bluuebunny/crossref_metadata_2025 huggingface dataset:
Pendekatan Fuzzy Servqual Untuk Mengevaluasi Tingkat Kepuasan Pasien di Praktik Dokter Karunia
Authors: Lina Rosina Limbong  , Entin Sutinah  , Nani Agustina
Published: December 2024

Measuring patient satisfaction is one of the main indicators of measuring the quality of service in health facilities. Health service providers have difficulty measuring patient satisfaction, problems that are often complained about based on patient perceptions include late arrival of doctors at the clinic, lack of toilet cleanliness, long examination times, and the attitude of some nurses who are not friendly. The purpose of the study was to evaluate the level of satisfaction of patients who were treated at the Karunia Doctor's Practice using the Fuzzy Servqual method. Service quality was analyzed through five dimensions in the Servqual framework, namely tangible evidence, reliability, responsiveness, assurance, and empathy. The results of the study showed that the gap value of the five dimensions was negative, indicating that the quality of service provided did not meet the expectations of patients who were treated at the Karunia Doctor's Practice. The dimension with the highest gap value was tangible evidence with a value of -0.77, while the lowest gap value was in the reliability dimension. Thus, it can be concluded that the tangible evidence dimension requires special attention to improve service quality.
Konversi ke Microservices Untuk Peningkatan Layanan Perpustakaan
Authors: Sumadyo Malikus , Handayanto Rahmadya Trias , Setiawan Ramdhani
Published: December 2024

Most web-based applications are applications that provide services to users. The services themselves often change according to policies that are usually based on user satisfaction information. Unfortunately, existing applications are mostly based on open-source which is mostly monolithic. If there is an addition of a new service, it requires development from the beginning again. Especially when there is an imbalance between one service and another where one service requires large resources while other services do not require too many resources such as processors, network speed, or database size. This study tries to propose a system change in the library based on PHP-MySQL to be based on microservices.
Sintomatología depresiva y trastornos de ansiedad en niños víctimas de maltrato infantil
Authors: Delgado Reyes Andrés Ricardo , Piña García Karla Isamar , Peña Herrera Bernardo
Published: December 2024

Introducción: Este estudio examina la relación entre el maltrato infantil y los trastornos psicológicos, específicamente la depresión y la ansiedad, en una muestra de 200 niños y adolescentes derivados a la Unidad de Atención Especializada en Psicología por maltrato físico, psicológico o negligencia. Metodología: Utilizando un diseño no experimental, transversal y correlacional, se aplicaron instrumentos como la Escala de Ansiedad Infantil de Spence (SCAS) y el Inventario de Depresión Infantil (CDI). Los resultados muestran que el 37.7% de los niños evaluados presenta algún nivel de depresión y una prevalencia significativa de ansiedad, destacándose el trastorno de ansiedad generalizada. Resultados: Estos hallazgos subrayan la necesidad de intervenciones psicológicas tempranas para mitigar los efectos a largo plazo del maltrato infantil. Conclusiones: El artículo concluye que los niños que sufren maltrato tienen un mayor riesgo de desarrollar problemas de salud mental en el futuro si no reciben atención adecuada. Además, sugiere que la severidad de los trastornos varía según el tipo de maltrato, su duración y los recursos de apoyo disponibles, lo que resalta la importancia de enfoques personalizados en el tratamiento.
Spike in Dengue Infections Across Maharashtra During 2024
Authors: Sahai Dr. Swati
Published: December 2024

The year 2024 has witnessed a concerning rise in the number of dengue cases throughout the state of Maharashtra, posing a significant threat to the public health. The total cases had sharply risen and reached alarming levels in the large cities with Pune and Mumbai being two of the most affected areas. As a result, there was an immediate call for enhanced vector control measures and public health initiatives to stop the transmission of the disease.
La biblioteca de Joaquín Sabina : influencias e intertextualidades en sus letras
Authors: Soto Zaragoza Javier
Published: December 2024

Partiendo del concepto de la intertextualidad, este libro estudia las letras escritas por Joaquín Sabina. En una primera parte se explican sus influencias, procedentes tanto del mundo de la poesía (César Vallejo, Pablo Neruda, Francisco de Quevedo, Jaime Gil de Biedma y Ángel González, entre otros), como de la canción (Bob Dylan, José Alfredo Jiménez, Georges Brassens, Javier Krahe y los letristas de tango y copla, entre otros). La segunda parte analiza su empleo del préstamo intertextual y cataloga las palabras de otros que Sabina ha utilizado en sus letras
Teachers’ Social and Emotional Competencies and Their Role in Occupational Well-Being
Authors: Mornar Mirta
Published: December 2024

The teaching profession is characterised by high levels of stress and numerous emotional challenges, especially in the early stages of a career. Previous research suggests that teachers’ social and emotional competencies (SEC) are related to their occupational well-being as they influence the way they cope with everyday emotional challenges at work. This points to the role of SEC as potential psychological resources that can mitigate negative outcomes such as burnout and leaving the profession among teachers in the early stages of their career. However, research in this area is still scarce and it is unclear how certain SEC are related to different aspects of occupational well-being and commitment to the teaching profession. The aim of this paper is to review conceptual frameworks of SEC and existing research in the field, discuss the role they play in education and compare them with related constructs in the domain of individual differences. Furthermore, it will provide an overview of research on teachers’ occupational well-being and examine the relevance of teachers’ SEC for outcomes such as burnout, work engagement, and job satisfaction. The paper will conclude by examining methodological aspects of SEC assessment and review challenges and directions for future research.
Eksperimentalna provjera nove slikovne vizualno-analogne skale za odgovore
Authors: Modić Stanke Koraljka , Skokandić Lea , Mikac Una
Published: December 2024

