• Journal of Environmental Science International
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• v.29 no.11
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• pp.1125-1139
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• 2020

This study investigated the distributional pattern of meiobenthos associated with future deep-sea mining in the Korea Deep Ocean Study area present in the Clarion-Clipperton Fracture Zone (CCFZ) located in the southeastern part of the North Pacific Ocean. Standing stocks of meiobenthos were investigated in benthic impact experiment sites (BIS) and Korea Institute of Ocean Science & Technology long-term monitoring (KOMO) sites during the 2008-2014 annual field survey. A total of 14 taxa of meiobenthos were identified. Nematodes were the most abundant taxon (60-86%). Harpacticoid copepods (5-26%) and benthic foraminifera (1-12%) were also dominant at all sites. The total meiobenthic densities varied from 4 to 150 ind./10 cm2. The mean value of total meiobenthic abundance was higher at BIS than at KOMO sites, but there was no significant difference between the two sites. The mean values of the number of taxa and biomass at BIS and KOMO sites were similar. The mean abundance of nematodes that were the most dominant taxa was also higher at BIS than at KOMO sites. The standing stocks in our study sites were relatively lower than those previously reported at other CCFZ sites. These results seem to reflect a low organic concentration in the study area.

• The KIPS Transactions:PartC
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• v.10C no.7
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• pp.857-866
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• 2003

For detecting an intrusion based on the anomaly of a user's activities, previous works are concentrated on statistical techniques in order to analyze an audit data set. However. since they mainly analyze the average behavior of a user's activities, some anomalies can be detected inaccurately. In this paper, a new clustering algorithm for modeling the normal pattern of a user's activities is proposed. Since clustering can identify an arbitrary number of dense ranges in an analysis domain, it can eliminate the inaccuracy caused by statistical analysis. Also, clustering can be used to model common knowledge occurring frequently in a set of transactions. Consequently, the common activities of a user can be found more accurately. The common knowledge is represented by the occurrence frequency of similar data objects by the unit of a transaction as veil as the common repetitive ratio of similar data objects in each transaction. Furthermore, the proposed method also addresses how to maintain identified common knowledge as a concise profile. As a result, the profile can be used to detect any anomalous behavior In an online transaction.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.1-15
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• 2017

Recently terrorism targets unspecified masses and causes massive destruction, which is so-called Super Terrorism. Many countries have tried hard to protect their citizens with various preparation and safety net. With inexpensive and advanced technologies of sensors, the surveillance systems have been paid attention, but few studies associated with the classification of the pedestrians' trajectories and the difference among themselves have attempted. Therefore, we collected individual trajectories at Samseoung Station using an analytical solution (system) of pedestrian trajectory by LiDAR sensor. Based on the collected trajectory data, a comprehensive framework of classifying the types of pedestrians' trajectories has been developed with data normalization and "trajectory association rule-based algorithm." As a result, trajectories with low similarity within the very same cluster is possibly detected.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.6
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• pp.1079-1090
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• 2014

Data mining is a technique to get the useful information that can be utilized for marketing and pattern analysis by processing the data that we have. However, when we use this technique, data provider's personal data can be leaked by accident. To protect these data from leakage, there were several techniques have been studied to preserve privacy. Vertically partitioned data is a state called that the data is separately provided to various number of user. On these vertically partitioned data, there was some methods developed to distinguishing kth element and (k+1) th element by using score. However, in previous method, we can only use on two-party case, so in this paper, we propose the extended technique by using paillier cryptosystem which can use on multi-party case.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.1115-1118
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• 2005

With the development of the internet technology, The on-line conference system have been producted. Now, the on-line conference system is developing for using pattern recognition system and voice recognition system. Comparing with the off-line conference, the on-line conference is excellent in free from distance limitation. But, the on-line meetings have unavoidable weak points. it is the same as the off-line conference that when the conference goes on, the content orthopedic and the content consistency is weak. So the conference members can not seize the conference flow. Therefore, in this paper, we introduce the ontology concept. Design a new architecture using ontology mining technique for making the conference content and conference knowledge ontological. Then in order to inspection the new architecture, We design and implementation the new conference management system based knowledge.

• Journal of the korean society of oceanography
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• v.32 no.4
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• pp.181-190
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• 1997

A large subtidal sand ridge (Jungang Satoe) in Asan Bay, on the west coast of Korea, was studied in order to understand the morphology and sediment transport trend in a macrotidal setting, by means of analyzing sediment samples, current data, side-scan sonographs and seismic profiles. The ridge is about 15 km long and 2-5 km wide, with a relief of about 15 m. It is elongated in the flow direction of flood (SE) and ebb (NW) tidal currents, but asymmetrical in cross section. The western and southwestern side of the ridge is characterized by relatively gentle slopes averaging 0.4$^{\circ}$, whereas on the northeastern side, relatively steep slopes were mapped with 1.6$^{\circ}$ slope angles. Tidal currents associated with the ridge are very strong; maximum surface velo-cities range from neap values of 50 cm/s to spring values of 130 cm/s. The shear velocities during flood and ebb are strong enough to erode and transport sands on the ridge. Sand waves and megaripples (dunes) are the most common bedforms produced by the tidal currents, which show regional differences in shape and size on the ridge. The distribution pattern of these bedforms in-dicates that the flood tidal currents are dominant on the offshore (northwest) side of the ridge, whereas the onsho.e (southeast) side of the ridge is ebb-dominated. The sand transport path as inferred from bedform orientations is directed toward the ridge crest on the flanks, whereas on the crest, it is near-longitudinal to the ridge axis. The convergent, upslope movement of sands on the ridge flanks appears to be important in sand ridge building and maintenance. A significant ridge migration toward the northeast can be suspected on the basis of the ridge morphology, which may cause offshore hazards for navigation.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.380-385
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• 2019

