• Journal of the Korean Data and Information Science Society
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• v.26 no.2
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• pp.399-408
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• 2015

This paper presented airquality data through data visualization in several ways and described its characteristics related to statistical methods for analysis. Software R was used for visualization tools. The airquality data was measured in New York city from May to September of year 1973. First, simple, exploratory data analysis was done in terms of both data visualization and analysis to find out univariate characteristics. Then through data transformation and multiple regression analysis, model for describing the airquality level was found. Also, after some data categorization, overall feature of the data was explored using box plot and three-dimensional perspective drawing and scatter plot.

• Communications for Statistical Applications and Methods
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• v.17 no.2
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• pp.153-164
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• 2010

This study is about the dynamic graphics which can be used for the exploration of the characteristics of data comprising discrete and continuous variables. Simultaneously using line mosaic plot for the relation of discrete variables and box plot together with scatter plot for the relation of continuous variables, we have applied dynamic methods among these plots to demonstrate that the structure and characteristics of the multivariate data could be easily analyzed.

• Korean journal of applied entomology
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• v.32 no.1
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• pp.68-75
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• 1993

Morphometric investigations of the leg characters of both sexes of brachypterous Korean N. lugens biotypes were made. Simple and multivariate statistical analyses revealed that the three N. lugens biotypes differed from one another. The amount of variation and segregation between and among the three biotype populations were approximated by the scatter plot diagrams based on the computed discriminant scores. The variables of leg characters provided the most significant segregations of three biotype populations, thus, categorizing the three biotypes as distinct intraspecific populations of N. lugens.

• Korean journal of applied entomology
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• v.31 no.1
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• pp.37-44
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• 1992

Morphometrics of the sensory appendages for host plant discrimination such as antenna, leg, rostrum of S. furcifera sampled from Korea, China, and Philippines were determined and compared. Computed discriminant scores of 89 characters produced scatter diagrams and group centroids revealing discrete segregations of the three populations.

• Journal of the Korean Data and Information Science Society
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• v.25 no.1
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• pp.119-130
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• 2014

This paper is based on water information system of NIE, National Institute of Environmental Research. We used monthly data of water quality from January, 2013 to August, 2013 starting from measuring point A (nbA) to measuring point N (nbN) located along the Nakdong river main stream. Statistical water quality analysis of BOD (biological oxygen demand) is specified by R programming depending on month, year, and points. Based on BOD measured from Nakdong river's measuring points, we used exploratory data analysis and locally weighted scatter plot smoother (Lowess) trend analysis, which is a method of non-parametic regression analysis, to analyze long-term water tendency and water quality distribution depending on points. Also, we analyzed the period and the measuring point of which the outliers are abundant. As a result, compared to BOD measured in nbM located in Busan along the downstream, BOD measured in nbG located in Daegu and nbI located in Changwon along the midstream showed higher rate of water pollution at a severe level.

• Journal of Engineering Education Research
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• v.17 no.2
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• pp.3-10
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• 2014

How to teach calculus is an important issue since Calculus is the first mathematics in college curriculum which highly influences other subjects including Physics, Engineering Mathematics like differential equations, and other engineering major subjects. This study suggests that a class model of Engineering Mathematics include Calculus review test so that students can study for themselves Calculus 'outside Calculus class'. First of all, a systematic process of administrating a review test is presented. Secondly, scores of the Calculus review test is statistically analyzed to confirm that ability in Calculus is highly correlated to their achievements in Engineering mathematics. Through a survey, it is confirmed that students in Engineering Mathematics study Calculus for themselves as they think Calculus review test is helpful.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.59.2-59.2
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• 2014

Radiative transfer models in a spherical, turbulent interstellar medium (ISM), in which the photon source is situated at the center, are calculated to investigate the correlation between the scattered light and the dust column density. The medium is modeled using fractional Brownian motion structures that are appropriate for turbulent ISM. The correlation plot between the scattered light and optical depth shows substantial scatter and deviation from simple proportionality. It was also found that the overall density contrast is smoothed out in scattered light. In other words, there is an enhancement of the dust-scattered flux in low-density regions, while the scattered flux is suppressed in high-density regions. The correlation becomes less significant as the scattering becomes closer to being isotropic and the medium becomes more turbulent. Therefore, the scattered light observed in near-infrared wavelengths would show much weaker correlation than the observations in optical and ultraviolet wavelengths. We also find that the correlation plot between scattered lights at two different wavelengths shows a tighter correlation than that of the scattered light versus the optical depth.

• Journal of the Korean Data and Information Science Society
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• v.25 no.1
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• pp.177-185
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• 2014

Under bivariate normal distribution assumptions, the interaction and quadratic terms are needed in the logistic regression model with two predictors. However, depending on the correlation coefficient and the variances of two conditional distributions, the interaction and quadratic terms may not be necessary. Although the need for these terms can be determined by comparing the two scatter plots, it is not as useful for interaction terms. We explore the structure and usefulness of the 3-D residual plot as a tool for dealing with interaction in logistic regression models. If predictors have an interaction effect, a 3-D residual plot can show the effect. This is illustrated by simulated and real data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.1
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• pp.169-178
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• 2010

The main purpose of this study is to evaluate the feasibility and the accuracy of ASTER DEM and SRTM DEM covering 99% of the earth surface using large-scale Digital Topographic Map in mountainous area(Sokcho), mixed area(Jinan, mountainous area and even land area) and even land area(Anyang). We made DEM using contour lines of 1:5,000 Digital Topographic Map of study area and also acquired ASTER DEM and SRTM DEM of their corresponding area. In order to verify accuracy of DEM, this study compared ASTER DEM and SRTM DEM data using 15m resolution DEM generated from contour lines of Digital Topographic Map as basis for each study area. To evaluate the accuracy of ASTER and SRTM DEM data, statistical such as RMSE and correlation were calculated and histogram and scatter plot were drawn. The analysis result shows that, both ASTER DEM and SRTM DEM have high accuracy but in aspects of future availability, ASTER DEM covering larger areas bas relatively more potential than SRTM data.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.76-82
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• 1998

Increase of greenhouse gas due to $CO_2$ and CH$_4$ gases would cause the global warming in the atmosphere. According to the global circulation model, it is pointed out in the Okhotsk Sea that the large increase of atmospheric temperature might be occurredin this region by global warming due to the doubling of greenhouse effectgases. Therefore, it is very important to monitor the sea ice extents in the Okhotsk Sea. To improve the sea ice extents and concentration with more highly accuracy, the field experiments have begun to comparewith Airborne Microwave Radiometer (AMR) and video images installed on the aircraft (Beach-200). The sea ice concentration is generally proportional to the brightness temperature and accurate retrieval of sea ice concentration from the brightness temperature is important because of the sensitivity of multi-channel data with the amount of open water in the sea ice pack. During the field experiments of airborned AMR the multi-frequency data suggest that the sea ice concentration is slightly dependending on the sea ice types since the brightness temperature is different between the thin and small piece of sea ice floes, and a large ice flow with different surface signatures. On the basis of classification of two sea ice types, it is cleary distinguished between the thin ice and the large ice floe in the scatter plot of 36.5 and 89.0GHz, but it does not become to make clear of the scatter plot of 18.7 and 36.5GHz Two algorithms that have been used for deriving sea ice concentrations from airbomed multi-channel data are compared. One is the NASA Team Algorithm and the other is the Bootstrap Algorithm. Intrercomparison on both algorithms with the airborned data and sea ice concentration derived from video images bas shown that the Bootstrap Algorithm is more consistent with the binary maps of video images.