Hasil untuk "Periodicals"

Anton Ponomarev, Lutz Gröll, Veit Hagenmeyer

The classical asymptotic gain (AG) is a concept known from the input-to-state stability theory. Given a uniform input bound, AG estimates the asymptotic bound of the output. Sometimes, however, more information is known about the input than just a bound. In this paper we consider the case of a periodic input. Under the assumption that the system converges to a periodic solution, we introduce a new gain, called period-aware asymptotic gain (PAG), which employs periodicity to enable a sharper asymptotic estimation of the output. Since the PAG can distinguish between short-period ("high-frequency") and long-period ("low-frequency") signals, it is able to rigorously quantify such properties as bandwidth, resonant behavior, and high-frequency damping. We discuss how the PAG can be computed and illustrate it with a numerical example from the field of power electronics.

Mesafint Tarekegn Yalew

This article delves into the development of the diplomatic relationship between Ethiopia and China during Emperor Haile Selassie. The author utilizes a combination of primary and secondary sources. The primary sources were collected from various institutions and offices such as the Institute of Ethiopian Studies (IES), the Ministry of Foreign Affairs of Ethiopia, and periodicals that included memoirs, speeches, and correspondence exchanges. Secondary sources were gathered from both published and unpublished materials. The study focuses on defining the evolution of diplomatic relations between the two countries throughout the 1970s. This particular period witnessed China’s diplomatic triumph on the global stage, prompting Ethiopia to seek an alternative ally to the West. This development occurred when the United States attempted to exploit this advantage by re-establishing its ties with the People’s Republic of China (PRC). The findings of this study assert that after Ethiopia set aside all obstacles and endeavored to establish diplomatic ties with China on December 1, 1970, it became evident that the country was adopting a hedging strategy to distance itself from its long ally, the US. Following Haile Selassie’s visit to Beijing, Ethiopia and China signed a joint communiqué on economic and technical cooperation. Consequently, the study concludes that the development of diplomatic relations between the two countries coincided with the gradual decline of the US’s influence in Ethiopia.

Sozont Singh, Ekaterina Konopleva

The activity of the navy chaplains outside the framework of worship is still a little-studied aspect of the service of the Orthodox clergy in the navy. This article attempts, based on the analysis of various written sources, to reconstruct the activities of representatives of the naval clergy in organizing libraries on the ships of the Russian Imperial Navy in the late 19th - early 20th centuries. This is one of the least studied areas of ministry of navy chaplains. The authors, relying on personal sources, office materials and periodicals, analyze the existing practice in the fleet of creating and completing ship libraries, their types and features of functioning, and also determine the role of navy chaplains in these processes. It is important to note that many sources are introduced into scientific circulation for the first time. The authors came to the conclusion that, despite the frequent lack of initiative on the part of the officers or even with a certain opposition, the navy chaplains were directly related to the organization of both church and sailor's libraries. Some clerics acted quite effectively in this field, but they could not significantly change the general situation that had developed with librarianship on the ships of the Russian Imperial Navy.

Aidar G. Khairutdinov

The author of the review introduces the voluminous research work written by Adilkhan Adiloglu, a young Turkish scholar, and dedicated to the problem of women's rights and freedoms in the Tatar literature and periodicals of the Jadid era (mid-19th – early 20th centuries). The work’s value lies in the fact that, using rich factual material, the researcher presented the history of the emergence of the national-cultural revival among the Tatars and its outstanding participants. He managed to show the scale of participation of an educated Tatar Muslim woman in this process.

Oinam Romesh Meitei, Troy Van Voorhis

Bootstrap embedding (BE) is a recently developed electronic structure method that has shown great success at treating electron correlation in molecules. Here, we extend BE to treat surfaces and solids where the wave function is represented in periodic boundary conditions using reciprocal space sums (i.e. $k$-point sampling). The major benefit of this approach is that the resulting fragment Hamiltonians carry no explicit dependence on the reciprocal space sums, allowing one to apply traditional non-periodic electronic structure codes to the fragments even though the entire system requires careful consideration of periodic boundary conditions. Using coupled cluster singles and doubles (CCSD) as an example method to solve the fragment Hamiltonians, we present minimal basis set CCSD-in-HF results on 1D conducting polymers. We show that periodic BE-CCSD can typically recover $\sim$99.9% of the electron correlation energy. We further demonstrate that periodic BE-CCSD is feasible even for complex donor-acceptor polymers of interest to organic solar cells - despite the fact that the monomers are sufficiently large that even a $Γ-$point periodic CCSD calculation is prohibitive. We conclude that BE is a promising new tool for applying molecular electronic structure tools to solids and interfaces.