U psihološkim se mjerenjima uglavnom koriste numeričke (NS) i/ili verbalne (VS) skale za odgovore koje nekim pojedincima/skupinama mogu biti teže razumljive, dovodeći u pitanje valjanost prikupljenih podataka. Iako je manje istraživan dio procesa odgovaranja, odgovaranje pomoću skala za odgovore također je moguć izvor ugrožavanja kvalitete mjerenja. Stoga je konstruirana opće primjenjiva slikovna vizualno-analogna skala (VAS) te su se psihometrijska svojstva podataka dobivenih njezinom primjenom i stav prema njoj provjerili pomoću dvostruko slijepoga eksperimenta. U istraživanju su sudjelovali studenti prosječne dobi od 21 godine čiji je zadatak bio davati samoprocjene na upitniku ličnosti IPIP (podljestvice neuroticizma i ekstraverzije) pomoću jedne od skala za odgovore. Sudionici su po slučaju bili uvršteni u jednu od triju skupina: 1) neuroticizam – VAS i ekstraverzija – NS (n = 59), 2) neuroticizam – NS i ekstraverzija – VAS (n = 60) ili 3) neuroticizam – NS i ekstraverzija – NS (n = 58; kontrola). Analize su pokazale da se valjanost u smislu strukture, odnosa s drugim varijablama, procesa odgovaranja i razine mjerenoga svojstva te pouzdanost ne razlikuju ovisno o načinu davanja odgovora, odnosno, faktorska struktura, povezanost ekstraverzije i neuroticizma, korištenje pojedinih stupnjeva odgovora, trajanje ispunjavanja, prosječna razina neuroticizma i ekstraverzije te koeficijent Cronbachova alfa bili su podjednaki u svim skupinama. Sudionici su pokazali pozitivne stavove prema objema skalama te blagu preferenciju za NS. Rezultati upućuju na mogućnost upotrebe takve skale za odgovore, kao i važnost toga aspekta mjerenja u kontekstu valjanosti, te na moguća daljnja istraživanja nove vizualno-analogne skale u različitim kontekstima.
Uloga separacije – individuacije u odnosu roditeljskoga prihvaćanja – odbacivanja i psihološke prilagodbe u razdoblju prijelaza u odraslost
Authors: Saganić Klara , Smojver-Ažić Sanja , Večerin Mihaela
Published: December 2024

Prethodna istraživanja ukazuju na negativne učinke percipiranoga roditeljskog odbacivanja u djetinjstvu na psihološku prilagodbu u prijelazu u odraslost. U kontekstu teorije interpersonalnoga prihvaćanja – odbacivanja (teorije IPAR) kao mogući zaštitni faktor predložen je diferencirani pojam o sebi. S obzirom na to da je riječ o ishodu koji je rezultat uspješne sekundarne separacije – individuacije, cilj je ovoga istraživanja bio ispitati je li separacija – individuacija moderator u odnosu roditeljskoga prihvaćanja – odbacivanja i psihološke prilagodbe u prijelazu u odraslost. Budući da i sam proces separacije – individuacije može biti narušen zbog lošega odnosa s roditeljima u djetinjstvu, ispitana je i moguća medijacijska uloga toga konstrukta u odnosu roditeljskoga odbacivanja i psihološke prilagodbe. U istraživanju su analizirani odgovori 169 sudionica u dobi od 18 do 27 godina (M = 21.87) prikupljeni online upitnikom. Korišteni su sljedeći instrumenti: Upitnik roditeljskoga prihvaćanja – odbacivanja (Rohner i Ali, 2020), Upitnik psihološke prilagodbe (Rohner i Ali, 2020) i Upitnik separacije – individuacije za adolescente (Smojver-Ažić, 1998). Utvrđeno je da samo jedna dimenzija separacije – individuacije (sputanost zbog roditeljske kontrole) djeluje kao zaštitni faktor, odnosno ublažava negativne efekte percipiranoga majčina odbacivanja u djetinjstvu na trenutnu psihološku prilagodbu. Tri dimenzije separacije – individuacije (sputanost zbog roditeljske kontrole, negiranje potrebe za drugima i zdrava nezavisnost) značajni su medijatori u odnosu roditeljskoga odbacivanja i psihološke prilagodbe. Također, očevo odbacivanje ima značajan izravan doprinos lošoj psihološkoj prilagodbi. Dobiveni rezultati proširuju spoznaje o važnosti odnosa s roditeljima u djetinjstvu, kao i ishoda procesa separacije – individuacije, za uspješnu psihološku prilagodbu u prijelazu u odraslost.
Uloga pobuđenosti prije spavanja u odnosu kognitivne emocionalne regulacije i kvalitete spavanja kod studenata
Authors: Čikotić Anamarija , Šimić Nataša
Published: December 2024

