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1.
Sensors (Basel) ; 24(2)2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38257691

RESUMO

Integrated chassis control systems represent a significant advancement in the dynamics of ground vehicles, aimed at enhancing overall performance, comfort, handling, and stability. As vehicles transition from internal combustion to electric platforms, integrated chassis control systems have evolved to meet the demands of electrification and automation. This paper analyses the overall control structure of automated vehicles with integrated chassis control systems. Integration of longitudinal, lateral, and vertical systems presents complexities due to the overlapping control regions of various subsystems. The presented methodology includes a comprehensive examination of state-of-the-art technologies, focusing on algorithms to manage control actions and prevent interference between subsystems. The results underscore the importance of control allocation to exploit the additional degrees of freedom offered by over-actuated systems. This paper systematically overviews the various control methods applied in integrated chassis control and path tracking. This includes a detailed examination of perception and decision-making, parameter estimation techniques, reference generation strategies, and the hierarchy of controllers, encompassing high-level, middle-level, and low-level control components. By offering this systematic overview, this paper aims to facilitate a deeper understanding of the diverse control methods employed in automated driving with integrated chassis control, providing insights into their applications, strengths, and limitations.

2.
Sensors (Basel) ; 21(21)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34770447

RESUMO

With the automotive industry moving towards automated driving, sensing is increasingly important in enabling technology. The virtual sensors allow data fusion from various vehicle sensors and provide a prediction for measurement that is hard or too expensive to measure in another way or in the case of demand on continuous detection. In this paper, virtual sensing is discussed for the case of vehicle suspension control, where information about the relative velocity of the unsprung mass for each vehicle corner is required. The corresponding goal can be identified as a regression task with multi-input sequence input. The hypothesis is that the state-of-art method of Bidirectional Long-Short Term Memory (BiLSTM) can solve it. In this paper, a virtual sensor has been proposed and developed by training a neural network model. The simulations have been performed using an experimentally validated full vehicle model in IPG Carmaker. Simulations provided the reference data which were used for Neural Network (NN) training. The extensive dataset covering 26 scenarios has been used to obtain training, validation and testing data. The Bayesian Search was used to select the best neural network structure using root mean square error as a metric. The best network is made of 167 BiLSTM, 256 fully connected hidden units and 4 output units. Error histograms and spectral analysis of the predicted signal compared to the reference signal are presented. The results demonstrate the good applicability of neural network-based virtual sensors to estimate vehicle unsprung mass relative velocity.


Assuntos
Condução de Veículo , Redes Neurais de Computação , Teorema de Bayes , Estudos de Viabilidade , Memória de Longo Prazo
3.
Sensors (Basel) ; 20(21)2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33143279

RESUMO

The work presents an approach to instrument the load-sensing bearings for automotive applications for estimation of the loads acting on the wheels. The system comprises fiber-optic sensors based on addressed fiber Bragg structures (AFBS) with two symmetrical phase shifts. A mathematical model for load-deformation relation is presented, and the AFBS interrogation principle is described. The simulation includes (i) modeling of vehicle dynamics in a split-mu braking test, during which the longitudinal wheel loads are obtained, (ii) the subsequent estimation of bearing outer ring deformation using a beam model with simply supported boundary conditions, (iii) the conversion of strain into central frequency shift of AFBS, and (iv) modeling of the beating signal at the photodetector. The simulation results show that the estimation error of the longitudinal wheel force from the strain data acquired from a single measurement point was 5.44% with a root-mean-square error of 113.64 N. A prototype load-sensing bearing was instrumented with a single AFBS sensor and mounted in a front right wheel hub of an experimental vehicle. The experimental setup demonstrated comparable results with the simulation during the braking test. The proposed system with load-sensing bearings is aimed at estimation of the loads acting on the wheels, which serve as input parameters for active safety systems, such as automatic braking, adaptive cruise control, or fully automated driving, in order to enhance their effectiveness and the safety of the vehicle.

4.
Eur Radiol ; 27(7): 2737-2743, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27807699

RESUMO

EUSOBI and 30 national breast radiology bodies support mammography for population-based screening, demonstrated to reduce breast cancer (BC) mortality and treatment impact. According to the International Agency for Research on Cancer, the reduction in mortality is 40 % for women aged 50-69 years taking up the invitation while the probability of false-positive needle biopsy is <1 % per round and overdiagnosis is only 1-10 % for a 20-year screening. Mortality reduction was also observed for the age groups 40-49 years and 70-74 years, although with "limited evidence". Thus, we firstly recommend biennial screening mammography for average-risk women aged 50-69 years; extension up to 73 or 75 years, biennially, is a second priority, from 40-45 to 49 years, annually, a third priority. Screening with thermography or other optical tools as alternatives to mammography is discouraged. Preference should be given to population screening programmes on a territorial basis, with double reading. Adoption of digital mammography (not film-screen or phosphor-plate computer radiography) is a priority, which also improves sensitivity in dense breasts. Radiologists qualified as screening readers should be involved in programmes. Digital breast tomosynthesis is also set to become "routine mammography" in the screening setting in the next future. Dedicated pathways for high-risk women offering breast MRI according to national or international guidelines and recommendations are encouraged. KEY POINTS: • EUSOBI and 30 national breast radiology bodies support screening mammography. • A first priority is double-reading biennial mammography for women aged 50-69 years. • Extension to 73-75 and from 40-45 to 49 years is also encouraged. • Digital mammography (not film-screen or computer radiography) should be used. • DBT is set to become "routine mammography" in the screening setting in the next future.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Detecção Precoce de Câncer/métodos , Mamografia/métodos , Programas de Rastreamento/organização & administração , Adulto , Idoso , Neoplasias da Mama/prevenção & controle , Europa (Continente) , Feminino , Humanos , Pessoa de Meia-Idade , Oriente Médio
5.
Folia Med (Plovdiv) ; 65(1): 16-19, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36855969

