• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.594-604
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• 2017

The Korean National Institute of Fisheries Science (NIFS) has biannually (spring and fall, respectively) deployed a bottom trawl survey along the coastal areas for last decade, taking samples on a regular basis (i.e., a systematic sampling). Despite the availability of the survey data, NIFS has not yet officially reported the estimates of the groundfish population sizes as well as has not evaluated uncertainty of the estimates. The objectives of our study were to infer the relative size of a fish population, applying two different sampling techniques (namely simple and stratified sampling) with different observation units to the NIFS survey data, and to compare those two techniques in bias and precision. For demonstration purposes, we used data on Pacific cod (Gadus macrocephalus) collected by the 2011-2015 surveys, and the results of simple and stratified sampling showed that the point estimates and precision varied by observation unit as well as the sampling technique.

• Journal of Korean society of Dental Hygiene
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• v.15 no.5
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• pp.925-932
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• 2015

Objectives: The aim of this study is to investigate the relationship between diabetes mellitus and oral disease in the Korea adults by using the representative data of Korea National Health and Nutrition Examination Survey (KNHANES) V. Methods: Using data from a cross-sectional survey of Korea National Health and Nutrition Examination Survey V. The subjects were 5,602 adults over 19 years old. The survey data and the examination data are used for the independent variables. KNHANES included health status, nutrition survey, and oral examination. The health status was obtained by a self-reported questionnaire of the study subjects and direct interview was carried out on economic status, prevalence rate, and use of medical services. Results: The regular dental checkup of diabetes patients was significantly lower than the general population. Regular dental visits allow adults to receive early diagnosis and obtain restorative care at the first visit. The regular annual oral examination is very important to prevent and manage the chronic diseases including diabetes mellitus. Conclusions: Diabetes mellitus can be fully prevented and managed by the regular annual dental checkup. The establishment of the regular dental checkup system can prevent and manage the complication due to diabetes mellitus and other chronic diseases.

• IE interfaces
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• v.13 no.4
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• pp.619-626
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• 2000

In this paper, we place the focus on suggesting a method of forecasting demand for PCS resale service with survey data in Korea. It is important for the service provider to forecast the diffusion process when designing marketing strategies and analyzing the costs and benefits. For the reason, we conduct a survey of three groups composed of non-subscribers, cellular subscribers, and PCS subscribers in order to forecast the demand according to several possible scenarios and business strategies. We consider the survey item that is measured by multiple point scales in response to a question if he would subscribe to the mobile telephone service in the future. We propose a method to forecast the size of market potential by classifying each individual into the two extreme groups, that is, yes or no. Then, by integrating survey data and historical data, we forecast the demand for PCS resale service that varies according to scenarios and strategies. From the results, we can find several implications for the provider of PCS resale service.

• Smart Structures and Systems
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• v.30 no.2
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• pp.145-157
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• 2022

The design of safe and economical structures depends on the reliable live load from load survey. Live load surveys are traditionally conducted by randomly selecting rooms and weighing each item on-site, a method that has problems of low efficiency, high cost, and long cycle time. This paper proposes a deep learning-based method combined with Internet big data to perform live load surveys. The proposed survey method utilizes multi-source heterogeneous data, such as images, voice, and product identification, to obtain the live load without weighing each item through object detection, web crawler, and speech recognition. The indoor objects and face detection models are first developed based on fine-tuning the YOLOv3 algorithm to detect target objects and obtain the number of people in a room, respectively. Each detection model is evaluated using the independent testing set. Then web crawler frameworks with keyword and image retrieval are established to extract the weight information of detected objects from Internet big data. The live load in a room is derived by combining the weight and number of items and people. To verify the feasibility of the proposed survey method, a live load survey is carried out for a meeting room. The results show that, compared with the traditional method of sampling and weighing, the proposed method could perform efficient and convenient live load surveys and represents a new load research paradigm.

• Journal of Cadastre & Land InformatiX
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• v.45 no.2
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• pp.1-13
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• 2015

The national land survey is implemented for the purpose of accomplishing the basic goal called an effective development of national land through close survey on physical/social conditions and periodic/social requirements of national land. However, the situation is that there isn't much difference from other data because the data constructed at the local governments or other ministries are gathered to be processed and provided as national land index which is not a field survey while the situation is that the national land index are changed frequently according to domestic and foreign circumstances and transition so that the applicability is low because there is no data accumulated for a long period of time on the same index. Considering that most government offices and local governments are performing surveys out of their own unique necessity to construct the results followed by such survey as data which includes spatial data as a form of database since the importance of statistics data and map data has become highlighted recently, it is necessary to make a new approach in the aspect of investigating the current situation of national territory on the national level. Accordingly, this study has proposed a new national land survey system to prepare for unification of North and South Korea as well as to provide the decision making data necessary for setting up the policies for effective land development and value conservation of the national land.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.4
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• pp.235-245
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• 1979

