scholarly journals Identifying the structure of students’ argumentation in covariational reasoning of constructing graphs

2020 ◽  
Vol 13 (1) ◽  
pp. 61-80
Author(s):  
Sutini Sutini ◽  
Iffana Fitrotul Aaidati ◽  
Kusaeri Kusaeri
Keyword(s):  
Average Rate ◽  
Rate Of Change ◽  
Interview Data ◽  
The Other ◽  
Mental Action ◽  
Instantaneous Rate ◽  
Covariational Reasoning ◽  
Mental Actions ◽  
Grade 11

[English]: This study aimed to identify students’ claim, evidence, and reasoning in covariational reasoning of constructing the graphs of a function. Covariational reasoning is one of the approaches to solve the problems of function. The study involved thirty grade 11 students. Data was collected through a covariation test and interview. The results of the test were grouped based on the criteria of mental action of covariational reasoning (Carlson et al., 2002), then the students who solve correctly two or three problems in the test were selected as the subjects. The interview data were analyzed to confirm and further dig students' structure of argumentation. The findings of this study indicate that only one student fulfils five mental actions of covariational reasoning; meanwhile, the other three students have similar components of argumentation which do not meet the mental actions. The claim and reasoning used by the latter students in covariational reasoning to construct graph are not identified in mental action 5 and the evidence is not found in mental action 3 (major coordination of change), mental action 4 (coordination the average rate of change), and mental action 5 (coordination of the instantaneous rate of change). Keywords: Argumentation, Claim, Evidence, Reasoning, Covariational reasoning [Bahasa]: Penelitian ini bertujuan untuk mengidentifikasi klaim, bukti, dan alasan siswa pada penalaran kovariasional dalam mengonstruk grafik fungsi. Penalaran kovariasional merupakan salah satu pendekatan dalam menyelesaikan permasalahan fungsi. Penelitian ini melibatkan 30 siswa kelas 11. Pengumpulan data dilakukan menggunakan tes kovariasi dan wawancara. Data hasil hasil tes kovariasi siswa dikelompokkan berdasarkan kriteria aksi mental penalaran kovariasional (Carlson et al., 2002), kemudian dipilih siswa yang mampu menyelesaikan minimal dua soal kovariasi. Data hasil wawancara dianalisis untuk mengonfirmasi dan menggali lebih dalam argumentasi siswa. Hasil penelitian menunjukkan hanya satu siswa yang memenuhi lima aksi mental penalaran kovariasional sedangkan ketiga siswa lain memiliki persamaan komponen argumentasi yang tidak memenuhi aksi mental. Untuk ketiga siswa tersebut, klaim dan alasan yang digunakan dalam membangun grafik fungsi tidak berada pada aksi mental 5 sedangkan bukti tidak berada pada aksi mental 3 (koordinasi besar perubahan), aksi mental 4 (koordinasi laju perubahan rata-rata), dan aksi mental 5 (koordinasi laju perubahan sesaat). Kata kunci: Argumentasi, Klaim, Bukti, Alasan, Penalaran kovariasional

The effect of topdressed superphosphate on changes in nitrogen:carbon:sulphur: phosphorus and pH on a red earth soil during a long term grazing experiment

Soil Research ◽  
1977 ◽  
Vol 15 (2) ◽  
pp. 147 ◽  
Author(s):  
GD Kohn ◽  
GJ Osborne ◽  
GD Batten ◽  
AN Smith ◽  
WJ Lill
Keyword(s):  
Average Rate ◽  
C:N Ratio ◽  
Rate Of Change ◽  
The Other ◽  
Wagga Wagga ◽  
Grazing Experiment ◽  
Rate Of Increase ◽  
Red Earth ◽  
Stocking Rates