RESUMO

INTRODUCTION: The essential tools doctors need to diagnose breast cancer tumors at the early stages and with no clinical presentation are screening mammography and ultrasonography. Nonpalpable breast lesions are a current problem nowadays and there are various types of navigation techniques that are utilized in order to achieve cancer cell-free resection margins in the first place. Intraoperative ultrasound has been proven to be a safe and effective way to excise this type of breast tumors. AIM: To study the correlation between the experience we obtained while using intraoperative ultrasound for excision of nonpalpable breast lesions, and the duration of surgery. MATERIALS AND METHODS: Twenty-five women with nonpalpable breast lesions underwent breast-conserving surgery using ultrasound navigation. Nominal and ordinal data were presented using numbers and percentages. Spearman's rank-order correlation was used to assess the effect of experience gained on the duration of surgery. RESULTS: The tumor distribution was 72% malignant tumors and 28% benign. A 100% identification rate in the effective surgical excisions was reported. In the process of gaining experience using the method, the duration of surgery shortened by 30%. No tumor cells on ink were found in all specimens and there was no need for secondary surgeries. CONCLUSIONS: Our results demonstrate a relatively short learning curve, and we believe that breast surgeons should be helped and encouraged to gather adequate expertise to ensure patient safety and gain confidence.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Duração da Cirurgia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/cirurgia , Detecção Precoce de Câncer , Mamografia , Ultrassonografia
6.
Folia Med (Plovdiv) ; 64(6): 884-888, 2022 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36876566

RESUMO

INTRODUCTION: Gastrointestinal stromal tumors (GISTs) usually present as an exophytic mass localized in stomach. Years ago, conventional surgery was the only option. Laparoscopic and robotic procedures have risen to prominence in recent decades as technology and surgical techniques have advanced.


Assuntos
Tumores do Estroma Gastrointestinal , Laparoscopia , Procedimentos Cirúrgicos Robóticos , Humanos
7.
Astron J ; 144(6)2012.
Artigo em Inglês | MEDLINE | ID: mdl-30555171

RESUMO

We present the discovery and spectroscopic follow-up of a nearby late-type L dwarf (2M0614+3950), and two extremely wide very-low-mass binary systems (2M0525-7425AB and 2M1348-1344AB), resulting from our search for common proper motion pairs containing ultracool components in the Two Micron All Sky Survey (2MASS) and the Wide-field Infrared Survey Explorer (WISE) catalogs. The near-infrared spectrum of 2M0614+3950 indicates a spectral type L9 ± 1 object residing at a distance of 26.0 ± 1.8 pc. The optical spectrum of 2M0525-7425A reveals an M3.0 ± 0.5 dwarf primary, accompanied by a secondary previously classified as L2. The system has an angular separation of ~ 44″, equivalent to ~ 2000 AU at distance of 46.0 ± 3.0 pc. Using optical and infrared spectra, respectively, we classify the components of 2M1348-1344AB as M4.5 ± 0.5 and T5.5 ± 1. The angular separation of ~ 68″ is equivalent to ~ 1400 AU at a distance of 20.7 ± 1.4 pc. 2M1348-1344AB is one of only six very wide (separation > 1000 AU) systems containing late T dwarfs known to date.

8.
Interact Cardiovasc Thorac Surg ; 13(1): 98-100, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21525030

RESUMO

Coarctation of thoracic aorta is an uncommon diagnosis in adults. Catheter-based intervention consisting of primary ballooning and stenting is becoming one of the methods of choice for the treatment of native coarctation. We describe the case of a young adult with coarctation of the aorta treated unsuccessfully with percutaneous transluminal angioplasty and stent implantation that resulted in stent migration into the aortic arch and led to an urgent operative intervention. In one step, we performed the evacuation of the foreign body from the aortic arch as well as the treatment of the aortic coarctation through an extra-anatomical vascular graft interposition between the ascending and descending thoracic aorta. In this article, we discuss the need for emergency surgical intervention in this case.


Assuntos
Angioplastia com Balão/instrumentação , Aorta Torácica/cirurgia , Coartação Aórtica/terapia , Implante de Prótese Vascular , Remoção de Dispositivo , Migração de Corpo Estranho/cirurgia , Stents , Angioplastia com Balão/efeitos adversos , Aorta Torácica/diagnóstico por imagem , Coartação Aórtica/cirurgia , Aortografia/métodos , Prótese Vascular , Implante de Prótese Vascular/instrumentação , Emergências , Migração de Corpo Estranho/diagnóstico por imagem , Migração de Corpo Estranho/etiologia , Humanos , Masculino , Desenho de Prótese , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Adulto Jovem
9.
Science ; 313(5791): 1279-81, 2006 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-16888101

RESUMO

We have identified a companion to the young planetary-mass brown dwarf Oph 162225-240515. This pair forms a resolved binary consisting of two objects with masses comparable to those of extrasolar giant planets. Several lines of evidence confirm the coevality and youth of the two objects, suggesting that they form a physical binary. Models yield masses of approximately 14 and approximately 7 times the mass of Jupiter for the primary and the secondary object, respectively, at an age of approximately 1 million years. A wide ( approximately 240-astronomical unit) binary in the ultra-low-mass regime poses a challenge to some popular models of brown dwarf formation.

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