Research on Mathematical Distribution of Failure Time and Engineering Evaluation for Medical Electrical Equipment Based on Operation and Maintenance Data / 中国医疗器械杂志

This study mainly discusses the contents, methods and characteristics of the collection of operation and maintenance data, as well as the establishment and evaluation methods of the distribution model of the failure time of medical electrical equipment. The distribution models of failure time at three levels of medical electrical equipment are established by linear regression method and goodness of fit test:The first is the device level MTBF distribution model, the second is the failure rate distribution model of the failure mode of key components, the third is the calculation model of the influence coefficient of influence factor on the failure mode of key components. This study presents a method of establishing MTBF segment model and implements a calculation model of influence coefficient varying with time.

Estudio climatológico de los vientos para la ciudad de Bogotá en el periodo 2010 - 2016 / Climatological study of the winds for the city of Bogotá in the period 2010-2016 / Estudo climatológico dos ventos para a cidade de Bogotá no período de 2010 a 2016

Resumen En Colombia, hay una carencia en los estudios climatológicos del viento, ya que, los que existen actualmente no aplican técnicas estadísticas ni periodos representativos adecuados. Por consiguiente, el presente estudio analiza el comportamiento climatológico del viento en la ciudad de Bogotá, para el periodo 2010 a 2016, buscando describir estadística, espacial y vectorialmente esta variable climatológica. Para empezar se realizó un análisis estadístico del conjunto de datos, de la velocidad del viento, mediante el software Windographer©, utilizando las técnicas exploratorias para la distribución Weibull, describiendo así los parámetros estadísticos de las estaciones en las principales zonas de la ciudad. Del mismo modo, se elaboraron las rosas de los vientos por estación, con el software WRPLOT™; y para finalizar se realizó un mapa vectorial mediante el método de interpolación Co-Kriging utilizando el sistema de información geográfica ArcGis®. Observando que el régimen de circulación atmosférico en Bogotá está estrechamente relacionado con la presencia de los cerros orientales y con la predominancia de los vientos alisios; así mismo, se encontró que la mayor velocidad del viento se presenta al suroeste, y las magnitudes más débiles, al norte y en cercanía a los cerros orientales.

Abstract In Colombia, there is a lack in wind weather studies, since those that currently exist do not apply statistical techniques or adequate representative periods. Therefore, the present study analyzes the wind weather behavior in the city of Bogotá, for the period 2010 to 2016, seeking to describe this weather variable statistically spatially and vectorially. To begin with, a statistical analysis of the data set, of the wind speed, was performed using the Windographer© software, using the exploratory techniques for the Weibull distribution, thus describing the statistical parameters of the stations in the main areas of the city. Similarly wind roses were made per season, using the WRPLOT ™ software; and, finally, a vector map was made using the Co-Kriging interpolation method, using the ArcGis® geographic information system. Noting that the atmospheric circulation regime in Bogotá is closely related to the presence of the eastern hills and the predominance of trade winds; Likewise, it was found that the highest wind speed is presented to the southwest, and the weakest magnitudes, to the north and in proximity to the eastern hills.

Resumo Na Colômbia, há falta de estudos sobre o clima do vento, uma vez que os existentes atualmente não aplicam técnicas estatísticas ou períodos representativos adequados. Portanto, o presente estudo analisa o comportamento do clima eólico na cidade de Bogotá, no período de 2010 a 2016, buscando descrever esta variável climática de forma estatística, espacial e vetorial. Para começar foi realizada uma análise estatística do conjunto de dados, da velocidade do vento, utilizando o software Windographer©, utilizando as técnicas exploratórias para a distribuição de Weibull, descrevendo assim os parâmetros estatísticos das estacoes nas principais áreas da cidade. Da mesma forma, foram feitas rosas de vento por temporada, usando o software WRPLOT ™; e, finalmente, foi feito um mapa vetorial usando o método de interpolação Co-Kriging, usando o sistema de informação geográfica ArcGis®. Observando que o regime de circulação atmosférica em Bogotá está intimamente relacionado com a presença dos montes orientais e predominância de ventos alísios; da mesma forma, verificou-se que a maior velocidade do vento é apresentada na região sudeste, e as magnitudes mais fracas, ao norte e nas proximidades das colinas orientais.

