bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Vibration Parameters of Mechanical System Utilizing Low-Cost MEMS Accelerometers
Authors: Quang Khanh Duong , Thi Huong Vuong , Van Anh Luu
Published: September 2019

Multi-axial mechanical systems commonly encounter the problem of vibration while attempting to drive machining systems at high speed. Many effective methods based on feed-forward and feedback control have been proposed and applied for vibration reduction. In order to design controllers all methods require the exact knowledge of system parameters: vibration frequency and damping ratio. In recent years, low-cost Micro Electro Mechanical Systems (MEMS) accelerometers have been used for many applications in industry. This paper presents the advantage of low cost MEMS accelerometer to identify vibration parameters of mechanical systems in comparison to conventional expensive devices.
Numerical Study of a Small Droplet Movement in a Microchannel under Heat Source
Authors: Le Thanh Long , Chen Jyh Chen , Nguyen Huy-Bich
Published: September 2019

In this study, the numerical computation is used to investigate the transient movement of a water droplet in a microchannel. For tracking the evolution of the free interface between two immiscible fluids, we employed the finite element method with the two-phase level set technique to solve the Navier-Stokes equations coupled with the energy equation. Both the upper wall and the bottom wall of the microchannel are set to be an ambient temperature. 40mW heat source is placed at the distance of 1 mm from the initial position of a water droplet. When the heat source is turned on, a pair of asymmetric thermocapillary convection vortices is formed inside the droplet and the thermocapillary on the receding side is smaller than that on the advancing side. The temperature gradient inside the droplet increases quickly at the initial times and then decreases versus time. Therefore, the actuation velocity of the water droplet first increases significantly, and then decreases continuously. The dynamic contact angle is strongly affected by the oil flow motion and the net thermocapillary momentum inside the droplet. The advancing contact angle is always larger than the receding contact angle during actuation process.
Structural Dynamics Analysis of 3-U CubeSat
Authors: Chau Vu Minh , Vo Hien Bich
Published: September 2019

The development of CubeSats has been advanced significantly during the past two decades for both scientific research and industrial purposes. During the manufacturing process, every CubeSat must satisfy various system requirements in which the structural analysis is one of the most vital necessity in order to assure a normal operation of the CubeSat during its working time in space. In the conceptual design phase, structural dynamics is a mandatory step to determine the natural frequencies of individual bodies, the deformation and stress induced at the corresponding vibration modes to prevent structural failure. In this work, IGOSat, a 3-Unit CubeSat, which was developed at the Paris Diderot University is exanimated in term of modal, harmonic response, and random vibration analysis at the time of ground testing as well as the launching phase using ANSYS software. These numerical simulations conducted according to the CubeSat Design Specification and the system requirements of QB50 project. The minimum natural frequency of the CubSat obtained to be 363.17 (Hz), which passed the required frequency of 90 (Hz). Moreover, the Harmonic and Random vibration analyses indicate that the peak response of normal stress, as well as deformation values obtained, are far lesser compared to the yield strength of the frame structure and subsystem materials. Hence, our numerical analysis found that the CubeSat remains intact during the launch environment.
A Study on Active Closed-Loop Gap Control for Hydrostatic Bearing
Authors: Renn Jyh Chyang , Wu Guan Yi
Published: September 2019

In this paper, a hydrostatic bearing controlled by servo-valve for precise closed-loop oil-film gap control is developed. Due to the increasing demands of larger dimension, heavier load and higher precision for current and future machine tools, the development of hydrostatic bearing has become a more and more important issue over the past decades. Nowadays, the most commonly used active pressure feedback restrictor for hydrostatic bearing is membrane type, in which a thin and flexible metal sheet serves as the key component to meter the hydraulic oil flow precisely. However, the membrane type pressure feedback restrictor is not quite suitable for extremely heavy load. Therefore, an alternative to design the active restrictor for hydrostatic bearing using servo-valve is presented in this paper. Different controllers are also designed and compared in this paper. There are two significant features regarding the proposed design. The first one is the introduced orifice restrictor inside the servo-valve which avoids the influence of possible oil temperature variation. The second feature is the introduced closed-loop oil-film gap control scheme that widens the application range effectively. Finally, a test rig of servo-valve controlled hydrostatic bearing is implemented and the experimental results prove the validity of the hydrostatic bearing with the proposed servo-valve and the closed-loop gap control scheme.
Research on Application of 3D Parametric Software for Design and Shaping of Bus Frame Structure
Authors: NGUYEN THANH CONG
Published: September 2019

The bus frame structure is mainly subject to the complex loads that affect the vehicle during operation, so the design of frame structure is always a key issue in the design, consuming a lot of time and effort. To enhance the flexibility of the design and calculation process, minimize the changes in design of the same type of bus, enhance the level of standardization and mass production of the product, the using of 3D parametric software to carry out designing the bus frame structure has become an indispensable trend in the development of automotive manufacturing technology. This article presents the results of research on the features of the geometric model establishment of Solidworks software as well as the interactive ability, data access between Solidworks and Excel software. Based on the features of the software and on the basis of the analysis of the design process, the structural features of the bus frame, the method of rapid shaping is set up. The application of rapid shaping by using Solidworks and Excel software to increase productivity, reduce time, effort and budget for frame structure design process of bus.
In Vivo Function of the Lipid Raft Protein Flotillin-1 during CD8+ T Cell–Mediated Host Surveillance
Authors: Ficht Xenia , Ruef Nora , Stolp Bettina , Samson Guerric P. B. , Moalli Federica , Page Nicolas , Merkler Doron , Nichols Ben J. , Diz-Muñoz Alba , Legler Daniel F. , Niggli Verena , Stein Jens V.
Published: September 2019

