• Journal of KIISE
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• v.45 no.3
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• pp.294-302
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• 2018

With the emergence of the new service industry due to the development of information and communication technology, cyber space risks such as personal information infringement and industrial confidentiality leakage have diversified, and the security problem has emerged as a critical issue. In this paper, we propose a behavior-based anomaly detection method that is suitable for real-time and large-volume data analysis technology. We show that the proposed detection method is superior to existing signature security countermeasures that are based on large-capacity user log data according to in-company personal information abuse and internal information leakage. As the proposed behavior-based anomaly detection method requires a technique for processing large amounts of data, a real-time search engine is used, called Elasticsearch, which is based on an inverted index. In addition, statistical based frequency analysis and preprocessing were performed for data analysis, and the DBSCAN algorithm, which is a density based clustering method, was applied to classify abnormal data with an example for easy analysis through visualization. Unlike the existing anomaly detection system, the proposed behavior-based anomaly detection technique is promising as it enables anomaly detection analysis without the need to set the threshold value separately, and was proposed from a statistical perspective.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6D
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• pp.541-552
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• 2010

The light rail transit (LRT) having bus lines as subsystem is being constructed or planned in the suburban area of metropolitans and medium size cities. However, there is difficulty in establishing the service coverage (SC) of the LRT because the LRT is a completely new transit mode in Korea. The purpose of this study is to provide the basic data and techniques to be used for establishing the SC of the future LRT by understanding the SC characteristics of buses and subways and building models to estimate the walking distances of their users. Busan City is selected as the study city and the SC's of buses and subways are surveyed simultaneously. A total of 9 variables for 82 stations are collected and the cluster analysis is conducted about the variables. The station areas are divided to three types of CBD (Central Business District), sub-CBD and regional center based on the analysis. A station in each area is selected as the study station. At the walking distance (WD) analysis for each mode, the 80 percentile WD of the subway is 672 m and that of the bus is 472 m. In comparing the SC's of both modes by the type of station areas, there are not significant differences between the SC's of sub-CBD and regional center except CBD. At analysis of the relationship between the personal attributes and the WD, for subway users the WD of female is longer than that of male and apartment residents use subway more positively than single house residents do. For the models to estimate the walking distances, the simple regression models were built employing the income as independent variable by dividing the stations into CBD abd non-CBD stations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.441-453
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• 2017

This paper described the spatio-temporal distributions in the phytoplankton community, such as species composition, standing crops, and dominant species, from July 2012 to April 2013 in the Coastal Waters of Central South Sea (CWoCSS) of Korea. A total of 87 species of phytoplankton belonging to 52 genera were identified. In particular, diatoms and phytoflagellates comprised more than 62.1% and 37.9% of the total species, respectively. The phytoplankton cell density fluctuated with an annual mean of $7.9{\times}10^4cells{\cdot}L^{-1}$ between the lowest value of $1.0{\times}10^3cells{\cdot}L^{-1}$ in spring and the highest value of $4.5{\times}10^5cells{\cdot}L^{-1}$ in winter. The seasonal succession of the dominant species were Chaetoceros curvisetus, Ch. debilis in summer, Eucampia zodiacus in autumn, E. zodiacus, Thalassiosira curviseriata in winter and Skeletonema costatum -ls (like species), Leptocylindrus danicus in spring. According to principal component analysis, the phytoplankton community of the CWoCSS was characterized by the mixing rate between the freshwater inflow from Somjin River and the seawater of the South Sea, Korea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.2
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• pp.76-86
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• 2012

Macrozoobenthos were collected from 24 sites using small grab ($0.05m^2$) in order to see the spatial distribution of them at Sueocheon stream at the northern part of Gwangyang Bay during summer season when the maximum ecological processes are occurring. A total of 44 species of macrozoobenthos occurred, and their mean density was $789individuals/m^2$. Mollusks was the dominant faunal group accounted for 43.1% and 86.8% of the whole community density and biomass, respectively. Top five dominant species were a molluscan, Corbicula japonica (40.7%), two polychaete worms, Neanthes japonica (19.3%) and Heteromastus filiformis( 8.1%), and two crustaceans, Paranthura japonica (6.9%) and Jaeropsis sp. (6.9%). Species diversity index was very low with mean value of 1.12 and maximum value was recorded at the river mouth. At the upper stream, a brackish water species such as Corbicula japonica showed their maximum population density. The overall distribution of stream macrobenthos showed a rather simple pattern along with salinity and grain size gradients with few brackish water species occurring at coarse sediments in the stream but more diverse faunas inhabiting fine sediments in the river mouth.