The land utilization of Korea composed about 22.7% of arable land, 66.9% of forest land and 10.4% for the rest like a house site, road, and lake etc. The ratio of arable land is too small as compared with forest land which is occuping two-thirds of Korea. The expansion of arable land by the reclamation will solve the food problems for increasing populations. First, we have to know the exact extents and distribution of reclaimable land but the reported total extent of reclaimable land in Korea is variable according to the authority which carried out the soil survey. The different reported data of reclaimable land is owing to the method and criteria of soil survey. 840,522ha in Land Capability Survey of the Farm Land Improvement Association and 321,203ha in the Forest Land Survey by the Office of Forest was reported but the Office of Rural Development said that total reclaimable land was 1,400,540ha including grazing and fruit land. To assume the extent of reclaimable land, the soil survey method and criteria of soil survey should be considered. It can be considered that the main reasons of less in extent of reclaimable land in the other authorities than the Office of Rural Development is due to the following. The grazing land and the fruits land are not included by the Farm Land Improvement Association and only relative forest is considered by the Office of Forest. The main purpose of soil survey carried out by the Office of Rural Development is to utilize land of Korea at most. The soil characteristics and potential productivity are considered in soil survey and the reported data was based on reconnaissance soil survey. The more accurate data will be find out by the end of 1979 when the detailed soil survey will be done. In selection of cropping system and management, the soil condition should be considered, because the soil characteristics of reslaimed land is less fertile than the arable lands.

• Journal of Korea Technology Innovation Society
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• v.5 no.2
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• pp.228-244
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• 2002

The survey of research and development (R&D) in science and technology (S&T) covers the current status of R&D activities in S&T in Korea, and provides a basis for decision making regarding S&T policy. Continuous improvement of the survey is widely needed to present reliable national basic statistics. Therefore, the purpose of the study is two-fold: to introduce sampling survey method in industrial sector and to make statistical technique to deal with non-response data from industrial sector. To these ends, first, case studies of the United States and Japan are illustrated. A new sampling design for the R&D survey is proposed and implementing stratified random sampling scheme is suggested. Moreover, statistical analysis of the non-response data is dealt with. Based on several screening criteria, we develop a new imputation method suitable for the R&D survey and also provide more detailed implementation plan. Various solutions to a problem arising from non-response item are also presented. Finally, some implications of the results are discussed.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.349-352
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• 2007

Estimating the physical properties of the survey area and mapping the geotechnical basement play an important role in ocean engineering and construction field. In this study, we performed marine seismic reflection and refraction survey as an engineering application at shallow marine. We made use of the dual boomer - single channel streamer as a source-receiver in reflection seismic survey and air-gun source - the manufactured OBC(Ocean Bottom Cable)-type streamer in refraction survey. In the seismic reflection data, we could easily find the geological layers and basement. Moreover, seismic refraction data could present sediment thickness and velocity distribution.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.2
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• pp.97-102
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• 2004

The objective of this survey is to characterize personal magnetic field exposure of the general population in Korea. Participants for the survey on magnetic field exposure were selected randomly in some occupations. Those wore the magnetic field meter for about 25∼28 hours and the measured data were stored in the meter. In this first step survey, the number of participant is 244 and for the second step, about 400 participants will be surveyed in the near future. The statistics of the 24-hour exposure data are the major concern of this survey. However the survey provided the opportunity to analyze exposures corresponding to different types of activities. It was analyzed by separating periods of time corresponding to the following activities: entire 24-hour period, in bed, at work and by occupation. Therefore the database will be able to be established to analyze the status of personal magnetic field exposure and safety.

• Korean Journal of Remote Sensing
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• v.39 no.2
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• pp.233-246
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• 2023

In terms of understanding the water cycle and efficient water resource management, the importance of soil moisture has been highlighted. However, in Korea, the lack of qualified in-situ soil moisture data results in very limited utility. Even if satellite-based data are applied, the absence of ground reference data makes objective evaluation and correction difficult. The cosmic-ray neutron probe (CRNP) can play a key role in producing data for satellite data calibration. The installation of CRNP is non-invasive, minimizing damage to the soil and vegetation environment, and has the advantage of having a spatial representative for the intermediate scale. These characteristics are advantageous to establish an observation network in Korea which has lots of mountainous areas with dense vegetation. Therefore, this study was conducted to evaluate the applicability of the CRNP soil moisture observatory in Korea as part of the establishment of a Korean cOsmic-ray Soil Moisture Observing System (KOSMOS). The CRNP observation station was installed with the Gunup-ri observation station, considering the ease of securing power and installation sites and the efficient use of other hydro-meteorological factors. In order to evaluate the CRNP soil moisture data, 12 additional in-situ soil moisture sensors were installed, and spatial representativeness was evaluated through a temporal stability analysis. The neutrons generated by CRNP were found to be about 1,087 counts per hour on average, which was lower than that of the Solmacheon observation station, indicating that the Hongcheon observation station has a more humid environment. Soil moisture was estimated through neutron correction and early-stage calibration of the observed neutron data. The CRNP soil moisture data showed a high correlation with r=0.82 and high accuracy with root mean square error=0.02 m³/m³ in validation with in-situ data, even in a short calibration period. It is expected that higher quality soil moisture data production with greater accuracy will be possible after recalibration with the accumulation of annual data reflecting seasonal patterns. These results, together with previous studies that verified the excellence of CRNP soil moisture data, suggest that high-quality soil moisture data can be produced when constructing KOSMOS.