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Beta Regression for Modeling a Covariate Adjusted ROC
Sarah Stanley,
Jack Tubbs
Issue:
Volume 6, Issue 4, August 2018
Pages:
110-118
Received:
24 July 2018
Accepted:
9 August 2018
Published:
11 September 2018
Abstract: Background: Several regression methodologies have been developed to model the ROC as a function of covariate effects within the generalized linear model (GLM) framework. In this article, we present an alternative to two existing parametric and semi-parametric methods for estimating a covariate adjusted ROC. The existing methods utilize GLMs for binary data when the expected value equals the probability that the test result for a diseased subject exceeds that of a non-diseased subject with the same covariate values. This probability is referred to as the placement value. Objective: The new method directly models the placement values through beta regression. Methods: We compare the proposed method to the existing models with simulation and a clinical study. Conclusion: The proposed method performs favorably with the commonly used parametric method and has better performance than the semi-parametric method when modeling the covariate adjusted ROC regression.
Abstract: Background: Several regression methodologies have been developed to model the ROC as a function of covariate effects within the generalized linear model (GLM) framework. In this article, we present an alternative to two existing parametric and semi-parametric methods for estimating a covariate adjusted ROC. The existing methods utilize GLMs for bin...
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Towards the Solution of Abysmal Performance of Fraction in Navrongo Presbyterian Primary School: Comparing the Sets of Objects and Paper Folding Designed Interventions
Christiana Subaar,
Juliana Awune Asechoma,
Vincent Ninmaal Asigri,
Victor Alebna,
Francis Xavier Adams
Issue:
Volume 6, Issue 4, August 2018
Pages:
119-123
Received:
10 August 2018
Accepted:
29 August 2018
Published:
21 September 2018
Abstract: This is an interventional study sought to find the difference in the performance of pupils who were taught using sets of objects (sets model) and paper folding activities, to solve word problems involving addition and subtraction of proper fractions. A total of thirty pupils, of Navrongo Presbyterian Primary School Basic Five A, were used in the study. A well-structured lesson, with teaching and learning materials, was used. A pretest and posttest assessments were deployed to ascertain the effect of the interventional teaching strategies. Prior, to the intervention of the study, 73.3% of the pupils (total of 30) scored below the average mark ranging from 5-7. These represented the experimental group of the study. 26.7% of the pupils (control group) scored the average mark. However, after the intervention, both strategies (sets of objects and paper folding activities) showed remarkable performance. Although both strategies showed remarkable performance in pupils, 59% of the experimental group (total of 22 pupils) scored above the average mark in the paper folding as compared to 50% of the experimental group who scored above the average mark in the usage of sets model. While 87.5% of the control group scored above the average marks ranging from 8-10 during the paper folding activities, 62.5% of the control group scored above the average marks from 8-10 during the use of sets model. The posttest results of both the control and experimental groups taught using paper folding performed far better compared to sets model. The study has shown that pupils’ level of performance had improved drastically with the help of paper folding method. In conclusion, paper folding activities help pupils to appreciate word problems involving addition and subtraction of proper fractions.
Abstract: This is an interventional study sought to find the difference in the performance of pupils who were taught using sets of objects (sets model) and paper folding activities, to solve word problems involving addition and subtraction of proper fractions. A total of thirty pupils, of Navrongo Presbyterian Primary School Basic Five A, were used in the st...
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Predicting Technical Problems of Hydropower Engineering Using eXtreme Gradient Boosting
Jing Zhu,
Yi Chen,
Liming Huang,
Chunyong She,
Yangfeng Wu,
Wenyu Zhang
Issue:
Volume 6, Issue 4, August 2018
Pages:
124-129
Received:
17 October 2018
Published:
18 October 2018
Abstract: Nowadays, water shortage is increasingly severe, which has huge negative influence on daily life. Constructing hydropower engineering is one of the approaches to alleviate such problem. Therefore, it’s worth settling technical problems of hydropower engineering timely, which will help people not only make better use of water resources but also get rid of various security risks. To achieve such goal, this study predicts potential technical problems that hydropower engineering might happen. In order to utilize the large amount of data, data mining techniques are used to solve this multi-classification problem. First of all, plenty of data is preprocessed. Particularly, because of the complexity of text data, text mining techniques are applied to transform the unstructured data to structural data. Then, eXtreme Gradient Boosting (XGBoost) is applied to make the classification. To validate efficiency of the model, comparisons are made among XGBoost, Gradient Boosting Decision Tree, Random Forest, Decision Tree, k-Nearest Neighbor and Bernoulli Naïve Bayes from the perspective of accuracy, precision, recall and f-score. The experimental result shows that XGBoost is more suitable to solve this classification problem. This study provides engineering inspectors with helpful suggestions of particular technical problems that need attention, and further enables people to inspect engineering more efficiently and effectively.
Abstract: Nowadays, water shortage is increasingly severe, which has huge negative influence on daily life. Constructing hydropower engineering is one of the approaches to alleviate such problem. Therefore, it’s worth settling technical problems of hydropower engineering timely, which will help people not only make better use of water resources but also get ...
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The Effect of HIV Related Risk Factors on HIV Status: A Case of Gamo-Gofa Free Standing Voluntary Counseling and Testing Center
Tesfahun Zewde Legisso,
Markos Abiso Erango
Issue:
Volume 6, Issue 4, August 2018
Pages:
130-134
Received:
28 July 2018
Accepted:
17 October 2018
Published:
12 November 2018
Abstract: HIV/AIDS is a major development concern in many countries and is destroying the lives and livelihoods of many people around the world. This study is aimed to assess the demographic and HIV related risk behavior factors that may affect HIV status of the visitors of VCT centers. A cross sectional study was conducted in Gamo-Gofa districts, Southern Nations Nationalities and Peoples Regional State of Ethiopia. A total of 4028 sample were selected using stratified random sampling technique. Data were collected with a designed questionnaire from 20 voluntary counseling and testing center of the districts. If the clients visit VCT center is HIV-infected, it is categorized as HIV positive and if the client test is indicated not HIV-infected, then the visitor categorized as HIV negative status. The Binary logistic regression model was used to analyze the data using the SPSS software. The results of the study revealed that the probability of an individual being HIV positive was 0.0286 and the predictor’s variables age, marriage status, education level, alcohol use, knowledge about HIV, monthly income, condom use and residence of the individual were significantly effect on being HIV-positive. Health professionals and responsible bodies should work on these significant variables to reduce the probability of being HIV positive.
Abstract: HIV/AIDS is a major development concern in many countries and is destroying the lives and livelihoods of many people around the world. This study is aimed to assess the demographic and HIV related risk behavior factors that may affect HIV status of the visitors of VCT centers. A cross sectional study was conducted in Gamo-Gofa districts, Southern N...
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