunity to reflect on the assessment and treatment of firesetting with renewed understanding.
Prevalence and Correlates of Criminal Activity in Adolescents Treated in Adult Inpatient Mental Health Beds in Ontario, Canada
Authors: Stewart Shannon L. , Baiden Philip , den Dunnen Wendy , Hirdes John P. , Perlman Christopher M.
Published: April 2015

Using logistic regression, this study seeks to examine the prevalence and correlates of criminal involvement in the previous year among adolescents in inpatient psychiatric facilities across Ontario, Canada. A sample of 2,613 adolescents aged 12 to 18 years who were admitted to adult inpatient mental health beds were examined. Just over one quarter of adolescents engaged in criminal activity within the past year. Older age, male gender, previous psychiatric admissions, a history of child abuse, poor insight into mental illness, substance use, specific types of mental health disorders, and aggressive behavior were all significantly associated with the presence of prior criminal activity. The well-founded association between mental health problems, substance use, and criminal behavior highlights the need for effective screening in settings providing services in the areas of juvenile justice, mental health, and addictions. Clinician awareness in all three settings is recommended so that these factors associated with at-risk behavior can be identified and appropriate treatment and referrals can be provided at the earliest point of involvement with any of these service systems.
Evaluating Predominant Causes of Insanity in Cases of Drug-Induced Psychoses
Authors: Wondemaghen Meron
Published: April 2015

The insanity defense operates on the basis that individuals who do not have the capacity to understand the consequences or wrongness of their action should not be held criminally responsible because there is a defect of reason. The defect must arise from a ‘disease of mind’ having internal causes. This raises questions about the way the law deals with externally caused defects of reason—such as drug-induced psychoses—because it depends on whether voluntary intoxication caused acute psychosis and ensuing insanity directly linked to voluntary intoxication; triggered or exacerbated an existing psychotic mental illness; or triggered a psychotic illness that was fixed and permanent due to chronic substance abuse but is independent of acute intoxication: a case of ‘settled insanity.’ The latter two conditions can form a sufficient basis for the defense. But can cognitive impairments arising from mental disorders be distinguished from those arising from substance abuse disorders? How are such distinctions made? This article uses an Australian case to illuminate the nuanced operations of the defense because a verdict of ‘not guilty because of mental impairment’ was reached even though the defendant had no prior history of mental illness and had consumed cocaine and methamphetamine prior to his killings. Evaluators should consider the predominant rather than precise cause of insanity in cases in which voluntary intoxication and mental illness are pertinent issues for the purposes of the defense.
Predictive Validity of the J-SOAP-II: Does Accuracy Differ Across Settings?
Authors: Martinez Ricardo , Rosenfeld Barry , Cruise Keith , Martin Jacqueline
Published: April 2015

Court and mental health workers are frequently asked to determine which juvenile sex offenders (JSOs) are most likely to reoffend. One instrument commonly used to guide decision making with JSOs is the Juvenile Sex Offender Assessment Protocol-II (J-SOAP-II). However, research utilizing this instrument has often generated contradictory results, perhaps related to the types of samples studied. The current study sought to compare the predictive accuracy of the J-SOAP-II across two samples of JSOs (a medium-security correctional setting versus an unlocked residential sex offender treatment program). Although the overall predictive accuracy for identifying post-release arrests for sexual offenses (i.e., sexual recidivism) was modest (AUC = .64) and not statistically significant, differences emerged with regard to the accuracy of some individual scales and subscales. Similarly, while no significant differences in predictive accuracy were observed between the two study sites, a number of interesting findings were observed. These findings highlight the need to consider risk assessment measures in light of the setting in which they are used in order to maximize predictive accuracy and optimize treatment and dispositional decision making.
Social Cohesion as Peacebuilding in the Central African Republic and Beyond
Authors: Brown Michael J. , Zahar Marie-Joëlle
Published: April 2015

Social cohesion has increasingly been touted as a tool of peacebuilding. Theoretically, the concept is linked with efforts to address inequality and build social capital. Practically, social cohesion is bandied about in settings such as the Central African Republic (CAR) as an important objective for building sustainable peace. We argue that peacebuilding scholars focus more on social cohesion as an end goal than they do on the policy-making and implementation aspects of the concept. After reviewing two key social cohesion initiatives in CAR, we find practitioners equally remiss in thinking about process. Also, both communities involved in the initiatives face challenges in grasping the complexity of the horizontal and vertical linkages that sustain conflict and which need to be restructured to build social cohesion. The paper documents these shortcomings and suggests tentative ways forward.
Bringing the Local Back In: Haiti, Local Governance and the Dynamics of Vertically Integrated Peacebuilding
Authors: Donais Timothy
Published: April 2015

