IMPLEMENTASI DESAIN DIDAKTIS KONSEP PROGRAM LINEAR DALAM MENGATASI KESULITAN BELAJAR SISWA

One way that can be done in overcoming these students' learning difficulties is by making improvements related to the teaching materials presented. This is done so that students can understand the concept of linear programming that is not textual. Therefore, this research was developed to develop a design of teaching materials (didactic design) that is more relevant for students so that students' learning difficulties can be overcome. Abstract is different from summary. The research method used is qualitative research methods with design research using Didactical Design Research (DDR). The subjects in this study were 37 high school students in class X in one of the schools in Kabupaten Cirebon. This study has three important stages, namely, preparing ADP, metapedadidactic analysis, and retrospective analysis. The results obtained in this study are that the didactic design was developed with four didactic situations to solve students' difficulties in determining the optimum value of the problem using the test point method and the probing line method.

On the One-Point Model for the Productivity Evaluation in Jingbian Sector of Yan’an Gas Field

The productivity equation of a gas well is, in the final analysis, an expression that describes the relationship between the production of a gas well and its bottom-hole flowing pressure. There are two kinds of productivity equations in common use at present: binomial productivity equation and exponential productivity equation. Combined with the modified isochronal well test, the test data are interpreted, and it is found that the open flow rates calculated by the two productivity equations are basically the same when the pressure difference at the test point is large, and the deviation of the exponential productivity equation is large when the pressure difference at the test point is small. Using binomial productivity equation and modifying isochronous well test, we established the single-point deliverability formula for the Jingbian sector of the Yan’an gas field. The field experience formula and production data are used to verify it. Their average errors are 2.59% and 7.12%, respectively; and the coincidence rate of productivity evaluation is 90%. The one-point productivity formula established has high precision and is suitable for productivity analysis of gas wells in paleozoic reservoirs in the Jingbian sector of the Yan’an gas field. This paper provides insights into the one-point productivity evaluation and its future application in the gas field.

Intracranial compartment volumes and their distribution among clinically diagnosed patients with normal pressure hydrocephalus and brain atrophy in a Nigerian population

Normal pressure hydrocephalus is a form of non-obstructive hydrocephalus characterized by the triad of symptoms. These symptoms are typical or atypical. Because of its potential reversibility, researchers have paid attention to its diagnosis and in differentiating it with other forms of dementia such as brain atrophy. To determine the intracranial compartment volumes and their differences among patients with NPH and Brain Atrophy (BA). This was a cross-sectional study involving consenting patients diagnosed with NPH and BA who were referred for routine brain CT. Medical conditions known to influence intracranial volume were excluded. Age -matched normal control were clinically and radiologically confirmednormal and were also recruited. Intracranial volumes and CSF distribution determination was based on Cavalieri test point computation principle. Test point summation was on a locally developed software for this purpose. Overall, the values of BA recorded higher mean values for most of the intracranial compartment volumes. Intraventricular volume was consistently higher in NPH groups. Statistical difference exists among intraventricular and total intracranial CSF volume across patients with BA, NPH and control. A post hoc test revealed control-NPH comparison across these variables. Control-BA comparison was evident in total intracranial CSF volume only. Higher mean values of intracranialcompartment volumes were observed in patients with BA than among patients with NPH and their control. Anthropometric indices did not show any difference between patients with BA, NPH and their control. These indices can be used as basis in objectively differentiating NPH from BA.

Concrete Spalling Severity Classification Using Image Texture Analysis and a Novel Jellyfish Search Optimized Machine Learning Approach

During the phase of building survey, spalling and its severity should be detected as earlier as possible to provide timely information on structural heath to building maintenance agency. Correct detection of spall severity can significantly help decision makers develop effective maintenance schedule and prioritize their financial resources better. This study aims at developing a computer vision-based method for automatic classification of concrete spalling severity. Based on input image of concrete surface, the method is capable of distinguishing between a minor spalling in which the depth of the broken-off material is less than the concrete cover layer and a deep spalling in which the reinforcing steel bars have been revealed. To characterize concrete surface condition, image texture descriptors of statistical measurement of color channels, gray-level run length, and center-symmetric local binary pattern are used. Based on these texture-based features, the support vector machine classifier optimized by the jellyfish search metaheuristic is put forward to construct a decision boundary that partitions the input data into two classes of shallow spalling and deep spalling. A dataset consisting of 300 image samples has been collected to train and verify the proposed computer vision method. Experimental results supported by the Wilcoxon signed-rank test point out that the newly developed method is highly suitable for concrete spall severity classification with accuracy rate = 93.33%, F1 score = 0.93, and area under the receiver operating characteristic curve = 0.97.

