• Geomechanics and Engineering
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• v.35 no.5
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• pp.511-523
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• 2023

Canal-side roads frequently collapse due to an unexpectedly greater soft-clay thickness with a rapid drawdown situation. This causes annually increased repair and reconstruction costs. This paper aims to explore the effect of soft-clay thickness on the failure in the canal-side road in the case study of Phra Nakhon Si Ayutthaya rural road no. 1043 (AY. 1043). Before the actual construction, a field vane shear test was performed to determine the undrained shear strength and identify the thickness of the soft clay at the AY. 1043 area. After establishing the usability of AY. 1043, the resistivity survey method was used to evaluate the thickness of the soft clay layer at the failure zone. The screw driving sounding test was used to evaluate the undrained shear strength for the road structure with a medium-stiff clay layer at the failure zone for applying to the numerical model. This model was simulated to confirm the effect of soft-clay thickness on the failure of the canal-side road. The monitoring and testing results showed the tendency of rapid drawdown failure when the canal-side road was located on > 9 m thick of soft clay with a sensitivity > 4.5. The result indicates that the combination of resistivity survey and field vane shear test can be successfully used to inspect the soft-clay thickness and sensitivity before construction. The preliminary design for preventing failure or improving the stability of the canal-side road should be considered before construction under the critical thickness and sensitivity values of the soft clay.

• The Journal of Engineering Geology
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• v.28 no.3
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• pp.341-348
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• 2018

Landslides can be caused by localized intense rainfall. The loss of human lives and damage to property from landslides is increasing. However, little information exists on the movement and flow of sediment material at the time of rapid landslides. In this study, a field survey was conducted of landslides that occurred in 2013 in the Hadari area of Yeoju city in Korea. This was followed by numerical analysis. The purpose is to analyze the characteristics of a consequent debris flow and its movement at the time of failure. The results of the field survey and numerical analysis are consistent with each other. The maximum velocity of the debris flow was ~9.335 m/s and the maximum sediment thickness ~4.674 m. The latter is similar to the traces of debris flow observed in the field.

• Journal of Astronomy and Space Sciences
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• v.27 no.2
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• pp.75-80
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• 2010

Several survey observations have produced light curves of more than five thousand eclipsing binaries for last 15 years. Future missions such as the Large Synoptic Survey Telescope (LSST), the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) and Gaia are expected to yield hundreds thousands of new variable stars and eclipsing binaries. Current methods require a week to analyze the light curves of an eclipsing binary for its physical and orbital parameters. The current methods of analyzing the light curves will be inadequate to treat the overwhelming influx of new data. Therefore we developed a new method to treat large numbers of light curves of eclipsing binaries. We tested the new method by analyzing more than one hundred light curves of the detached and semi-detached eclipsing binaries discovered in the Small Magellan Cloud and present their fitted light curves with observations.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.6
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• pp.35-43
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• 2018

As rapid increasing of domestic apartments, decline of the market value of the old apartment and to be announced policy by government are re-lighting to be insufficient growth than the past 15 years in market of apartment remodeling. In this study, research the conflicts on apartment remodeling project and analysis of importance and satisfaction by survey. Also, the survey was being progressed for every participant who are related in an apartment remodeling project. After this study, this study will propose basic data for effective way to improve on apartment remodeling project. For this purpose, generalize the project stage level by level. And analysis status of business progress to be felt from participants of project. According to the results by a survey, the each result of elements can be a reference value for a good way of apartment remodeling to proceed and improve.

• Korean Journal of Organic Agriculture
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• v.31 no.3
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• pp.229-247
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• 2023

This study investigates the facility use status of smart farming farmers to improve facility use rate of farmers. To this end, a survey was conducted on smart farming farmers in Jeonnam province, and the main survey contents are as follows: facility use rate, the reasons for low facility use, the perception of the introduction and use of smart farming etc. As a result of the survey, many farmers have introduced smart farming facilities even though they do not have enough use capacity. Thus it is necessary to improve the use capacity of farmers. Second, the average facility use rate of farmers was 65.1%, and 37.5% of respondents did not use even 50% of smart farming facilities. To improve the use rate, education on how to use facilities and continuous consulting support for farmers are needed. And the largest number of farmers perceived the risk like crop damage or facility failure due to poor use of facilities. This means that risk management due to the smart farming facilities is important. Third, farmers answered that rapid and continuous repair service were the most important when using facilities. Thus it is important to foster rear industries such as maintenance companies to stably operate smart farming facilities.

• Journal of Korean Society of Transportation
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• v.31 no.3
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• pp.33-44
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• 2013

Personal Rapid Transit(PRT) has emerged as a promising transportation mode for transit-oriented sustainable communities. In this study, an alternative design of questionnaire survey is proposed in order to capture traveler's perception of an unexperienced transportation mode. This study aims at predicting the mode choice diversion behavior of potential PRT users who do not have experience of using it previously, considering their willingness-to-pay. The proposed model was applied to predict an aggregate forecast of PRT patronage for the city of Songdo where PRT is considered to be constructed. For validation of the proposed model, the price elasticity of PRT demand was analyzed, compared with existing models. The analysis results suggest that the proposed design of questionnaire survey is able to capture respondents' attitude and perception to unexperienced transportation mode in an effective manner. Also, they show that the proposed diversion rate model is more realistic than existing models in explaining the effects of users' willingness-to-pay for predicting PRT patronage.