Dosadašnja istraživanja ukazuju na to da je viša razina kognitivne i/ili somatske pobuđenosti prije spavanja snažan posrednik putem kojega se može održati maladaptivan odnos stresa, odnosno načina suočavanja sa stresom, i spavanja. Polazeći od navedenoga, cilj je istraživanja bio ispitati medijacijsku ulogu pobuđenosti prije spavanja u odnosu između korištenja različitih strategija kognitivne emocionalne regulacije i kvalitete spavanja. Istraživanje je provedeno online na uzorku od 276 studenata koji su ispunili Upitnik kognitivne emocionalne regulacije (engl. Cognitive Emotion Regulation Questionnaire, Garnefski i sur., 2001; hrvatska adaptacija Soldo i Vulić-Prtorić, 2018), Indeks kvalitete spavanja Pittsburgh (engl. Pittsburgh Sleep Quality Index, Buysse i sur., 1989; hrvatska verzija Brajević-Gizdić i sur., 2010) te Skalu pobuđenosti prije spavanja (engl. Pre-Sleep Arousal Scale, Nicassio i sur., 1985) kojom se procjenjuju kognitivna i somatska pobuđenost. Dobivenim rezultatima pokazano je da čestina korištenja strategija samookrivljavanja, ruminacije, katastrofiziranja, pozitivnoga refokusiranja, pozitivne reprocjene i stavljanja u perspektivu doprinosi kvaliteti spavanja isključivo posredno preko obiju komponenata pobuđenosti, tj. kognitivne i somatske pobuđenosti prije spavanja. Za korištenje strategije okrivljavanja drugih utvrđeno je da doprinosi kvaliteti spavanja isključivo posredno, i to preko kognitivne pobuđenosti. Dobiveni rezultati interpretirani su u terminima aktivacije i produljene aktivacije stresnoga odgovora te oporavka od stresa. U radu se raspravlja o smjernicama za daljnja istraživanja i praktičnim implikacijama dobivenih rezultata.
Historia y futuro del destruido archivo de Alta California
Authors:   City College of San Francisco, Brick Aarón
Published: December 2024

This article explores the history and prospects of reconstructing the destroyed Archive of Alta California, a crucial repository of Spanish and Mexican administrative documents lost in the 1906 San Francisco fire. Despite the physical loss, the 19th-century bibliographic summaries known as the Archives of California, housed in the Bancroft Library, preserve much of its content. These documents, however, are highly disorganized due to war damages and inadequate archival practices during the American takeover. By analyzing the archive’s original administrative structure, the impact of subsequent mishandling, and its transformation into a bibliographic collection, this study underscores the challenges of historical reconstruction. Employing archival and bibliographic methodologies, I propose two strategies to improve access: producing detailed descriptions or comprehensive transcriptions with indexing. A cost-benefit analysis reveals that, while both approaches are feasible, full transcription would yield the most significant benefits for historical research, providing a robust platform for exploring Alta California's legal, social, and political heritage.
Leakage and rotordynamic coefficients of labyrinth-scallop seals
Authors: Izemenko V. , Zahorulko A. , Zahorulko Yu.
Published: December 2024

Reducing leakages and improving the rotor-dynamic damping characteristics of annular seals is an essential problem of sealing technology. A whole range of damping seals are used to seal the shafts of turbomachines, such as honeycomb, hole pattern, pocket, and scallop seals. To reduce the cost and production time, the scallop seals are increasingly used. They showed quite good dynamic and leakage characteristics in the modernization of compressors in the chemical industry. Some designs of scallop seals are able not only to increase dynamic performance (additional use of swirl brakes in the form of semi-open scallops at the inlet) but also thanks to the hybrid design of the scallop and labyrinth seal made of PEEK material, which ensures a minimum clearance between the seal and the shaft, reduce leakages of pumped fluid.
This paper presents the results of calculating the rotordynamic and flow rate characteristics of scallop and labyrinth-scallop seals depending on the operating parameters using computational fluid dynamics (CFD) methods. The CFD was used to calculate the hydrodynamic and rotordynamic characteristics of the seal with shaft whirl. The rotordynamic coefficients were obtained using the frequency excitation method. The obtained characteristics were compared with experimental data available from the literature for annular and labyrinth seals. The study confirmed the relatively low leakages, the high dynamic characteristics of the labyrinth-scallop seals, and the frequency dependence of the stiffness and damping coefficients. It has been confirmed that sickle-shaped scallops create obstacles to the circumferential flow of the working medium. Reducing the circumferential gas flow increases the hydraulic resistance in the grooves and simultaneously minimizes the circulation forces that create shaft whirl, increasing vibration
Modeling of contact stresses and evaluation of wear life of a valve mechanism guide with lubricating grooves
Authors: Holenko K.E. , Vychavka A.A. , Dykha M.O. , Dytyniuk V.O.
Published: December 2024

Valve guides are crucial for maintaining proper alignment, positioning, and valve stem clearance as it moves in the cylinder head. Valve bushings are subjected to load and sliding friction; with excessive wear of the guides, the engine begins to consume oil and the valve mechanism becomes noisy. This paper proposes the use of a special knurling to restore and increase the wear resistance of guide bushings. The profile tool is designed to restore valve guides by rolling a spiral groove on the inner surface of the sleeve. After applying this technology, a spiral oil-retaining profile remains on the surface of the sleeve bore. . Using the Solid model, the effect of changing the geometry of the guide bore by the lubricating grooves on the maximum and average stress indices in the guide-valve contact was analyzed. It was found that the maximum stresses of the model with grooves are lower than those of the model with a smooth guide surface. Based on the finite element model, the durability of the valve-guide pair with oil-retaining grooves was analyzed and it was determined how many cycles the contact surface of the guide can withstand. It was established that by reducing the contact pressure, the actual resource of the guide with grooves increased.
Miquel's Theorem and its Elementary Geometric Relatives
Authors: Weiss Gunter , Odehnal Boris
Published: December 2024