Flotillin-1 (Flot1) is an evolutionary conserved, ubiquitously expressed lipid raft–associated scaffolding protein. Migration of Flot1-deficient neutrophils is impaired because of a decrease in myosin II–mediated contractility. Flot1 also accumulates in the uropod of polarized T cells, suggesting an analogous role in T cell migration. In this study, we analyzed morphology and migration parameters of murine wild-type and Flot1−/− CD8+ T cells using in vitro assays and intravital two-photon microscopy of lymphoid and nonlymphoid tissues. Flot1−/− CD8+ T cells displayed significant alterations in cell shape and motility parameters in vivo but showed comparable homing to lymphoid organs and intact in vitro migration to chemokines. Furthermore, their clonal expansion and infiltration into nonlymphoid tissues during primary and secondary antiviral immune responses was comparable to wild-type CD8+ T cells. Taken together, Flot1 plays a detectable but unexpectedly minor role for CD8+ T cell behavior under physiological conditions.
The Italian Society of Rheumatology clinical practice guidelines for the diagnosis and management of gout
Authors: Ughi N. , Prevete I. , Ramonda R. , Cavagna L. , Filippou G. , Manara M. , Bortoluzzi A. , Parisi S. , Ariani A. , Scirè C.A.
Published: September 2019

Gout is a chronic disease with an increased risk of premature death related to comorbidities. Treatment of gout has proved suboptimal and clinical practice guidelines (CPGs) are expected to have a key role in achieving improvement. Since new evidence has become available, the Italian Society for Rheumatology (SIR) has been prompted to update the 2013 recommendations on the diagnosis and management of gout. The framework of the Guidelines International Network Adaptation Working Group was adopted to identify, appraise (AGREE II), synthesize, and customize the existing gout CPGs to the needs of the Italian healthcare context. The task force consisting of rheumatologists from the SIR Epidemiology Unit and a committee with experience on gout identified key health questions to guide a systematic literature review. The target audience includes physicians and health professionals who manage gout in practice, and the target population includes adult patients suspected or diagnosed as having gout. These recommendations were finally rated by an external multi-disciplinary commission. From a systematic search in databases (Medline, Embase) and grey literature, 8 CPGs were selected and appraised by two independent raters. Combining evidence and statements from these CPGs and clinical expertise, 14 recommendations were developed and graded according to the level of evidence. The statements and potential impact on clinical practice were discussed and assessed. These revised recommendations are intended to provide guidance for the diagnosis and the treatment of gout and to disseminate the best evidence-based healthcare for this disease.
Optimum source-receiver orientations to capture PP, PS, SP, and SS reflected wave modes
Authors: Pugin A , Yilmaz Ö
Published: September 2019

We conducted a field experiment at the geotechnical research soil site #1 in Ottawa, Ontario, Canada, and recorded 9-C seismic data along a short line traverse 90 m in length using a multicomponent vibrator source named Microvibe and a landstreamer receiver array
with 48 3-C 28-Hz geophones at 0.75-m intervals. The receiver spread length is 35.25 m, and the near-offset is 1.50 m. We used three source and three receiver orientations - vertical (V), inline-horizontal (H1), and transverse-horizontal (H2). We identified several reflection wave modes in the field
records - PP, PS, SP, and SS, in addition to refracted waves, and Rayleigh-mode and Love-mode surface waves. We computed the semblance spectra of the selected shot records and ascertained the wave modes based on the semblance peaks. We then performed CMP stacking of each of the 9-C data sets using
the PP, PS/SP, and SS stacking velocities. This field test convincingly demonstrates that there is no pure P- or S-wave land seismic source - any source type can generate any combination of wave modes - PP, PS, SP, and SS, and partitioning of the source energy depends on the source orientation and
VP/VS ratio. All three receiver orientations will capture all reflected wave modes - PP, PS, SP, and SS - but with varying strength. The magnitude of the reflection amplitude captured by one of the three receiver orientations will depend on the reflector depth, source-receiver offset, and the
near-surface P- and S-wave velocities in the vicinity of the receiver location. The most prominent PP reflection energy is recorded by the VV source-receiver orientation, whereas the most prominent SS reflection energy is recorded by the H2H2 source-receiver orientation. Additionally, the optimum
source-receiver orientation for PS reflection mode is VH1, and the optimum source-receiver orientation for SP reflection mode is H1V.
Generation of damped response spectra from an undamped response specfrum by constrained interpolation
Authors: McMechan G A
Published: September 2019

The calculation of damped response spectra can be greatly simplified if only approximate spectra are required. The procedure proposed here is based on the observations that the shape of damped response spectra are similar to that of the undamped spectrum of the
same record, and that a highly damped spectrum is smoother, and of smaller average value than a spectrum corresponding to a lower percentage damping . Guided by these general properties of damped spectra, a fast, approximate algorithm has been empirically devised for the production of damped spectra
from an undamped spectrum. The technique is basically one of constrained interpolation. It is general in that it is independent of the physical significance of the data to which it is applied. As the number of constraint points increases, the approximations converge to a desired solution, so that
any required degree of precision can be obtained. Computational costs, which are typically of the order of 10% of the cost of direct integration, are low enough that the approach described here should be competitive with all other techniques for most applications.
The measurement of the magnetic properties of rock specimens
Authors: Roy J L
Published: September 2019

