• Journal of Korean Society for Geospatial Information Science
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• v.21 no.3
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• pp.11-17
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• 2013

With high social demands for the diverse utilizations of forest lands, the illegal forest land use changes have increased. We studied change detection technique to detect changes in forest land use using an object-oriented segmentation of RED bands differencing in multi-temporal aerial photographs. The new object-oriented segmentation method consists of the 5 steps, "Image Composite - Segmentation - Reshaping - Noise Remover - Change Detection". The method enabled extraction of deforested objects by selecting a suitable threshold to determine whether the objects was divided or merged, based on the relations between the objects, spectral characteristics and contextual information from multi-temporal aerial photographs. The results found that the object-oriented segmentation method detected 12% of changes in forest land use, with 96% of the average detection accuracy compared by visual interpretation. Therefore this research showed that the spatial data by the object-oriented segmentation method can be complementary to the one by a visual interpretation method, and proved the possibility of automatically detecting and extracting changes in forest land use from multi-temporal aerial photographs.

• Development and Reproduction
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• v.5 no.1
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• pp.59-71
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• 2001

Since the first radioimmunoassay (RIA) was developed in 1970s, many conventional RIAs and non-isotopic immunoassays (NIA) had been developed in which the degree of precision, accuracy, specificity and practicability have progressively increased. Recently ultrasensitive assay method at femtogram to determine testosterone in serum, saliva and feces is required for the study of sexual dysfunctions in male and female, monitoring the psychological stress and conditions, aging process such as menopause and partial androgen deficiency in aging male, the hormonal changes of small experimental animals etc. This review discussed the recentd evelopments of steroid assay methods, based upon the testosterone assay results of authors far 20 years, and the problems associated the assay set-up, the characterizations and applications of the established procedures, and desifls of assay, reliablity criteria, and the practical aspects of assay set-up and application, based upon the data of the authors. The present study demonstrates the general problems methods to be consider in order to set up the highly sensitive assay methods and to increase the assay quality and the necessity of assay quality control program. To improve the assay quality of each laboratory and to compare the assay results in homeland, the national QC programs should be organized.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.1-14
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• 2015

Climate change caused by elevated greenhouse gases would affect crop production through different pathways in agricultural ecosystems. Because an agricultural ecosystem has complex interactions between societal and economical environment as well as organisms, climate, and soil, adaptation measures in response to climate change on a specific sector could cause undesirable impacts on other sectors inadvertently. An integrated system, which links individual models for components of agricultural ecosystems, would allow to take into account complex interactions existing in a given agricultural ecosystem under climate change and to derive proper adaptation measures in order to improve crop productivity. Most of models for agricultural ecosystems have been used in a separate sector, e.g., prediction of water resources or crop growth. Few of those models have been desiged to be connected to other models as a module of an integrated system. Threfore, it would be crucial to redesign and to refine individual models that have been used for simulation of individual sectors. To improve models for each sector in terms of accuracy and algorithm, it would also be needed to obtain crop growth data through construction of super-sites and satellite sites for long-term monitoring of agricultural ecosystems. It would be advantageous to design a model in a sector from abstraction and inheritance of a simple model, which would facilitate development of modules compatible to the integrated prediction system. Because agricultural production is influenced by social and economical sectors considerably, construction of an integreated system that simulates agricultural production as well as economical activities including trade and demand is merited for prediction of crop production under climate change.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.4
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• pp.255-267
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• 2020

Under SLD conditions, due to the large size of droplets, physical phenomena such as wall-droplet interaction and deformation have a significant effect on the icing process. Accordingly, many studies have been conducted in order to computationally simulate SLD effects. As one of the efforts, post-processing method have been proposed to describe wall-droplet interaction effect, which modified collection efficiency using Wright model. However, since the model doesn't properly consider the wall condition, it still overestimated collection efficiency and impingement limit. To solve this problem, impingement areas were divided into 3 different regions, and the post-processing method was introduced with the new wall-droplet interaction model developed based on Bai and Gosman rebound model. In order to consider the effect of deformation, the most suitable model was selected by comparing the deformation models used in the various icing codes. As a result, the modified post-processing method showed improved accuracy in predicting the impingement limits and collection efficiency by further estimating mass flux loss due to rebound, and it was observed that the result was the closest to the experimental data when the deformation effect was included by using Wiegand model.