Assessment of the Impact of a Motorway on Content andSpatial Distribution of Mercury in Adjacent Agricultural Soils

The distribution of Hg in the vicinity of roads is probably not exclusively dependent on car emissions, but also on the presence of other point or diffuse sources of Hg emissions located from metres to several km away. The source of mercury in urbanised areas is pollution derived from the burning of fuels and industrial and transport waste, while in agricultural areas, it is constituent in mineral fertilisers and crop protection products. The research objective was to evaluate the content and spatial distribution of mercury in arable soils adjacent to the A1 motorway in Poland. The research material consisted of 40 soil samples taken from 20 test points on four transects at distances of 5, 10, 25 and 50 m from a noise barrier and in the direction of an arable field, and 10 m from the noise barrier in the direction of the motorway. Total mercury content was determined by atomic absorption spectrometry using an AMA 254 analyser. The spatial relationship between adjacent observations of variables was assessed using Moran’s I overall autocorrelation coefficient. Probability maps of mercury distribution in the field and pollution indicators were elaborated in ArcGIS 10.4.1. using Inverse Distance Weighted interpolation. Analysis of the spatial correlation of Moran’s I showed a lack of spatial dependence between tested points, which may evidence that the motorway does not affect mercury contents in the soil. The elevated mercury content at a single test point may indicate a random event unrelated to the motorway’s operation.

Sound Performances of Partition Board from Waste Materials

This study is on the sound performances of a selected number of partition boards in Industrialised Building System (IBS) buildings. The proposed bespoke board were made from squandered or waste materials, namely, coconut shells and newspapers. Each board had been tested for six different distances from the speaker in four different levels of sound, changing the level of the sound frequency. Thereon, the results were analysed. The average result of each board with various distances from the sound source, starting from 0 cm to 220 cm, was combined into under one sound level. The percentage of the noise reduction coefficient is designated by the vertical line whereas the levels of the sound is designated by the horizontal line. Point 1 stands for the low frequency and low intensity test. Point 2 stands for low frequency and high intensity test. The board that is being made of 80% coconut shell, 15% cement and 5% newspaper has an average of noise reduction coefficient of 0.21 in low frequency and low intensity, 0.21 in low frequency and high intensity, 0.24 in high frequency, high intensity and 0.12 in high frequency low intensity.

Estimation of current and post-treatment retinal function in chronic central serous chorioretinopathy using artificial intelligence

Refined understanding of the association of retinal microstructure with current and future (post-treatment) function in chronic central serous chorioretinopathy (cCSC) may help to identify patients that would benefit most from treatment. In this post-hoc analysis of data from the prospective, randomized PLACE trial (NCT01797861), we aimed to determine the accuracy of AI-based inference of retinal function from retinal morphology in cCSC. Longitudinal spectral-domain optical coherence tomography (SD-OCT) data from 57 eyes of 57 patients from baseline, week 6–8 and month 7–8 post-treatment were segmented using deep-learning software. Fundus-controlled perimetry data were aligned to the SD-OCT data to extract layer thickness and reflectivity values for each test point. Point-wise retinal sensitivity could be inferred with a (leave-one-out) cross-validated mean absolute error (MAE) [95% CI] of 2.93 dB [2.40–3.46] (scenario 1) using random forest regression. With addition of patient-specific baseline data (scenario 2), retinal sensitivity at remaining follow-up visits was estimated even more accurately with a MAE of 1.07 dB [1.06–1.08]. In scenario 3, month 7–8 post-treatment retinal sensitivity was predicted from baseline SD-OCT data with a MAE of 3.38 dB [2.82–3.94]. Our study shows that localized retinal sensitivity can be inferred from retinal structure in cCSC using machine-learning. Especially, prediction of month 7–8 post-treatment sensitivity with consideration of the treatment as explanatory variable constitutes an important step toward personalized treatment decisions in cCSC.

