• Journal of Korean Society for Geospatial Information Science
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• v.13 no.1 s.31
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• pp.71-80
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• 2005

Recently, water quality problems are emerging as important social issues since water quality in rivers and lakes are significantly deteriorated. Thus, an accurate prediction system on reservoir water quality is required, as well as an integrated system which can provide a solution for taking away contaminated materials. This research aims to develop an intelligent decision support system, which uses a GIS enabling management and spatial analysis. The developed system is a prototype that can be applied into real spot. This research area includes the following main subjects; system analysis and design, geometry data collection and database implementation, data acquisition and analysis on reservoir water quality, interface design and development GIS, and development of an expert system for water quality forecasting by WASPS.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.3
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• pp.193-198
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• 2003

The population is increased in the area of a subway station because the accessibility of passengers is improved. Therefore, facilities for commercial purpose are concentrated in this area. To develop the station area as the center among the most urbanized area, overall mater plan should be constructed far the station area. This study was to construct web server for management a variety of 3D spatial object database of station areas using GIS and web 3D technology. These results will be used to manage efficiently a urban space by the connection of a subway station and a adjacent facilities.

• Journal of Korea Spatial Information System Society
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• v.5 no.2 s.10
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• pp.33-53
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• 2003

This study presents the system to develop the web-based pro-environmental road planning and evaluation system in order to support the decision making for the land development. It was found that the proposed system can display the analysis result 3 dimensionally based on digital map and it can be applied to document development towards efficient operations.

• Spatial Information Research
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• v.14 no.3 s.38
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• pp.335-347
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• 2006

The GIS has grown in its quantity as local authorities established the urban information system for better city administration, civilian services and decision-making support services. Recently, local authorities have expressed much interest on the introduction of ubiquitous technology to improve citizens' safety and convenience. This has become the drive behind the construction of ubiquitous city(u-City). Construction of a u-City requires the multitude of information and telecommunication networks and digital contents; the existing information resources need to be put to use in entirety for that end. In that regard, the integration of GIS established and currently operated by local authorities needs to be strategically promoted. This study intends to propose GIS integration strategies in various aspects for the future u-City and directions for the development of urban information systems in the coming of the Ubiquitous Age.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.1
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• pp.69-75
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• 2007

The information in physical planning field shows the socio-economic potentials of land resources while cadastral data does the physical and legal realities of the land. The two domains commonly deal with land information but have different views. Cadastre has to evolved to the multi-purpose ones which provide value-added information and support a wide spectrum of decision makers by mixing their own information with other spatial/non-spatial databases. In this context, the demands of data exchange between the two domains is growing up but this cannot be done without resolving the heterogeneity between the two information applications. Both of either discipline sees the reality within its own scope, which means each has a unique way to abstract real world phenomena to the database. The heterogeneity problem emerges when an GIS is autonomously and independently established. It causes considerable communication difficulties since heterogeneity of representations forms unique data semantics for each database. The semantic heterogeneity obviously creates an obstacle to data exchange but, at the same time, it can be a key to solve the problems too. Therefore, the study focuses on facilitating data sharing between the fields of cadastre and physical planning by resolving the semantic heterogeneity. The core job is developing a conversion mechanism of cadastral data into the information for the physical planning by DB coupling techniques.

• Journal of Korean Association for Spatial Structures
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• v.23 no.3
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• pp.87-94
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• 2023

Chloride is one of the most common threats to reinforced concrete (RC) durability. Alkaline environment of concrete makes a passive layer on the surface of reinforcement bars that prevents the bar from corrosion. However, when the chloride concentration amount at the reinforcement bar reaches a certain level, deterioration of the passive protection layer occurs, causing corrosion and ultimately reducing the structure's safety and durability. Therefore, understanding the chloride diffusion and its prediction are important to evaluate the safety and durability of RC structure. In this study, the chloride diffusion coefficient is predicted by machine learning techniques. Various machine learning techniques such as multiple linear regression, decision tree, random forest, support vector machine, artificial neural networks, extreme gradient boosting annd k-nearest neighbor were used and accuracy of there models were compared. In order to evaluate the accuracy, root mean square error (RMSE), mean square error (MSE), mean absolute error (MAE) and coefficient of determination (R2) were used as prediction performance indices. The k-fold cross-validation procedure was used to estimate the performance of machine learning models when making predictions on data not used during training. Grid search was applied to hyperparameter optimization. It has been shown from numerical simulation that ensemble learning methods such as random forest and extreme gradient boosting successfully predicted the chloride diffusion coefficient and artificial neural networks also provided accurate result.