• The Journal of Engineering Geology
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• v.26 no.2
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• pp.235-250
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• 2016

In Korea, 70% of the annual rainfall falls in summer, and the number of days of extreme rainfall (over 200 mm) is increasing over time. Because rainfall is the most important trigger of landslides, it is necessary to decide a rainfall threshold for landslide warning and to develop a landslide warning model. This study selected 12 study areas that contained landslides with exactly known triggering times and locations, and also rainfall data. The feasibility of applying a Rainfall Triggering Index (RTI) to Korea is analyzed, and three RTI models that consider different time units for rainfall intensity are compared. The analyses show that the 60-minute RTI model failed to predict landslides in three of the study areas, while both the 30- and 10-minute RTI models gave successful predictions for all of the study areas. Each RTI model showed different mean response times to landslide warning: 4.04 hours in the 60-minute RTI model, 6.08 hours in the 30-minute RTI model, and 9.15 hours in the 10-minute RTI model. Longer response times to landslides were possible using models that considered rainfall intensity for shorter periods of time. Considering the large variations in rainfall intensity that may occur within short periods in Korea, it is possible to increase the accuracy of prediction, and thereby improve the early warning of landslides, using a RTI model that considers rainfall intensity for periods of less than 1 hour.

• Health Policy and Management
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• v.21 no.2
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• pp.329-348
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• 2011

This research analyzed 168,010 cases of death of the aged over 65 from 244,867cases of death excluding 7 unknown age cases from 244,874 all age cases of death by using the death data of the National Statistical Office for 2007 to figure out factors affecting the quality of causes of death statistics of the aged and to suggest the ways of improving the quality of death statistics of the aged in korea. This research tried to derive factors affecting ill-defined cause of death category in acordance with WHO's guidelines and to find causes of lowering the accuracy of causes of death statistics of the aged. This research identified the problems of causes of death statistics of the aged by using both demographic characteristics such as sex, age, marital status, educational attainment, residential region, region size and factors of death items as independent variable to find causes of ill-defined cause of death of the aged. Logistic regression analysis was executed to calculate the hazard ratio about the ill-defined causes of death of the aged and multiple regression analysis was conducted to derive factors affecting the ill-defined cause of death by regional groups through using these independent variables such as the component ratio of over age 65, female death rates, doctors insitutions rate, medical institutions rate, attaching rates of death certificate by neighborhood. As a results of this research, R-code was the highest of ill-defined causes of death, accounting for 82.1%, and senility death(R54) of R-code was the highest, accounting for 91.2%. through subdivided order distribution of the ill-defined causes of death of the aged. As ill-defined causes of death by regional groups, attaching rates of death certificate by neighborhood was the most important factor(p<0.05) and also showed regression model's description with 83.8% ($R^2$=83.8%). Furthermore, Jeon-nam was the highest in the regional groups and these regions such as Je-ju, Jeon-buk, Chung-nam were not only attaching the death certificate by neighborhood but also were high at the rate of ill-defined causes of death. Therefore, this research found that both reconsideration about death certificate by neighborhood and education for doctors who write death certificate were needed the most.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.39-46
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• 2015

This paper presents an automatic method to detect and count the cells from microorganism images based on mobile environments. Cell counting is an important process in the field of biological and pathological image analysis. In the past, cell counting is done manually, which is known as tedious and time consuming process. Moreover, the manual cell counting can lead inconsistent and imprecise results. Therefore, it is necessary to make an automatic method to detect and count cells from biological images to obtain accurate and consistent results. The proposed multi-step cell counting method automatically segments the cells from the image of cultivated microorganism and labels the cells by utilizing topological analysis of the segmented cells. To improve the accuracy of the cell counting, we adopt watershed algorithm in separating agglomerated cells from each other and morphological operation in enhancing the individual cell object from the image. The system is developed by considering the availability in mobile environments. Therefore, the cell images can be obtained by a mobile phone and the processed statistical data of microorganism can be delivered by mobile devices in ubiquitous smart space. From the experiments, by comparing the results between manual and the proposed automatic cell counting we can prove the efficiency of the developed system.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.398-410
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• 2020

