Abstract
This research was motivated by the low ability of creative thinking in mathematics and students’ self-confidence. This study aims to compile a didactic vector mathematical design to develop ...students’ creative thinking skills and self-confidence. This type of research is Didactic Design Research (DDR). The participants were 50 Year 12 students and 24 Year 10 science students. Data collection on learning obstacle was carried out on Year 12 students using tests, interviews, and textbook analysis. It was found that most students had didactical obstacles. Students had low creative thinking ability, and students with mathematical skills low had low self-confidence. The didactic design was implemented online twice for Year 10 students using the zoom meeting application and google classroom. Students’ creative thinking skills develop well for questioning and guessing and product improvement. Most of the students’ self-confidence is in good condition. Further research should provide an explanation of the related material before the test, make a didactic design using e-learning, add formulas for student activities, and provide examples and explanations for each completion step.
Purpose:
To describe and mathematically validate the superiorization methodology, which is a recently developed heuristic approach to optimization, and to discuss its applicability to medical physics ...problem formulations that specify the desired solution (of physically given or otherwise obtained constraints) by an optimization criterion.
Methods:
The superiorization methodology is presented as a heuristic solver for a large class of constrained optimization problems. The constraints come from the desire to produce a solution that is constraints-compatible, in the sense of meeting requirements provided by physically or otherwise obtained constraints. The underlying idea is that many iterative algorithms for finding such a solution are perturbation resilient in the sense that, even if certain kinds of changes are made at the end of each iterative step, the algorithm still produces a constraints-compatible solution. This property is exploited by using permitted changes to steer the algorithm to a solution that is not only constraints-compatible, but is also desirable according to a specified optimization criterion. The approach is very general, it is applicable to many iterative procedures and optimization criteria used in medical physics.
Results:
The main practical contribution is a procedure for automatically producing from any given iterative algorithm its superiorized version, which will supply solutions that are superior according to a given optimization criterion. It is shown that if the original iterative algorithm satisfies certain mathematical conditions, then the output of its superiorized version is guaranteed to be as constraints-compatible as the output of the original algorithm, but it is superior to the latter according to the optimization criterion. This intuitive description is made precise in the paper and the stated claims are rigorously proved. Superiorization is illustrated on simulated computerized tomography data of a head cross section and, in spite of its generality, superiorization is shown to be competitive to an optimization algorithm that is specifically designed to minimize total variation.
Conclusions:
The range of applicability of superiorization to constrained optimization problems is very large. Its major utility is in the automatic nature of producing a superiorization algorithm from an algorithm aimed at only constraints-compatibility; while nonheuristic (exact) approaches need to be redesigned for a new optimization criterion. Thus superiorization provides a quick route to algorithms for the practical solution of constrained optimization problems.
Monolithic scintillator detectors can offer a combination of spatial resolution, energy resolution, timing performance, depth-of-interaction information, and detection efficiency that make this type ...of detector a promising candidate for application in clinical, time-of-flight (TOF) positron emission tomography (PET). In such detectors the scintillation light is distributed over a relatively large number of photosensor pixels and the light intensity per pixel can be relatively low. Therefore, monolithic scintillator detectors are expected to benefit from the low readout noise offered by a novel photosensor called the digital silicon photomultiplier (dSiPM). Here, we present a first experimental characterization of a TOF PET detector comprising a 24 × 24 × 10 mm(3) LSO:Ce,0.2%Ca scintillator read out by a dSiPM array (DPC-6400-44-22) developed by Philips Digital Photon Counting. A spatial resolution of ~1 mm full-width-at-half-maximum (FWHM) averaged over the entire crystal was obtained (varying from just below 1 mm FWHM in the detector center to ~1.2 mm FWHM close to the edges). Furthermore, the bias in the position estimation at the crystal edges that is typically found in monolithic scintillators is well below 1 mm even in the corners of the crystal.
Abstract
Achievement emotions have an important role in students’ Mathematics learning outcomes. The dynamic of achievement emotions in mathematics learning evaluation is very important to be ...considered by the teachers so that students’ academic achievement can be improved. This study was conducted to investigate female students’ achievement emotions in mathematical problem-solving situations. The study involved 50 seventh grade female students selected by using purposive sampling technique. The data were collected through achievement emotions questionnaires and mathematical problem-solving ability tests. The data were analyzed using Wilcoxon test and Kendal’s Tau correlation test. The findings indicated that mathematical problem-solving situation gave significant small negative effect in decreasing students’ joyful emotion. Moreover, it also gave significant small positive effect in increasing students’ depressed emotion. In addition, there was a significant moderate correlation between mathematical problem-solving ability and students’ joyful emotions after the test. Based on the findings, Mathematics teachers were recommended to take control over the students and improve students’ perceived control and confidence value during Mathematics evaluation so that their emotional condition could be well-controlled. Therefore, they could acquire good achievement and the learning objectives could be attained.
