• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.3
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• pp.42-51
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• 2017

Snowfall is an important natural hazard in Korea. In recent years, the socioeconomic importance of impact-based forecasts of meteorological phenomena have been highlighted. To further develop forecasts, we first need to analyze the climatic characteristics of each region. In this study, homogeneous regions for snowfall analysis were classified using a self-organizing map for impact-based forecast and warning services. Homogeneous regions of snowfall were analyzed into seven clusters and the characteristics of each group were investigated using snowfall, observation days, and maximum snowfall. Daegwallyeong, Gangneung-si, and Jeongeup-si were classified as areas with high snowfall and Gyeongsangdo was classified as an area with low snowfall. Comparison with previous studies showed that representative areas were well distinguished, but snowfall characteristics were found to be different. The results of this study are of relevance to future policy decisions that use impact-based forecasting in each region.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.425-430
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• 2017

This study was conducted to measure the antimicrobial activity and antiseptic effect of Smilax china root extracts against Propionibacterium acnes and to develop natural antimicrobial extracts as an alternative for synthetic preservatives, which have recently been controversial. Extracts were obtained from dried Korean Smilax china root at room temperature using two solvents, distilled water and 95% EeOH, separately. According to the results of this study, the antimicrobial effect of Propionibacterium acnes 3314 and Propionibacterium acnes 3320 against Propionibacterium acnes was outstanding. In particular, the clear zone of the extract using distilled water showed the highest activity with 16.61 mm. As for the result of the collection of contaminated skin sample, the clear zone was 24.48 mm. This indicates that Smilax china root extracts show a high activity against skin flora as well as a high antimicrobial activity against Propionibacterium acnes. In conclusion, it is confirmed that Smilax china root extracts can be used as raw materials for cosmetics that have antimicrobial activity and antiseptic effect, and it is expected that Smilax china root extracts will be used as basic materials for the development of future natural preservatives.

• Journal of Korean Society of Transportation
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• v.24 no.1 s.87
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• pp.73-84
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• 2006

This study was carried out to set up the logic to determine lengths of the homogeneous sections effectively in order to provide dynamic travel time on real time base for the application of the model. First, considering real time traffic pattern fluctuation, lengths of the homogeneous sections for each time period and the final homogeneous sections were determined. In order to determine lengths of the homogeneous sections according to traffic condition, the cluster analysis was used based on real time data. In order to verify the homogeneous section the case with detectors in all links and the case with detectors in homogeneous section for each time period are used. As the results of verification, each cases showed similar estimation results. The results of this study are expected to be used for National Highway traffic management and the system to Provide a traffic information in the future. According to this study, when the homogeneous section decision model are used to the ITS project for National Highway, operation cost is expected to be cut by effectively establishing point detectors.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.336-341
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• 2016

The object of this study was to classify the local types in relation to regional differences using Height-DBH growth of Pinus densiflora in Korea. The regional types were clustered according to Getis-Ord's $G_i$ among Local indicators of spatial association (LISA) by characteristics of spatial distribution which were calculated the residual of sample plots by fitting Height-DBH growth model using Weibull growth equation. Accordingly, Pinus densiflora were classified 3 groups, It indicated that annual precipitation had one of the biggest impacts among the considered site and climate factors. This results can become the standard for regional management of Pinus densiflora forests.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6D
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• pp.557-563
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• 2012

The purpose of this study is to analyze the spatial structure of Mega-Economic Region particularly in Daegu using Freight Origin-Destination (O/D) Data which comes from KTDB. To diagnose the appropriate separation of Regions, the mean of three standardized indices was calculated. The indicates measured are Freight Occupancy Ratio (FOR), Freight Dependancy Ratio (FDR), Scale Parameter (SP), respectively. The result of analysis showed that FOR FDR SP indicators gave effective explanation about characteristic of Regions depending on Freight moving patterns. Especially, Gyeongsan and Gumi had high correlation Regions with FOR FDR indicator. Also, the major industries of Daegu Metropolitan based on the SP indicator are Chemical and Metal machinery industry.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.312-320
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• 2011