A method of measuring non-uniformly magnetized specimens by means of an astatic magnetometer is described.
The first section gived the theory of the design of a two-magnet system. It is shown that the magnet assembly should be designed for maximum efficiency under the restrictions that are imposed by the physical and magnetic properties of the magnet, the magnet assembly and the specimen. The design of a
magnetometer with a period as short as 13 seconds and yet sensitive enought to measure accurately most sedimentary rocks is given. The sensitivity can be varied by changing the suspension and can possibly be increased by a factor of 20. It is concluded that, in general, it is preferable to use
transversely magnetized magnets. This section also gives a brief description of a magnetometer capable of measuring extremely weak magnetic fields: 1.2x10-10 oersted.
The magnetometer built and used at the Dominion Observatory is described in the second section. This section also gives a bried description of fluxgate system that permits the taking of measurements on magnetically disturbed days.
Specimens of cylindrival form are often used for measurements with an astatic magnetometer. The last section shows that the response of the instrument depends on the relative dimensions of the specimen, i.e. on the ratio of height to radius. While is has been standard practice to use thin discs, it
is concluded that the ratio of height to radius should be approximately equal to 2.5.
Spider checklist for the Blouberg, in the Vhembe Biosphere Reserve, South Africa
Authors: Foord Stefan , Dippenaar-Schoeman Anna S. , Haddad Charles R. , Schoeman Colin , Hahn Norbert , Lyle Robin
Published: September 2019

Background: The north-eastern mountainous region of South Africa has been identified as a spider diversity hotspot and centre of endemisim. The Blouberg is an isolated inselberg that forms part of the Soutpansberg geological complex, the northernmost mountain in South Africa.Objectives: This article provides an updated species list of the Blouberg spiders, which includes details of the distribution patterns and conservation statuses of all taxa. Exotic species and species of special conservation concern are identified.Method: Surveys were conducted between 2005 and 2012, and a range of collecting methods were used to sample both the ground and field layers.Results: A total of 47 families were sampled in 210 genera and 346 species. The families of Salticidae (45 spp.), Gnaphosidae (32 spp.), Thomisidae (31 spp.), Araneidae (26 spp.) and Lycosidae (24 spp.) were the most diverse. Five species are of conservation concern, one species is Vulnerable, one is possibly exotic and 62 species are South African endemics.Conclusion: Presently, 17% of South African species are protected on the mountain and its surrounding foothills. The latter are of particular conservation concern, while the mountaintop and its associated habitats are under-sampled.
Ultracontractive Properties for Directed Graph Semigroups with Applications to Coupled Oscillators
Authors: Bramburger Jason J.
Published: September 2019

It is now well known that ultracontractive properties of semigroups with infinitesimal generator given by an undirected graph Laplacian operator can be obtained through an understanding of the geometry of the underlying infinite weighted graph. The aim of this work is to extend these results to semigroups with infinitesimal generators given by a directed graph Laplacian operator through an analogous inspection of the geometry of the underlying directed graph. In particular, we introduce appropriate nomenclature to discuss the geometry of an infinite directed graph, as well as provide sufficient conditions to extend ultracontractive properties of undirected graph Laplacians to those of the directed variety. Such directed graph Laplacians can often be observed in the study of coupled oscillators, where recent work made explicit the link between synchronous patterns to systems of identically coupled oscillators and ultracontractive properties of undirected graph semigroups. Therefore, in this work we demonstrate the applicability of our results on directed graph semigroups by extending the aforementioned investigation beyond the idealized case of identically coupled oscillators.
Почти разрешимость классов нелинейных интегральных уравнений первого рода на конусах
Authors: Kokurin Mikhail Yur'evich
Published: September 2019

С использованием свойств выпуклости образов вполне непрерывных нелинейных интегральных операторов дано описание выпуклых замкнутых конусов, которые, в зависимости от характеристик интегранта, входят в рецессивный конус, либо в касательный конус для замкнутого образа рассматриваемого оператора. Построенные конусы определяются главной частью асимптотики интегранта на бесконечности и не зависят от вариации его подчиненной части. Обсуждаются приложения к вопросам обобщенной разрешимости нелинейных интегральных уравнений первого рода.
Библиография: 14 наименований.
Конформно инвариантные неравенства в областях евклидова пространства
Authors: Avkhadiev Farit Gabidinovich
Published: September 2019

Изучены конформно инвариантные интегральные неравенства для вещественнозначных функций, заданных в областях $\Omega$ евклидова пространства размерности $n$. Рассматриваются области гиперболического типа, т.е. такие области, в которых определен гиперболический радиус $R=R(x, \Omega)$, удовлетворяющий нелинейному дифференциальному уравнению Лиувилля и обращающийся в нуль на границе области. Доказаны несколько неравенств, справедливых для всех гладких финитных функций $u$, определенных в заданной области гиперболического типа. Приведем два из них:
\begin{gather*}
\int|\nabla u|^2R^{2-n} dx \geqslant n (n-2)\int|u|^2R^{-n} dx,