Elementarnogeometrijski Miquelov teorem odnosi se na trokut ABC i točke R, S, T na njegovim stranicama, i kaže da kružnice k(ART), k(BRS), k(CST) imaju jednu zajedničku točku M, Miquelovu točku zadane figure. Posebnim odabirom točaka R, S, T dobivaju se takozvani beermat teorem, Brocardovi teoremi i Steinerov Simson-Wallaceov teorem kao specijalni slučajevi Miquelovog teorema. Stoga, činjenice vezane za Brocardov teorem slijede iz svojstava Miquelovog teorema. Ako npr. R, S, T zadavoljavaju Cevin uvjet, Miquelova konstrucija inducira preslikavanje Cevine točke u Miquelovu točku. Proučavamo ovo i druga preslikavanja koja su direktna posljedica Miquelovog teorem. Nadalje, kreću li se točke R, S, T stranicama trokuta tako da su npr. afini omjeri ar(ARB), ar(BSC), ar(CTA) jednaki, Miquelove točke M opisuju kružnicu opisanu trokutu čiji su vrhovi dvije Brocardove točke i središte opisane kružnice trokuta. Osim spomenutih triju posebnih točaka trokuta, na ovoj kružnici leži još nekoliko osobitih točaka trokuta. Iako je većina predstavljenih tema dobro poznata, čini se da njihove međusobne veze još nisu razmatrane u standardnoj literaturi iz geometrije trokuta i stoga bi mogle opravdati dodatnu obradu.
Science Mapping the Knowledge Base on Student Retention in Higher Education: A Bibliometric Review of Research Papers from 1914-2022
Authors: Gök Enes , Gür Bekir S. , Bellibaş Mehmet Şükrü , Öztürk Murat
Published: December 2024

In this study, we systematically review existing research on college student retention. It utilizes a total of 5277 publications indexed either in Scopus or Web of Science from 1914 to 2022. The results show that most of the research on student retention has been conducted in English-speaking countries such as the United States, Australia, the United Kingdom, and Canada. The United States produces almost two-thirds of scholarly publications worldwide. The term ‘retention’ is commonly used alongside ‘persistence,’ ‘attrition,’ ‘engagement,’ and ‘success.’ Moreover, the term higher education is associated with dropout, completion, and academic performance, as well as new methodological terms like data mining, machine learning, learning analytics, and logistic regression. Retention is also studied in fields such as nursing, engineering, and STEM. Special attention is given to community colleges due to higher dropout rates. Unlike the United States, Australia, the United Kingdom, and Canada, where higher education research on retention is extensive, countries like China and India, which have recently expanded their higher education systems, show a comparatively limited volume of research output concerning student retention.
Rate of attraction to a non‐hyperbolic attractor
Authors: Kostin I.N.
Published: December 2024

The behaviour of trajectories of a nonlinear semigroup in the neighbourhood of a non‐hyperbolic stationary point is studied. The obtained results are used to derive an estimate for the rate of convergence of solutions of the Chafee–Infante problem to its attractor in the case of non‐hyperbolic zero stationary solution.
Asymptotic distribution of eigenvalues for some elliptic operators with intermediate remainder estimate
Authors: Zielinski Lech
Published: December 2024

We consider the Weyl formula for the asymptotic number of eigenvalues $N(\lambda)$ for some elliptic operators. We prove remainder estimates of the form $N(\lambda){\rm O}(\lambda^{-\mu})$ with $\mu$ depending on the regularity of coefficients and ranging between 0 and the optimal value in the standard situation of smooth coefficients, i.e., $0<\mu<2/m$ in the case of globally elliptic operators on ${\NBbbR}^d$ , and $0<\mu<1/m$ in the case of a smooth compact manifold without boundary, where $m$ is the degree of the considered operators.
Asymptotic analysis of dynamic problems for linearly elastic shells – Justification of equations for dynamic membrane shells
Authors: Xiao Li‐ming
Published: December 2024

Starting from the three‐dimensional dynamic equations of elastic shells, by the asymptotic analysis, under certain conditions we give the justification of dynamic equations of membrane shells.
La forme normale de Birkhoff pour un opérateur intégral de Fourier
Authors: Iantchenko Alexei
Published: December 2024

We define the Birkhoff normal form for the Fourier integral operator $M$ associated to canonical transformation of the real hyperbolic type using the representation of $M$ as an exponent of $h$ ‐pseudodifferential operator (microlocally near the fixed point of the transformation).
A two‐scale convergence result for a nonlinear scalar conservation law in one space variable
Authors: Junca Stéphane
Published: December 2024

We prove a general result of two‐scale convergence for BV‐functions. We then use this result to show the validity of nonlinear geometric optics for weak solutions to scalar conservation laws when the small perturbation of the initial datum is only BV and periodic with respect to the slow and the fast variable.
Semi‐classical limit of random walks II
Authors: Porod Ursula , Zelditch Steve
Published: December 2024

Let $(G, \mu)$ be a symmetric random walk on a compact Lie group $G$ . We will call $(G, \mu)$ a Lagrangean random walk if the step distribution $\mu$ , a probability measure on $G$ , is also a Lagrangean distribution on $G$ with respect to some Lagrangean submanifold $\varLambda \subset T^*G$ . In particular, we are interested in the cases where $\mu$ is a smooth $\delta$ ‐function $ \delta_C$ along a ‘positively curved hypersurface’ $C$ of $G$ or where $\mu$ is a sum of $\delta$ ‐functions $\sum_j \delta_{C_j}$ along a finite union of regular conjugacy classes $C_j$ in $G$ . The Markov (transition) operator $T_{\mu}$ of the Lagrangean random walk is then a Fourier integral operator and our purpose is to apply microlocal techniques to study the convolution powers $\mu^{*k}$ of $\mu.$

In cases where all convolution powers are ‘clean’ (such as for $\delta$ ‐functions on positively curved hypersurfaces), classical FIO methods will be used to determine

the Sobolev smoothing order of $T_{\mu}$ on $W^s(G)$ ,

the minimal power $k = k_{\mu}$ for which $\mu^{*k} \in L^2$ ,

the asympotics of the Fourier transform $\widehat {\mu}(\rho)$ of $\mu$ along rays $L = \mathbb{N}\rho$ of representations.

