Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Adv Mater ; 36(5): e2306205, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37847822

RESUMO

Despite the great potential of solid oxide electrochemical cells (SOCs) as highly efficient energy conversion devices, the undesirable high operating temperature limits their wider applicability. Herein, a novel approach to developing high-performance low-temperature SOCs (LT-SOCs) is presented through the use of an Er, Y, and Zr triple-doped bismuth oxide (EYZB). This study demonstrates that EYZB exhibits > 147 times higher ionic conductivity of 0.44 S cm-1 at 600 °C compared to commercial Y-stabilized zirconia electrolyte with excellent stability over 1000 h. By rationally incorporating EYZB in composite electrodes and bilayer electrolytes, the zirconia-based electrolyte LT-SOC achieves the unprecedentedly high performance of 3.45 and 2.02 W cm-2 in the fuel cell mode and 2.08 and 0.95 A cm-2 in the electrolysis cell mode at 700 °C and 600 °C, respectively. Further, a distinctive microstructural feature of EYZB that largely extends triple phase boundary at the interface is revealed through digital twinning. This work provides insights for developing high-performance LT-SOCs.

2.
Sensors (Basel) ; 22(21)2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36366256

RESUMO

In general, it is very difficult to visually locate blood vessels for intravenous injection or surgery. In addition, if vein detection fails, physical and mental pain occurs to the patient and leads to financial loss in the hospital. In order to prevent this problem, NIR-based vein detection technology is developing. The proposed study combines vein detection and digital hair removal to eliminate body hair, a noise that hinders the accuracy of detection, improving the performance of the entire algorithm by about 10.38% over existing systems. In addition, as a result of performing venous detection of patients without body hair, 5.04% higher performance than the existing system was detected, and the proposed study results were verified. It is expected that the use of devices to which the proposed study is applied will provide more accurate vascular maps in general situations.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador , Humanos , Processamento de Imagem Assistida por Computador/métodos , Razão Sinal-Ruído
3.
Sensors (Basel) ; 20(24)2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33371291

RESUMO

With the recent development of artificial intelligence along with information and communications infrastructure, a new paradigm of online services is being developed. Whereas in the past a service system could only exchange information of the service provider at the request of the user, information can now be provided by automatically analyzing a particular need, even without a direct user request. This also holds for online platforms of used-vehicle sales. In the past, consumers needed to inconveniently determine and classify the quality of information through static data provided by service and information providers. As a result, this service field has been harmful to consumers owing to such problems as false sales, fraud, and exaggerated advertising. Despite significant efforts of platform providers, there are limited human resources for censoring the vast amounts of data uploaded by sellers. Therefore, in this study, an algorithm called YOLOv3+MSSIM Type 2 for automatically censoring the data of used-vehicle sales on an online platform was developed. To this end, an artificial intelligence system that can automatically analyze an object in a vehicle video uploaded by a seller, and an artificial intelligence system that can filter the vehicle-specific terms and profanity from the seller's video presentation, were also developed. As a result of evaluating the developed system, the average execution speed of the proposed YOLOv3+MSSIM Type 2 algorithm was 78.6 ms faster than that of the pure YOLOv3 algorithm, and the average frame rate per second was improved by 40.22 fps. In addition, the average GPU utilization rate was improved by 23.05%, proving the efficiency.

4.
J Ethnopharmacol ; 133(2): 642-6, 2011 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-21040773

RESUMO

AIM OF THE STUDY: So-cheong-ryong-tang (SCRT) and Yeon-gyo-pae-dok-san (YPS) extracts are widely used in treatment of the common cold. The purpose of this study is to evaluate the efficacy of SCRT and YPS on the common cold. METHODS: Four hundred eighty participants with symptoms of the common cold within 48 h were recruited for this randomized, double-blind, placebo-controlled trial. SCRT extract and YPS extract were put in gelatin capsules and orally administered 3 times a day. The pattern of participants was determined according to the Questionnaire for Common Cold Pattern Identification (QCCPI), and the severity of illness was assessed by Wisconsin Upper Respiratory Symptom Survey-21 Korean version (WURSS-21-K) every 7 days. RESULTS: The test and control groups were not significantly different in gender, age, smoking history, and baseline score of WURSS-21-K at the time of enrollment. SCRT treatment significantly decreased the total WURSS-21-K score on the 6th and 7th day (p<0.05) of the enrollment compared with the placebo group. YPS treatment decreased the total WURSS-21-K score on the 5th and 6th day (p<0.05 vs. the placebo group) of the enrollment. In the patients with Wind-cold pattern cold, SCRT significantly decreased the total WURSS-21-K score from 4th to 8th day (p<0.05), and YPS significantly decreased the total WURSS-21-K score from 4th to 6th day (p<0.05). For the Wind-heat pattern cold, neither SCRT nor YPS group showed significant difference from the placebo group. SCRT and YPS did not significantly decrease the time to complete resolution of the cold symptoms. CONCLUSIONS: SCRT and YPS have beneficial, albeit limited, effects on common cold patients, especially those with the Wind-cold pattern cold.