Background Obesity and asthma often coexist. We hypothesized that detailed body fat distribution measures might be more strongly associated than body mass index (BMI) with childhood asthma. Objective ...We examined the associations of total body and abdominal fat measures with respiratory resistance (Rint), fractional exhaled nitric oxide (F eno ), and risks of wheezing and asthma in school-aged children. Methods In a population-based prospective cohort study among 6178 children aged 6 years, we measured BMI, fat mass index, android/gynoid ratio, and preperitoneal and subcutaneous fat mass by physical examinations, dual-energy x-ray absorptiometry, and ultrasound, respectively. We performed Rint and F eno measurements, and assessed physician-diagnosed wheezing and asthma by questionnaires. Results A higher BMI was associated with a higher Rint ( Z score 95% CI, 0.06 0.01-0.12) and increased risk of wheezing (odds ratio 95% CI, 1.07 1.00-1.14, per Z score BMI increase), but not with F eno or asthma. A high fat mass index was associated with a higher Rint ( Z score 95% CI, 0.40 0.13-0.68). A high android/gynoid fat mass ratio was associated with a lower F eno (Sym% 95% CI, −9.8 −16.3 to −3.4), whereas a high preperitoneal fat mass was associated with a higher F eno (Sym% 95% CI, 6.5 0.1-12.9). Subcutaneous fat mass was not associated with any respiratory outcome. Conclusions Studying detailed body fat distribution measures might provide better insight into the obesity-asthma paradigm.
Abstract
Visualization is a mental act representing a visual information. In solving geometry problem, we need visualization to identify and illustrate the information. This study aimed to analyse ...student visualization in solving the reflection problems. We studied a female high school athlete at grade eleven. There were three steps in this study. First, we designed two reflection problems. Next, we assessed and interviewed her by semi structure interviewed. Finally, we analysed student spatial visual comparing to types of visualization by Presmeg. Lot of athletes do not have time enough in learning about some topic in their class, so we have to find an appropriate approach to led her in learning activity for creating an efective learning. We found that she has two types of visualization that are pattern imagery and kinaesthetic imagery. In the future, we can design instructional tasks that are convenient for this visualizer.
Aligned unidirectional collagen scaffolds may aid regeneration of those tissues where alignment of cells and extracellular matrix is essential, as for instance in cartilage, nerve bundles, and ...skeletal muscle. Pores can be introduced by ice crystal formation followed by freeze-drying, the pore architecture reflecting the ice crystal morphology. In this study we developed a wedge-based system allowing the production of a wide range of collagen scaffolds with unidirectional pores by directional freezing. Insoluble type I collagen suspensions were frozen using a custom-made wedge system, facilitating the formation of a horizontal as well as a vertical temperature gradient and providing a controlled solidification area for ice dendrites. The system permitted the growth of aligned unidirectional ice crystals over a large distance (>2.5 cm), an insulator prolonging the freezing process and facilitating the construction of crack-free scaffolds. Unidirectional collagen scaffolds with tunable pore sizes and pore morphologies were constructed by varying freezing rates and suspension media. The versatility of the system was indicated by the construction of unidirectional scaffolds from albumin, poly(vinyl alcohol) (a synthetic polymer), and collagen-polymer blends producing hybrid scaffolds. Macroscopic observations, temperature measurements, and scanning electron microscopy indicated that directed horizontal ice dendrite formation, vertical ice crystal nucleation, and evolutionary selection were the basis of the aligned unidirectional ice crystal growth and, hence, the aligned unidirectional pore structure. In conclusion, a simple, highly adjustable freezing system has been developed allowing the construction of large (hybrid) bioscaffolds with tunable unidirectional pore architecture.
This article discusses the gesture of slow learner students in solving the problem of mathematical communication. Gesture aims to understand and deepen the thinking process of students who have ...difficulty conveying ideas either with oral or written. This research is a qualitative research. Data were collected by giving two items of mathematical communication test to a fourth-grade slow learner student of elementary school, then the student gesture was observed through video recording which was obtained when students did the question. The results of this study reveal the pattern of slow learner gesture, i.e.: Iconic gesture: using the fingers and toes in counting. Representational gesture: the student could not answer a question with a clear rational, student was less able to explain her ideas, but did not feel embarrassed to ask. Writing gesture: student could write her ideas in writing after a given direction, but she still made a mistake in writing the mathematical symbols (like numbers) and forgot to write arithmetic operations (addition operation). For further research it is necessary to look at gestures with a greater number of samples and variations, both in terms of gender, grade, or cases of other children with Special Needs.
This study aims to determine the mathematical critical thinking skills and the level of self-confidence of high school students in solving vector problems. Mathematical critical thinking skills and ...self-confidence are basic capital that students must have, so students are confident in solving each vector problem based on critical thinking processes. The type of this research was a qualitative descriptive. Participants in this study were high school students of class X IPA in a public high school in Cimahi city, consisting of 30 students who were determined by purposive sampling technique. The instruments in this study were researchers as the main instruments and supporting instruments, namely a test of mathematical critical thinking skills, a self-confidence questionnaire, and an interview guideline. The results are students have low critical thinking skills and medium self-confidence. The low of critical thinking is indicated by students unable to provide reasons, evaluate answers and identify data/concepts/definitions. Suggestions for further research are habituation of students with mathematical critical thinking skills.
Asthma exacerbations are among the most frequent causes of hospitalization during childhood, but the underlying mechanisms are poorly understood. We performed a genome-wide association study of a ...specific asthma phenotype characterized by recurrent, severe exacerbations occurring between 2 and 6 years of age in a total of 1,173 cases and 2,522 controls. Cases were identified from national health registries of hospitalization, and DNA was obtained from the Danish Neonatal Screening Biobank. We identified five loci with genome-wide significant association. Four of these, GSDMB, IL33, RAD50 and IL1RL1, were previously reported as asthma susceptibility loci, but the effect sizes for these loci in our cohort were considerably larger than in the previous genome-wide association studies of asthma. We also obtained strong evidence for a new susceptibility gene, CDHR3 (encoding cadherin-related family member 3), which is highly expressed in airway epithelium. These results demonstrate the strength of applying specific phenotyping in the search for asthma susceptibility genes.
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