In general, convolutions of Lagrangean measures are not ‘clean’ and there can occur a large variety of possible singular behaviour in the convolution powers $\mu^{*k}$ . Classical FIO methods are then no longer sufficient to analyze the asymptotic properties of Lagrangean random walks. However, it is sometimes possible to restore the simple ‘clean convolution’ behaviour by restricting the random walk to a fixed ‘ray of representations’. In such cases, classical Toeplitz methods can be used to determine restricted versions of the above features along the ray. We will illustrate with the case of sums of $\delta$ ‐functions along unions of regular conjugacy classes.
The Leontovich boundary value problem for the time‐harmonic Maxwell equations
Authors: Ammari H. , Latiri‐Grouz C. , Nédélec J.‐C.
Published: December 2024

The limiting behavior of the unique solution to Maxwell equations in an exterior domain with a Leontovich boundary condition as the impedance tends to zero is investigated. This is accomplished by reducing the impedance boundary value problem for the Maxwell equations to a system of three integral equations. It is shown that the Leontovich boundary condition leads to a singular perturbation problem for the Maxwell equations. A specific numerical treatment is required to achieve a sufficient accuracy.
Critical asymptotic behaviour for a perturbed conservation law
Authors: Reyes G.
Published: December 2024

In this paper we study the intermediate asymptotics as t→∞ of nontrivial, nonnegative solutions to the Cauchy problem for the following nonlinear first order equation: ut+(um)x+up=0, with m>1, p=m+1. We prove that for any bounded, nonnegative, compactly supported initial data the asymptotic behaviour is given in first approximation by a universal function W, which is a contracted “N‐wave” with logarithmically decaying mass.
Uniform stabilization for Maxwell's equations with boundary conditions with memory
Authors: Kapitonov Boris V. , Perla Menzala G.
Published: December 2024

We consider a transmission problem for Maxwell's equations with a dissipative boundary condition of memory type. Under suitable geometric conditions imposed on the domain and the interfaces where the coefficients are allow to have a jump discontinuity, results on uniform stabilization are established.
Mathematical model for elastic beams with longitudinally variable depth
Authors: Alvarez‐Vázquez L.J. , Samartín A. , Viaño J.M.
Published: December 2024

In this work we introduce a new mathematical model for elastic beams with a cross‐section of constant width and longitudinally variable depth, obtained from the classical three‐dimensional linear elasticity problem by using an asymptotic expansion method. We characterize the first‐ and second‐order displacements and the first‐order stress field, giving results related to existence, uniqueness and convergence for the limit model solution. Finally, we present the computations for a classical example.
Spatial asymptotic behaviour in incremental thermoelasticity
Authors: Quintanilla R.
Published: December 2024

This paper derives spatial decay bounds in a dynamical problem of incremental thermoelasticity defined on a semi‐infinite cylindrical region. Previous results for isothermal elastodynamics and the parabolic heat equation lead us to suspect that the solution of the problem should tend to zero faster than a decaying exponential of the distance from the finite end of the cylinder. We prove that an energy expression is actually bounded above by a decaying exponential of a quadratic polynomial of the distance. As it has been previously proved for usual linear thermoelasticity, this is reminiscent of the decay rate in second order parabolic problems.
On some conjectures of Askey
Authors: Volkmer Hans
Published: December 2024

Using the Darboux method of asymptotic analysis, it is shown that the coefficients of the power series expansions of the functions f(w)=(1−w)−c(1−2xw+w2)−c and (1+w)f(w), 1<c<2, at w=0 are positive if x lies in certain intervals. This partially answers some questions raised by Askey.
Asymptotic behaviour of the solutions and optimal location of the actuator for the pointwise stabilization of a string
Authors: Ammari Kais , Henrot Antoine , Tucsnak Marius
Published: December 2024

We study the large time behavior of the solutions of a homogenous string equation with a homogenous Dirichlet boundary condition at the left end and a homogenous Neuman boundary condition at the right end. A pointwise interior actuator gives a linear viscous damping term. We give a complete characterization of the positions of the actuator for which the system becomes exponentially stable in the energy space. In the case of nonexponential decay in the energy space we give explicit polynomial decay estimates valid for regular initial data. Moreover we show that the fastest decay rate is obtained if the actuator is located at the middle point of the string.
Life‐span of subcritical semilinear wave equation
Authors: Di Pomponio S. , Georgiev V.
Published: December 2024

We establish a new weighted Strichartz estimate for the classical wave equation and apply this estimate to the study of life‐span of solution of subcritical semilinear wave equation.
Traveling wave speeds of nonlocally perturbed reaction–diffusion equations
Authors: Dkhil F. , Stevens A.
Published: December 2024