Assuntos
Resfriado Comum/tratamento farmacológico , Fitoterapia , Extratos Vegetais/uso terapêutico , Adolescente , Adulto , Método Duplo-Cego , Etnofarmacologia , Feminino , Humanos , Masculino , Medicina Tradicional Coreana , Extratos Vegetais/efeitos adversos , Plantas Medicinais/efeitos adversos , República da Coreia , Índice de Gravidade de Doença , Adulto Jovem
5.
Artigo em Inglês | MEDLINE | ID: mdl-22254483

RESUMO

The pulmonary function test (PFT) is a widely used test in patients or for those who are at risk of respiratory dysfunction. In this study, we aimed to develop a more convenient system, namely, the impedance pulmonary function measurement system (IPFS), for overcoming the restrictions posed by the prevalent spirometric PFT. IPFS employs tetra polar electrodes that can measure pulmonary function using the subjects' hands alone. The impedance measured by IPFS extracts AC values of pulmonary impedance from DC values of body impedance in respiration. This system yields changes in the impedance of volume and flow. In order to verify IPFS, we compared the continuous waveforms obtained from the PFT module and developed IPFS using Pearson linear correlation coefficients (p < 0.01) for volume and flow. Further, we evaluated the potential application of IPFS for detecting pulmonary functions such as volume (FEV(1)/FVC Ratio) and flow (PEF), and compared the measured parameters between IPFS and spirometric PFT. Our results demonstrate that the measurements obtained using IPFS reflect pulmonary function parameters.


Assuntos
Algoritmos , Diagnóstico por Computador/métodos , Medidas de Volume Pulmonar/métodos , Pletismografia de Impedância/métodos , Troca Gasosa Pulmonar , Testes de Função Respiratória/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
Yonsei Med J ; 51(3): 345-53, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20376886

RESUMO

PURPOSE: Photoplethysmography (PPG) is a noninvasive optical technology that detects changes in blood volume in the vascular system. This study aimed to investigate the possibilities of monitoring the cardiovascular system status by using PPG. MATERIALS AND METHODS: Forced hemodynamic changes were induced using cardiac stimulants; dopamine and epinephrine, and PPG components were recorded by a noninvasive method at the peripheral blood vessels. The results were compared among 6 dogs. Endotracheal intubation was performed after an intramuscular injection of 25 mg/kg ketamine sulfate, and anesthesia was maintained with 2% enflurane. After stabilizing the animals for 15 min, 16 mg/mL diluted dopamine was injected into a vein for 2 min at 20 microg/kg min(-1) by using an infusion pump. Thereafter, the infusion pump was stopped, and 1 mg epinephrine was injected intravenously. Fluid administration was controlled to minimize preload change in blood pressure. RESULTS: After stimulant administration, systolic blood pressure (SBP) and diastolic blood pressures (DBP) increased. The direct current (DC) component, which reflects changes in blood volume, decreased while the alternating current (AC) component, which reflects changes in vascular compliance and resistance, increased. The correlation coefficient between SBP and the foot of the DC component was 0.939 (p < 0.01), while it was 0.942 (p < 0.01) for DBP and the peak of the DC component. The AC component could predict the increase in vascular resistance from a stable pulse blood volume, even with increased pulse pressure. CONCLUSION: These results support the possibility that PPG components may be used for easy and noninvasive measurement of hemodynamic changes in the cardiovascular system.


Assuntos
Monitores de Pressão Arterial , Pressão Sanguínea/fisiologia , Cães/fisiologia , Fotopletismografia/métodos , Animais , Humanos , Modelos Animais
7.
Artigo em Inglês | MEDLINE | ID: mdl-19163795

RESUMO

In this research, a device, which has a thermotherapic and massaging function and relaxes muscles, was used to evaluate the effect muscle relaxation has on stress relief. Therefore, the physiological changes namely Heart Rate (HR), Heart Rate Variability (HRV) and Skin Temperature (SKT) of the subjects which reflect the autonomic nervous system and cardiovascular relationship were obtained and analyzed. In order to evaluate the assumption that the treatment relieves the subject's physiological and psychological stress, experiment was carried out on 25 adults (13 male and 12 female, age 52.32+/-18.121) through stages consisted of relaxation, pre-treatment, treatment and post-treatment. Treatment was provided to the back, stomach and leg area by massaging 55 degrees C heat to the back. According as the physiological changes of subjects before and after treatment were compared, the present research was able to prove that thermotherapy and massage treatment induces physiological change of patients thus relieves stress.


Assuntos
Eletrocardiografia/instrumentação , Hipertermia Induzida/instrumentação , Massagem/instrumentação , Temperatura Cutânea , Estresse Psicológico/diagnóstico , Estresse Psicológico/terapia , Termografia/instrumentação , Eletrocardiografia/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Humanos , Hipertermia Induzida/métodos , Masculino , Massagem/métodos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estresse Psicológico/fisiopatologia , Termografia/métodos , Resultado do Tratamento
8.
Artigo em Inglês | MEDLINE | ID: mdl-19162711

RESUMO

The purpose of this study is to determine an individual physiological signal and based on the information; develop equipment that will encourage the efficiency of exercise. To evaluate the practical use of equipment an experiment is carried out. The signal of twenty adult male is determined under condition of Exercise Stress Test. Measured physiological signals are ECG from ears, chest (Lead I), PPG from earlap, activity from ear and arm, and the body skin temperature of arm. For ECG data, there are two signals: one is ear-arm signal, and the other is chest (Lead I) signal. When compare those two, ear-arm detection rate shows 92.08% detection, and 93.13% at chest. The error rate occurred average 0.035(+/-0.014) seconds and 0.026(+/-0.017) seconds. For PPG, we can reduce the influence of motion artifact by Autocorrelation method, and as a result, peak detection rate increased from 94.3% to 98.4%, decreased the error rate with 0.058+/-0.076 to 0.023+/-0.031, Also, we certified that if the speed and elevation of the treadmill increase, physical activity increase, and the body temperature gets decreased. Upon this consequence, we developed a physiological data acquisition system that is convenient to user while they are exercising.


Assuntos
Teste de Esforço/instrumentação , Monitorização Fisiológica/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Medicina Esportiva/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...