• Proceedings of the KSRS Conference
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• v.2
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• pp.582-585
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• 2006

Augustine volcano is an active stratovolcano located southwest of Anchorage, Alaska. Augustine volcano experienced seven significantly explosive eruptions in 1812, 1883, 1908, 1935, 1963, 1976, and 1986, and a minor eruption in January 2006. To measure ground surface deformation of Augustine volcano, we applied satellite radar interferometry with ERS-1/2 and ENVISAT SAR images acquired from three descending and three ascending satellite tracks. Multiple interferograms are stacked to reduce artifacts due to changes in atmospheric condition and retrieve temporal deformation sequence. For this, we used Least Square (LS) method for reducing atmospheric effects and Singular Value Decomposition (SVD) method for the retrieval of a temporal deformation sequence. Interferograms before 2006 eruption show about 3 cm/year subsidence by contraction of pyroclastic flow deposits from the 1986 eruption. Interferograms during 2006 eruption do not show significant deformation around volcano crater. Interferograms after 2006 eruption show again a several cm subsidence by compaction and contraction of pyroclastic flow deposits for a few months. This study demonstrates that satellite radar interferometry can monitor deformation of Augustine volcano to help understand the magma plumbing system driving surface deformation.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.73-78
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• 2008

We introduce OBS and sonobuoy systems which are the typical wide-angle reflection/refraction seismic recorders made by KORDI for the investigation of crustal structure and the sediment/basement structure in the coastal area. These recording devices are examined for their usage through the test survey. The normal operation of these devices were proved and good recordings were obatined. The head waves are recognized in the sonobuoy records, which shows the possibility of velocity structure survey by the refraction and/or tomography method.

• Journal of Environmental Health Sciences
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• v.35 no.1
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• pp.36-44
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• 2009

Hand-washing has been recognized as a critical factor in controlling infection and cross-contamination. This study was performed to investigate hygienic behavior of male university students focusing on awareness of hand-washing, their hand washing practices, and the difference between their awareness and practices. Both a self-administered questionnaire survey and a separate direct observation in restrooms were carried out at a university campus over a four week period. In the survey, 93.6% of the responded students claimed to wash their hands after using toilet. However, just 16.9% of the observed students actually did so, according to a separate and unnoticed observational study. Among the observed students who washed their hands, 25.0% of them used soap, only 5.0% of them washed four parts of their hands, and 15.0% of them washed their hands for more than 10 seconds. Paper towel was the most common hand drying method in the direct observation and also in the survey. Significant differences between the questionnaire survey and the direct observation (p<0.0l) were found in hand-washing practices, duration of hand-washing, using soap, washing parts of the hand, and hand-drying method after using the toilet. This study indicates that there is a remarkable difference between the male university students' awareness of hand-washing and their hand-washing practices. This study reveals that there is the need for programs or campaigns to increase hand-washing practices of male university students.

• The Korean Journal of Applied Statistics
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• v.24 no.2
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• pp.393-400
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• 2011

In a large scale survey, cluster sampling design in which a set of observation units called clusters are selected is often used to satisfy practical restrictions on time and cost. Especially, a two stage cluster sampling design is preferred when a strong intra-class correlation exists among observation units. The sample Primary Sampling Unit(PSU) and Secondary Sampling Unit(SSU) size for a two stage cluster sample is determined by the survey cost and precision of the estimator calculated. For this study, we derive the optimal sample PSU and SSU size when the population SSU size across the PSU are di erent by extending the result obtained under the assumption that all PSU have the same number of SSU. The results on the sample size are then applied to the $4^{th}$ Korea Hospital Discharge results and is compared to the conventional method. We also propose the optimal sample SSU (discharged patients) size for the $7^{th}$ Korea Hospital Discharge Survey.

• Journal of Intelligence and Information Systems
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• v.17 no.2
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• pp.77-96
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• 2011

An exhibition is defined as market events for specific duration to present exhibitors' main products to business or private visitors, and it plays a key role as effective marketing channels. As the importance of exhibition is getting more and more, domestic exhibition industry has achieved such a great quantitative growth. But, In contrast to the quantitative growth of domestic exhibition industry, the qualitative growth of Exhibition has not achieved competent growth. In order to improve the quality of exhibition, we need to understand the preference or behavior characteristics of visitors and to increase the level of visitors' attention and satisfaction through the understanding of visitors. So, in this paper, we used the observation survey method which is a kind of field research to understand visitors and collect the real data for the analysis of behavior pattern. And this research proposed the following methodology framework consisting of three steps. First step is to select a suitable exhibition to apply for our method. Second step is to implement the observation survey method. And we collect the real data for further analysis. In this paper, we conducted the observation survey method to obtain the real data of the KIDS & EDU EXPO for Children in SETEC. Our methodology was conducted on 160 visitors and 78 booths from November 4th to 6th in 2010. And, the last step is to analyze the record data through observation. In this step, we analyze the feature of exhibition using Demographic Characteristics collected by observation survey method at first. And then we analyze the individual booth features by the records of visited booth. Through the analysis of individual booth features, we can figure out what kind of events attract the attention of visitors and what kind of marketing activities affect the behavior pattern of visitors. But, since previous research considered only individual features influenced by exhibition, the research about the correlation among features is not performed much. So, in this research, additional analysis is carried out to supplement the existing research with data mining techniques. And we analyze the relation among booths using data mining techniques to know behavior patterns of visitors. Among data mining techniques, we make use of two data mining techniques, such as clustering analysis and ARM(Association Rule Mining) analysis. In clustering analysis, we use K-means algorithm to figure out the correlation among booths. Through data mining techniques, we figure out that there are two important features to affect visitors' behavior patterns in exhibition. One is the geographical features of booths. The other is the exhibit contents of booths. Those features are considered when the organizer of exhibition plans next exhibition. Therefore, the results of our analysis are expected to provide guideline to understanding visitors and some valuable insights for the exhibition from the earlier phases of exhibition planning. Also, this research would be a good way to increase the quality of visitor satisfaction. Visitors' movement paths, booth location, and distances between each booth are considered to plan next exhibition in advance. This research was conducted at the KIDS & EDU EXPO for Children in SETEC(Seoul Trade Exhibition & Convention), but it has some constraints to be applied directly to other exhibitions. Also, the results were derived from a limited number of data samples. In order to obtain more accurate and reliable results, it is necessary to conduct more experiments based on larger data samples and exhibitions on a variety of genres.