Study on low temperature moisture regain drying characteristics of different grades of Angelicae Sinensis Radix based on Weibull distribution function / 中国中药杂志

The drying process of different grades of Angelicae Sinensis Radix under low temperature and resurgence conditions was simulated based on the Weibull distribution function,in order to clarify the low-temperature moisture regain drying characteristics of different grades of Angelicae Sinensis Radix,and explore the effect of grade and drying conditions on the drying process of Angelicae Sinensis Radix. Research results indicated that the Weibull function can be used to simulate different grades of Angelicae Sinensis Radix low-temperature moisture regain drying process,and the lower the drying temperature,the smaller the grade,and the better the simulation effect. The grade and drying temperature showed a significant effect on the low-temperature moisture regain drying process of Angelicae Sinensis Radix,and the effect of temperature on the relative moisture regain rate of Angelicae Sinensis Radix was greater than the grade. The relative moisture regain rate of different grades of Angelicae Sinensis Radix at 40 ℃ was higher than 55 ℃,and the relative moisture regain rate at 40 ℃ was first class > second class > third class. After drying,the moisture ratio at 40 ℃ was lower than that at 55 ℃; the effect of the grade on the effective diffusion coefficient of dry water was greater than the temperature. Under different conditions of 40 ℃ and 55 ℃ moisture regain,the effective diffusion coefficient of water was between 2. 941 6×10-6-7. 991 5×10-6 and3. 093 8×10-6-8. 483 8×10-6 for different grades. Under the same temperature conditions,the effective diffusion coefficient of water was first class > second class > third class. Therefore,Weibull function can be used to study and simulate the drying characteristics of different grades of Angelicae Sinensis Radix under low-temperature moisture regain conditions,providing experimental basis for the improvement of traditional drying technology of Angelicae Sinensis Radix and the optimization of drying process of different specifications or grades of Angelicae Sinensis Radix.

Study on Weibull function simulation and drying characteristics of Angelicae Sinensis Radix drying based on low temperature and resurgence conditions / 中草药

Objective: To clarify the effects of low temperature and dry in shade on the drying process of Angelicae Sinensis Radix (ASR), the drying and regain characteristics of ASR under low temperature drying and low temperature resurgence drying conditions were studied. Methods: Weibull distribution function and 1stOpt software were used to simulate the functional model of ASR under low temperature dry and low temperature (40, 55 ℃) resurgence conditions, analyze model parameters, drying curve, relative dry moisture regain, moisture effective diffusion coefficient (Deff), dry activation energy and other indicators, and compare the drying characteristics of ASR under low temperature dry and low temperature resurgence drying conditions. Results: Both low temperature drying and low temperature resurgence drying methods can make ASR dry, while low temperature resurgence drying method can greatly shorten the drying cycle of ASR, the Weibull function model and the linear regression fitting equation result meet the requirements. The Deff of ASR under low temperature drying conditions was 0.209 59 mm2/h, and the Deff under low temperature resurgence and drying conditions was between 4.489 40-4.566 90 mm2/h, the dry activation energy under low temperature drying condition was 80.75 kJ/mol. Conclusion: The low temperature resurgence drying method has obvious advantages over the traditional low temperature drying, this research can provide theoretical and technical basis for improving the traditional low temperature drying technology of ASR and establishing a new drying method suitable for the processing of ASR origin.

Far infrared drying characteristics and kinetics of Angelicae Sinensis Radix slices / 中草药

Objective: Taking Angelicae Sinensis Radix (ASR) slices as the research object, the far infrared drying characteristics and kinetic model of ASR slice were explored, which provided a theoretical basis for improving the quality of dry products and establishing a suitable processing method. Methods: The far-infrared drying technique was applied to the drying of ASR. The far-infrared drying characteristics and dry product quality of ASR were studied under different drying temperature, slice thickness and irradiation height, and the Weibull function was used to fit the drying curve. The quantitative relationship between test factors and model parameters were established. Results: With the increase of drying temperature and the decrease of the slice thickness and the irradiation height, the water ratio was decreased significantly, and the drying rate was increased significantly. The far-infrared drying process of the ASR slice obeyed the Weibull distribution function (R2 = 0.983 34-0.999 34, χ2 = 0.001 3-0.006 5), both the size parameter and the shape parameter were related to the drying temperature, slice thickness and irradiation height; The interval for estimating the water diffusion coefficient (Dcal) was 4.698 × 10-11-2.084 × 10-10 m2/s. The effective moisture diffusion coefficient (Deff) was in the range of 3.891 × 10-9-2.179 2 × 10-8 m2/s, both of which tended to increase with the increase of drying temperature, slice thickness and irradiation height. Compared with dry products from hot-hair drying, the color difference and water activity of far infrared drying were smaller, and it was easier to retain ferulic acid and volatile oil in ASR. Scanning electron microscopy analysis of the microstructure of dry products under different drying conditions showed that far infrared increased the interior of ASR slices. The number of micropores was increased, the cells were arranged more neatly, so as to increase the rate of thermal mass migration during the drying process and reduce the drying time. Conclusion: The Weibull distribution function can predict the water migration law of the drying process of ASR. It is of great significance for the prediction of the drying process of ASR and the process optimization.