In recent years, ‘the local’ has moved to the forefront of the contemporary peacebuilding debate, as evidenced both by growing scholarly interest in ‘the local turn’ in peacebuilding and by the emphasis on legitimate, inclusive politics in policy discussions surrounding the New Deal for Engagement in Fragile States. What is less clear, however, is how community-level peacebuilding activities can be effectively integrated with longstanding efforts to build peace by building viable, accountable state-level institutions; there remains, in other words, a conceptual and empirical gap between top-down and bottom-up peacebuilding processes. This article draws upon a case study of community-level peacebuilding and violence reduction in the urban slums of the Haitian capital of Port-au-Prince to illustrate the importance of vertical integration for sustainable peacebuilding. It argues that in the absence of explicit linkage — in particular through local-level institutions of governance — with broader statebuilding processes, community-based peacebuilding efforts may ultimately prove to be more palliative than transformative.
Grassroots Peacebuilding and Vertical Integration: A Case Study of the Peace-Rings Approach
Authors: Kamatsiko Valarie Vat
Published: April 2015

This article examines the practicalities of grassroots peacebuilding and discusses challenges they present to vertical integration through a case study of the Northern Uganda Early Recovery Project and its Peace Rings approach. Exploring both direct and indirect vertical integration, the article examines factors that both facilitated and undermined vertical integration, the impact that accrued, as well as the potential for bottom-up approaches to enhance vertical integration. A key conclusion is that in assessing the character and quality of vertical integration, the linkages among various local-level actors are just as important as linkages across international, national, and local divides.
Physical activities during pregnancy and type of delivery in nulliparae
Authors: Ko Yi‐Li , Chen Chie‐Pein , Lin Pi‐Chu
Published: April 2015

The aim of this study was to investigate changes in physical activity across pregnancy and the relationship between trimester‐specific physical activity and unplanned caesarean sections (CSs). A cohort study design was carried out. A cohort of 150 pregnant women was established when they received prenatal care at 29–40 weeks of gestation at a medical centre in northern Taiwan. Participants were asked to recall the amounts of physical activity in which they had engaged in the three trimesters as assessed by the Pregnancy Physical Activity Questionnaire (PPAQ). Overall self‐reported physical activity for the cohort decreased by 31% in the first trimester compared to the pre‐gravid period, then increased in the second trimester and remained stable until delivery. A repeated measures analysis of variance was used to evaluate the data and revealed significantly more physical activity during the second trimester than in the first and third trimesters (F = 36.471, P = 0.000). In addition, there was a significant difference between normal spontaneous delivery and unplanned CS groups (F = 4.770, P = 0.031). Logistic regression determined that the odds ratio of undergoing a CS increased by 0.644 (95% confidence interval: 0.429–0.968) for women in the third trimester who performed low levels of physical activity. Results support the benefits of physical activity, and professionals are encouraged to provide pregnant women with information on recommendations for physical activity, particularly in terms of reducing unplanned CSs.
Uncertainty and predictiveness determine attention to cues during human associative learning
Authors: Beesley Tom , Nguyen Katherine P. , Pearson Daniel , Le Pelley Mike E.
Published: April 2015

Prior research has suggested that attention is determined by exploiting what is known about the most valid predictors of outcomes and exploring those stimuli that are associated with the greatest degree of uncertainty about subsequent events. Previous studies of human contingency learning have revealed evidence for one or other of these processes, but differences in the designs and procedures of these studies make it difficult to pinpoint the crucial determinant of whether attentional exploitation or exploration will dominate. Here we present two studies in which we systematically manipulated both the predictiveness of cues and uncertainty regarding the outcomes with which they were associated. This allowed us to demonstrate, for the first time, evidence of both attentional exploration and exploitation within the same experiment. Moreover, while the effect of predictiveness persisted to influence the rate of novel learning about the same cues in a second stage, the effect of uncertainty did not. This suggests that attentional exploration is more sensitive to a change of context than is exploitation. The pattern of data is simulated with a hybrid attentional model.
The social dominance orientation in adolescence: the role of gender identity and stereotypical male and female traits / La orientación a la dominancia social en la adolescencia: el papel de la identidad de género y los rasgos estereotípicos femeninos y masculinos
Authors: Aranda María , Montes-Berges Beatriz , Castillo-Mayén María-Rosario
Published: April 2015

This study aims to evaluate the invariance hypothesis proposed by Social Dominance Theory in adolescents. Moreover, it also suggests an alternative model which describes the influence of stereotypes and gender identity on social dominance orientation. To do so, the three variables were measured using scales in a sample consisting of 107 participants aged between 14 and 16. The results showed there was no significant relationship between gender and social dominance scores, nor were there significant differences in the levels of this variable between males and females. Multiple regression analysis showed that the assignment of male stereotypes in both males and females explained social dominance orientation scores and the direction of the positive relationship. Furthermore, with regard to gender identity dimensions, results showed that the dimension related to private self-esteem was the factor that explained the scores in males’ dominance orientation, while the self-perception of having a feminine physique explained females’ social dominance.
Workplace bullying and interpersonal conflicts: the moderation effect of supervisor’s power / Acoso laboral y conflictos interpersonales: el papel moderador de las bases de poder del supervisor
Authors: Arenas Alicia , León-Pérez José-María , Munduate Lourdes , Medina Francisco J.
Published: April 2015