\int|(\nabla u, \nabla R)|^p R^{p-s} dx\geqslant \frac{2^pn^p}{p^p}\int|u|^pR^{-s} dx,
\end{gather*}
где $n\geqslant 2$, $1\leqslant p< \infty$ и $1+n/2 \leqslant s <\infty$.
Изучены также некоторые связи между евклидовыми и гиперболическими характеристиками областей.
Библиография: 28 наименований.
О свойствах факторизационных операторов в граничных задачах для случайных блужданий
Authors: Lotov Vladimir Ivanovich
Published: September 2019

Изучаются свойства операторов, возникающих при нахождении двойных преобразований Лапласа-Стилтьеса над распределениями в различных граничных задачах для случайных блужданий. Такие операторы определяются через компоненты факторизации Винера-Хопфа. В работе приводятся оценки для норм этих операторов и доказываются теоремы непрерывности.
Библиография: 16 наименований.
Распределение рациональных точек на окружности единичного радиуса
Authors: Korolev Maxim Aleksandrovich , Ustinov Alexey Vladimirovich
Published: September 2019

В работе получено выражение для плотности распределения длин дуг, соединяющих соседние рациональные точки единичной окружности со знаменателями, не превосходящими заданной границы.
Библиография: 10 наименований.
Адаптивная энергетически эффективная аппроксимация стационарных процессов
Authors: Kabluchko Zakhar Al'bertovich , Lifshits Mikhail Anatolievich
Published: September 2019

Рассматривается стационарный процесс (с дискретным или непрерывным временем) и строится адаптивно связанный с ним аппроксимирующий стационарный процесс, сочетающий достаточно высокое качество аппроксимации с дополнительными хорошими свойствами, которые можно интерпретировать как бо́льшую гладкость или низкий расход энергии. Задача решается в терминах спектральных характеристик аппроксимируемого процесса с использованием классических аналитических методов теории прогнозирования.
Библиография: 11 наименований.
Case Report: Disseminated Mycobacterium kansasii Disease in a Patient with Anti–Interferon-Gamma Antibody
Authors: Kashihara Eriko , Fujita Kohei , Uchida Naohiro , Yamamoto Yuki , Mio Tadashi , Koyama Hiroshi
Published: September 2019

Disseminated nontuberculous mycobacterial (NTM) infections usually occur in severely immunosuppressed patients. These infections may also occur in previously immunocompetent patients with acquired anti–interferon-gamma antibodies (anti–IFN-γ Abs). A previously healthy 33-year-old man presented with a 3-week history of cough and fever. Chest computed tomography showed air-space consolidation in the middle lobe of the right lung and enlargement of the supraclavicular, mediastinal, and hilar lymph nodes. Tissue samples obtained via mediastinoscopy showed granuloma formation with acid-fast bacteria; cultures from the tissue revealed Mycobacterium kansasii. Accordingly, a diagnosis of disseminated M. kansasii disease was made. The positive control tested negative in the QuantiFERON-TB Gold In-tube test, suggesting the presence of anti–IFN-γ Abs. The ELISA test for anti–IFN-γ Abs demonstrated an increased titer. Antimycobacterial drug treatments were initiated after diagnosis. His symptoms improved over 2 months, and he remains well on outpatient management. Disseminated M. kansasii disease is a very rare condition suggestive of immunosuppression. Testing for anti–IFN-γ antibodies might be important in all cases of disseminated M. kansasii disease.
Narratives of Women Using a 24-Hour Ride-Hailing Transport System to Increase Access and Utilization of Maternal and Newborn Health Services in Rural Western Kenya: A Qualitative Study
Authors: Onono Maricianah , Odhiambo Gladys Ombonya , Congo Ouma , Waguma Lawrence Wandei , Serem Titus , Owenga Mildred Anyango , Wekesa Pauline
Published: September 2019

Between 1990 and 2015, Kenya had a 0.9% annual reduction in maternal mortality, one of the lowest reductions globally. This slow decline was linked to the relatively low utilization of delivery services. We designed a mobile phone–enhanced 24-hour transport navigation system coupled with personalized and interactive gestation-based text messages (MAccess) to address maternal child health service utilization. The primary purpose of this analysis is to explore the ways in which pregnant and postnatal women made decisions regarding care-seeking for pregnancy and childbirth services, the processes of getting care from home to the hospital as well their perceptions on how the MAccess intervention affected their pregnancy and childbirth care-seeking and utilization experience. We conducted semistructured, individual interviews with 18 postpartum women. Participants were purposively sampled. Interviews were audiotaped, transcribed, and analyzed using thematic analysis. For participants in this study, all three delays interacted in a complex manner to affect women’s utilization of pregnancy and childbirth services. Even though women were aware of the benefits of skilled birth attendance, other health system factors such as opening hours, or health workers’ attitudes still deterred women from delivering in health facilities. The MAccess innovation was highly acceptable to women throughout pregnancy and childbirth and helped them navigate the complex and layered individual, infrastructural, and health system factors that put them at risk of adverse maternal and newborn outcomes. These findings emphasize that an integrated approach, which addresses all delays simultaneously, is important for reducing perinatal morbidity and mortality.
Detection of Antibodies to Spotted Fever Group Rickettsiae and Arboviral Coinfections in Febrile Individuals in 2014–2015 in Southern Coastal Ecuador
Authors: Farovitch Lorne , Sippy Rachel , Beltrán-Ayala Efraín , Endy Timothy P. , Stewart-Ibarra Anna M. , Leydet Brian F.
Published: September 2019

