An Improved Temperature Compensation Method for Fiber Bragg Grating Pressure Sensor Based on Extreme Learning Machine

According to the problem of the sensor nonlinear changes occur at high temperatures, extreme learning machine model, is presented in this thesis the pressure sensitive grating and removing the temperature of the grating experiment data for training, establish a nonlinear model of wavelength, temperature, predict the experimental temperature, then the temperature data of pressure-sensitive grating the training set of training samples, the nonlinear model, temperature - wavelength prediction test set sample output wavelength, achieve the goal of improved temperature compensation method. The experimental results show that the algorithm can achieve a more ideal temperature compensation effect.

U-Net-Based Surrogate Model for Evaluation of Microfluidic Channels

Microfluidics have shown great promise in multiple applications, especially in biomedical diagnostics and separations. While the flow properties of these microfluidic devices can be solved by numerical methods such as computational fluent dynamics (CFD), the process of mesh generation and setting up a numerical solver requires some domain familiarity, while more intuitive commercial programs such as fluent and StarCCM can be expensive. Hence, in this work, we demonstrated the use of a U-Net convolutional neural network as a surrogate model for predicting the velocity and pressure fields that would result for a particular set of microfluidic filter designs. The surrogate model is fast, easy to set-up and can be used to predict and assess the flow velocity and pressure fields across the domain for new designs of interest via the input of a geometry-encoding matrix. In addition, we demonstrate that the same methodology can also be used to train a network to predict pressure based on velocity data, and propose that this can be an alternative to numerical algorithms for calculating pressure based on velocity measurements from particle image velocimetry measurements. Critically, in both applications, we demonstrate prediction test errors of less than 1%, suggesting that this is indeed a viable method.

An Analysis of the Students’ Difficulties in TOEFL Prediction Test of Listening Section

This study is to know the students’ difficulty in doing the TOEFL prediction test, especially the listening section in ITB AAS Indonesia. This study uses descriptive qualitative research by using a questionnaire. The result shows that the students’ difficulty in doing TOEFL listening both external and internal factors. In external factors, include: 1) the speaker's accent (75.5 %), 2) the speakers’ speed (75.9 %), 3) the speakers’ intonation/emphasis (73 %), 4) the speakers’ pause in pronouncing a sentence (70.3 %), 5) the choice of words and foreign terms conveyed by the speaker (71 %), 6) the sentence structure conveyed by the speaker is too complex (54.8 %), 7) audio interruption causes the audio sounds less/unclear (54.8 %). In internal factors, include: 1) 64.3 % of students do not have previous experience doing TOEFL test, 2) 58.5 % of students have lack of practice in TOEFL listening, 3) 78.8 % of students have limited time in doing TOEFL listening test, 4) 62.2 % of students feel a lot of listening questions which consist of 50 questions, 5) 76.2 % of students do not have hearing impairment in listening, 6) 51 % of students have memory limitations when listening to TOEFL, 7) 48.1 % of students lack of motivation and enthusiasm, 8) 52.7 % of students lack of concentration or focus, 9) 53.5 % of students have limited mastery of foreign/unfamiliar vocabularies, 10) 47.3 % of students feel boredom when listening, 11) 56 % of students feel easily distracted by sounds or other things, 12) 51 % of students tend to translate any foreign vocabularies when listening, 13) 52.7 % of students have trouble catching or finding keywords, 14) 44.4 % of students are busy along with other activities when listening, such as playing writing instruments, taking notes or doing other things. Keywords: Listening, TOEFL, TOEFL Prediction Test