Workplace bullying is considered the final stage of a prolonged conflict where there is a power imbalance between the affected parties and where emotional and relational problems exist. Thus, this study aims to explore the role of employee perceptions about the supervisor’s power bases on the relationship of conflict (i.e., task and relationship conflicts) and bullying at work. A cross-sectional survey study was conducted ( N = 211). Results support a moderated-mediation model in which relationship conflict mediates the association between task conflict and workplace bullying, suggesting a conflict escalation process in bullying situations. In addition, establishing personal power bases seems to reduce the intensity of the link between task conflict and relationship conflict and, in turn, workplace bullying, whereas establishing positional power bases was not related to this association. Practical implications for bullying prevention are discussed.
Daily work events and state work engagement: the mediating role of affect / Eventos diarios y work engagement: el rol mediador del afecto
Authors: Miralles Cibeles , Navarro José , Unger Dana
Published: April 2015

According to Affective Events Theory, the emotional elicitation process is initiated by the appraisal of affective events happening to employees. Moreover, the theory states that these elicited affective experiences influence attitude and behaviour in the workplace. In the present study this theoretical frame is applied to explain the interplay of variables influencing state work engagement. We analyse the mediating role of affect between work events’ appraisals and daily work engagement, using a diary study. One hundred and seventeen workers answered a daily questionnaire for at least 10 days generating a total of 1,203 registers. Multilevel analysis proved that daily events’ appraisal is positively related to state work engagement, and that this relationship is partially mediated by positive and negative affect. Moreover, the effect of positive affect was bigger than the one of negative affect. The explored relations provide new theoretical elements for models that explain which variables influence state work engagement.
The role of mothers in economic socialization of saving behaviour in Polish adolescents / El rol de las madres en la socialización ecónomica del comportamiento de ahorro de los adolescentes polacos
Authors: Trzcińska Agata , Goszczyńska Maryla
Published: April 2015

The present study investigated the role of mothers in the economic socialization of saving-related attitudes, motives and behaviours in Polish adolescents. Research to date has shown that economic education in the family and parental models (especially the mother) are particularly important for the development of adolescent saving behaviour. Youth saving was hypothesized to be enhanced by active economic education (direct teaching) in the family and certain attitudes of mothers towards money (attitude modelling). A questionnaire-based approach was used and responses from 154 mother-adolescent (aged 13–19 years) dyads were analysed. Correlation and regression analyses showed that modelling of attitudes is more important for the formation of pro-saving attitudes and behaviour than direct teaching of children to engage in economic activities.
On simultaneous Pell equations and related Thue equations
Authors: He Bo , Pintér Ákos , Togbé Alain
Published: April 2015

In this paper, we prove that the simultaneous Pell equations
\[

x
2

−
(

m
2

−
1
)

y
2

=
1
,

z
2

−
(

n
2

−
1
)

y
2

=
1

x^2-(m^2-1)y^2=1,\, z^2-(n^2-1)y^2=1

\]
have only a positive integer solution

(
x
,
y
,
z
)
=
(
m
,
1
,
n
)

(x, y, z) = (m, 1, n)

if

m
>
n
≤
m
+

m

ε

,
0
>
ε
>
1

m > n \le m+m^{\varepsilon }, 0 > \varepsilon > 1

and

m
≥

202304

1

1
−
ε

m \ge 202304^{\frac {1}{1-\varepsilon }}

. Using a computational reduction method we can omit the lower bound for

m
m

when

m
>
n
≤

m

1
5

m>n\le m^{\frac {1}{5}}

. Moreover, we apply our main result to a family of Thue equations in two parameters studied by Jadrijević.
A remark on the nonnegativity of the Paneitz operator
Authors: Lai Mijia
Published: April 2015

In this short article, we interpret the condition of a theorem of Gursky-Viaclovsky concerning the nonnegativity of the Paneitz operator as the metric being

3
3

-positive Ricci. By a result of Wolfson, this condition can be preserved under the surgery of codimension

q
≥
3

q\geq 3

. Combining these two observations, we expand the list of manifolds which admit metrics with a nonnegative Paneitz operator. Consequently, there exist metrics of constant

Q
Q

-curvature on these manifolds.
Obstacles for splitting multidimensional necklaces
Authors: Lasoń Michał
Published: April 2015

The well-known “necklace splitting theorem” of Alon (1987) asserts that every

k
k

-colored necklace can be fairly split into

q
q

parts using at most

t
t

cuts, provided

k
(
q
−
1
)
≤
t

k(q-1)\leq t

. In a joint paper with Alon et al. (2009) we studied a kind of opposite question. Namely, for which values of

k
k

and

t
t

is there a measurable

k
k

-coloring of the real line such that no interval has a fair splitting into

2
2

parts with at most

t
t

cuts? We proved that

k
>
t
+
2

k>t+2

is a sufficient condition (while

k
>
t

k>t

is necessary).

We generalize this result to Euclidean spaces of arbitrary dimension

d
d

, and to arbitrary number of parts

q
q

. We prove that if

k
(
q
−
1
)
>
t
+
d
+
q
−
1

k(q-1)>t+d+q-1

, then there is a measurable

k
k

-coloring of

R

d

\mathbb {R}^d

such that no axis-aligned cube has a fair

q
q

-splitting using at most

t
t

axis-aligned hyperplane cuts. Our bound is of the same order as a necessary condition

k
(
q
−
1
)
>
t

k(q-1)>t

implied by Alon’s 1987 work. Moreover, for

d
=
1
,
q
=
2

d=1,q=2

we get exactly the result of the 2009 work.

