A case study of condition-based maintenance modeling based upon the vibration analysis data of wind machines

Author(s):  
Wenbin Wang ◽  
Xiaoyang Ma
2021 ◽  
Vol 11 (11) ◽  
pp. 4982
Author(s):  
Anahita Davoodi ◽  
Peter Johansson ◽  
Myriam Aries

Validation of the EBD-SIM (evidence-based design-simulation) framework, a conceptual framework developed to integrate the use of lighting simulation in the EBD process, suggested that EBD’s post-occupancy evaluation (POE) should be conducted more frequently. A follow-up field study was designed for subjective–objective results implementation in the EBD process using lighting simulation tools. In this real-time case study, the visual comfort of the occupants was evaluated. The visual comfort analysis data were collected via simulations and questionnaires for subjective visual comfort perceptions. The follow-up study, conducted in June, confirmed the results of the original study, conducted in October, but additionally found correlations with annual performance metrics. This study shows that, at least for the variables related to daylight, a POE needs to be conducted at different times of the year to obtain a more comprehensive insight into the users’ perception of the lit environment.


2021 ◽  
Vol 296 ◽  
pp. 126420
Author(s):  
Emilia Ingemarsdotter ◽  
Marianna Lena Kambanou ◽  
Ella Jamsin ◽  
Tomohiko Sakao ◽  
Ruud Balkenende

Author(s):  
Jaroslav Smutny ◽  
Viktor Nohal ◽  
Daniela Vukusicova ◽  
Herbert Seelmann

This paper deals with description and application of the Wigner-Ville transformation for vibration analysis. This transformation belongs to the group of non-linear time-frequency processes. Thanks to its properties, it may be successfully used in the area of non-stationary and transitional signals describing various natural processes. The use in the field of the railway constructions testing represents a quite an interesting application area of the transformation. This paper contains mathematical analysis of the transformation, a case study and practical experience obtained and recommendations for its practical use.


2019 ◽  
Vol 9 (1) ◽  
pp. 87
Author(s):  
Rully Agung Yudhiantara ◽  
Ade Yeti Nuryantini

<span lang="EN-US">This study sought to explore students’ experience in using Instagram to participate in mobile collaborative language learning (MCLL)</span><span lang="EN-US">. T</span><span lang="EN-US">he</span><span lang="EN-US"> contents they </span><span lang="EN-US">produced and shared, a</span><span lang="EN-US">s well as</span><span lang="EN-US"> their interaction and collaboratio</span><span lang="EN-US">n, were analyzed</span><span lang="EN-US">. The participants of this study were </span><span lang="EN-US">110 students in an </span><span lang="EN-US">English education department</span><span lang="EN-US">, in three different classes,</span><span lang="EN-US">who all had taken a </span><span lang="EN-US">translation course</span><span lang="EN-US">their third semester. Online tasks were assigned to students and they were required to produce, share, interact and collaborate to accomplish tasks. This study applied </span><span lang="EN-US">a </span><span lang="EN-US">qualitative method </span><span>with case study research design </span><span lang="EN-US">using observation, focus group discussion and content analysis. Data were analyzed through stages namely categorization, reduction and interpretation. </span><span>Results showed </span><span lang="EN-US">that </span><span>the </span><span lang="EN-US">students were able to participate in MCLL using Instagram. They produced and shared contents that met the requirement of MCLL. The contents include</span><span lang="EN-US">d</span><span lang="EN-US"> English sentences for structural collaboration in terms of subject-verb agreement and English sentences for word meaning collaborations. They interacted with their peer</span><span lang="EN-US">s</span><span lang="EN-US"> by writing feedback and comment</span><span lang="EN-US">s on the uploaded content</span><span lang="EN-US">. They collaborated with their peer</span><span lang="EN-US">s</span><span lang="EN-US"> by providing multiple interactions to accomplish tasks in MCLL like writing structural analysis, word meaning, paraphrasing sentences, and sentence translation.</span>


2020 ◽  
Vol 13 (2) ◽  
pp. 564
Author(s):  
Renata Cristina Mafra ◽  
Mayara Maezano Faita Pinheiro ◽  
Rejane Ennes Cicerelli ◽  
Lucas Prado Osco ◽  
Marcelo Rodrigo Alves ◽  
...  