Increases in total nitrogen in a grazing experiment at Wagga Wagga (N.S.W.) over the years 1962-1966 were related to the levels of superphosphate applied (0-375 kg ha-1), the average rate of increase being 59 kg ha-1 year-1. The rate of change varied between years and was negative in a dry year. Total sulphur levels were not influenced by phosphate treatments (mean 150 ppm), but sulphate sulphur was only maintained by the highest superphosphate level. Total, aluminium, iron, calcium and 'available' phosphate increased with superphosphate levels. The level of aluminium-bound phosphate increased more rapidly than the other fractions. In the treatments without applied phosphate the aluminium bound phosphate declined more rapidly than the other fractions. Organic carbon was not influenced by treatments but showed an increase with time. The C:N ratio declined from 13 to 11.8 during the experiment. Soil pH declined by 0.18 pH units, but this was not affected by superphosphate levels. Stocking rates had no effect on these parameters of soil fertility.

scholarly journals A calculus student’s understanding of graphical approach to the derivative through quantitative reasoning

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Aytug Ozaltun-Celik
Keyword(s):  
Mathematical Modelling ◽  
Rate Of Change ◽  
Quantitative Reasoning ◽  
First Year ◽  
Instantaneous Rate ◽  
Graphical Approach ◽  
Global View ◽  
Concept Of Function ◽  
Support Students ◽  
Mental Actions

The concept of derivative is used in many areas including applied problems and requiring mathematical modelling in different disciplines. One of the most important approaches for teaching the derivative is to support students in visualizing the concept. Also, it is necessary to shift researchers and teachers’ focuses to students’ dynamic mental actions while learning derivative in order to conduct effective teaching process. With this necessity, I focused on the perspective of quantitative reasoning related to the graphical approach to the derivative. This study aims to reveal a calculus student’s mental actions related to the graphical approach to the derivative. The data were collected from a first-year calculus student engaged in the task requiring graphical interpretation of the derivative. Results showed that the student’s understanding of the slope shaped her inferences about the tangent line because the quantity of ratio is prior knowledge for learning the instantaneous rate of change. Besides, as the student had the idea of correspondence related to the concept of function, she had difficulties in interpreting the global view of the derivate. This result suggests that having global view of the derivative requires a strong understanding of function and rate.

scholarly journals Weight Feedback-Based Harmonic MDG-Ensemble Model for Prediction of Traffic Accident Severity

2021 ◽  
Vol 11 (11) ◽  
pp. 5072
Author(s):  
Byung-Kook Koo ◽  
Ji-Won Baek ◽  
Kyung-Yong Chung
Keyword(s):  
Traffic Accidents ◽  
Average Rate ◽  
Modern Society ◽  
Rate Of Change ◽  
Weighted Voting ◽  
Independent Variables ◽  
Dependent Variables ◽  
Accident Severity ◽  
Harmonic Average ◽  
Bagging Method

Traffic accidents are emerging as a serious social problem in modern society but if the severity of an accident is quickly grasped, countermeasures can be organized efficiently. To solve this problem, the method proposed in this paper derives the MDG (Mean Decrease Gini) coefficient between variables to assess the severity of traffic accidents. Single models are designed to use coefficient, independent variables to determine and predict accident severity. The generated single models are fused using a weighted-voting-based bagging method ensemble to consider various characteristics and avoid overfitting. The variables used for predicting accidents are classified as dependent or independent and the variables that affect the severity of traffic accidents are predicted using the characteristics of causal relationships. Independent variables are classified as categorical and numerical variables. For this reason, a problem arises when the variation among dependent variables is imbalanced. Therefore, a harmonic average is applied to the weights to maintain the variables’ balance and determine the average rate of change. Through this, it is possible to establish objective criteria for determining the severity of traffic accidents, thereby improving reliability.

scholarly journals ON THE MECHANISM OF TONIC IMMOBILITY IN VERTEBRATES

1928 ◽  
Vol 11 (6) ◽  
pp. 715-741 ◽  
Author(s):  
Hudson Hoagland
Keyword(s):  
Tonic Immobility ◽  
Threshold Value ◽  
Temperature Characteristic ◽  
The State ◽  
Rate Of Change ◽  
The Other ◽  
Negative Slope ◽  
Selective Inhibitors ◽  
Initial Stimulus ◽  
Temperature Range