Additionally, we prove that if a stronger inequality

k
(
q
−
1
)
>
d
t
+
d
+
q
−
1

k(q-1)>dt+d+q-1

is satisfied, then there is a measurable

k
k

-coloring of

R

d

\mathbb {R}^d

with no axis-aligned cube having a fair

q
q

-splitting using at most

t
t

arbitrary hyperplane cuts. The proofs are based on the topological Baire category theorem and use algebraic independence over suitably chosen fields.
A controlling norm for energy-critical Schrödinger maps
Authors: Dodson Benjamin , Smith Paul
Published: April 2015

We consider energy-critical Schrödinger maps with target either the sphere

S

2

\mathbb {S}^2

or hyperbolic plane

H

2

\mathbb {H}^2

and establish that a unique solution may be continued so long as a certain space-time

L
4

L^4

norm remains bounded. This reduces the large data global wellposedness problem to that of controlling this norm.
Stabilization of a system of anisotropic thermoelasticity by nonlinear boundary and internal feedbacks
Authors: Heminna Amar , Nicaise Serge , Sène Abdoulaye
Published: April 2015

We consider the stabilization of an anisotropic thermoelasticity system with a natural Neumann boundary condition on part of the boundary and combined nonlinear internal and boundary feedbacks. We then give an answer to a problem raised by Liu and Zuazua.
𝐿²-well-posedness of 3d div-curl boundary value problems
Authors: Auchmuty Giles , Alexander James
Published: April 2015

Criteria for the existence and uniqueness of weak solutions of div-curl boundary-value problems on bounded regions in space with

C
2

C^2

-boundaries are developed. The boundary conditions are either given normal components of the field or else given tangential components of the field. Under natural integrability assumptions on the data, finite-energy (

L
2

L^2

) solutions exist if and only if certain compatibility conditions hold on the data. When compatibility holds, the dimension of the solution space of the boundary-value problem depends on the differential topology of the region. The problem is well-posed with a unique solution in

L
2

(
Ω
;

R

3

)

L^2(\Omega ;\mathbb {R}^3)

provided, in addition, certain line or surface integrals of the field are prescribed. Such extra integrals are described. These results depend on certain weighted orthogonal decompositions of

L
2

L^2

vector fields which generalize the Hodge-Weyl decomposition. They involve special scalar and vector potentials. The choices described here enable a decoupling of the equations and a weak interpretation of the boundary conditions. The existence of solutions for the equations for the potentials is obtained from variational principles. In each case, necessary conditions for solvability are described and then these conditions are shown to also be sufficient. Finally

L
2

L^2

-estimates of the solutions in terms of the data are obtained. The equations and boundary conditions treated here arise in the analysis of Maxwell’s equations and in fluid mechanical problems.
The exponential decay of global solutions to the generalized Landau equation near Maxwellians
Authors: Yu Hongjun
Published: April 2015

Global-in-time classical solutions near Maxwellians are constructed for the generalized Landau equation in a periodic box for

γ
≥
−
2

\gamma \geq -2

. The exponential decay of such a solution is also obtained.
Total gravitational energy of a slightly ellipsoidal trilayer planet
Authors: Grinfeld Pavel , Wisdom Jack
Published: April 2015

We use a perturbational technique to compute the total gravitational energy of a slightly ellipsoidal trilayer planet as a function of the two sets of Euler angles. A second order computation is required since the torque is proportional to the product of the ellipticities of the inner core and the mantle. Although we focus on ellipsoidal perturbations, the intermediate analytical expressions are valid for arbitrary small deformations of the spherical configuration. The primary application of the expression for the total gravitational energy is in the Lagrangian formulation of dynamics. As a by-product, we determine the gravitationally stable equilibrium orientation of the rigid inner core. Due to symmetry, the six coaxial configurations are equilibrium. We show how to identify the stable configuration and to prove its uniqueness.
Finite-dimensional attractor for the viscous Cahn-Hilliard equation in an unbounded domain
Authors: Bonfoh Ahmed
Published: April 2015

We consider the viscous Cahn-Hilliard equation in an infinite domain. Due to the noncompactness of operators, we use weighted Sobolev spaces to prove that the semigroup generated by this equation has the global attractor which has finite Hausdorff dimension.
Ray methods for free boundary problems
Authors: Addison J. , Howison S. , King J.
Published: April 2015

We discuss the use of the WKB ansatz in a variety of parabolic problems involving a small parameter. We analyse the Stefan problem for small latent heat, the Black–Scholes problem for an American put option, and some nonlinear diffusion equations, in each case constructing an asymptotic solution by the use of ray methods.
Viscous flow due to a shrinking sheet
Authors: Miklavčič M. , Wang C.
Published: April 2015

The viscous flow induced by a shrinking sheet is studied. Existence and (non)uniqueness are proved. Exact solutions, both numerical and in closed form, are found.
Existence of optimal shape for a system of conservation laws in a free air-porous domain
Authors: Novruzi Arian
Published: April 2015