In this paper we consider a nonlocal integro-differential model as it was discussed by Bates and Chen [Electron. J. Differential Equations 1999(26) (1999), 1–19]. It is known that unique, stable traveling waves exist for the classical reaction–diffusion model as well as for the nonlocal model and for combinations of both for certain bistable nonlinearities. Here we are concerned with the traveling wave speed and how small perturbations with a nonlocal term affect the speed of the original reaction–diffusion problem. We show that an expansion for the wave speed of the perturbed problem exists and calculate the sign of the first-order coefficient.
Wigner measures and quantum Aubry–Mather theory
Authors: Gomes Diogo A. , Valls Claudia
Published: December 2024

In this paper we investigate the quantum action problem using Wigner measures on the torus. We prove existence, study its main properties, and prove convergence to Mather measures in the semiclassical limit. We also indicate how to extend these techniques to the study of stochastic Mather measures.
Decay estimates for a viscous Hamilton–Jacobi equation with homogeneous Dirichlet boundary conditions
Authors: Benachour Saïd , Dăbuleanu-Hapca Simona , Laurençot Philippe
Published: December 2024

Global classical solutions to the viscous Hamilton–Jacobi equation ut−Δu=a|∇u|p in (0,∞)×Ω with homogeneous Dirichlet boundary conditions are shown to converge to zero in W1,∞(Ω) at the same speed as the linear heat semigroup when p>1. For p=1, an exponential decay to zero is also obtained but the rate depends on a and differs from that of the linear heat equation. Finally, if p∈(0,1) and a<0, finite time extinction occurs for non-negative solutions.
A modified nonlinear Reynolds equation for thin viscous flows in lubrication
Authors: Nazarov Sergueï A. , Videman Juha H.
Published: December 2024

We derive a nonlinear second-order differential equation for the pressure approximation in hydrodynamic lubrication. This equation, in contrast to the classical Reynolds equation, takes into account both the inertial and the curvature effects and its solution corresponds to the first two terms in the asymptotic pressure expansion.

The equation is rigorously justified with optimal error estimates in parameter dependent Sobolev norms and in Hölder norms. It is also applied to the classical problem of journal bearing.
Remarks on existence or loss of minima of infinite energy
Authors: Porretta A.
Published: December 2024

Given a nonnegative bounded Radon measure μ on Ω⊂RN, we discuss the existence or nonexistence of minima of infinite energy (so-called weak minima, T-minima, renormalized minima) for functionals like J(v)=∫Ωa(x,v)|∇v|p dx−∫Ωv dμ, where p>1. In most of our results, a(x,s) is coercive. According to the behavior of $s\mapsto a(x,s)$ at infinity, existence or nonexistence of such minima is proved, and the convergence of approximating minima of regularized functionals is studied. Differences arise whether the measure charges or not sets of null p-capacity and/or a(x,s) blows-up at infinity. Lastly, some results are proved when a(x,s) degenerates at infinity.
Lattice approximation of a surface integral and convergence of a singular lattice sum
Authors: Schlömerkemper Anja
Published: December 2024

Let ℒ be a lattice in $\mathbb{R}^{d}$ , d≥2, and let $A\subset\mathbb{R}^{d}$ be a Lipschitz domain which satisfies some additional weak technical regularity assumption. In the first part of the paper we consider certain lattice sums over points which are close to $\curpartial A$ . The main result is that these lattice sums approximate corresponding surface integrals for small lattice spacing. This is not obvious since the thickness of the domain of summation is comparable to the scale of the lattice.

In the second part of the paper we study a specific singular lattice sum in d≥2 and prove that this lattice sum converges as the lattice spacing tends to zero. This lattice sum and its convergence are of interest in lattice-to-continuum approximations in electromagnetic theories—as is the above approximation of surface integrals by lattice sums.

This work generalizes previous results (Schlömerkemper, Arch. Rational Mech. Anal. 176 (2005), 227–269) from d=3 to d≥2 and to a more general geometric setting, which is no longer restricted to nested sets.
Asymptotics of Maxwell–Chern–Simons vortices on the unit disc
Authors: Han Jongmin , Kim Namkwon
Published: December 2024

In this paper we are concerned with the asymptotic behavior of the relativistic Maxwell–Chern–Simons (MCS) vortices on the unit disc. We establish the existence of a radial solution of the static MCS equations which is a minimizer of the MCS functional in the class of radial functions, and derive the asymptotic limit of the radial solution. As a consequence, we obtain a set of elliptic linear equations which is a generalization of the London equation for the Ginzburg–Landau model.
Asymptotic analysis of piezoelectric shells with variable thickness
Authors: Sabu N.
Published: December 2024

In this paper, we consider the boundary value problem for thin piezoelectric shells with variable thickness subjected only to mechanical body force and we show that, as the thickness of the shell goes to zero, the solution of the three-dimensional equations converge to the solution of two-dimensional problem.
Low-frequency dispersive estimates for the Schrödinger group in higher dimensions
Authors: Moulin Simon , Vodev Georgi
Published: December 2024

For a large class of real-valued potentials, V(x), x∈Rn, n≥4, we prove dispersive estimates for the low-frequency part of eit(−Δ+V)Pac, provided the zero is neither an eigenvalue nor a resonance of −Δ+V, where Pac is the spectral projection onto the absolutely continuous spectrum of −Δ+V. This class includes potentials V∈L∞(Rn) satisfying V(x)=O(〈x〉−(n+2)/2−ε), ε>0. As a consequence, we extend the results in Commun. Pure Appl. Math. 44 (1991) to a larger class of potentials.
Singular limit of radial solutions in an annulus
Authors: Gladiali Francesca , Grossi Massimo
Published: December 2024

In this paper we study the radial solutions of the problem

[Formula: see text]

where Ω is an annulus of RN, N≥2 and λ is close to zero.