Anne Cadin

The French press was a crucial intermediary for the circulation of US literature in France during the 1940s. However, its role in this importing process has rarely been studied. Yet, the study of some forty journals (Combat, La Bataille, Action, Carrefour, Esprit...) confirms the construction of a “French taste” in American literature and suggests that the praise of American literary contributions was quickly criticized in periodicals with quite different editorial lines. Furthermore, it is in the press that some unknown mediators forged a critical discourse about a foreseeable influence of US texts on French writers: they were academics (Las Vergnas, Sigaux, Larnac), demanding aficionados (Beaumont, Blanzat, Fauchery, Hoog, Lalou, Morel), but also detractors of this importation (Henriot, Kanapa). The massive arrival of American literature in France did not create an ephemeral fever in the media. On the contrary, the French press scrutinized this American literary “moment” and addressed some fundamental questions, such as the reality of the American literary input or the advent of a literary massification caused by American influence.

Leydi Paola Mosquera Jiménez

El presente artículo se desprende de la investigación titulada ‘Caracterización del desarrollo de los procesos de aprendizaje mediante el estímulo del sistema sensorial en los escolares del nivel preescolar de la institución educativa San Roque sede la Lajita del municipio de Oporapa, Huila’, cuyo objetivo principal fue implementar una estrategia didáctica de estimulación sensorial en cinco niños del grado prescolar, mediante actividades lúdicas que les permitieron vivir experiencias significativas y motivaron al placer de aprender y de interactuar de manera significativa con los demás componentes de su entorno. La metodología se basó en el paradigma cualitativo, tipo acción participativa, con enfoque socio-crítico mediante el diseño e implementación de técnicas e instrumentos de recolección de datos como la observación directa y el diario de campo, fundamentados en los principios teóricos del aprendizaje significativo y estimulación sensorial de Ausubel, Piaget, Vygotsky, Bruner, Montessori y Pestalozzi. La observación directa mostró la problemática y el estado inicial de las situaciones educativas de los niños en la desmotivación por aprender, deficiencia de material didáctico de estimulación sensorial y, procesos de aprendizaje no participativos. La implementación de la estrategia de estimulación sensorial tuvo impacto en la motivación y cambio de actitud ante el aprendizaje de los niños, evidenciando la interacción continua entre docente y estudiantes, con una participación de alegría y disfrute en el desarrollo de cada actividad. La ejecución de esta propuesta es una evidencia más de la importancia de la estimulación y exploración sensorial en los procesos de aprendizaje.

Deisy Viviana Cagüeño Garzón, José Eriberto Cifuentes Medina

Introducción: la investigación se basa en el diseño, validación y desarrollo de una secuencia didáctica para el fortalecimiento del desarrollo del pensamiento geométrico, mediada por recursos concretos, tecnológicos, prácticos y dinámicos, a los estudiantes de los grados tercero, cuarto y quinto de primaria de la Escuela El toro, sede del Centro Educativo Castilla la Nueva del departamento del Meta. Metodología: el estudio se desarrolla en el enfoque cualitativo y tipo de investigación acción según los aportes de la línea de investigación ‘Desarrollo del pensamiento matemático’, permitiendo establecer una relación sistemática entre cada una de las fases propuestas. Resultados: en la primera de ellas se realiza un diagnóstico mediante un cuestionario, evidenciando que los estudiantes presentan dificultades en cada una de las categorías del pensamiento geométrico. Se diseña y desarrolla una secuencia didáctica para cada grado, que consta de tres sesiones, donde cada una de ellas se basa en el desarrollo de las categorías del pensamiento geométrico propuestas a través del uso de recursos tecnológicos y de manipulación. Se evalúa la incidencia de la propuesta didáctica a través de un cuestionario de salida, permitiendo hacer una comparación y análisis de los resultados obtenidos. Conclusiones: la didáctica de la matemática es un campo de investigación que entraña diferentes enfoques e interpretaciones sobre el proceso de enseñanza y aprendizaje del área en cuestión. De esta forma, al diseñar y ejecutar una secuencia didáctica teniendo en cuenta el modelo de Escuela Nueva en los estudiantes de grado tercero, cuarto y quinto, se puede generar cambios significativos en el desarrollo y fortalecimiento del pensamiento geométrico.