• Journal of Food Hygiene and Safety
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• v.24 no.2
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• pp.128-135
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• 2009

Hand-washing is one of the most important factors in infection control and in preventing cross-contamination. The objective of this study was to investigate female university students' awareness of hand-washing, their hand washing practices, and the difference between their awareness and practices. A self-administered questionnaire survey and direct observation in restrooms were separately carried out in a university campus and over four weeks' period. A total of 97.4% of the survey respondents claimed to wash their hands after using toilet, and 98.2% of the observed students actually did so according to the unnoticed observational study. However, only 6.3% of the students who washed their hands in the direct observation washed for more than 10 seconds, although 46.4% of respondents in the survey reported that they usually wash their hands for more than 10 seconds. Among the observed students who washed their hands, only 0.9% used soap, and 0.9% washed four parts of their hands. Paper towel was the most common hand-drying method in the direct observation and also in the survey. Significant differences were found in duration, use of soap, part of washing, and hand-drying method between the questionnaire survey and the direct observation (p<0.05). This study indicates that there is a noticeable difference between the awareness of hand-washing and hand-washing practices among female university students. Further research should examine hand-washing practices of female university students in restrooms outside the university campus.

• Journal of the Korean Home Economics Association
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• v.24 no.3
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• pp.11-18
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• 1986

The height of pillow was investigated from the ergonomics standpoint. The main concern of this research was to investigated the appropriate height of the pillow in lying on one's side. The infestigation in this study was administered to a sample of forty men who were similar to Korean standard body-build. The experiment was conducted under the awakening state. The experimental method was performed using ; 1) Sensuous test 2)Electromyogram survey 3) X-ray observation Sensuous test was performed using both a plain wood board and a slope wood board by jack to objectify. RESULTS : 1) By sensuous test, the height of pillow for the most comfortable state turned up 9.4±1.1cm in lying on one's side. 2) By electromyogram survey and X-ray observation, the numerical value was substantially confirmed well-grounded physiologically and anatomically. Ihope this research will be useful to establishing the suitable height of pillow for Korean.

• Journal of Digital Convergence
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• v.13 no.12
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• pp.217-224
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• 2015

OBJECTIVES Handwashing rate of Korean people was lower than the rates of people in developed countries. The purpose of this study was to investigate handwashing rate, the factors influence people's handwashing behaviors during use of public restroom. METHODS This study used the data of '2013 Korea National Handwashing Survey'. The survey was done through direct observation on the user of subway and train station restroom from September 10 to 12, 2013. RESULTS Factors influencing handwashing with soap were administrative region(OR 0.490-2.255), purpose of toilet use(urination 1.000, defecation 2.505), drying method after handwashing(OR 0.497-3.107). CONCLUSIONS The results of this study will provide the evidence data of national handwashing promotion activities for preventing and controlling communicable diseases.

• Journal of Ocean Engineering and Technology
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• v.5 no.1
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• pp.35-44
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• 1991

This study was carried out for the purpose of pre-estimating long-term settlement under condition of actual field soil's property, in case of building up industrial sites on the marine deposit silty clay located at West Coast in Korea. This study analyzed Hyperbolic Method, Square Root Time Method and Exponential Function Method with utilization of measured survey values of settlement in In-Cheon Namdong Industrial Sites. In the future, for the continuos utilization, it seemed to be needed that further the survey values of fields should be accurartely measured for the analysis of more accurate pre-estimate about long-term settlement. Among the prediction methods of settlement Hyperbolic Method seemed to be the best fitting method for measured data. The settlement equations were derived from above three methods, for long-term settlements.

• Korean Institute of Interior Design Journal
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• v.14 no.5 s.52
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• pp.236-244
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• 2005

This study investigates the effects of the spatial elements of the mulit-purpose commercial complex on visitors' circulation pattern and wayfinding by employing method of space syntax, observation, and interview survey. Two commercial complexes were investigated; Techno-mart represented a vertical type and COEX mall rendered a horizontal one. Analysis of the spatial elements using space-syntax method provided a base line for comparing analyses by the two other methods. Analysis of the interview additionally survey identified the factors affecting wayfinding behavior and contributing satisfaction. The findings suggest that level of the effects of the spatial configuration on visitors' circulation pattern is greater in Techno-mart(vertically oriented) than COEX(horizontally). In COEX, for instance, specific route that connects sub-way station and cinema complex carries far more traffic than main route, even though the main route indicates higher degree of integration of spatial configuration. Similar with observation, the degree of integration is corresponding with the satisfaction and easiness of wayfinding behavior In COEX, specific place and feature seem to have more effects on visitors' wayfinding behavior and circulation pattern than the level of integration of spatial configuration.