Modeling of Statistical Variation Effects on DRAM Sense Amplifier Offset Voltage

With the downscaling in device sizes, process-induced parameter variation has emerged as one of the most serious problems. In particular, the parameter fluctuation of the dynamic random access memory (DRAM) sense amplifiers causes an offset voltage, leading to sensing failure. Previous studies indicate that the threshold voltage mismatch between the paired transistors of a sense amplifier is the most critical factor. In this study, virtual wafers were generated, including statistical VT variation. Then, we numerically investigate the prediction accuracy and reliability of the offset voltage of DRAM wafers using test point measurement for the first time. We expect that this study will be helpful in strengthening the in-line controllability of wafers to secure the DRAM sensing margin.

The Limits of Marginality

The “marginality principle” for linear regression models states that when a higher order term is included, its constituent terms must also be included. The target article relies on this principle for the fixed-effects part of linear mixed models of ANOVA designs and considers the implication that if extended to combined fixed-and-random-effects models, model selection tests specific to some fixed-effects ANOVA terms are not possible. We review the basis for this principle for fixed-effects models and delineate its limits. We then consider its extension to combined fixed-and-random-effects models. We conclude that we have been unable to find in the literature, including the target article, and have ourselves been unable to construct any satisfactory argument against the use of incomplete ANOVA models. The only basis we could find requires one to assume that it is not possible to test point-null hypotheses, something we disagree with, and which we believe is incompatible with the Bayesian model-selection methods that are the basis of the target article.

Investigation of progression pattern and associated risk factors in glaucoma patients with initial paracentral scotomas using Humphrey 10-2

Central visual field (VF) progression could directly threaten patientss visual function compared to glaucomatous damage. This study was designed to investigate visual field (VF) progression pattern and associated risk factors including optical coherence topography angiographic (OCT-A) findings in glaucoma patients with initial paracentral scotoma. This prospective, observational study included 122 eyes presenting as initial paracentral scotomas with serial 24-2 and 10-2 VF tests at the glaucoma clinic of Seoul St Mary's Hospital between November 2017 and August 2020. The participants underwent at least 5 serial VF exams and OCT-A at baseline. Numerical values of the initial and final 10-2 VF tests were averaged for each VF test point using the total deviation map. Innermost 10-2 VF progression was defined as three or more new contiguous points at the central 12 points on 10-2 VF. Other clinical characteristics were collected including history of disc hemorrhage and vessel density (VD) was measured from OCT-A images. Linear regression analysis was performed to obtain the change of mean deviation and a cut-off for progression was defined for both 24-2 and 10-2 VFs. The average total deviation maps of the initial 10-2 VF tests shows initial paracentral scotoma located in the superior region in an arcuate pattern that was deep in the 4°–6° region above fixation. This arcuate pattern was more broadly located in the 4°–10° region in the primary open-angle glaucoma (POAG) group, while it was closer to fixation in 0°–4° region in the normal-tension glaucoma (NTG) group. The final average map shows deepening of scotomas in the 4°–10° region in POAG, which deepened closer to the region of fixation in NTG. The diagnosis of NTG (β 1.892; 95% CI 1.225–2.516; P = 0.035) and lower choroidal VD in the peripapillary atrophy (PPA) region (β 0.985; 95% CI 0.975 to 0.995; P = 0.022) were significantly related to innermost 10-2 VF progression. Initial paracentral scotomas in NTG tended to progress closer to the region of fixation, which should be monitored closely. Important progression risk factors related to paracentral scotoma near the fixation were the diagnosis of NTG and reduced choroidal VD in the β-zone PPA region using OCT-A. We should consider vascular risk factors in NTG patients presenting with initial paracentral scotoma to avoid vision threatening progression of glaucoma.