Tick-borne diseases (TBDs) are a growing public health threat and are increasingly identified as the cause of undifferentiated febrile illness. There is a significant gap in our understanding of ticks and their associated pathogens in Ecuador. An arboviral surveillance study allowed us to explore potential exposure to TBDs in febrile subjects. We tested plasma samples from 222 febrile subjects for spotted fever group rickettsial (SFGR) antibodies from southern coastal Ecuador in 2014–2015 via ELISA. Fifty-five (25%) subjects had evidence of anti-SFRG IgG or IgM antibodies. Although attempts to detect Rickettsia species in plasma by polymerase chain reaction were unsuccessful, these preliminary data suggest the possibility of endemic SFGR transmission in Ecuador. To better understand the burden and entomological risk for TBDs in Ecuador, future studies should expand TBD surveillance in humans, document common human-biting ticks, and measure pathogen carriage rates in questing ticks.
Prevalence and Molecular Characterization of Enterocytozoon bieneusi among Pigs in Chonburi Province, Eastern Thailand
Authors: Thathaisong Umaporn , Siripattanapipong Suradej , Leelayoova Saovanee , Mungthin Mathirut
Published: September 2019

Enterocytozoon bieneusi is an organism that infects a wide variety of vertebrates, including humans. Pigs also harbor E. bieneusi, of which several genotypes have been recently detected in human feces. The aim of this study was to determine the prevalence of E. bieneusi infection among pigs raised in three smallholder farms and eight small large-scale farms in Chonburi Province, Eastern Thailand, using nested polymerase chain reaction of the internal transcribed spacer (ITS) of the small subunit of ribosomal RNA gene and to investigate genotypes of E. bieneusi isolates using nucleotide sequencing and phylogenetic tree analysis of the ITS region. Of 244 stool samples, E. bieneusi was detected in 14.8% (36/244). Two known zoonotic genotypes, that is, genotypes E (77.8%) and F (22.2%), were identified. Using phylogenetic tree analysis, these two genotypes were clustered in human pathogenic and zoonotic potential groups, designated as group 1. The high prevalence of zoonotic genotypes of E. bieneusi among pigs suggests that pig farming is one of the potential sources of human infection. This is the first report of E. bieneusi genotypes among pigs raised in pig farms in Eastern Thailand.
Perfil epidemiológico dos pacientes com Transtorno do Espectro Autista do Centro Especializado em Reabilitação
Authors: Reis Deyvson Diego de Lima , Neder Patrícia Regina Bastos , Moraes Marcos da Conceição , Oliveira Nicolas Mousinho
Published: September 2019

Objetivo: Caracterizar o perfil epidemiológico dos pacientes diagnosticados com Transtorno do Espectro Autista (TEA). Método: O estudo caracteriza-se por ser observacional, transversal e descritivo, e foi realizado no período de setembro de 2018 a fevereiro de 2019, após aprovação do Comitê de Ética e Pesquisa (número 3.180.298). Os dados foram coletados dos prontuários dos pacientes com TEA atendidos no Centro Especializado em Reabilitação (CER) e contou com uma casuística de 100 prontuários, nos quais foram coletados dados para caracterizar o perfil epidemiológico, de acordo com o sexo, a idade, a escolaridade, as medicações em uso e as comorbidades apresentadas. Foram incluídos todos os pacientes diagnosticados com TEA desde março de 2016 até janeiro de 2019. Resultados: dos prontuários avaliados, 23% dos pacientes eram do sexo feminino e 77% do sexo masculino. A faixa etária predominante era dos 5 a 8 anos (44%). A maioria estava no Ensino Fundamental (49%) enquanto 18% não estudavam. As comorbidades mais prevalentes foram Transtorno do Déficit de Atenção e Hiperatividade (TDAH) (11%), deficiência intelectual (11%) e perda auditiva (9%). Em relação ao uso de medicamentos, 46% usam Risperidona e 40% não fazem uso de nenhuma medicação. Conclusão: o perfil epidemiológico dos pacientes com TEA atendidos no CER consiste na predominância de indivíduos do sexo masculino, na faixa etária entre 5 a 8 anos, cursando o Ensino Fundamental, com comorbidades mais frequentes TDAH, deficiência intelectual e perda auditiva, e em uso de medicações.
Seguimiento de trayectorias con incertidumbre del modelo usando un diferenciador robusto
Authors: Sánchez-Sánchez P. , Gutiérrez–Giles A. , Pliego–Jiménez J. , Arteaga–Pérez M.A.
Published: September 2019

En este artículo se presenta el uso de un diferenciador robusto de Levant aplicado a robots manipuladores cuyo objetivo es realizar el seguimiento de una trayectoria deseada. El modelo dinamico de los robots es desconocido. La velocidad obtenida empleando el diferenciador robusto se aplica en la estructura de control con la finalidad de cumplir con la tarea de seguimiento. Se realiza un estudio comparativo entre el diferenciador robusto de Levant y las tecnicas más usadas para calcular la velocidad. Son presentados resultados experimentales.
Modelado de baterías para aplicación en vehículos urbanos eléctricos ligeros
Authors: Gómez F.J. , Yebra L.J. , Giménez A. , Torres-Moreno J.L.
Published: September 2019