• Korean Journal of Environment and Ecology
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• v.28 no.6
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• pp.697-704
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• 2014

Mt. Hallasan in Jejudo has been well known as a habitat for both northern and southern limited butterflies and attracts the interests of many lepidopterists. In this study, the line transect method was used to monitor the community and similarity of butterflies monthly monitoring from May to September 2013, and the results were compared with the previous data. Through monitoring, 3,397 individuals in 26 species of 5 families were found in the present study. The monitored individuals belonging to 4 species (Aphantopus hyperantus, Eumenis autono, Lethe diana and Melanargia epimede) was 2,578 (75.9%), showing the prevalent species among the butterflies observed in the grassy area of the Mt. Hallasan. The butterflies inhabiting Mt. Hallasan showed higher similarity in the area where the open grassy space and the crowns of tree layer coexist than in landscape consisting of solely the tree layer or open grassy space. The habitation of butterflies by heights showed the altitudes between 1,665 to 1,700 m, located beneath the Baekrokdam (the crater) of Mt. Hallasan, possessed the most species and individuals. And it was also observed that the species that previously inhabited the subalpine zone moved to the area of higher altitudes together with the species that previously inhabited rather lower altitudes than the subalpine zone.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.75-87
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• 2014

This study describes about the spatio-temporal distributions in phytoplankton community such as species composition, standing crop and dominant species from May 2006 to February 2007 in the Jangsu bay and the northwestern parts of Gamak bay. Based on the principal component analysis (PCA) of the environmental factors as well as biological parameters, the bio-oceanographical characteristics were analysed. A total of 83 species of phytoplankton belonging to 47 genera were identified. Whereas diatoms and dinoflagellates occupied more than 65% and 30% of total species, respectively. The annual dominant species were Chaetoceros affinis, Paralia sulcata and Bacillaria paxillifera in spring, Chaetoceros didymus, Ch. affinis and Octactis octonaria in summer, Skeletonema costatum-like species and B. paxillifera in autumn. Moreover phytoplankton cell density was ranged between 3.1 $cells{\cdot}mL^{-1}$ in spring and 521.0 $cells{\cdot}mL^{-1}$ in winter. It fluctuated with an annual mean of 76.0 $cells{\cdot}mL^{-1}$ between the lowest value of 7.6 $cells{\cdot}mL^{-1}$ in spring and the highest value of 220.2 $cells{\cdot}mL^{-1}$ by Skeletonema costatum-like species in winter. Briefly, the phytoplankton cell density in the mixing seasons was higher in comparison with the other seasons. According to the PCA, the biological oceanographic characteristics of the Jangsu bay was affected by the introduction of outside seawater particularly in temperature increasing seasons, and the other seasons, it may be described the light intensity, and mix between inner and outer bay sea waters.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.211-218
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• 2007

In this study, we investigated the spatial distribution of macrozoobenthos in the estuarine sandy flat, the Bongam tidal flat located in Masan Bay during March, 2004. A total 13 species were identified at 12 stations within the tidal flat. The mean density was $20,267\;ind./m^2$, and mean biomass was $228.1g/m^2$. Dominant species in the Bongam tidal flat were all polychaetes: Prionospio japonicus ($11,716\;ind./m^2$, 57.8%) and Polydora ligni ($3,929\;ind./m^2$, 19.4%) of spionoid polychaete, and Neanthes succinea ($3,425\;ind./m^2$, 16.9%) of nereid polychaete. The most dominant species, P. japonicus distributed evenly all stations in the tidal flat. But N. succinea showed high density at the upper area of the tidal flat. Species diversity index (H') was in the range of 0.6 to 1.2 which is relatively low due to the prominent of P. japonicus and few species richness at each station. The study area was divided into two station groups (group A and B) based on the cluster analysis and MDS ordination, and the spatial distribution of macrozoobenthos on the Bongam tidal flat seemed to be in the influence of exposure duration from tidal levels and specific geological topography.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.3
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• pp.93-107
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• 2019