In this study, the contents of soluble vitamins B₁ (thiamin), B₂ (riboflavin), and B₃ (niacin) in 13 kinds of rice, 11 kinds of noodles, and 15 kinds of sauces were identified. The limit of detection (LOD) and limit of quantification (LOQ) were checked to determine the reliability of the experimental results, and the accuracy of the results through the standard reference material (SRM 1849a) was verified to show excellent indicators. As for thiamin, japchaebab (stir-fried glass noodles with rice) was found to contain the highest content among rice dishes, makguksu (buckwheat noodles) among noodle dishes, and tomato spaghetti sauce among sauces. Riboflavin was identified as having the highest content in slightly spicy jajangbab (black-bean sauce with rice), bibimguksu (spicy noodles) for noodles, and spicy curry with turmeric for sauces. Niacin was highest in content in the deep and rich flavors of spicy chicken-fried rice, janchiguksu (banquet noodles), and black-bean sauce, respectively. As a result of checking the amount of recommended daily intake of water-soluble vitamins for Korean adult men and women, the highest content of riboflavin was 217.40% for men and 271.75% for women. Through this study, we are going to establish a database of nutrients for the water-soluble vitamins contained in rice, noodles, and sauces to provide the necessary dietary data concerning the content of the water-soluble vitamins contained in foods for daily recommended intake.

• Journal of Korea Port Economic Association
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• v.26 no.1
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• pp.222-233
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• 2010

This paper aims at predicting the BDI from Jan. to Dec. 2010 using such econometric techniues of the univariate time series as stochastic ARIMA-type models and Hodrick-Prescott filtering technique. The multivariate cause-effect econometric model is not employed for not assuring a higher degree of forecasting accuracy than the univariate variable model. Such a cause-effect econometric model also fails in adjusting itself for the post-sample. This article introduces the two ARIMA models and five Intervention-ARIMA models. The monthly data cover the period January 2000 through December 2009. The out-of-sample forecasting performance is compared between the ARIMA-type models and the random walk model. Forecasting performance is measured by three summary statistics: root mean squared error (RMSE), mean absolute error (MAE) and mean error (ME). The RMSE and MAE indicate that the ARIMA-type models outperform the random walk model And the mean errors for all models are small in magnitude relative to the MAE's, indicating that all models don't have a tendency of overpredicting or underpredicting systematically in forecasting. The pessimistic ex-ante forecasts are expected to be 2,820 at the end of 2010 compared with the optimistic forecasts of 4,230.

• Journal of the Korean Society for Library and Information Science
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• v.45 no.3
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• pp.327-343
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• 2011

The goal of this study was to examine ways to improve the quality of databases of the Korean National Assembly Digital Library(KNADL). In order to achieve the goal, we first designed an assessment tool that could measure the quality of the 'contents,' the 'service,' and the 'system' of the KNADL's databases. Each of the three categories also had sub-categories-i.e., eight sub-categories for 'contents'(e.g., accuracy, recency, ${\cdots}$), seven sub-categories for 'service'(e.g., convenience for request, rapid response, ${\cdots}$), and seven sub-categories for 'system'(e.g., usability, response time, ${\cdots}$). We thenconducted a survey using the assessment tool we developed and gathered a total of 270 responses from users of KNADL's databases. We used Excel and PASW Statistics 18 for data analysis. Each sub-category was measured by its importance and by the level of satisfaction(implemented from the DigiQUAL project). Finally, we performed an importance-satisfaction analysis(ISA) to identify what action(i.e., maintain, concentrate, low priority, and exceed) needs to be made in each sub-category. We concluded the paper with some useful suggestions for improving the quality of KNADL's databases.