1. The durations of successive periods of induced tonic immobility in the lizard Anolis carolinensis was examined as a function of temperature. An automatic recording method was employed and observations were made of 12,000 to 15,000 immobilizations with six animals over a temperature range of 5° to 35°C. during 5 months. 2. The durations of the immobile periods were found to vary rhythmically in most cases. The reciprocal of the duration of the rhythm, i.e., the rate of change of the process underlying the rhythms, when plotted as a function of temperature according to the Arrhenius equation show distributions of points in two straight line groups. One of these groups or bands of points extends throughout the entire temperature range with a temperature characteristic of approximately µ = 31,000 calories, and the other covers the range of 20° to 35°C. with µ equal to approximately 9,000 calories. 3. The initial stimulus in a series of inductions of immobility appears to set off a mechanism which determines the duration of the state of quiescence. Succeeding forced recoveries seem to have no effect on the normal duration of the rhythm. 4. These results are interpreted by assuming the release, through reflex stimulation, of hormonal substances, one effective between 5° and 35°C. and the other effective between 20° and 35°C. These substances are assumed to act as selective inhibitors of impulses from so called "higher centers," allowing impulses from tonic centers to pass to the muscles. 5. In some experiments a progressive lengthening in successively induced periods of immobility was observed. The logarithm of the frequency of recovery when plotted against time in most of these cases (i.e., except for a few in which irregularities occurred) gave a linear function of negative slope which was substantially unaffected by temperature. In these cases it is assumed that a diffusion process is controlling the amount of available A substance. 6. The results are similar to those obtained by Crozier with Cylisticus convexus. The duration of tonic immobility seems to be maintained in both arthropod and vertebrate by the chemical activity of "hormonal" selective inhibitors. The details of the mechanisms differ, but there is basic similarity. 7. Injections of small amounts of adrenalin above a threshold value are found to prolong the durations of tonic immobility of Anolis, by an amount which is a logarithmic function of the "dose." It is possible that internally secreted adrenalin, above a threshold amount, may be involved in the maintenance of tonic immobility. 8. The production of tonic immobility reflexly is a problem distinct from that of the duration of immobility. It is suggested that the onset may be induced by "shock" to the centers of reflex tonus causing promiscuous discharge of these centers with accompanying inhibition of the higher centers. Such a condition may result when an animal is suddenly lifted from the substratum and overturned, or when, as in the case of Anolis, it struggles with dorsum down. This reaction of the "tonic centers" may at the same time lead to discharge of the adrenal glands by way of their spinal connections thus prolonging the state.

Filtration by superficial and deep glomeruli of normovolemic and volume-depleted rats

1986 ◽  
Vol 250 (1) ◽  
pp. F86-F91
Author(s):  
R. V. Pinnick ◽  
V. J. Savin
Keyword(s):  
Basement Membrane ◽  
Maximum Rate ◽  
Rate Of Change ◽  
The Other ◽  
Membrane Area ◽  
Morphometric Analyses ◽  
Three Samples ◽  
Glomerular Size ◽  
Glomerular Ultrafiltration

We measured glomerular ultrafiltration coefficient (Kf) of isolated superficial (S) and deep (D) glomeruli of normovolemic and volume-depleted rats. Filtration was induced in vitro, and Kf was calculated from the maximum rate of change in glomerular size. Basement membrane area (A) for each glomerulus was estimated from morphometric analyses, and glomerular capillary hydraulic conductivity (Lp) was calculated by the formula Lp = Kf/A. Kf of S and D glomeruli of normovolemic rats were 2.98 +/- 0.98 and 4.25 +/- 0.07 nl . min-1 . mmHg-1, respectively. In hypovolemic rats, Kf of S glomeruli fell by approximately 50% to 1.52 +/- 0.14 nl . min-1 . mmHg-1 (P less than 0.001), whereas Kf of D glomeruli remained unchanged at 4.28 +/- 0.10 nl . min-1 . mmHg-1. Lp, calculated using the peripheral capillary area, averaged 1.98 +/- 0.09 and 1.98 +/- 0.06 microliter . min-1 . mmHg-1 . cm-2 in S and D glomeruli of normovolemic rats and 1.89 +/- 0.11 microliter . min-1 . mmHg-1 . cm-2 in D glomeruli of hypovolemic rats. Lp of S glomeruli of volume-depleted rats (0.90 +/- 0.03 microliter . min-1 . mmHg-1 . cm-2) was lower than in any of the other three samples. Mild hypovolemia causes the Kf of S glomeruli to decline, whereas Kf of D glomeruli remains constant. The decrease in Kf occurs without an alteration in capillary area and is most likely due to a decrease in Lp.