Ilya Burdukov

This article is devoted to the study of one of the least studied groups of historical sources - the personal files of clergy. The archive of the Smolensk diocesan administration was used as a representative material. Based on the causal method, it was possible to consider a number of personal affairs of clergymen and, on their basis, identify those thematic blocks, the study of which contributes to a fuller and deeper immersion in the historical realities of the existence of the Russian Orthodox Church through the prism of the life and work of the clergy. The documents of the diocesan archives are able to shed light on certain circumstances of the life of a clergyman of the Soviet period and see his true portrait thanks to the testimonies that have been preserved in personal files - service records, autobiographies, complaints, clippings from periodicals, etc. The determining factor in the objectivity of consideration of this kind of documents involves the use of an integrated approach that can fill those gaps that are inevitable in office work. In this regard, when studying the personal files of clergymen of the Soviet period, it is necessary to take into account the factor of verification of the information contained in them due to political realities and the subjectivity of decisions of one bishop or another, or employees of the diocesan administration. This work does not claim to be exhausted. On the contrary, this attempt at research is aimed, firstly, at drawing attention to the problem of the lack of knowledge of the designated kind of sources. Secondly, it seems important to pay attention to the safety and accessibility for researchers of diocesan archives. The latter requires special attention, and the fate of a significant layer of history not only of the Church, its ministers, but also of our state depends on the resolution of these issues

E.R. Rachev

The article discusses how Russian periodicals responded to the Ukrainophilic views that were widely supported by Russian society during the early 1860s. The writers from the bilingual magazine “Osnova” (‘Basis’), particularly N.I. Kostomarov and P.A. Kulish, actively contributed to the achievements of the first generation of Ukrainophiles. The latter elaborated and presented their program aimed to preserve the Little Russia culture. The results of the analysis of the periodical sources show that the printed media of the period under study had polarized views on the national identity of Little Russia and divided into two factions: the democratic and protective ones. The democratic approach was led by the magazines “Sovremennik” (‘The Contemporary’) and “Otechestvennye Zapiski” (‘Annals of the Fatherland’) that considered the new provincial movement as the beginning of Narodism. The key supporters of the protective approach were the newspaper “Den’” (‘The Day’) and the magazine “Russkii Vestnik” (‘The Russian Bulletin’) that criticized the Ukrainian legacy adherents for separating the Russian nationalities. The stages of the evolution of the Russian periodicals’ attitude to Ukrainophiles were singled out. The main factors that influenced it were revealed. The consequences of the short-term prevalence of the Ukrainian “selfhood” ideology among publicists of the Russian Empire and its influence on the subsequent development of the Ukrainophilia movement were summarized.

Michael B Chavez, Emily Y Chu, Vardit Kram et al.

ABSTRACT Micro–computed tomography (μCT) has become essential for analysis of mineralized as well as nonmineralized tissues and is therefore widely applicable in the life sciences. However, lack of standardized approaches and protocols for scanning, analyzing, and reporting data often makes it difficult to understand exactly how analyses were performed, how to interpret results, and if findings can be broadly compared with other models and studies. This problem is compounded in analysis of the dentoalveolar complex by the presence of four distinct mineralized tissues: enamel, dentin, cementum, and alveolar bone. Furthermore, these hard tissues interface with adjacent soft tissues, the dental pulp and periodontal ligament (PDL), making for a complex organ. Drawing on others' and our own experience analyzing rodent dentoalveolar tissues by μCT, we introduce techniques to successfully analyze dentoalveolar tissues with similar or disparate compositions, densities, and morphological characteristics. Our goal is to provide practical guidelines for μCT analysis of rodent dentoalveolar tissues, including approaches to optimize scan parameters (filters, voltage, voxel size, and integration time), reproducibly orient samples, define regions and volumes of interest, segment and subdivide tissues, interpret findings, and report methods and results. We include illustrative examples of analyses performed on genetically engineered mouse models with phenotypes in enamel, dentin, cementum, and alveolar bone. The recommendations are designed to increase transparency and reproducibility, promote best practices, and provide a basic framework to apply μCT analysis to the dentoalveolar complex that can also be extrapolated to a variety of other tissues of the body. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Diego Caicedo-Rosero, Hernán Benavides-Rosales, Luis Carvajal-Pérez Carvajal-Pérez et al.