En este artículo se propone un modelo dinámico de batería que permite simular el comportamiento de distintos tipos de baterías para su aplicación en vehículos eléctricos urbanos ligeros. El modelo es fácilmente parametrizable a partir de las curvas de descarga experimentales del equipo real y se ajusta adecuadamente al comportamiento particular de la curva de carga/descarga de las baterías de Litio-Ferrofosfato (LiFePo4). Se han utilizado los datos obtenidos sobre una instalación experimental para la calibración del modelo propuesto y se presentan resultados de la validación del mismo. El modelo se ha implementado en el lenguaje de modelado orientado a objetos Modelica reutilizando clases de su librería estándar Modelica Standard Library. La calibración y validación se ha realizado con la herramienta de modelado Dymola.
Enfoque híbrido metaheurístico AG-RS para el problema de asignación del buffer que minimiza el inventario en proceso en líneas de producción abiertas en serie
Authors: Hernández-Vázquez José Omar , Hernández-González Salvador , Jiménez-García José Alfredo , Hernández-Ripalda Manuel Darío , Hernández-Vázquez José Israel
Published: September 2019

El problema de asignación del buffer (BAP, por sus siglas en inglés) es clasificado como un problema de optimización combinatorio NP-Duro en el diseño de las líneas de producción. Éste consiste en definir la asignación de lugares de almacenamiento (buffers) dentro de una línea de producción, con el fin de aumentar al máximo la eficiencia del proceso.  Los métodos de optimización que han sido reportados con mayor éxito en los últimos años son las técnicas metaheurísticas. En este trabajo, se propone un enfoque híbrido que utiliza las técnicas metaheurísticas de: Algoritmos Genéticos (AG) y Recocido Simulado (RS), con el objetivo de determinar los buffers requeridos que minimicen el promedio de inventario en proceso (WIP, por sus siglas en inglés) en líneas de producción abiertas en serie M/M/1/K. La evaluación se realiza con un método analítico de descomposición. Los resultados obtenidos demuestran la eficiencia computacional del algoritmo híbrido propuesto con respecto a un RS o AG estándar.
Sistema híbrido inteligente para la predicción de la tensión de una pila de combustible basada en hidrógeno
Authors: Casteleiro-Roca José-Luis , Barragán Antonio Javier , Segura Francisca , Calvo-Rolle José Luis , Andújar José Manuel
Published: September 2019

Por razones de sostenibilidad y estrategia energética, entre otras, existe en la actualidad una tendencia clara hacia el uso de nuevas formas de obtención, almacenamiento y gestión de energía, más eficientes y con un carácter eminentemente sostenible. Con este fin, se está investigando sobre sistemas de almacenamiento de energía; de los que uno de los más prometedores, en lo que a capacidad y movilidad se refiere, es el basado en hidrógeno. En el presente trabajo se obtiene un modelo para predecir el comportamiento dinámico de una pila de combustible alimentada por hidrógeno, lo cual permitirá mejorar su control entre otras aplicaciones. Las variables usadas en esta investigación se han extraído de un banco de pruebas real, donde se monitoriza una pila de combustible mientras se producen variaciones en una carga programable conectada a la salida de la misma. Para realizar este modelado se opta por estudiar la implementación de un modelo híbrido basado en técnicas de agrupamiento y, posteriormente, técnicas inteligentes de regresión con redes neuronales artificiales sobre cada uno de los grupos. La propuesta se ha probado con dos conjuntos de datos de validación, consiguiendo resultados altamente satisfactorios.
Trajetos escolares e destinos profissionais: o caso das ciências sociais no Brasil
Authors: Bordignon Rodrigo Da Rosa
Published: September 2019

O presente texto focaliza as relações entre trajeto escolar e destinos profissionais nas ciências sociais brasileiras. Trata-se de uma primeira exploração de uma base de dados composta pelo conjunto dos professores vinculados aos programas de pós-graduação nas áreas de antropologia e arqueologia, ciência política e relações internacionais e sociologia. A hipótese geral que orienta a pesquisa é que as diferentes modalidades de trajeto escolar conectam-se às hierarquias dos cursos e instituições de destino. O objetivo é dimensionar o modo como a estrutura dos cursos de pós-graduação em ciências sociais diferencia modalidades de investimento escolar e impacta no perfil do corpo professoral. Para tanto, foi conduzida uma análise de correspondência múltipla (ACM), tomando a instituição escolar de origem, a data de fundação dos cursos, os conceitos de avaliação e o ponto de chegada em termos de vínculo profissional. Os resultados indicam que as conexões entre instituições de origem e de destino são dependentes das relações entre centro e periferia em nível nacional e internacional, impactando de modo diferencial nas chances de acesso às carreiras e de afirmação no campo das ciências sociais.
In situ constraints on the vertical distribution of global aerosol
Authors: Watson-Parris Duncan , Schutgens Nick , Reddington Carly , Pringle Kirsty J. , Liu Dantong , Allan James D. , Coe Hugh , Carslaw Ken S. , Stier Philip
Published: September 2019