• Journal of Korean Association for Spatial Structures
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• v.23 no.4
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• pp.81-88
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• 2023

Numerous factors contribute to the deterioration of reinforced concrete structures. Elevated temperatures significantly alter the composition of the concrete ingredients, consequently diminishing the concrete's strength properties. With the escalation of global CO2 levels, the carbonation of concrete structures has emerged as a critical challenge, substantially affecting concrete durability research. Assessing and predicting concrete degradation due to thermal effects and carbonation are crucial yet intricate tasks. To address this, multiple prediction models for concrete carbonation and compressive strength under thermal impact have been developed. This study employs seven machine learning algorithms-specifically, multiple linear regression, decision trees, random forest, support vector machines, k-nearest neighbors, artificial neural networks, and extreme gradient boosting algorithms-to formulate predictive models for concrete carbonation and thermal impact. Two distinct datasets, derived from reported experimental studies, were utilized for training these predictive models. Performance evaluation relied on metrics like root mean square error, mean square error, mean absolute error, and coefficient of determination. The optimization of hyperparameters was achieved through k-fold cross-validation and grid search techniques. The analytical outcomes demonstrate that neural networks and extreme gradient boosting algorithms outshine the remaining five machine learning approaches, showcasing outstanding predictive performance for concrete carbonation and thermal effect modeling.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.11-22
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• 2009

Recently the integration and development of ST(Spatial Technology) and forest geographic information have been used very efficiently for the forest administration. However, even though many application system related to forest information have been developed and improved, there are still paper based inventories management and hand work for data construction and upgrade. In this study the forest information warehouse, which is mapped and managed at work-site operations, was constructed based GIS technology so that the standardization and consistency of current data could be acquired in real time. In addition, these thematic maps were conducted on high resolution satellite images and managed in web based forest information data warehouse form and finally shared through Internet for the very first-line administration officials. This study shows that the forest information standardization service of municipal governments very first time in the Korea and provides the unified decision making support and enterprise formed forest database so that is expected to be the very successful sample to suggest the prototype of national forest spatial data infrastructure.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.2
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• pp.27-38
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• 2018

Environmental planning includes resource allocation and spatial planning process for the conservation and management of environment. Because the spatialization of the environmental planning is not specifically addressed in the relevant statutes, it actually depends on the qualitative methodology such as expert judgement. The results of the qualitative methodology have the advantage that the accumulated knowledge and intuition of the experts can be utilized. However, it is difficult to objectively judge whether it is enough to solve the original problem or whether it is the best of the possible scenarios. Therefore, this study proposed a methodology to quantitatively and objectively spatialize various environmental planning. At first, we suggested a quantitative spatial planning model based on an optimization algorithm. Secondly, we applied this model to two kinds of environmental planning and discussed about the model performance to present the applicability. Since the models were developed based on conceptual study site, there was a limitation in showing possibility of practical use. However, we expected that this study can contribute to the fields related to environmental planning by suggesting flexible and novel methodology.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.3
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• pp.31-37
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• 2014

It is usual for the officially land price of agricultural field parcels to be determined by real estate appraisers's experienced knowledge and intuition without considering quantitatively physical factors that directly influence agricultural productivity. Solar radiation is the most important predictor of agricultural productivity. GIS based simulation techniques were used to evaluate correlation between the officially land price and solar radiation for agricultural field parcels. The results show that officially land price shows random distribution patterns in relation to solar radiation, which proves that officially land price for agricultural field does not reflect agricultural productivity. It is anticipated that this research output could be used as a valuable reference to support more scientific and objective decision-making in the official pricing process of agricultural field parcels.