La presencia de árboles en un ecosistema de pastoreo aumenta las poblaciones edáficas y, por ende, las relaciones simbióticas. En los ecosistemas altoandinos de la zona norte del Ecuador existen escasas investigaciones sobre esta temática. El objetivo de esta investigación es determinar el crecimiento poblacional de la fauna edáfica en los sistemas silvopastoriles, para este caso, el sistema silvopastoril tiene las siguientes combinaciones: aliso (Alnus acuminata) y mezcla forrajera, acacia (Acacia melanoxylon) y mezcla forrajera, y un testigo con mezcla forrajera. El conteo se realizó en dos épocas, julio y diciembre, en los años 2016, 2017 y 2018. Para el análisis estadístico se realizó un análisis de varianza y la prueba de Tukey, que permitieron mostrar probabilidades e identificar la mejor respuesta de crecimiento de especies en función del tratamiento silvopastoril. Los análisis estadísticos muestran la evolución del sistema en el primer año, en el cual no existen diferencias significativas, debido al trasplante y crecimiento de los árboles; a partir del segundo año ya existen cambios edáficos entre tratamientos por aumento de materia orgánica, lo que influye sobre las especies en el suelo. Los resultados estadísticos concluyen que el sistema silvopastoril con acacia tiene más población edáfica.

Deborah T Gold, Richard Weiss, Tammy Beckett et al.

ABSTRACT Despite the availability of various osteoporosis treatments, adherence remains suboptimal. One contributing factor may be patient experience with therapy. This US, multicenter, combined retrospective chart review and patient questionnaire study included postmenopausal women at high risk for fracture and is the first study to describe real‐world patient experience with abaloparatide (ABL) injection. Eight geographically diverse secondary care sites in the United States participated (n = 193). Mean ± SD age was 67.4 ±8.62 years. Most patients (86%) were satisfied with the ABL regimen, especially with ease of preparation (82%), ease of storage (87%), and storage convenience (89%), an attribute 83% of the patients thought was important. The majority of patients reported complete satisfaction with the ABL regimen allowing for their ability to conduct daily activities (85%) and convenience to fit into their daily schedule (84%). All reported taking ABL as directed, by injection in the lower abdomen, and 83% of patients reported medium or high adherence. Patients were satisfied with the needle size (76% completely satisfied), and 93% reported never deliberately missing a dose. Although injecting medication (18%) and higher out‐of‐pocket costs (17%) were deemed the most bothersome attributes, the majority (69%) noted their healthcare team understands how osteoporosis impacts their lives. In multivariable analyses, ease of preparation (OR = 2.62; 95% CI, 1.01–6.81; p = 0.048) and fracture history (OR = 1.72; 95% CI, 1.03–2.86; p = 0.037) were significantly associated with overall satisfaction. Ease of preparation was a predictor of higher satisfaction with treatment convenience (coefficient = 13.60; 95% CI, 8.08–19.12; p = 0.00). Remembering to take the medication was a significant predictor of self‐reported adherence (OR = 16.66; 95% CI, 3.30–84.24; p = 0.001). In conclusion, the majority of patients were satisfied with ABL and found it convenient/easy to prepare and store. High self‐reported adherence may be associated with positive patient experience including ease of use and adequate support from healthcare providers. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Sébastien Salles, Jami Shepherd, Hendrik J. Vos et al.

ABSTRACT Intraosseous blood circulation is thought to have a critical role in bone growth and remodeling, fracture healing, and bone disorders. However, it is rarely considered in clinical practice because of the absence of a suitable noninvasive in vivo measurement technique. In this work, we assessed blood perfusion in tibial cortical bone simultaneously with blood flow in the superficial femoral artery with ultrasound imaging in five healthy volunteers. After suppression of stationary signal with singular‐value‐decomposition, pulsatile blood flow in cortical bone tissue is revealed, following the heart rate measured in the femoral artery. Using a method combining transverse oscillations and phase‐based motion estimation, 2D vector flow was obtained in the cortex of the tibia. After spatial averaging over the cortex, the peak blood velocity along the long axis of the tibia was measured at four times larger than the peak blood velocity across the bone cortex. This suggests that blood flow in central (Haversian) canals is larger than in perforating (Volkmann's) canals, as expected from the intracortical vascular organization in humans. The peak blood velocity indicates a flow from the endosteum to the periosteum and from the heart to the foot for all subjects. Because aging and the development of bone disorders are thought to modify the direction and velocity of intracortical blood flow, their quantification is crucial. This work reports for the first time an in vivo quantification of the direction and velocity of blood flow in human cortical bone. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Andrey Piatnitski, Sergei Pirogov, Elena Zhizhina

The paper deals with a family of jump Markov process defined in a medium with a periodic or locally periodic microstructure. We assume that the generator of the process is a zero order convolution type operator with rapidly oscillating locally periodic coefficient and, under natural ellipticity and localization conditions, show that the family satisfies the large deviation principle in the path space equipped with Skorokhod topology. The corresponding rate function is defined in terms of a family of auxiliary periodic spectral problems.