Abstract. Despite ongoing efforts, the vertical distribution of aerosols globally is
poorly understood. This in turn leads to large uncertainties in the
contributions of the direct and indirect aerosol forcing on climate. Using
the Global Aerosol Synthesis and Science Project (GASSP) database – the
largest synthesised collection of in situ aircraft measurements currently
available, with more than 1000 flights from 37 campaigns from around the
world – we investigate the vertical structure of submicron aerosols across
a wide range of regions and environments. The application of this unique
dataset to assess the vertical distributions of number size distribution and
cloud condensation nuclei (CCN) in the global aerosol–climate model
ECHAM-HAM reveals that the model underestimates accumulation-mode particles
in the upper troposphere, especially in remote regions. The processes
underlying this discrepancy are explored using different aerosol
microphysical schemes and a process sensitivity analysis. These show that
the biases are predominantly related to aerosol ageing and removal rather
than emissions.
Site representativity of AERONET and GAW remotely sensed AOT and AAOT observations
Authors: Schutgens Nick A. J.
Published: September 2019

Abstract. Remote sensing observations from the AERONET and GAW networks are intermittent in time and have a limited field-of-view. A global high-resolution simulation (GEOS5 Nature Run) is used to conduct an Observing System Simulation Experiment (OSSE) for AERONET and GAW observations of AOT and AAOT and estimate the spatio-temporal representativity of individual sites for larger areas (from 0.5° to 4° in size). G5NR and the OSSE are evaluated and shown to have sufficient skill, although daily AAOT variability is significantly underestimated while the frequency of AAOT observations is over-estimated (both resulting in an under-estimation of temporal representativity errors in AAOT). Yearly representation errors are provided for a host of scenarios: varying grid-box size, temporal collocation protocols, and site altitudes are explored. Monthly representation errors are shown to correlate strongly throughout the year, with a pronounced annual cycle. The collocation protocol for AEROCOM model evaluation (using daily data) is shown to be sub-optimal and the use of hourly data advocated instead. A previous subjective ranking of site spatial representativity (Kinne et al., 2013) is analysed and a new objective ranking proposed. Several sites are shown to have yearly representation errors in excess of 40 %. Lastly, a recent suggestion by Wang et al. (2018) that AERONET observations of AAOT suffer a positive representation bias of 30 % globally is analysed and evidence is provided that this bias is likely an overestimate (the current paper finds 4 %) due methodological choices.
Detecting the Melting Layer with a Micro Rain Radar Using a Neural Network Approach
Authors: Brast Maren , Markmann Piet
Published: September 2019

Abstract. A new method using the Micro Rain Radar (MRR) to determine the melting layer height is presented. The MRR is a small vertically pointing frequency modulated continuous wave radar which measures Doppler spectra of precipitation. From these Doppler spectra, various variables such as Doppler velocity or spectral width can be derived. The melting layer is visible through a higher reflectivity and an acceleration of the falling particles, among others. These characteristics are fed to a neural network to determine the melting layer height. For the training of the neural network, the melting layer height is determined manually. The neural network is trained and tested using data from two sites covering all seasons. For most cases, it is well able to detect the correct melting layer height. Sensitivity studies show that the neural network is able to handle different settings of the MRR. Comparisons to radiosonde data and cloud radar data show a good agreement in melting layer heights.
Strong influence of solar X-ray flares on low-frequency electromagnetic signals in middle latitudes
Authors: Rozhnoi Alexander , Solovieva Maria , Fedun Viktor , Gallagher Peter , McCauley Joseph , Boudjada Mohammed Y. , Shelyag Sergiy , Eichelberger Hans U.
Published: September 2019

Abstract. In this paper we analysed sudden phase anomalies (SPAs) of VLF–LF signals recorded at Graz (Austria), Birr (Ireland) and Moscow (Russia) stations during two strong solar flares in September 2017. The first X-class 9.3 flare occurred on 6 September at 12:02 UT, and the second X-class 8.2 flare was observed on 10 September 2017 at 16:06 UT. Data from seven transmitters in a frequency range between 20 and 45 kHz are used for the analysis. The SPAs were observed in all middle-latitude paths (differently orientated) with path lengths from 350 to 7000 km. Solar X-ray burst data were taken from GOES satellite observations in the wavelength band of 0.05–0.4 nm. It was found that (i) the amplitude of SPAs in different paths varies from 10 to 282∘, and (ii) the correlation between the amplitudes of SPAs, the lengths of paths and the signal frequency is weak. The change in effective height of reflection due to lowering of the reflecting layer during the flares was found to be about 12 km for the first event and about 9 km for the second event. Spectral analysis of the X-ray and LF data, filtered in the range between 5 s and 16 min, showed that the LF signal spectra are very similar to X-ray spectra. Maxima of both X-ray and LF spectra are in 2–16 min interval.
A Compact Ocean Bottom Electromagnetic Receiver and Seismometer
Authors: Chen Kai , Deng Ming , Wu Zhongliang , Luo Xianhu , Zhou Li
Published: September 2019