We consider a shape optimization problem related to a nonlinear system of PDE describing the gas dynamics in a free air-porous domain, including gas concentrations, temperature, velocity and pressure. The velocity and pressure are described by the Stokes and Darcy laws, while concentrations and temperature are given by mass and heat conservation laws. The system represents a simplified dry model of gas dynamics in the channel and graphite diffusive layers of hydrogen fuel cells. The model is coupled with the other part of the domain through some mixed boundary conditions, involving nonlinearities, and pressure boundary conditions. Under some assumptions we prove that the system has a solution and that there exists a channel domain in the class of Lipschitz domains minimizing a certain functional measuring the membrane temperature distribution, total current, water vapor transport and channel inlet/outlet pressure drop
The Lambert transform for small and large values of the transformation parameter
Authors: Ferreira Chelo , López José
Published: April 2015

We derive asymptotic expansions of the Lambert transform
\[

∫
0
∞

x
t
(

e

x
t

−
1

)

−
1

f
(
t
)
d
t

\int _0^\infty xt(e^{xt}-1)^{-1}f(t)dt

\]
of a locally integrable function

f
(
t
)

f(t)

for small and large

x
x

. All the expansions are accompanied by error bounds for the remainder at any order of the approximation.
Competitive systems with migration and the Poincaré-Bendixson theorem for a 4-dimensional case
Authors: Jiang Jifa , Liang Xing
Published: April 2015

In this paper, dynamics of the

n
n

-species competitive system with migration is studied. It is proved that if the Jacobian matrix of the system is irreducible at every point in Int 

R

+

2
n

\mathbb {R}^{2n}_+

, then there is a defined countable family of invariant

(
2
n
−
1
)

(2n-1)

-cells which attract all nonconvergent persistent trajectories. Moreover, it is proved that the Poincaré-Bendixson theorem holds for

2
2

-species competitive systems with migration.
Peristaltic transport of a Herschel-Bulkley fluid in contact with a Newtonian fluid
Authors: Vajravelu K. , Sreenadh S. , Babu V.
Published: April 2015

Peristaltic transport of Herschel-Bulkley fluid in contact with a Newtonian fluid in a channel is investigated for its various applications to flows with physiological fluids (blood, chyme, intrauterine fluid, etc.). The primary application is when blood flows through small vessels; blood has a peripheral layer of plasma and a core region of suspension of all the erythrocytes. That is, in the modeling of blood flow, one needs to consider the core region consisting of a yield stress fluid and the peripheral region consisting of a Newtonian fluid. Peristaltic pumping of a yield stress fluid in contact with a Newtonian fluid has not previously been studied in detail. Our goal is to initiate such a study. The Herschel-Bulkley fluid model considered here reduces to the power law model in the absence of yield stress. The stream function, the velocity field, and the equation of the interface are obtained and discussed. When the yield stress

τ
0

→
0

\tau _0\to 0

and when the index

n
=
1

n=1

, our results agree with those of Brasseur et al. (J. Fluid Mech. 174 (1987), 495) for peristaltic transport of the Newtonian fluid. It is observed that for a given flux

Q
¯

\overline Q

the pressure rise

Δ
p

\Delta p

increases with an increase in the amplitude ratio

ϕ
\phi

. Furthermore, the results obtained for the flow characteristics reveal many interesting behaviors that warrant further study of the peristaltic transport models with two immiscible physiological fluids.
Some remarks on homogenization and exact boundary controllability for the one-dimensional wave equation
Authors: Pedregal Pablo , Periago Francisco
Published: April 2015

This paper contains three results concerning the homogenization and exact controllability for the one-dimensional wave equation. First, we give sufficient conditions on the initial data to ensure the convergence of the conormal derivatives associated with the wave equation with a rapidly oscillating coefficient and zero Dirichlet boundary conditions. Secondly, we apply this result to prove the existence of a class of initial data whose associated boundary controls are uniformly bounded and obtain some information (in particular, its limit behavior) on this class of data. Finally, we prove that all initial data in

L
2

×

H

−
1

L^2\times H^{-1}

may be uniformly controlled but at the price of adding an internal feedback control in our system. The main advantage of this last procedure is that we have explicit formulae for both states and controls.
On local uniqueness in nonlinear elastodynamics
Authors: Knops R.
Published: April 2015

A conservation law, derived from properties of the energy-momentum tensor, is used to establish uniqueness of suitably constrained solutions to the initial boundary value problem of nonlinear elastodynamics. It is assumed that the region is star-shaped, that the data are affine, and that the strain-energy function is strictly rank-one convex and quasi-convex. It is shown how these assumptions may be successively relaxed provided that the class of considered solutions is correspondingly further constrained.
Asymptotic behaviour of solutions of lubrication problem in a thin domain with a rough boundary and Tresca fluid-solid interface law
Authors: Boukrouche Mahdi , Ciuperca Ionel
Published: April 2015

We study the asymptotic behavior of the solution of a Stokes flow in a thin domain, with a thickness of order

ε
\varepsilon

, and a rough surface. The roughness is defined by a quasi-periodic function with period

ε
\varepsilon

. We suppose that the flow is subject to a Tresca fluid-solid interface condition. We prove a new result on the lower-semicontinuity for the two-scale convergence, which allows us to obtain rigorously the limit problem and to establish the uniqueness of its solution.
Homoclinic orbits in predator-prey systems with a nonsmooth prey growth rate
Authors: Sugie Jitsuro , Kimoto Kyoko
Published: April 2015