Analysis of Time-to-Onset and Onset-Pattern of Drug-Induced Blood Disorders with Monoclonal Antibody Agents / 医薬品情報学

Objectives: The aim of this study was to investigate both the time‐to‐onset and the onset‐pattern of drug‐induced blood disorders (DIBD) following the administration of monoclonal antibody agents through the use of the spontaneous adverse reaction reporting system of the Japanese Adverse Drug Event Report （JADER) database.Methods: Data in the JADER database from April 2004 to October 2017 were downloaded from the Pharmaceuticals and Medical Devices Agency website.　The DIBD dataset for monoclonal antibody agents was constructed based on the data for the drug information and adverse drug reactions.　The information for the adverse drug reactions was categorized in accordance with the preferred terms of the Medical Dictionary for Regulatory Activities and included thrombocytopenia, platelet count decreased, neutropenia, neutrophil count decreased, leukopenia, white blood cell count decreased, pancytopenia, anaemia, agranulocytosis, granulocyte count decreased, granulocytopenia, and bone marrow failure.　This dataset was then used to calculate the median onset times for the DIBD and the Weibull distribution parameters.Results: The median onset times of the DIBD for gemtuzumab ozogamicin, cetuximab, ramucirumab, trastuzumab, panitumumab, bevacizumab, infliximab, rituximab, trastuzumab, and ibritumomab tiuxetan (90Y) were 4, 10, 13, 14, 14, 14, 16, 16, 27, and 28 days, respectively.　The Weibull distributions for cetuximab, trastuzumab, bevacizumab, infliximab, and tocilizumab were estimated to fit the early failure type profile, while those for gemtuzumab ozogamicin, ramucirumab, rituximab, and ibritumomab tiuxetan (90Y) were estimated to fit the wear out failure type profile.　The Weibull distributions for panitumumab were estimated to fit the random failure type profile.Conclusions: The results of the present study clarified both the most likely time period and the onset‐pattern of DIBD that can occur in patients after the administration of monoclonal antibody agents.

Modelación de distribuciones novedosas para la representación del Clutter de Radar / Modelagem de distribuições inovadoras para a representação da Clutter Radar / Modeling Innovative Distributions for Radar Clutter Representation

Resumen El clutter es una señal interferente causada por la reflexión de la emisión del radar sobre la superficie que rodea al blanco. Tradicionalmente, se han utilizado las distribuciones K, Weibull, Log-Normal, Rayleigh y Pareto para representar el comportamiento del clutter sin embargo, varios estudios han señalado la aplicación de otras alternativas novedosas que pudieran ser más adecuadas que las distribuciones tradicionales. Este artículo presenta la modelación de tres alternativas novedosas, las distribuciones Log-Weibull, Pearson (Lévy) y Lomax, en un conjunto de funciones informáticas de MATLAB. El código implementado permite un acceso fácil a la manipulación de las funciones de densidad y distribución, a la generación de variables aleatorias, al cálculo de los momentos y a la estimación de los parámetros de las distribuciones abordadas. La implementación está concebida para brindar a la comunidad de radares herramientas de simulación de la respuesta de los detectores de radar ante un amplio rango de condiciones de operación, lo cual permite la creación de nuevos mecanismos de procesamiento. Asimismo, se viabiliza el estudio del eco electromagnético que se obtiene de las superficies terrestres y marinas, con posibles aplicaciones medioambientales. El código creado formará parte de la librería MATE-CFAR 2 que incluirá varias distribuciones de clutter y detectores de radar.

Abstract The clutter is a distortion signal caused by the reflection of the radar emission on the surface surrounding the target. Traditionally, the K, Weibull, Log-Normal, Rayleigh and Pareto distributions have been used for representing the clutter behavior; however several studies have pointed out the application of other innovative alternatives that may be best suited than the traditional distributions. This paper presents the modeling of three innovative alternatives: the Log-Weibull, the Pearson (Lévy) and the Lomax distributions, in a set of MATLAB functions. The implemented code provides an easy access to the handling of density and accumulative distribution functions, to the generation of random variables, to the computation of moments and to the estimation of the parameters of the addressed distributions. The implementation is conceived for providing the radar community with a tool for simulating the response of radar detectors against a wide range of operating conditions, which allows the creation of new processing mechanisms. Likewise, the investigation contributes to the study of the electromagnetic echo received form the ground and sea surfaces, with possible environmental applications. The created code will be assembled into the MATE-CFAR 2 library that will include several clutter distributions and radar detectors.