scholarly journals A Comparison of Psychophysical Dose-Response Behaviour across 16 Sweeteners

Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1632 ◽  
Author(s):  
May Wee ◽  
Vicki Tan ◽  
Ciarán Forde
Keyword(s):  
Growth Rate ◽  
Dose Response ◽  
Rate Of Change ◽  
The Other ◽  
Rebaudioside A ◽  
Glycaemic Response ◽  
Sensory Panel ◽  
Response Behaviour ◽  
Sweetness Intensity ◽  
Sugar Replacement

Reduction or replacement of sucrose while maintaining sweetness in foods is challenging, but today there are many sweeteners with diverse physical and caloric compositions to choose from. The choice of sweetener can be adapted to match reformulation goals whether these are to reduce calories, lower the glycaemic response, provide bulk or meet criteria as a natural ingredient. The current study sought to describe and compare the sweetness intensity dose-response, sweetness growth rate, sweetness potency, and potential for calorie reduction across 16 different sweeteners including sucrose. Sweetness growth rate was defined as the rate of change in sweetness intensity per unit of sweetener concentration. Sweetness potency was defined as the ratio of the concentration of a sweetener to that of sucrose at equivalent sweetness intensity, whereas the potential for calorie reduction is the caloric value of a sweetener compared to sucrose at matched sweetness intensities. Sweeteners were drawn from a range of nutritive saccharide (sucrose, dextrose, fructose, allulose (d-psicose), palatinose (isomaltulose), and a sucrose–allulose mixture), nutritive polyol (maltitol, erythritol, mannitol, xylitol, sorbitol), non-nutritive synthetic (aspartame, acesulfame-K, sucralose) and non-nutritive natural sweeteners stevia (rebaudioside A), luo han guo (mogroside V). Sweetness intensities of the 16 sweeteners were compared with a sensory panel of 40 participants (n = 40; 28 females). Participants were asked to rate perceived sweetness intensity for each sweetener series across a range of concentrations using psychophysical ratings taken on a general labelled magnitude scale (gLMS). All sweeteners exhibited sigmoidal dose-response behaviours and matched the ‘moderate’ sweetness intensity of sucrose (10% w/v). Fructose, xylitol and sucralose had peak sweetness intensities greater than sucrose at the upper concentrations tested, while acesulfame-K and stevia (rebA) were markedly lower. Independent of sweetener concentration, the nutritive sweeteners had similar sweetness growth rates to sucrose and were greater than the non-nutritive sweeteners. Non-nutritive sweeteners on the other hand had higher potencies relative to sucrose, which decreases when matching at higher sweetness intensities. With the exception of dextrose and palatinose, all sweeteners matched the sweetness intensity of sucrose across the measured range (3.8–25% w/v sucrose) with fewer calories. Overall, the sucrose–allulose mixture, maltitol and xylitol sweeteners were most similar to sucrose in terms of dose-response behaviour, growth rate and potency, and showed the most potential for sugar replacement within the range of sweetness intensities tested.

Acetyl L-Carnitine Slows Decline in Younger Patients With Alzheimer's Disease: A Reanalysis of a Double-Blind, Placebo-Controlled Study Using the Trilinear Approach

1998 ◽  
Vol 10 (2) ◽  
pp. 193-203 ◽  
Author(s):  
John O. Brooks ◽  
Jerome A. Yesavage ◽  
Angelico Carta ◽  
Daniele Bravi
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Average Rate ◽  
The United States ◽  
Rate Of Change ◽  
Disease Assessment ◽  
Controlled Study ◽  
Double Blind ◽  
Parallel Group ◽  
Longitudinal Effects