This paper deals with Gause-type predator-prey models with a non-smooth prey growth rate. Our models have a unique positive equilibrium and are under the influence of an Allee effect. A necessary and sufficient condition is given for the existence of homoclinic orbits whose

α
\alpha

- and

ω
\omega

-limit sets are the positive equilibrium. The argument used here is based on some results of a system of Liénard type. The relation between homoclinic orbits and the Allee effect is clarified. A simple example is included to illustrate the main result. Some global phase portraits are also attached.
Electromagnetic inverse problems involving distributions of dielectric mechanisms and parameters
Authors: Banks H. , Gibson N.
Published: April 2015

We consider electromagnetic interrogation problems for complex materials involving distributions of polarization mechanisms and also distributions for the parameters in these mechanisms. A theoretical and computational framework for such problems is given. Computational results for specific problems with multiple Debye mechanisms are given in the case of discrete, uniform, log-normal, and log-bi-Gaussian distributions.
Parametrization of the two and three-dimensional motion of a viscous incompressible liquid
Authors: Ranger K.
Published: April 2015

A method is described for parametrizing the velocity components and space coordinates in terms of parametric functions and time for the two and three-dimensional motion of a viscous incompressible liquid. The two-dimensional motion contains four functions and the three-dimensional motion contains six functions satisfying minimal requirements.
Scattering relations for point-generated dyadic fields in two-dimensional linear elasticity
Authors: Athanasiadis C. , Sevroglou V. , Stratis I.
Published: April 2015

The problem of scattering of elastic waves by a bounded obstacle in two-dimensional linear elasticity is considered. The scattering problems are presented in a dyadic form. An incident dyadic field generated by a point source is disturbed by a rigid body, a cavity, or a penetrable obstacle. General scattering theorems are proved, relating the far-field patterns due to scattering of waves from a point source set up in either of two different locations. The most general reciprocity theorem is established, and mixed scattering relations are also proved. Finally, a relation between the incident and the scattered wave which refers to the mechanism of energy transfer of the scatterer, the so-called optical theorem, is established.
Large time decay of solutions to isentropic gas dynamics
Authors: Tsuge Naoki
Published: April 2015

We study the large time behavior of solutions to isentropic gas dynamics. For a constantγ\gamma(1>γ>3)(1>\gamma >3), we show the decay of theLγL^{\gamma }norm of density. To do this, we estimate approximate solutions constructed by a difference scheme.
Parabolic-hyperbolic time-dependent Ginzburg-Landau-Maxwell equations
Authors: Berti Valeria , Gatti Stefania
Published: April 2015

This article is devoted to the long-term dynamics of a parabolic-hyperbolic system arising in superconductivity. In the literature, the existence and uniqueness of the solution have been investigated but, to our knowledge, no asymptotic result is available. For the bidimensional model we prove that the system generates a dissipative semigroup in a proper phase-space where it possesses a (regular) global attractor. Then, we show the existence of an exponential attractor whose basin of attraction coincides with the whole phase-space. Thus, in particular, this exponential attractor contains the global attractor which, as a consequence, is of finite fractal dimension.
Non-linear and non-stationary modes of the lower branch of the incompressible boundary layer flow due to a rotating disk
Authors: Turkyilmazoglu M.
Published: April 2015

In this paper a theoretical study is undertaken to investigate the structure of the lower branch neutral stability modes of three-dimensional small disturbances imposed on the incompressible Von Karman’s boundary layer flow due to a rotating disk. Particular attention is given to the short-wavelength non-linear non-stationary cross-flow vortex modes at sufficiently high Reynolds numbers with reasonably small scaled frequencies. Following closely the asymptotic frameworks introduced in [Proc. Roy. Soc. London Ser. A406(1986), 93–106] and [Proc. Roy. Soc. London Ser. A413(1987), 497–513] for the stationary linear and non-linear modes, it is revealed here that the non-stationary modes with sufficiently long time scale can also be described by an asymptotic expansion procedure based on the triple-deck theory. Making use of this approach, which takes into account the non-linear and non-parallel effects, the asymptotic structure of the non-stationary modes is shown to be adjusted by a balance between viscous and Coriolis forces, and resulted from the fact of vanishing shear stress at the disk surface. As a consequence of the matching of the solutions in adjacent regions it is found that in the linear case the wavenumber and the orientation of the lower branch modes are governed by an eigenrelation, which is akin to the one obtained previously in [Proc. Roy. Soc. London Ser. A406(1986), 93–106] for the stationary modes. The asymptotic theory shows that the non-parallelism has a destabilizing effect. A Landau-type equation for the modulated vortex amplitude with coefficients that are often difficult to get from finite Reynolds number computations has also been obtained from a weakly non-linear analysis in the limit of infinitely large Reynolds numbers. The non-linearity has also been found to be destabilizing for both positive and negative frequency waves, though finite amplitude growth of a disturbance having positive frequency close to the neutral location is more effective.
A note on equilibrated stress fields for no-tension bodies under gravity
Authors: Lucchesi M. , Šilhavý M. , Zani N.
Published: April 2015