Resumo A clutter é uma comunicação de sinal pela reflexão da emisão do radar sobre a superfície que rodea ao branco. Tradicionalmente, utilizou as distribuições K, Weibull, Log-Normal, Rayleigh e Pareto para representar o comportamento da confusão; Sin embargo, vários estudos têm designado o uso de outras alternativas novedosas que contribuem para a garantia de reparações tradicionais. Este artigo apresenta a modelagem de três alternativas novedosas, as distribuições Log-Weibull, Pearson (Lévy) e Lomax, em conjunto de funções informáticas de MATLAB. O código implementado permite um acesso fácil à manipulação das funções de densidade e distribuição, uma geração de aleatorias de variáveis, uma avaliação dos momentos e uma estimativa dos parâmetros das distribuições abordadas. A implementação está projetada para brindar a comunidade de radares ferramentas de simulação de resposta de detectores de radar ante um amplio alcance de condições de operação, por favor permita a criação de novos mecanismos de processamento. Além disso, é possível viabilizar o estudo do eletro-eletromagnético eletrico que se ocupa das superfícies terrestres e marítimas, com possíveis aplicações meioambientales. O código criado formará parte da libração MATE-CFAR 2 que inclui várias distribuições de clutter e detectores de radar.

Characterization and in vitro release of Periplaneta americana-loaded nanoparticles / 中草药

Objective: To prepare Periplaneta americana extract CII-3-loaded nanoparticles for oral administration, and to investigate the in vitro release profile of CII-3-loaded nanoparticles and the protection of nanoparticles for CII-3 extract in vitro. Methods: The in vitro release behavior of the CII-3-loaded nanoparticles was carried out in the artificial gastric juice, artificial intestinal juice, and pH 7.4 PBS, and the fitting of different models was performed based on the accumulative drug release percentages observed by Folin-reagent method; The amino acid content of CII-3 and CII-3-loaded nanoparticles at different time points in artificial gastric juice was determinated by ninhydrin colorimetry and degradation rates of the two drugs were compared. Results: The mean size of the resulted nanoparticles was about (109.9 ± 0.6) nm and the Zeta potential was (-37.5 ± 3.5) mV; The accumulative release level of CII-3-loaded nanoparticles Qt was (22.63 ± 1.17)% in the artificial gastric juice in the first 2 h, and then, in the artificial intestinal juice, the accumulative release level of CII-3-loaded nanoparticles over a period of 60 h was (72.35 ± 1.90)%, which was in line with Higuchi model release equations, Qt = 8.287 2 t1/2 + 7.758 6. The accumulative release level of CII-3-loaded nanoparticles was (72.67 ± 1.65)% over a period of 10 d, which was in line with Weibull equation, lnln[1/(1-Qt)] = 0.403 7 ln(t-0.411 9)-1.713 3; The CII-3 was completely degraded in 4 h in the artificial gastric juice, while about 70% of CII-3 contained in nanoparticles was degraded. Conclusion: CII-3-loaded nanoparticles have a satisfactory sustained in vitro release effect, and the stability of CII-3 contained in the nanoparticles is improved in the artificial gastric juice.

The gamma-Weibull distribution revisited

The five parameter gamma-Weibull distribution has been introduced by Leipnik and Pearce (2004). Nadarajah and Kotz (2007) have simplified it into four parameter form, using hypergeometric functions in some special cases. We show that the probability distribution function, all moments of positive order and the characteristic function of gamma-Weibull distribution of a random variable can be explicitely expressed in terms of the incomplete confluent Fox-Wright Psi-function, which is recently introduced by Srivastava and Pogány (2007). In the same time, we generalize certain results by Nadarajah and Kotz that follow as special cases of our findings.

A distribuição gamma-Weibull a cinco parâmetros foi introduzida for Leipnik e Pearce (2004). Nadarajah e Kotz (2007) a simplificaram para uma forma a quatro parâmetros usando funções hipergeométricas em alguns casos especiais. Nós mostramos que a função de distribuição cumulativa, todos os momentos de ordem positiva e a função característica da distribuição gamma-Weibull de uma variável randômica pode ser explicitamente expressa em termos da função-Psi de Fox-Wright confluente incompleta, recentemente introduzida por Srivastava and Pogány (2007). Ao mesmo tempo, generalizamos certos resultados de Nadarajah e Kotz que decorrem como casos especiais de nossos achados.