Among the other results we show the existence of a singular limit and some qualitative properties of the solution.
Two Problems on Reduction Graphs in Lambda Calculus
Authors: Intrigila Benedetto , Laurenzi Anna R.
Published: December 2024

In this paper we solve two open problems in the theory of reduction graphs in lambda calculus. The first question is whether the condensed reduction graph of a lambda term is always locally finite (conjecture of M.Venturini Zilli 1984). We give a negative answer to the conjecture by providing a counterexample. The second problem is whether there is a term such that its reduction graph is composed of two reduction cycles (not loops) intersecting in just one point (problem of J.W.Klop 1980). We show that such a term cannot exist.
Platek Spaces
Authors: Ivanov Lyubomir
Published: December 2024

The aim of this work is to axiomatize and enhance the recursion theory on monotonic hierarchies of operative spaces developed in [1]. This is to be accomplished by employing a special new variety of operative spaces called Platek spaces. The original structure studied by Platek in [2] corresponds to the particular Platek space with structural class O=ω and a bottom operative space consisting of single-valued partial functions over an arbitrary domain (Example 1.1 below). We believe that Platek spaces not only redefine Platek's approach in an abstract manner, but also provide the appropriate setting for an intrinsic Generalized Recursion Theory.
Computational Complexity of Multimodal Logics \newline Based on	Rough Sets
Authors: Demri Stéphane , Stepaniuk Jarosław
Published: December 2024

We characterize the computational complexity of a family of approximation multimodal logics in which interdependent modal connectives are part of the language. Those logics have been designed to reason in presence of incomplete information in the sense of rough set theory. More precisely, we show that all the logics have a PSPACE-complete satisfiability problem and we define a family of tolerance approximation multimodal logics whose satisfiability is EXPTIME-complete. This illustrates that the PSPACE upper bound for this kind of multimodal logics is a very special feature of such logics. The PSPACE upper bounds are established by adequately designing Ladner-style tableaux-based procedures whereas the EXPTIME lower bound is established by reduction from the global satisfiability problem for the standard modal logic B.
Representability of Pairing Relation Algebras Representability of	Pairing Relation Algebras Depends on our Ontology
Authors: Kurucz Agnes , Németi István
Published: December 2024

We consider classes of relation algebras expanded with new operations based on the formation of ordered pairs. Examples for such algebras are pairing (or projection) algebras of algebraic logic and fork algebras of computer science. It is proved by Sain and Németi [38] that there is no `strong' representation theorem for all abstract pairing algebras in most set theories including ZFC as well as most non-well-founded set theories. Such a `strong' representation theorem would state that every abstract pairing algebra is isomorphic to a set relation algebra having projection elements which are defined with the help of the real (set theoretic) pairing function. Here we show that, by choosing an appropriate (non-well-founded) set theory as our metatheory, pairing algebras and fork algebras admit such `strong' representation theorems.
Uniform Generation of Languages by Scattered Context	Grammars
Authors: Meduna Alexander
Published: December 2024

The present paper discusses the uniform generation of languages by scattered context grammars. More specifically, it demonstrates that every recursively enumerable language can be generated by a scattered context grammar, G, so that every sentential form in a generation of a sentence has the form y_1…y_m u, where $u$ is a terminal word and each y_i is a permutation of either of two equally long words, z_1∈{A, B, C}* and z_2∈{A, B, D}*, where A, B, C, and D are G's nonterminals. Then, it presents an analogical result so that u precedes y_1…y_m.
A Possibilistic Decision Logic with Applications
Authors: Liau Churn-Jung , Liu Duen-Ren
Published: December 2024

In this paper, we investigate a knowledge representation formalism in the context of fuzzy data tables. A possibilistic decision logic incorporating linguistic terms is proposed for representing and reasoning about knowledge in fuzzy data tables. Two applications based on the logic are described. The first is the extraction of fuzzy rules from general fuzzy data tables. In this application, the knowledge in the tables may be made explicit by the formulas of the logic or used implicitly in decision-making. The second is for the fuzzy quantization problem of precise data tables. It can be viewed as a special case of the first, however, due to some special properties of the problem, a polynomial time rule extraction process can be obtained. Finally, the relationship of the logic with some works for handling uncertain information in data tables is also discussed.
Reduction and a Simple Proof of Characterization of Fuzzy Concept	Lattices
Authors: Bělohlávek Radim
Published: December 2024

Presented is a reduction of fuzzy Galois connections and fuzzy concept lattices to (crisp) Galois connections and concept lattices: each fuzzy concept lattice can be viewed as a concept lattice (in a natural way). As a result, a simple proof of the characterization theorem for fuzzy concept lattices is obtained. The reduction enables us to apply the results worked out for concept lattices to fuzzy concept lattices.
Some Algorithms for Extension Computation of Nonmonotonic Rule	Systems
Authors: Zhao Xishun , Ding Decheng
Published: December 2024

In this paper, we will place our emphasis on the problem of existence of extensions and on finding more efficient algorithms for computing extensions of nonmonotonic rule systems. First, in order to dedicate further research into nonmonotonic rule systems a new characterization and some new results are given. This characterization and these results lead to new algorithms for computing extensions. Second, a class of nonmonotonic rule systems, called regular nonmonotonic rule systems, is developed. The existence of extensions and semi-monotonicity of regular nonmonotonic rule systems are proved. Third, we prove that each regular nonmonotonic rule system has at most 1.47^n extensions, where n is the number of elements occurring in the system.
Types for Active Objects with Static Deadlock Prevention
Authors: Puntigam Franz , Peter Christof
Published: December 2024