We study the equilibrium problem for two-dimensional bodies made of a no-tension material under gravity, subjected to distributed or concentrated loads on their boundary. Admissible and equilibrated stress fields are interpreted as tensor-valued measures with distributional divergence represented by a vector-valued measure, as developed by the authors of the present paper. Such stress fields allow us to consider stress concentrations on surfaces and lines. Working in

R

n

,

\mathbb {R}^n,

we calculate the weak divergence of a stress field that is asymptotically of the form

|

x

|

−
n
+
1

T

0

(

x

/

|

x

|

)

|\mathbfit {x} |^{-n+1}\mathbfit {T} _0(\mathbfit {x} /|\mathbfit {x} |)

for

x

→

0

\mathbfit {x} \to \mathbf {0}

on a region that is asymptotically a cone with vertex

0

\mathbf {0}

. Such stress fields arise as parts of our solutions for two-dimensional panels. Proceeding to problems in dimension two, we first determine an admissible equilibrated solution for a half-plane under gravity that underlies two subsequent solutions for rectangular panels. For the latter we give solutions for three types of loads.
Well-posedness of two-phase Darcy flow in 3D
Authors: Ambrose David
Published: April 2015

We prove the well-posedness, locally in time, of the motion of two fluids flowing according to Darcy’s law, separated by a sharp interface in the absence of surface tension. We first reformulate the problem using favorable variables and coordinates. This results in a quasilinear parabolic system. Energy estimates are performed, and these estimates imply that the motion is well-posed for a short time with data in a Sobolev space, as long as a condition is satisfied. This condition essentially says that the more viscous fluid must displace the less viscous fluid. It should be true that small solutions exist for all time; however, this question is not addressed in the present work.
Stability estimates of the Boltzmann equation in a half space
Authors: Chae Myeongju , Ha Seung-Yeal
Published: April 2015

In this paper, we study the large-time behavior and the stability of continuous mild solutions to the Boltzmann equation in a half space. For this, we introduce two nonlinear functionals measuring future binary collisions and

L
1

L^1

-distance. Through the time-decay estimates of these functionals and the pointwise estimate of the gain part of the collision operator, we show that continuous mild solutions approach to collision free flows time-asymptotically in

L
1

L^1

, and

L
1

L^1

-distance at time

t
t

is uniformly bounded by that of corresponding initial data, when initial datum is a small perturbation of the vacuum.
Some analytical results for acoustic scattering through a periodic array of elastic membranes
Authors: Scarpetta Edoardo , Sumbatyan Mezhlum
Published: April 2015

In the context of wave propagation through acoustic media, an analytical approach is developed to study the (normal) incidence of a pressure wave into a periodic array of (thin) elastic membranes. The frequency of this wave is assumed in a range implying the so-called one-mode (far field) propagation, so that mild approximations holding in this range can be employed. Thus, the problem is reduced to some integral equations based on the opening between adjacent membranes and independent of the frequency. By means of the (analytical) solutions of such equations, an explicit formula for the transmission coefficient is set up and reflected in some figures for concrete values of the various parameters involved. The peculiarities of the scattering structure are discussed.
On existence of a classical solution and non-existence of a weak solution to the Dirichlet problem in a planar domain with slits for Laplacian
Authors: Krutitskii P.
Published: April 2015

The Dirichlet problem for the Laplacian in a planar domain bounded by smooth closed curves and smooth double-sided open arcs (slits) is considered in the case when the solution is not continuous at the ends of the slits. The cases of both interior and exterior domains are considered. The well-posed formulation of the problem is given, theorems on existence and uniqueness of a classical solution are proved, and the integral representation for a solution is obtained. It is shown that a weak solution of the problem does not typically exist, though the classical solution exists.
Global existence and stability of mild solutions to the Boltzmann system for gas mixtures
Authors: Ha Seung-Yeal , Noh Se , Yun Seok
Published: April 2015

We present the global existence and stability of mild solutions to the Boltzmann system with inverse power molecular interactions for a binary gas mixture, when initial data are sufficiently small and decay exponentially in phase space. For the existence and stability of mild solutions, we employ a modified Kaniel-Shinbrot’s scheme and a weighted nonlinear functional approach. Time-asymptotic convergence toward the free molecular motion is established using a weighted collision potential, and we show that the weighted

L
1

L^1

-distance between two mild solutions is uniformly controlled by that of initial data.
On the completeness of a method of potentials in elastodynamics
Authors: Pak Ronald , Eskandari-Ghadi Morteza
Published: April 2015

In this paper, the theoretical foundation of a compact scalar potential method in three-dimensional classical elastodynamics is substantiated. Beginning with a derivation of two basic lemmas on the decomposition and integration of wave solutions and vector fields which are apt to be of interest to general mechanics and analysis, the treatment proceeds to a proof of the completeness of the proposed representation as well as its extension to non-zero body forces.
An analysis of the paraxial wave equation
Authors: McCoy Peter , Malek-Madani Reza
Published: April 2015