This paper is concerned with departure passengers' dwell time analysis using real system data. Previous researches emphasize the importance of dwell time analysis from perspective of airport terminal planning and non-aeronautical revenue. However, short-term airport operation using passengers' dwell time is considered impossible due to absence of passengers' behavior data. Recently, in accordance with the wave of smart airport, world leading airports are systematically collecting passenger data. So there is high possibility of analyzing passengers' dwell time with the data stacked in the airport database. We conducted dwell time analysis using data from Incheon Int'l airport. In order to handle passenger data, we adapted clustering algorithm which is one of data mining techniques. As a clustering result, passengers are divided into 3 clusters. One is the cluster for passengers whose dwell time is relatively short and who tend to spend longer time in the airside. Another is the cluster for passengers who have near 3 hours dwell time. The other is the cluster for passengers whose total dwell time is extremely long.

• Structural Engineering and Mechanics
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• v.60 no.6
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• pp.939-952
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• 2016

A compression to tensile load transforming (CTT) device was developed to determine indirect tensile strength of concrete material. Before CTT test, Particle flow code was used for the determination of the standard dimension of physical samples. Four numerical models with different dimensions were made and were subjected to tensile loading. The geometry of the model with ideal failure pattern was selected for physical sample preparation. A concrete slab with dimensions of $15{\times}19{\times}6cm$ and a hole at its center was prepared and subjected to tensile loading using this special loading device. The ratio of hole diameter to sample width was 0.5. The samples were made from a mixture of water, fine sand and cement with a ratio of 1-0.5-1, respectively. A 30-ton hydraulic jack with a load cell applied compressive loading to CTT with the compressive pressure rate of 0.02 MPa per second. The compressive loading was converted to tensile stress on the sample because of the overall test design. A numerical modeling was also done to analyze the effect of the hole diameter on stress concentrations of the hole side along its horizontal axis to provide a suitable criterion for determining the real tensile strength of concrete. Concurrent with indirect tensile test, the Brazilian test was performed to compare the results from two methods and also to perform numerical calibration. The numerical modeling shows that the models have tensile failure in the sides of the hole along the horizontal axis before any failure under shear loading. Also the stress concentration at the edge of the hole was 1.4 times more than the applied stress registered by the machine. Experimental Results showed that, the indirect tensile strength was clearly lower than the Brazilian test strength.

• Journal of the Korea Fashion and Costume Design Association
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• v.21 no.3
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• pp.109-119
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• 2019

The purpose of this study is to examine fashion trends and the direction of the four fashion collections by analyzing the design key-words of the four major international fashion collections in 2018. The data of this study was collected by extracting the key-words from Marie Claire Korea in 2018, with the total of the collected data numbering 2,144. The data was analyzed by text mining using the R program and word-cloud, and a co-occurrence network analysis was conducted. The results of this study are as follows: First, the key-words of fashion collection designs in 2018 were fringe and ruffle detail, silk and denim fabric, vivid color, stripe and check pattern, pants suit item, and oversized silhouette, focusing on romanticism and sport. Second, seasonal characteristics of the fashion collections were pastel colors in S/S, primary and vivid colors in F/W. Details were embroidery and cutouts in S/S, patchwork and fringe in F/W. Third, the design trends of the four major fashion collections were presented in the Paris collection: stripes, check patterns, embroidery, lace, tailoring, draping, romanticism, and glamor. In the Milan collection, checks, prints, denim, and minidresses reflected sport and romanticism. The London collection included fringe, ruffles, floral patterns, flower patterns, and romanticism. The New York collections included vivid colors, neon colors, pastel colors, oversize silhouettes, bodysuits, and long dresses.

• Journal of Environmental Health Sciences
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• v.48 no.4
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• pp.206-215
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• 2022

Background: Fragrance substances in consumer products can cause adverse health effects such as contact allergy. In South Korea, consumer chemical products must list 26 known fragrance allergens on product labels when they contain more than 0.01%. Fragrance substances are mostly used in combination, so co-exposure can occur via use of a consumer chemical product. Co-exposure to fragrance allergens may show a synergistic effect on the human body. Objectives: The aims of the study were to analyze the characteristics of fragrance allergens in consumer chemical products available on public websites and to identify the co-occurrence patterns of fragrance allergens. Methods: The chemicals in 1,443 ingredient disclosures for consumer chemical products were collected through the Ecolife database. The 26 labelled fragrance allergens were identified by category of consumer chemical product. The co-occurrence patterns of the 26 labelled fragrance allergens were analyzed by frequent pattern mining. The unlabelled fragrance allergens presented by European Union Scientific Committee on Consumer Safety were also identified. Results: Consumer chemical products contained an average of 5.3±4.2 substances among the 26 labelled fragrance allergens. More than 85% of air fresheners, deodorizing agents, and fabric softeners contained at least one of the 26 labelled fragrance allergens. The most frequently contained fragrance allergens were limonene (50.5%), linalool (49.9%), hexyl cinnamal (34.0%), and citronellol (28.3%). 16.7% of consumer chemical products showed a co-occurrence of limonene, linalool, hexyl cinnamal, and citronellol. Thirty-eight unlabelled fragrance allergens were found in the consumer chemical products, with hexamethylindanopyran (25.2%) being the most frequently contained substance. Conclusions: The characteristics and co-occurrence patterns of 26 labelled fragrance allergens would be useful information for the management of co-exposure to fragrance allergens in consumer chemical products. It is necessary for attention to be paid to unlabelled fragrance allergens.