Process types statically ensure the acceptability of all messages sent to an object even if the set of acceptable messages changes dynamically. As proposed so far, process types do not ensure the return of answers; deadlocks may prevent objects from behaving as expected. In this article we propose an object calculus with types distinguishing between obligatory messages (that must be sent, for example, as answer to a question) and optional messages (that can, but need not be sent). A type checker enforces the sending of obligatory messages and ensures that obligatory messages are not suppressed by deadlocks. The proposed type concept supports subtyping.
Computability by Sequences of Queries
Authors: Tyszkiewicz Jerzy
Published: December 2024

We consider a model of querying remote databases, in which we compute results of queries not supported by the database system, by using sequences of supported queries and analysing locally their results. We study the expressiveness of this model of computation, as well as its complexity, measured in terms of the number of queries used.
Optimal Unification and Learning Algorithms for Categorial	Grammars
Authors: Dziemidowicz Barbara
Published: December 2024

In this paper continuing [1], we present a more general approach to restricted optimal unification, introduced and applied to learning algorithms for categorial grammars in [2] and further developed in [7,8,4,5]. We introduce a procedure of finding minimal unifiers with respect to some preordering relation between substitutions and solve a general problem of finding all minimal (in several senses) categorial grammars compatible with a given language sample.
On Decision Trees for (1,2)-Bayesian Networks
Authors: Moshkov Mikhail Ju.
Published: December 2024

Bayesian Networks (BN) are convenient tool for representation of probability distribution of variables. We study time complexity of decision trees which compute values of all observable variables from BN. We consider (1,2)-BN in which each node has at most 1 entering edge, and each variable has at most 2 values. For an arbitrary (1,2)-BN we obtain lower and upper bounds on minimal depth of decision tree that differ not more than by a factor of 4, and can be computed by an algorithm which has polynomial time complexity. The number of nodes in considered decision trees can grow as exponential on number of observable variables in BN. We develop an polynomial algorithm for simulation of the work of decision trees which depth lies between the obtained bounds.
A Linear Time Special Case for MC Games
Authors: Poranen Timo , Nummenmaa Jyrki
Published: December 2024

MC games are infinite duration two-player games played on graphs. Deciding the winner in MC games is equivalent to the the modal mu-calculus model checking. In this article we provide a linear time algorithm for a class of MC games. We show that, if all cycles in each strongly connected component of the game graph have at least one common vertex, the winner can be found in linear time. Our results hold also for parity games, which are equivalent to MC games.
Real Time Control for Autonomous Mobile Robots
Authors: Burkhard Hans-Dieter
Published: December 2024

Control of autonomous mobile robots in dynamical environments is interesting from a cognitive point of view as well as under application view points. Stimulus response controls are often favored for fast reactions to the environment. On the other hand, goals and plans are needed to guide long term behavior by deliberative control. Layered architectures are used for combination, but they inherit advantages as well as problems from both approaches. The paper proposes the Double Pass Architecture with hierarchically structured options/behaviors providing fast reactions on all levels.
Collective Intentions
Authors: Dunin-K{\c{e}}plicz Barbara , Verbrugge Rineke
Published: December 2024

In this paper the notion of collective intention in teams of agents involved in cooperative problem solving (CPS) in multiagent systems (MAS) is investigated. Starting from individual intentions, goals}, and beliefs defining agents' local asocial motivational and informational attitudes, we arrive at an understanding of collective intention in cooperative teams. The presented definitions are rather strong, in particular a collective intention implies that all members intend for all others to share that intention. Thus a team is created on the basis of collective intention, and exists as long as this attitude between team members exists, after which the group may disintegrate. For this reason it is crucial that collective intention lasts long enough. Collective intentions are formalized in a multi-modal logical framework. Completeness of this logic with respect to an appropriate class of Kripke models is proved. Two versions of collective intentions are discussed in the context of different situations. It is assumed that these definitions reflect solely vital aspects of motivational attitudes, leaving room for case-specific extensions. This makes the framework flexible and not overloaded. Together with individual and collective knowledge and belief, collective intention constitutes a basis for preparing a plan, reflected in the strongest attitude, i.e., in collective commitment, defined and investigated in our other papers.
A Study of Interconnections Between Rough and 3-Valued	Łukasiewicz Logics
Authors: Sen Jayanta , Chakraborty Mihir K.
Published: December 2024

Sequent calculi for topological quasi-Boolean algebras, topological quasi-Boolean algebras without distributivity, pre-rough algebras and Wajsberg algebras have been presented. It is shown that the calculi for the latter two classes of algebras are equivalent. A connection between some logics for the first class of algebras and the linear logic or linear logic with distributivity has been established.
A Simple Architecture for Computing Moments and Orientation of an	Image
Authors: Dey Sabyasachi , Bhattacharya Bhargab B. , Kundu Malay K. , Acharya Tinku Acharya
Published: December 2024

In this paper, a new methodology for computing orientation of a gray-tone image by the method of moments is described. Orientation is an essential feature needed in many image processing and pattern recognition tasks. Computation of moments is accomplished by a new projection method that leads to a fast algorithm of determining orientation. Using a simple architecture, the proposed algorithm can be implemented as a special purpose VLSI chip. The hardware cost of the proposed design is significantly lower compared to that of the existing architecture.