• Journal of Korean Society for Geospatial Information Science
• /
• v.7 no.2 s.14
• /
• pp.23-34
• /
• 1999

The most widely used measure for indicating the accuracy of DEM is RMSE(nut Mean Square Error), which is used by many national mapping agencies such as the USGS and the Ordnance Survey. Its prevalent use can be followed by the relative ease of calculation and understanding the concepts. However, there are many problems with the measure and the way from which it is often derived. First of all, the index does not involve my description of the mean donation between the two measures of elevation,. This means that it cannot interpret the distributions or patterns of errors involved in DEMs. The distribution of errors in DEMs will show some forms of spatial patterning. In order to explore the real quality of DEMs as a useful database, alternative approaches are needed. In this paper, we examined so called ESDA(Exploratory Spatial Data Analysis) approaches, which were attributed by both aspatial and spatial exploration methods. Our experimental research shows that even simple ESDA methods reveal new aspects of errors, especially spikes, striation, and terracing effect in DEMs, which my be ignored by RMSE measure.

• Journal of Internet Computing and Services
• /
• v.24 no.4
• /
• pp.65-76
• /
• 2023

This paper identifies the aspects of living environment elements (PM^2.5, PM¹⁰, Noise) throughout Seoul and the urban characteristics that affect them by utilizing the big data of the S-Dot sensors in Seoul, which has recently become a hot topic. In other words, it proposes a big data based urban computing research methodology and research direction to confirm the relationship between urban characteristics and living environments that directly affect citizens. The temporal range is from 2020 to 2021, which is the available range of time series data for S-Dot sensors, and the spatial range is throughout Seoul by 500mX500m GRID. First of all, as part of analyzing specific living environment patterns, simple trends through EDA are identified, and cluster analysis is conducted based on the trends. After that, in order to derive specific urban planning factors of each cluster, basic statistical analysis such as ANOVA, OLS and MNL analysis were conducted to confirm more specific characteristics. As a result of this study, cluster patterns of environment elements(PM^2.5, PM¹⁰, Noise) and urban factors that affect them are identified, and there are areas with relatively high or low long-term living environment values compared to other regions. The results of this study are believed to be a reference for urban planning management measures for vulnerable areas of living environment, and it is expected to be an exploratory study that can provide directions to urban computing field, especially related to environmental data in the future.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.2
• /
• pp.145-150
• /
• 2015

Needs about safety of residents are important in urbanized society, elderly and small-size family. People are looking for safety information system and device of CPTED. That is, Needs and Installations of CCTV increased steadily. But, scientific analysis about validity, systematic plan and location of security CCTV is nonexistent. It is simply put these devised in more demanded areas. It has limits to look for safety of residents by increasing density of CCTVs. One of the characteristics of crime is clustering and stong interconnectivity. So, exploratory spatial data of crime is geo-coded using 2 years data and carried out cluster analysis and space statistical analysis through GIS space analysis by dividing 18 variables into social economy, urban space, crime prevention facility and crime occurrence index. The result of analysis shows cluster of 5 major crimes, theft, violence and sexual violence by Nearest Neighbor distance analysis and Ripley's K function. It also shows strong crime interconnectivity through criminal correlation analysis. In case of finding criminal cluster, you can find criminal hotspot. So, in this study I found concept of hotspot and considered technique about selection of hotspot. And then, selected hotspot about 5 major crimes, theft, violence and sexual violence through Nearest Neighbor Hierarchical Spatial Clustering.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.7
• /
• pp.3112-3127
• /
• 2018

Since time series clustering is performed without prior information, it is used for exploratory data analysis. In particular, clusters of time series with similar shapes can be used in various fields, such as business, medicine, finance, and communications. However, existing time series clustering algorithms have a problem in that time series with different shapes are included in the clusters. The reason for such a problem is that the existing algorithms do not consider the limitations on the size of the generated clusters, and use a dimension reduction method in which the information loss is large. In this paper, we propose a method to alleviate the disadvantages of existing methods and to find a better quality of cluster containing similarly shaped time series. In the data preprocessing step, we normalize the time series using z-transformation. Then, we use piecewise aggregate approximation (PAA) to reduce the dimension of the time series. In the clustering step, we use density-based spatial clustering of applications with noise (DBSCAN) to create a precluster. We then use a modified K-means algorithm to refine the preclusters containing differently shaped time series into subclusters containing only similarly shaped time series. In our experiments, our method showed better results than the existing method.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• v.2 no.3
• /
• pp.144-152
• /
• 2021

Sanankerto is one of pilot projects for tourism villages in Indonesia due to its natural tourism potential with a 24-ha bamboo forest located in Boon Pring Andeman area. However, the distribution of existing bamboo has never been identified or mapped. Thus, the mana gement is facing difficulty in planning and developing tourism potential as well as spatial management in the area. Therefore, the objectives of this study were to identify and analyze the structure of bamboo vegetation in the Boon Pring Tourism village an d to perform vegetation mapping. The type of research was descriptive exploratory with a cluster sampling technique (i.e., a two-stage cluster) covering an area of ± 10 ha. Bamboo vegetation analysis was performed by calculating diversity index (H'), evenness index (E), and Species Richness index (R). Data were collected through observation and interviews with local people and the manager to determine zonation division. Mapping of bamboo vegetation based on zoning was processed into thematic maps using ArcG is 10.3. Micro climatic factors were measured with three replications for each sub -cluster. Data were analyzed descriptively and quantitatively. Nine species of bamboo identified. Diversity, evenness, and species richness indices differed at each location. Activities of local communities, tourists, and manager determined the presence, number, and distribution of bamboo species. These bamboo distribution maps in three zoning (utilization, buffer, and core) can be used by manager for planning and developing natural tourism potential.

