Indonesia Conference Directory

Corresponding Author
Ayu Kurniasih

Institutions
Universitas Negeri Medan

Abstract
Abstract. The purpose of this study is to describe daily problems related to distance, speed and time, and solve the problem of distance, speed and time using a magic triangle. This research is library research so that the data collection method used is documentation, based on books and journals as written sources that contain various themes and subjects discussed. Research data were collected and analyzed by descriptive methods that describe what is being investigated. The initial step of this research is to conduct research to study the results made from references in journals, books or previous researchers. After the data is collected, data processing is carried out. Then do the data analysis with descriptive analysis. The results of this study obtained problems of daily activities related to distance, time and speed. Solving the problem of distance, speed and time can be easily solved with a magic triangle. Keywords: Problem-solving, distance, time, speed, the magic triangle

Keywords
Problem-solving, distance, time, speed, the magic triangle

Topic
Applied Mathematics and statistics

Link: https://ifory.id/abstract/NZXCKWRjrF8p

Corresponding Author
Tanachot Chaito

Institutions
a) Department of Statistics, Faculty of Science, Chiang Mai University, Chiang Mai 50200,Thailand
*tanachot.boy[at]gmail.com
b) Data Science Research Center, Department of Statistics, Faculty of Science, Chiang Mai University, Chiang Mai 50200,Thailand

Abstract
The objective of this research is to compare methods of parameter estimation for a zero inflated Weibull distribution (ZIW). The methods used to estimate parameters include the maximum likelihood estimation (MLE), the expectation maximization (EM) algorithm and the percentile estimation (PE). The results of a simulation study; the MLE and EM methods gave small mean square error (MSE) values and both methods are effective in estimating parameters which are not different while the PE method (using the 25th and 75th) had small average relative bias (AvRB) values when sample size and shape parameters increase. Therefore, the MLE and EM methods were the best parameter estimation method for a ZIW distribution. In this research the monthly rainfall data from two rain gauging stations at Pua and Mueang, Nan, Thailand during the period of 1960 to 2017 were used in this study. The goodness of fit test of monthly rainfall data from two stations found that a ZIW distribution was the most appropriate. Moreover, when we analyzed the tendency of drought, Mueang station had no tendency for drought but Pua station had a rain trend.

Keywords
Expectation Maximization algorithm; Maximum Likelihood estimation; percentile estimation; rainfall data

Topic
Applied Mathematics and statistics

Link: https://ifory.id/abstract/uGQXLzy89frR

Corresponding Author
Elmanani Simamora

Institutions
a) Department of Mathematics of Faculty of Mathematics and Natural Sciences, State University of Medan, Jalan Willem Iskandar/Pasar V, Medan 20221, Indonesia
*elmanani_simamora[at]unimed.ac.id
b)Department of Mathematics of Faculty of Mathematics and Natural Sciences, State University of Medan, Jalan Willem Iskandar/Pasar V, Medan 20221, Indonesia

Abstract
In practice, the parameters in the kriging model are unknown, but they can be estimated based on the behavior of the observed data. Parameters in the kriging model can be estimated based on the consideration of Regression-Kriging models. Regression-Kriging models are Universal Kriging models with polynomials of degree zero (Ordinary Kriging), one (Universal Kriging with degree one), or two (Universal Kriging with degree two). A new method for estimating the parameters in the Kriging model with semiparametric bootstrapping is proposed in this paper. The semiparametric bootstrapping procedure works by combining the bootstrap method and Kriging

Keywords
Kriging; regression; Simulation; Deterministic ; Semiparametric; Bootstrapping

Topic
Applied Mathematics and statistics

Link: https://ifory.id/abstract/EuZAvp8KWjkd

Corresponding Author
Irwan Irwan

Institutions
Universities Negeri Padang

Abstract
Mathematical reasoning skill of students from several schools was still not optimal yet. One of ways to solve this problem was by developing mathematics lesson equipment based on Model Eliciting Activities (MEAs) approach. This research was development research, which aimed to produce lesson equipment based on Model Eliciting Activities (MEAs) approach. From results of preliminary analysis, it was found the lesson equipment that was in accordance with students characteristics and used curriculum as well as the order of the content based on the result of concept analysis. This learning equipment would have the role in improving students mathematical reasoning skill.

Keywords
Model Eliciting Activities (MEAs) approach, lesson equipment, mathematical reasoning skill

Topic
Applied Mathematics and statistics

Link: https://ifory.id/abstract/Z2TBw8KfRxub