Belkacem Chaouchi, Marko Kostić, Stevan Pilipović et al.

In this paper, we introduce the notions of semi-Bloch periodic functions and semi-anti-periodic functions. Stepanov semi-Bloch periodic functions and Stepanov semi-anti-periodic functions are considered, as well. We analyze the invariance of introduced classes under the actions of convolution products and briefly explain how one can use the obtained results in the qualitative analysis of solutions of abstract inhomogeneous integro-differential equations.

Iryna Kulchytska-Ruchka, Sebastian Schöps

This paper presents a novel parallel-in-time algorithm able to compute time-periodic solutions of problems where the period is not given. Exploiting the idea of the multiple shooting method, the proposed approach calculates the initial values at each subinterval as well as the corresponding period iteratively. As in the Parareal method, parallelization in the time domain is performed using discretization on a two-level grid. A special linearization of the time-periodic system on the coarse grid is introduced to speed up the computations. The iterative algorithm is verified via its application to the Colpitt oscillator model.

Suchuan Dong, Naxian Ni

We present a simple and effective method for representing periodic functions and enforcing exactly the periodic boundary conditions for solving differential equations with deep neural networks (DNN). The method stems from some simple properties about function compositions involving periodic functions. It essentially composes a DNN-represented arbitrary function with a set of independent periodic functions with adjustable (training) parameters. We distinguish two types of periodic conditions: those imposing the periodicity requirement on the function and all its derivatives (to infinite order), and those imposing periodicity on the function and its derivatives up to a finite order $k$ ($k\geqslant 0$). The former will be referred to as $C^{\infty}$ periodic conditions, and the latter $C^{k}$ periodic conditions. We define operations that constitute a $C^{\infty}$ periodic layer and a $C^k$ periodic layer (for any $k\geqslant 0$). A deep neural network with a $C^{\infty}$ (or $C^k$) periodic layer incorporated as the second layer automatically and exactly satisfies the $C^{\infty}$ (or $C^k$) periodic conditions. We present extensive numerical experiments on ordinary and partial differential equations with $C^{\infty}$ and $C^k$ periodic boundary conditions to verify and demonstrate that the proposed method indeed enforces exactly, to the machine accuracy, the periodicity for the DNN solution and its derivatives.

V. Dogotar, A. Yurutkina

The article considers the main characteristics of the national system of scientific and technical information in the Republic of Moldova. In the context of determining the possible development prospects of this system, such areas are studied as: structure and special centers for managing scientific and technical information, the main directions of state policy, financing of projects in 2019, as well as scientific journals.

Tanvir Mustafy, Irène Londono, Florina Moldovan et al.

ABSTRACT Bone is a unique living tissue, which responds to the mechanical stimuli regularly imposed on it. Adolescence facilitates a favorable condition for the skeleton that enables the exercise to positively influence bone architecture and overall strength. However, it is still dubious for how long the skeletal benefits gained in adolescence is preserved at adulthood. The current study aims to use a rat model to investigate the effects of in vivo low‐ (LI), medium‐ (MI), and high‐ (HI) intensity cyclic loadings applied during puberty on longitudinal bone development, morphometry, and biomechanics during adolescence as well as at adulthood. Forty‐two young (4‐week‐old) male rats were randomized into control, sham, LI, MI, and HI groups. After a 5 day/week for 8 weeks cyclic loading regime applied on the right tibia, loaded rats underwent a subsequent 41‐week, normal cage activity period. Right tibias were removed at 52 weeks of age, and a comprehensive assessment was performed using μCT, mechanical testing, and finite element analysis. HI and MI groups exhibited reduced body weight and food intake at the end of the loading period compared with shams, but these effects disappeared afterward. HI cyclic loading increased BMD, bone volume fraction, trabecular thickness, trabecular number, and decreased trabecular spacing after loading. All loading‐induced benefits, except BMD, persisted until the end of the normal cage activity period. Moreover, HI loading induced enhanced bone area, periosteal perimeter, and moment of inertia, which remained up to the 52nd week. After the normal cage activity at adulthood, the HI group showed increased ultimate force and stress, stiffness, postyield displacement and energy, and toughness compared with the sham group. Overall, our findings suggest that even though both trabecular and cortical bone drifted through age‐related changes during aging, HI cyclic loading performed during adolescence can render lifelong benefits in bone microstructure and biomechanics. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.