O processo erosivo é um fenômeno que acontece devido às condições climáticas ou uso inadequado da terra. O mapeamento dos níveis de vulnerabilidade à erosão de uma área pode ocorrer usando diferentes modelos de inferência geográfica. No entanto, definir o método apropriado é ainda uma questão a ser respondida. Este trabalho apresenta uma abordagem de validação de mapa de vulnerabilidade à erosão elaborado por diferentes métodos de inferência. Como estudo de caso, adotou-se uma bacia hidrográfica e considerou-se os seguintes critérios: geomorfologia, pedologia, declividade, densidade de drenagem e cobertura da terra. Dentre os métodos testados tem-se: Combinação Linear Ponderada (CLP) e três operadores Fuzzy: soma algébrica, produto algébrico e gamma, variando o expoente “γ” entre os valores 0,4; 0,6 e 0,8. Os pesos dos critérios foram definidos com base no Processo Analítico Hierárquico. A validação dos mapas ocorreu usando 1902 pontos, sendo 951 pontos de erosão na área, definidos com base em imagens do Google Earth Pro, e 951 pontos sem erosão, gerados aleatoriamente no QGIS 3.8. O modelo de regressão logística foi usado parar comparar o desempenho de cada mapa ao apontar as áreas com maior e menor grau de vulnerabilidade. A melhor modelagem foi alcançada com o operador Fuzzy gamma quando parametrizado com γ = 0,6. Embora o CLP seja a abordagem recorrente em estudos ambientais envolvendo inferência geográfica, nossos resultados demostram que outros operadores podem produzir resultados mais próximos aos encontrados com a realidade observada em campo.  Machine learning erosion and vulnerability map validation A B S T R A C TErosion is a natural phenomenon that happens in all ecosystems, whether due to weather conditions or inappropriate land use. Mapping the erosion vulnerability levels of an area can occur using different methods of geographic inference. However, defining the appropriate method is still a question to be answered. This paper presents an erosion vulnerability map validation approach elaborated by different inference methods. As a case study, a watershed was adopted and the following criteria were considered: geomorphology, pedology, slope, drainage density and land cover. Among the tested methods are: Weighted Linear Combination (WLC) and three Fuzzy operators: algebraic sum, algebraic product and gamma, varying the exponent “γ” between the values 0.4; 0.6 and 0.8. The weights of the criteria were defined based on the Hierarchical Analytical Process. The validation of the maps took place using 1902 points, with 951 erosion points in the area defined based on Google Earth Pro images and 951 points without erosion randomly generated in QGIS 3.8. The logistic regression model was used to compare the performance of each map by pointing out the areas with the highest and lowest degree of vulnerability. The best modeling was achieved with the Fuzzy gamma operator when parameterized with γ = 0.6. Although WLC is the recurring approach in environmental studies involving geographic inference, our results show that other operators can produce results closer to those encountered with the reality observed in the field.Keywords: Geographical inference; multicriteria analysis; data validation; environmental impact.


Author(s):  
I Gusti Ayu Vina Widiadnya Putri

The aims of this study is to find out and analyzed about students’ influences of Computer-assisted assessment (CAA) It is the case study and field research of one school in Nusa Dua Badung-Bali. The data sources chosen in this study were several high schools that carried out online examinations at Nusa Dua Vocational high school Bali-Indonesia. Data collection is done by random sampling from data sources, observation, interviews, recording, and note taking. Distribution of questionnaires was also carried out to strengthen data analysis. Data is analyzed based on the formulation of the problem and the study of theory that has been, then analyzed in qualitative description. The descriptive study used paper-based surveys and interviews for data collection. To obtain information about the students’ influences of Computer-assisted assessment (CAA). Based on our review and study result, there are some influences that found. The Computer-assisted assessment (CAA) systematics is held with the aim that students become more critical and independent in solving the questions given.


2015 ◽  
Vol 4 (2) ◽  
pp. 211
Author(s):  
M. Irfani Hendri ◽  
Indarti Rochayati ◽  
M. Fahmi

This paper is to describe what has been done by the Faculty of Economics UNTAN in growing interest and entrepreneurship skills among students through student activities and currentevaluation tried to offer a development design of student activities with the approach ofpsychological capital that includes (1) the existence of self-confidence (self confidence); (2)positive attribution (optimism); (3) resistance in achieving its objectives with the ability toredefine the path to reach the goal with the ability to redefine the path to peak at the destination ifrequired (hope); and (4) when facing problems and difficulties, able to survive and continueforward (resiliency) to achieve success. The approach taken in this study is qualitative, type ofresearch is a case study. For purposes of analysis, data can be collected using triangulation ofdata collection methods which involves observation, interview documentation and Focus GroupDiscussion (FGD). It can be concluded that the hardest thing in the printing of an entrepreneur isthe mental change that is formed because of the mindset that the synergy of a wide range of ourdaily interactions (family, education, environment, etc.). It is an attempt to solve the mentalproblem needs to be a synergy of various growth entrepreneurship program that has a good andconcrete step in creating the entrepreneurs.


Author(s):  
Anjan Pakhira ◽  
Peter Andras

Testing is a critical phase in the software life-cycle. While small-scale component-wise testing is done routinely as part of development and maintenance of large-scale software, the system level testing of the whole software is much more problematic due to low level of coverage of potential usage scenarios by test cases and high costs associated with wide-scale testing of large software. Here, the authors investigate the use of cloud computing to facilitate the testing of large-scale software. They discuss the aspects of cloud-based testing and provide an example application of this. They describe the testing of the functional importance of methods of classes in the Google Chrome software. The methods that we test are predicted to be functionally important with respect to a functionality of the software. The authors use network analysis applied to dynamic analysis data generated by the software to make these predictions. They check the validity of these predictions by mutation testing of a large number of mutated variants of the Google Chrome. The chapter provides details of how to set up the testing process on the cloud and discusses relevant technical issues.


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