Function theoretic methods are used to characterize solutions of the paraxial wave equation in an isotropic homogeneous medium in 3-space. A new class of function theoretic solutions whose singularities are manifested as sectionally analytic functions is constructed via integral transforms.
Instability intervals and growth rates for Hill’s equation
Authors: Keller Joseph
Published: April 2015

Hill’s equation is a real linear second-order ordinary differential equation with a periodic coefficient

f
(
t
)

f(t)

:
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="StartLayout 1st Row with Label left-parenthesis 0.1 right-parenthesis EndLabel y double-prime left-parenthesis t right-parenthesis plus left-bracket lamda plus epsilon f left-parenthesis t right-parenthesis right-bracket y left-parenthesis t right-parenthesis equals 0 period EndLayout">

(0.1)

y

′
′

(
t
)
+

[
λ
+
ε
f

(
t
)

]

y
(
t
)
=
0.

\begin{equation} y^{\prime \prime } (t) +\left [ \lambda +\varepsilon f\left (t\right ) \right ] y(t) =0. \tag *{(0.1)} \end{equation}

It has unbounded solutions for certain intervals of the real parameter

λ
\lambda

, called instability intervals. Here these intervals, and the growth rate of the unbounded solutions, are determined for

ε
\varepsilon

small, and also for

λ
\lambda

large. This is done by constructing a fundamental pair of solutions which are power series in

ε

/

λ

1

/

2

\varepsilon /\lambda ^{1/2}

, with coefficients that are bounded functions of

λ
\lambda

.
𝐻^{𝑜}-type Riemannian metrics on the space of planar curves
Authors: Shah Jayant
Published: April 2015

Michor and Mumford have shown that the distances between planar curves in the simplest metric (not involving derivatives) are identically zero. We derive geodesic equations and a formula for sectional curvature for conformally equivalent metrics. We show if the conformal factor depends only on the length of the curve, then the metric behaves like an

L
1

L^1

-metric, the sectional curvature is not bounded from above, and minimal geodesics may not exist. If the conformal factor is superlinear in curvature, then the sectional curvature is bounded from above.
Homoclinic and heteroclinic orbits for the 0² or 0²𝑖𝜔 singularity in the presence of two reversibility symmetries
Authors: Wang Ling-Jun
Published: April 2015

This paper is devoted to the study of the dynamics of reversible vector fields close to an equilibrium when a

0
2

0^2

or a

0
2

i
ω

0^2i\omega

resonance occurs in the presence of two symmetries of reversibility. In the presence of a unique reversibility symmetry the existence of a homoclinic connection to 0 is known for the

0
2

0^2

resonance whereas for the

0
2

i
ω

0^2i\omega

resonance there is generically no homoclinic connection to 0 but there is always a homoclinic connection to an exponentially small periodic orbit.

In the presence of a second symmetry of reversibility, the situation is more degenerate. Indeed, because of the second symmetry the quadratic part of the normal forms vanishes, and so the dynamics of the normal forms is governed by the cubic part. For the

0
2

0^2

resonance we prove the existence of homoclinic connections to 0 and of heteroclinic orbits. For the

0
2

i
ω

0^2i\omega

resonance we prove that in most of the cases the second symmetry induces the existence of homoclinic connections to 0 and of heteroclinic orbits whereas with a unique symmetry there is generically no homoclinic connection to 0. Such a reversible vector field with two reversibility symmetries occurs for instance after center manifold reduction when studying 2-dimensional waves in NLS type systems with one-dimensional potential or when studying localized waves in nonlinear chains of coupled oscillators. It also occurs when studying localized buckling in rods with noncircular cross section.
Transport of heat and mass in a fluid with vanishing mobility
Authors: Choquet Catherine
Published: April 2015

We study a model describing the compressible displacement of a mixture in a porous medium. The transport of heat and mass is described by a nonlinear, fully coupled and degenerate parabolic system. Using a series of compensated compactness and convexity arguments, we prove the existence of relevant weak solutions.
Solving SPDEs driven by colored noise: A chaos approach
Authors: Lototsky S. , Stemmann K.
Published: April 2015

An Itô-Skorokhod bilinear equation driven by infinitely many independent colored noises is considered in a normal triple of Hilbert spaces. The special feature of the equation is the appearance of the Wick product in the definition of the Itô-Skorokhod integral, requiring innovative approaches to computing the solution. A chaos expansion of the solution is derived and several truncations of this expansion are studied. A recursive approximation of the solution is suggested and the corresponding approximation error bound is computed.
Stochastic partial differential equations driven by multi-parameter white noise of Lévy processes
Authors: Øksendal Bernt
Published: April 2015

We give a short introduction to the white noise theory for multiparameter Lévy processes and its application to stochastic partial differential equations driven by such processes. Examples include temperature distribution with a Lévy white noise heat source, and heat propagation with a multiplicative Lévy white noise heat source.
Orthogonal projections and the dynamics of constrained mechanical systems
Authors: Balseiro Paula , Solomin Jorge
Published: April 2015

A coordinate-free version of the approach to mechanical systems with non-ideal restrictions developed by Udwadia (2002) and Udwadia and Kalaba (2002) in a series of articles is introduced. Some of its properties are then reinterpreted in a general geometric setting in terms of orthogonal projections. A geometric view of other aspects of constrained systems, inspired by their insight, is also presented.