Objectives: To assess the longitudinal effects of acetyl-L-carnitine (ALC) on patients diagnosed with Alzheimer's disease. Design: Longitudinal, double-blind, parallel-group, placebocontrolled. Setting: Twenty-four outpatient sites across the United States. Participants: A total of 334 subjects diagnosed with probable Alzheimer's disease by NINCDS-ADRDA criteria. These data were originally reported by Thal and colleagues (1996). Measurements: Cognitive subscale of the Alzheimer Disease Assessment Scale (ADAS) given every 3 months for 1 year. Results: The average rate of change was estimated using the trilinear approach, which allows for periods of both change and stability. Both the ALC group and the placebo group exhibited the same mean rate of change on the ADAS (0.68 points/month). However, a multiple regression analysis revealed a statistically significant Age × Drug interaction characterized by younger subjects benefiting more from ALC treatment than older subjects. Further analyses suggested that the optimal, though not statistically significant, cutpoint for ALC benefit was 61 years of age. Conclusions: ALC slows the progression of Alzheimer's disease in younger subjects, and the use of the trilinear approach to estimate the average rate of change may prove valuable in pharmacological trials.

scholarly journals Comparison of Deep Neural Network Models and Effectiveness of EMG Signal Feature Value for Estimating Dorsiflexion

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2767
Author(s):  
Muhammad Akmal Bin Mohammed Zaffir ◽  
Praveen Nuwantha ◽  
Daiki Arase ◽  
Keiko Sakurai ◽  
Hiroki Tamura
Keyword(s):  
Neural Network ◽  
Average Rate ◽  
Network Models ◽  
Rate Of Change ◽  
Estimation Accuracy ◽  
Neural Network Models ◽  
Emg Signal ◽  
Minimum Number ◽  
Deep Learning Network ◽  
Simple Network

(1) Background: Robotic ankle–foot orthoses (AFO) are often used for gait rehabilitation. Our research focuses on the design and development of a robotic AFO with minimum number of sensor inputs. However, this leads to degradation of gait estimation accuracy. (2) Methods: To prevent degradation of accuracy, we compared a few neural network models in order to determine the best network when only two input channels are being used. Further, the EMG signal feature value of average rate of change was used as input. (3) Results: LSTM showed the highest accuracy. However, MLP with a small number of hidden layers showed results similar to LSTM. Moreover, the accuracy for all models, with the exception of LSTM for one subject (SD), increased with the addition of feature value (average rate of change) as input. (4) Conclusions: In conclusion, time-series networks work best with a small number of sensor inputs. However, depending on the optimizer being used, even a simple network can outrun a deep learning network. Furthermore, our results show that applying EMG signal feature value as an input tends to increase the estimation accuracy of the network.

scholarly journals Pengaruh Gambut Terbakar Terhadap Beberapa Sifat Fisika Gambut di Kecamatan Tripa Makmur

2020 ◽  
Vol 4 (2) ◽  
pp. 416-425
Author(s):  
Teuku Muhammad Afrizal ◽  
Hairul Basri ◽  
Muhammad Rusli Alibasyah
Keyword(s):  
Organic Matter ◽  
Physical Properties ◽  
Water Content ◽  
Statistical Tests ◽  
Peat Soil ◽  
Rate Of Change ◽  
The Other ◽  
Volume Weight ◽  
Top Soil ◽  
Significant Difference