In order to estimate a better methodological factor to understand phytoplankton ecology between abundance and bio-volume of phytoplankton, each 1,160 phytoplankton data, including abundance, classification and chlorophyll $a$ concentration were collected in Korean coastal waters of Incheon (Yellow sea), Tongyeong (South sea), and Ulsan (East sea). Based on these data, phytoplankton bio-volume can be calculated through a geometric model. The correlation coefficient between abundance and chlorophyll $a$ concentration was higher than the coefficient between biovolume and chlorophyll $a$ concentration, because a small size phytoplankton has relatively dense chlorophyll contents compared with the proportion of chlorophyll in a large size phytoplankton. Thus, the interpretation using abundance to understand phytoplankton ecology in Korean coastal waters may be more effective than that using bio-volume.

• Journal of Korea Spatial Information System Society
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• v.11 no.2
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• pp.177-181
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• 2009

Developing u-Public facilities for application u-City is to combine both the state-of-the art of the construction and ubiquitous computing and must be flexibly comprised of the facilities for the basic service of the building such as air conditioning, heating, lighting and electric equipments to materialize a new format of spatial planning and the public facilities inside or outside. Accordingly, in this paper we suggested the time pattern system for predicting the most basic power system loads for the basic service. To application the tim e pattern we applied SOM algorithm and k-means method and then clustered the data each weekday and each time respectively. The performance evaluation results of suggestion system showed that the forecasting system better the ARIMA model than the exponential smoothing method. It has been assumed that the plan for power supply depending on demand and system operation could be performed efficiently by means of using such power load forecasting.

• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.59-70
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• 2009

This study presents a novel traffic information system which is capable of detecting unsafe traffic events leading to accident occurrence and providing warning information to drivers for safer driving. Unsafe traffic events are captured by a vehicle image processing-based detection system in real time. Surrogate safety measures (SSM) representing quantitative accident potentials were derived, and further utilized to develop a data processing algorithm and analysis techniques in the proposed system. This study also defined 'emergency warning area' and 'general warning area' for more effective provision of warning information. In addition, methodologies for determining thresholds to trigger warning information were presented. Technical issues and further studies to fully exploit the benefits of the proposed system were discussed. It is expected that the proposed system would be effective for better management of traffic flow to prevent traffic accidents on freeways.

• Journal of Korean Society of Transportation
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• v.28 no.3
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• pp.99-107
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• 2010

Analyzing mode choice among transportation demand estimate procedures is complicated and understanding characteristics of travelers is also difficult. Generally, it is well known that traveler choose mode considering psychometric factors and characteristic besides socio-demographic indicators. Accordingly, many researches has investigated on methodology that can be applied in mode choice to reflect psychometric factor or specific preference. Latent Class Analysis among various studies is recognized as the theoretically potential approach. This study focuses on class segmented using latent class cluster to analyze impact that included psychometric factors and characteristics on mode choice. It also provides evidence that mode choice model for each class and mode choice model not considering latent class are different. This study based on citizen's stated preference and revealed preference on a new transit on the Han river shows that latent class cluster analysis is the potential approach considering latent preference.

• Journal of Navigation and Port Research
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• v.30 no.1 s.107
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• pp.35-43
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• 2006

This study suggests strategies to prevent traffic accidents by utilizing impact factors per each cluster and the typical patterns of 81 cities based on the statistical analysis of the data concerning the TCI which was developed from the partnership of the Traffic Safety Authority and the Green Traffic Movement Corporation in 2002 and 2003. The Principal Component Analysis and Cluster Analysis on impact factors and TCI result in 4 components and 4 clusters. Also as the results of Stepwise Multiple Regression Analysis examining the relationship between impact factors and TCI, R2 values of these models show high to all clusters. According to the results, we suggest strategies to prevent traffic accidents per cluster concretely and it is necessary to analyze how effective the invested facilities are in reducing traffic accidents in the future.