ПИСАЊЕ КОД ДЕЦЕ СА СМЕТЊАМА У РАЗВОЈУ

The paper presents the results of a study aimed at examining the ability and level of writing proficiency in students with disabilities at primary school age. The sample consisted of 58 students with disabilities of primary school age. Dysgraphic Prediction Test and Lilien Lirs graphomotor array were used to assess visual perception and graphomotor skills, while the handwriting was evaluated by the Scale for Assessment of Dysgraphic Forms in handwriting. The obtained results show that a large number of subjects (24 or 41,4%) did not score a single point on Dysgraphic Prediction Test, while only 21 subjects (36,2%) successfully completed the test (M = 7,98, SD = 7,062). Also, the obtained results show that the highest number of respondents (39 or 67,2%) did not score a single point on the Lilian Lirs test, while only 10 respondents or 17,2% successfully completed the test (M = 1,60, SD = 2,46). Using the Scale for the Assessment of Dysgraphic Forms in handwriting, we found that out of 22 written samples, 9 students (41%) have a well-developed handwriting, 8 (36%) have an ugly handwriting, 3 (14%) respondents have dysgraphic handwriting, while 2 (9%) respondents have a pronounced dysgraphic handwriting. Out of the total number of respondents, 36 (62%) of the sample students could not write the appropriate text on the basis of which the sample of the handwriting was taken. The obtained results provide the exact knowledge of the presence of difficulties in adopting writing by students with disabilities.Teaching students with disabilities, according to the results obtained, imperatively imposes the need to respect the developmental characteristics of this population of students and the individualization of the initial teaching of writing. This involves major changes to the standards and outcomes of achievements required by the regular curriculum and the development of an IOP for each student with more complex individualized contents to support the child in order to adopt writing. However, effective work with this student population also entails the need to adopt special curricula intended for teaching in schools for students with disabilities.

Influence of natural discontinuities and mechanical properties on the fragmentation of marble by blasting in Central Africa

This research focuses on the influence of natural discontinuities and mechanical properties in the fragmentation of marble by blasting. These natural discontinuities and mechanical properties are the parameters which are difficult to control and which considerably influence the fragmentation of marble after blasting. This paper aims at predicting the fragmentation of the Bidzar quarry rock, the only marble quarry in Central Africa, while improving the knowledge on it. This quarry has been facing problems of fragmentation of marble blocks for decades, which requires secondary firing and incurs enormous costs. The Kuz-Ram method was used for this study. The dip of the discontinuity planes, the compressive strength, the distance between the discontinuities and the density of the discontinuities are the operational parameters that were used to study the influence of natural discontinuities and the mechanical properties of the rocks on the fragmentation after firing. This work consists precisely in studying the pullability as a function of the dip of the discontinuity planes, then the fragmentation as a function of the powder factor, the compressive strength and the drilling mesh. The results of this study were compared with those of the other authors. Qualitative and quantitative studies were carried out in order to highlight the influence of natural discontinuities and mechanical characteristics on fragmentation. The fragmentation pattern of the Bidzar quarry was examined and compared with those obtained in other regions of the world, namely, Northern Europe, Central America, South-East Asia and West Africa. The variation in the intensity of fragmentation caused on the one hand by differences in the dips of the firing planes and their compressive strength, and on the other hand by the variation in the drilling mesh was also discussed. The prediction test was carried out with seven plans of existing discontinuities in the Bidzar quarry and at different mesh sizes in order to estimate the distribution of the fragments of marble thatcan through the crsuher after being fired. Several suggestions were put forward for the evaluation of the fragmentation. Three practical tables were created to predict the result of the shot. The specific graphs, which were proposed to analyse fragmentation in this quarry, made it possible to assess the quantity of fragments passing through the crusher after firing. Predicting fragmentation by considering the dip of the firing planes and the powder factor can effectively optimise the fragmentation of the rocks by blasting and achieve the desired result.

Development and validity of a hazard prediction test for Chinese drivers

Background Hazard perception ability, which develops with driving experience, has been proven to be associated with drivers' traffic involvement. Although classic reaction time-based hazard perception tests have been developed in many developed counties, experience-related differences may not be found in drivers from developing countries due to their increased opportunities to experience hazards on roads. Therefore, the present study aims to develop a hazard prediction test for Chinese drivers based on a predictive paradigm called “What happens next?” and assess its reliability and validity. Method Thirty-six video clips filmed from drivers’ perspectives of Chinese driving settings were presented to 54 novice drivers and 47 experienced drivers. Participants were asked to answer three questions after each video clip was blacked out and to then quickly press the mouse button on a reaction time-based hazard perception test. Both the differences in the test scores between novice and experienced drivers and the differences in scores between drivers with and without traffic violations were compared. Results The final hazard prediction test consisted of 20 video clips. A high internal consistency coefficient of the test, i.e., Cronbach's alpha = 0.862, was obtained. The total scores of the test were positively and significantly correlated with reaction times as measured on the video-based hazard perception test, thus providing evidence regarding the discriminant validity of the test. More importantly, drivers with traffic violations obtained significantly lower total scores on the test than did drivers without traffic violations. Conclusion The newly developed hazard prediction test exhibited adequate psychometric properties and provided a practical alternative for assessing drivers’ hazard perception ability in China.