• Journal of Medicine and Life Science
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• v.17 no.1
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• pp.29-32
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• 2020

As respiratory syncytial virus(RSV) is transmitted either via directly contact with an infected case or via indirectly contaminated fomites or skin, the major preventive measures are strict hand hygiene, early detection of transmitted sources, and rapid isolation of RSV patients. Especially early detection of hidden cases is the most critical control measure when an index case was notified in a postpartum center. The Guideline of Korea Centers for Diseases Control and Prevention defines potential contacts in an epidemiologic survey as admitted newborns, parents of index cases, center's workers, and visitors for 10 days before the first diagnosis day of index case. However, it needs to classify potential contacts in more detail in order to conduct a successful survey. Authors conducted to search related literatures and appraise the evidences. Firstly, potential contacts would be classified into RSV-related symptomatic contacts(SxC) and asymptomatic contacts. And then, mother, caring workers, and visitors of the index cases among asymptomatic contacts would be defined as the asymptomatic close contacts(ASCC). Finally, the rest would be defined as the asymptomatic regular contacts(ASRC). The defined test using reverse transcription-PCR is applied to SxC and ASCC, and decision of isolation or regular activities are made according to the results. The rapid antigen detection test kits are applied to ASRC. These suggestions might be helpful to detect hidden cases earlier and prevent a further infection.

• Survey Research
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• v.3 no.2
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• pp.91-122
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• 2002

The use of internet is expanding globally in a rapid way. The situation is similar in Korea. The growth of internet affects the various aspects of a social system. Such an impact is not an exception in the field of survey data-collection. The internet survey method has gained a recognition as an important survey approach in the U.S and Europe. A number of Korean research organizations have already started implementing the new survey method, too. The time is quite ripe for the internet survey in Korea. However, it is hard to find ever a good literature review on the subject. This study intends to review the results of the past studies about the question of what factors influence the response rate, speed, and quality. The influencing factors incorporated in this review include six elements: personalization, the survey sponsorship, incentives, the questionaire format, prenotification, and follow-ups. Regarding there sis factors, the results of the past studies relating to the internet survey response are reviewed in a systematic way.

• Survey Research
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• v.11 no.1
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• pp.107-121
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• 2010

The purpose of this paper is to design and implement a Computer Assisted Personal Interviewing (CAPI) system for Panel Survey of Employment for the Disabled (PSED) using Blaise software developed by Statistics Netherlands which is a powerful and flexible system used for computer-assisted survey processing. CAPI system for PSED is consisted of three parts, which are survey management program, electronic questionnaire program, and postprocessing program. These programs are constructed with modular approach and are integrated into CAPI system. The developed software is highlighted in its reusability which results in the improved efficiency and reduced cost of software maintenance. CAPI system for PSED proved its effectiveness in carrying out the survey by guaranteeing correctness of survey data, improved timeliness of survey, easy reforming the questionnaires, easy control on the interviewers, and rapid data processing in spite of the complexity of PSED.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.556-563
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• 2015

Chinese cabbage is one of the most important vegetables in Korea and a target crop for market stabilization as well. Remote sensing has long been used as a tool to extract plant growth, cultivated area and yield information for many crops, but little research has been conducted on Chinese cabbage. This study refers to the derivation of simple Chinese cabbage growth prediction equation by using RapidEye derived vegetation index. Daesan-myeon area in Gochang-gun, Jeollabuk-do, Korea is one of main producing district of Chinese cabbage. RapidEye multi-spectral imagery was taken on the Daesan-myeon five times from early September to late October during the Chinese cabbage growing season. Meanwhile, field reflectance spectra and five plant growth parameters, including plant height (P.H.), plant diameter (P.D.), leaf height (L.H.), leaf length (L.L.) and leaf number (L.N.), were measured for about 20 plants (ten plants per plot) for each ground survey. The normalized difference vegetation index (NDVI) for each of the 20 plants was measured using an active plant growth sensor (Crop $Circle^{TM}$) at the same time. The results of correlation analysis between the vegetation indices and Chinese cabbage growth data showed that NDVI was the most suited for monitoring the L.H. (r=0.958~0.978), L.L. (r=0.950~0.971), P.H. (r=0.887~0.982), P.D. (r=0.855~0.932) and L.N. (r=0.718~0.968). Retrieval equations were developed for estimating Chinese cabbage growth parameters using NDVI. These results obtained using the NDVI is effective provided a basis for establishing retrieval algorithm for the biophysical properties of Chinese cabbage. These results will also be useful in determining the RapidEye multi-spectral imagery necessary to estimate parameters of Chinese cabbage.