Abstrak. Gambut mengandung bahan organik yang tinggi. Gambut yang didrainase rentan terhadap kebakaran. Pemanfaatan gambut di Aceh sangat luas. Umumnya, gambut sering dibakar agar dapat dengan cepat dimanfaatkan., khususnya di Kecamatan Tripa Makmur Kabupaten Nagan Raya. Penelitian ini bertujuan untuk melihat seberapa jauh tingkat perubahan sifat fisika gambut terbakar Rawa Tripa Kabupaten Nagan Raya. Hasil penelitian menunjukkan bahwa rata-rata berat volume tertinggi terdapat pada sampel T1 (top soil) yaitu  0,36 g cm-3 dan terendah pada T0 (sub soil) yaitu  0,17 g cm-3. Kadar air tertinggi  terdapat pada sampel T0 (sub soil)  yaitu 234,82% dan terendah pada T1 (top soil) yaitu 81,96%. Porositas tertinggi terdapat pada sampel gambut T0  (sub soil) yaitu 94,93% dan terendah pada T1 (top soil) yaitu 65,28%. Permeabilitas tertinggi terdapat pada T0 (sub soil) yaitu 33,80 cm/jam dan terendah pada T1 (top soil) yaitu 16,10 cm/jam. Hasil uji statistik menunjukkan bahwa ada perbedaan yang signifikan pada parameter berat volume dengan t hitung (3,482) t tabel (1, 943), sedangkan pada parameter lainnya tidak ada perbedaan yang signifikan. Tingkat kematangan gambut di kawasan Tripa Makmur adalah hemik. Kedalaman gambut sebesar 3 meter.  Subsiden tertinggi adalah 100 cm pada gambut terbakar di tahun 2015. Warna  gambut adalah coklat kehitaman. The Effect of Burning Peat on Some of The Physical Porperties of Peat Soil in The Tripa Makmur Sub DistrictAbstract. Peat contains high organic matter. Drained peat is susceptible to fire. The use of peat in Aceh is very broad. Peat is often burned so that it can be quickly utilized especially in Tripa makmur Sub Districk, Nagan Raya Districk. This study aims to see how far the rate of change in the physical properties of peat is burning Rawa Tripa in Nagan Raya District. The results showed that the highest average of volume weight was found in T1(top soil) 0,36 g cm-3 and the lowest in T0(sub soil) 0,17 g cm-3. The highest water content was found inT0(sub soil) 234,82%  and the lowest was on T1(top soil) 81,96%. The highest porosity was found T0(sub soil) 94,93% and the lowest in T1(top soil) 65,28%. The highest permeability is found in T0(sub soil) 33,80 cm/hour and the lowest is on T1(top soil) 16,10 cm/hour. The results of statistical tests show that there is a significant difference in the parameters of volume weight with t count 3,482 t table 1,943, while in the other parameters have no significant differences. The level of maturity in the Tripa Makmur area is hemik. Peat depth of 3 meters. The highest subsidance is 100 cm on burning peat in 2015. The color of this peat is blackish brown. 

scholarly journals SOLVING INVERSE PROBLEM OF CHEMICAL KINETICS WITH USE OF CUBIC SPLINES

2020 ◽  
Vol 63 (7) ◽  
pp. 61-66
Author(s):  
Nikolay I. Kol'tsov
Keyword(s):  
Experimental Data ◽  
Inverse Problem ◽  
Chemical Kinetics ◽  
Good Accuracy ◽  
Cubic Splines ◽  
Rate Of Change ◽  
Reference Points ◽  
Additional Advantage ◽  
Instantaneous Rate ◽  
Relaxation Curves

A simple effective method for solving the inverse problem of chemical kinetics based on non-stationary experiments for multistage reactions occurring in an isothermal reactor of ideal mixing is described. The idea of the method is based on taking into account the distinctive features (informativeness) of different fragments of relaxation curves for chemical reactions with arbitrary (non-monotonic) kinetics and their as accurate approximation as possible. For this purpose, non-linear (cubic) splines are used to describe different informative fragments of relaxation curves, which allow to approximate and interpolate experimental data as accurately as possible. An additional advantage of cubic splines, from the point of view of the implementation of the described method, is their continuity at all given points up to and including second-order derivatives (smoothness). This allows us to calculate with good accuracy not only the concentration of reagents, but also the instantaneous rate of change at any time. The consequence of this is the possibility of a sufficiently accurate solution of the inverse problem based on the data of non-stationary experiments. The correctness of the mathematical model used and the stability of the method were tested using variations of the original data. An example of using the method for determining the intervals of physical values of the rate constants of the stages of a two-stage reaction is given. The influence of the method of selecting the reference points (structure) of the spline and measurement errors (noise) of experimental data on the error of determining the speed constants of the stages is estimated. The efficiency of application and good accuracy of the method for solving the inverse problem of chemical kinetics of multistage reactions occurring in non-gradient systems with taking into account of noise is shown.

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