• Journal of the Korean Regional Science Association
• /
• v.38 no.1
• /
• pp.3-20
• /
• 2022

The purpose of this study is to exploratory analyze the transition pattern of establishments and workers in new growth industries in the metropolitan area from 2010 to 2019 and to identify regional factors affecting the inflow and outflow of new growth industry start-ups. As for the analysis, the original data of the Census on Establishments were used, and spatial data at the sigungu level were constructed based on the inflow and outflow data of the number of new growth industry businesses and workers. For the analysis, the degree centrality of connection to outflow inflow by region was calculated, and an empirical analysis was conducted on regional-level factors affecting the inflow and outflow of new growth industries by applying a negative binomial regression model. According to the results, the new growth industry manufacturing sector was actively relocated in southern Gyeonggi Province, and the new growth industry service sector in Gangnam and Guro-Geumcheon-gu, and the impact of regional-level factors on the inflow and outflow of new growth industry start-ups varies depending on the industry. This study presented implications for regional industrial policies to improve the competitiveness of the local economy by attracting new industries by identifying spatial transition patterns for new growth industries and conducting empirical analysis to identify influencing factors.

• Tunnel and Underground Space
• /
• v.17 no.6
• /
• pp.493-502
• /
• 2007

Measurements of hydraulic conductivity are point or interval values, and are highly limited in their number. Meanwhile, results of geophysical prospecting can provide the information of spatial variation of geology, and abundant in number. In this study, it was aimed to develop a data integration tool for constructing a hydraulic conductivity map by integrating geophysical data and hydraulic conductivity measurements. The developed code employed a geostatistical optimization method, simulated annealing (SA), and consists of 4 distinct computation modules by which from exploratory data analysis to postprocessing of the simulation were processed. All these modules are equipped with Graphical User Interface (GUI). Validation of the developed code was evaluated in-situ in characterizing hydraulic characteristics of highly permeable fractured zone.

• Journal of the Korean Regional Science Association
• /
• v.37 no.2
• /
• pp.63-82
• /
• 2021

This study aims to explore how manufacturing start-up activities from 2000 to 2018 have changed spatially and to predict changes in distribution patterns of future start-up activities. For the analysis, the Census on Establishments microdata from 2000 to 2018 were used, and the manufacturing industry was classified into four detailed industrial groups according to the 40 manufacturing standards presented by the Korea Institute for Industrial Economics and Trade's ISTANS. According to the results, start-up activities in industries that require high technology levels are concentrated in southern Gyeonggi region, and other start-up activities are concentrated outside of the metropolitan area. When the distribution change from 2018 to 2036, extending the trend from 2000 to 2018, it was confirmed that there was a high possibility of a rise in the hierarchy in the future in regions adjacent to regions where start-up activities occur. This study aimed to provide implications for regional policies related to fostering start-ups and creating jobs by dynamically analyzing the location pattern of manufacturing start-ups, which is a major source of job creation.

• The Korean Journal of Applied Statistics
• /
• v.22 no.6
• /
• pp.1355-1364
• /
• 2009

This work propose a robust test for location parameters in multivariate data based on MVE and MCD with the affine equivariance and the high-breakdown properties. We consider the hypothesis testing satisfying high efficiency and high test power simultaneously to bring in the one-step reweighting procedure upon high-breakdown estimators, which generally suffer from the low efficiency and, as a result, usually used only in the exploratory analysis. Monte Carlo study shows that the suggested method retains nominal significance levels and higher testing power without regard to various population distributions than a Hotelling's $T^2$ test. In an example, a data set containing known outliers does not make an influence toward our proposal, while it renders a Hotelling's $T^2$ useless.

• The Journal of the Korea Contents Association
• /
• v.18 no.3
• /
• pp.1-10
• /
• 2018

The study aimed to explore media use by digital natives in Korea. To date, Korea is a country that has both the highest level of digital natives and fastest Internet access in the world. The study also intended to deeply understand the simultaneous activity use of different media and determined the characteristics of Korean digital natives. Based on Korea Media Panel Data for 2015, analyses of the digital natives' traits of time-space, media use, and simultaneous use of media were made through a statistic multi-correspondent method. The results showed that spatial attribute and media use of digital natives are homogeneous in pattern and the degree of simultaneous use of media seems to be limited in type. Moreover, the study suggested the new concept of digital natives' media use and the need for various studies showing the relationship between media use and the Internet generation.