The purpose of this paper is to explore the application of Chinese traditional garden space construction principle studied by predecessors in modern park landscape, and to find more methods of traditional garden space construction inheritance and innovation through research. Tian Chaoyang's book "Fifteen Lectures on Chinese Classical Gardens and Modern Translation" mentions that Chinese traditional gardens are combining time and space, so he draws a brief pattern diagram containing the principle of the space construction. According to this principle of space construction, the researchers chose Qujiang Pool Heritage Park, which combines modern and traditional, then analyzed its spatial structure and and space elements. The results are as follows. The complex spatial structure of the park is composed of spatial boundary lines and spatial routes. The complex boundary space is composed of bridges, squares, plants, rows of buildings and other elements. The water space in the center of the park is designed in accordance with the traces of the historical water system, and its natural zigzag shoreline expands the water space. The central water space is divided into the big pool and the small pool, the Yanbo island and Bird island are created respectively. The building at the park boundary connects the park's interior and exterior. Most of the buildings in the park are located in the convex corner of the route or space. Through this research, it can be concluded that Qujiang park also applies the space construction principle combining time and space. And then, the garden elements of Qujiang park are recreating the history and culture of Qin, Han, Sui and Tang dynasties with modern methods, thus creating a park with Chinese regional characteristics. Since the Tang dynasty was the most prosperous period in Qujiang, the park was dominated by Tang culture. Through the research of this paper, we can see that the space construction principle of Qujiang Pool Heritage Park is the inheritance of the space construction principle of Chinese traditional garden. And the landscape element of Qujiang park is the landscape created by combining traditional history and culture, which is the innovative part of modern garden. Through this study, the creation of modern landscape with Chinese characteristics can provide some hints on the direction of inheritance and innovation.

• Journal of Korea Multimedia Society
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• v.11 no.11
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• pp.1501-1514
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• 2008

The face shape extracted by the depth values has different appearance as the most important facial information. The face images decomposed into frequency subband are signified personal features in detail. In this paper, we develop a method for recognizing the range face images by multiple frequency domains for each depth image using the modified fuzzy c-mean algorithm. For the proposed approach, the first step tries to find the nose tip that has a protrusion shape on the face from the extracted face area. And the second step takes into consideration of the orientated frontal posture to normalize. Multiple contour line areas which have a different shape for each person are extracted by the depth threshold values from the reference point, nose tip. And then, the frequency component extracted from the wavelet subband can be adopted as feature information for the authentication problems. The third step of approach concerns the application of eigenface to reduce the dimension. And the linear discriminant analysis (LDA) method to improve the classification ability between the similar features is adapted. In the last step, the individual classifiers using the modified fuzzy c-mean method based on the K-NN to initialize the membership degree is explained for extracted coefficient at each resolution level. In the experimental results, using the depth threshold value 60 (DT60) showed the highest recognition rate among the extracted regions, and the proposed classification method achieved 98.3% recognition rate, incase of fuzzy cluster.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.3
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• pp.180-189
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• 2001

This study was conducted to investigate the macrobenthic community in Ulsan Bay and Onsan Bay, in November of 1997. The density of benthic animals was 535 md./m2, and the number of species was 117. Polychaeta was the most dominant faunal group, comprising a total of 63 species, and its density was 380 md./m2 The most dominant benthic macrofauna was Cirratulrus cirratulas (2.7%), and followed by Tharyx sp. (16.6%), Ruditapes philippinarum (16.1%), Lumbrineris longifolia (10.3%) and so on. The dominant species occupied their distinct unique distribution area. Tharyx sp., R. philippinarum and Grandidierella sp.1 occurred mainly in Ulsan Bay, L. longifolia and Euchone sp. in Onsan Bay, and C. cirratulas and Cirriforimia tentaculata in both bays. By cluster analysis, study area was divided into 4 station groups: Northern Ulsan Bay (Al), the middle area of Ulsan Bay (Bl), offsea area between Ulsan Bay and Onsan Bay (Bll), and Onsan Bay (C). Northern Ulsan Bay was characterized by low species number and high density. The dominant species were C. cirratulas R. philippinarum and Tharyx sp. The middle area of Ulsan Bay was by low species number and density, and its characteristic species was Grandidierella sp.1. The offsea area between Ulsan and Onsan Bay was by high species number and low density. Onsan Bay was by high species number and high density, and its important species were L. longifolia and Euchone sp.