Abstract. Joint marine electromagnetic (EM) and seismic interpretation are widely used for offshore gas hydrate and petroleum exploration, produce better estimates of lithology and fluids, and decrease the risk of low gas saturation. However, joint data acquisition is not commonly employed. Current marine EM data acquisition depends on an ocean bottom electromagnetic receiver (OBEM) and current seismic exploration methods use seismometers. Joint simultaneous data acquisition can decrease costs and improve efficiency; yet conventional independent data receivers have several drawbacks, including large size, high costs, position errors, and low operational efficiency. To address these limitations, we developed a compact ocean bottom electromagnetic receiver and seismometer (OBEMS). Based on existing ocean bottom E-field receiver (OBE) specifications, including low noise levels, low power consumption, and low clock-drift error, we integrated two induction coils for the magnetic sensor and a three-axis omnidirectional geophone for the seismic sensor and assembled an ultra-short base line (USBL) transponder as the position sensor, which improved position accuracy and operational efficiency while reducing field data acquisition costs. The resulting OBEMS has a noise level of 0.1 nV/m/rt (Hz) at 1 Hz in E-field and 0.1 pT/rt (Hz) at 1 Hz in B-field and a 30 day battery lifetime. It also supports a WiFi interface for configuring data acquisition parameters and data download. Offshore acquisition was performed to evaluate the system’s field performance during offshore gas hydrate exploration. The OBEMS functioned effectively throughout operation and field testing. The OBEMS therefore functions as a low cost, compact, and highly efficient joint data acquisition method.
MELPF version 1: Modeling Error Learning based Post-Processor Framework for Hydrologic Models Accuracy Improvement
Authors: Wu Rui , Yang Lei , Chen Chao , Ahmad Sajjad , Dascalu Sergiu M. , Harris Jr. Frederick C.
Published: September 2019

Abstract. This paper studies how to improve the accuracy of hydrologic models using machine-learning models as post-processors and presents possibilities to reduce the workload to create an accurate hydrologic model by removing the calibration step. It is often challenging to develop an accurate hydrologic model due to the time-consuming model calibration procedure and the nonstationarity of hydrologic data. Our findings show that the errors of hydrologic models are correlated with model inputs. Thus motivated, we propose a modeling-error-learning-based post-processor framework by leveraging this correlation to improve the accuracy of a hydrologic model. The key idea is to predict the differences (errors) between the observed values and the hydrologic model predictions by using machine-learning techniques. To tackle the nonstationarity issue of hydrologic data, a moving-window-based machine-learning approach is proposed to enhance the machine-learning error predictions by identifying the local stationarity of the data using a stationarity measure developed based on the Hilbert–Huang transform. Two hydrologic models, the Precipitation–Runoff Modeling System (PRMS) and the Hydrologic Modeling System (HEC-HMS), are used to evaluate the proposed framework. Two case studies are provided to exhibit the improved performance over the original model using multiple statistical metrics.
Identification of key parameters controlling demographically structured vegetation dynamics in a land surface model: CLM4.5(FATES)
Authors: Massoud Elias C. , Xu Chonggang , Fisher Rosie A. , Knox Ryan G. , Walker Anthony P. , Serbin Shawn P. , Christoffersen Bradley O. , Holm Jennifer A. , Kueppers Lara M. , Ricciuto Daniel M. , Wei Liang , Johnson Daniel J. , Chambers Jeffrey Q. , Koven Charlie D. , McDowell Nate G. , Vrugt Jasper A.
Published: September 2019

Abstract. Vegetation plays an important role in regulating global carbon cycles and is a key component of the Earth system models (ESMs) that aim to project Earth's future climate. In the last decade, the vegetation component within ESMs has witnessed great progress from simple “big-leaf” approaches to demographically structured approaches, which have a better representation of plant size, canopy structure, and disturbances. These demographically structured vegetation models typically have a large number of input parameters, and sensitivity analysis is needed to quantify the impact of each parameter on the model outputs for a better understanding of model behavior. In this study, we conducted a comprehensive sensitivity analysis to diagnose the Community Land Model coupled to the Functionally Assembled Terrestrial Simulator, or CLM4.5(FATES). Specifically, we quantified the first- and second-order sensitivities of the model parameters to outputs that represent simulated growth and mortality as well as carbon fluxes and stocks for a tropical site with an extent of 1×1∘. While the photosynthetic capacity parameter (Vc,max25) is found to be important for simulated carbon stocks and fluxes, we also show the importance of carbon storage and allometry parameters, which determine survival and growth strategies within the model. The parameter sensitivity changes with different sizes of trees and climate conditions. The results of this study highlight the importance of understanding the dynamics of the next generation of demographically enabled vegetation models within ESMs to improve model parameterization and structure for better model fidelity.
CREATING AND MAINTAINING IFC–CITYGML CONVERSION RULES
Authors: Tauscher H.
Published: September 2019

Abstract. We employ a triple graph grammar to enable configurable conversion from IFC to CityGML. In this paper, we present the mathematical framework behind the graph transformation approach as well as an application to create, store and maintain transformation rules implementing this framework. Particular emphasis is put on how the approach enables graphical representation and static analysis of rules and rulesets, both in the theoretical framework and prototypical implementation. Even if various publications and tools for general graph transformation do already exist, we hope that the BIM–GIS community will benefit from a domain-specific introduction to the theory and dedicated software tools.
REQUIREMENT ANALYSIS OF 3D ROAD SPACE MODELS FOR AUTOMATED DRIVING
Authors: Schwab B. , Kolbe T. H.
Published: September 2019

Abstract. Automated driving has received a high degree of public attention in recent years as it will lead to profound changes in mobility, society and urban development. Despite several product announcements from automobile manufacturers and mobility providers, many questions have not yet been answered completely. The need of lane-level HD maps was widely discussed and has been the reason for company acquisitions. HD maps are tailored towards supporting the operation of an automated vehicle. However, the development of this technology also requires road space models, but with a completely different focus and level of detail. Therefore, this article investigates the system development and testing challenges of automated driving. Based on this, requirements of road space models for developing automated driving are derived and gaps to current standards are indicated.