• The Journal of Engineering Geology
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• v.27 no.3
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• pp.305-312
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• 2017

The most effective way to distinguish subsurface interfaces that produce various geophysical responses is through the integration of multiple geophysical methods, with each method detecting both a complementary and unique set of distinct physical properties relating to the subsurface. In this study, shallow seismic reflection (SSR) and ground penetrating radar (GPR) surveys were conducted at the Cheongju-Gadeok site of the Korea National Groundwater Monitoring Network to map the water table, which was measured at 12 m depth during the geophysical surveys. The water table proved to be a good target reflector in both datasets, as the abrupt transition from the overlying unsaturated weathered rock to the underlying saturated weathered rock yielded large acoustic impedance and dielectric constant contrasts. The two datasets were depth converted and integrated into a single section, with the SSR and GPR surveys conducted to ensure subsurface imaging at approximately the same wavelength. The GPR data provided detailed information on the upper ~15 m of the section, whereas the SSR data imaged structures at depths of 10-45 m. The integrated section thus captured the full depth coverage of the sandy clay, water table, weathered rock, soft rock, and hard rock structures, which correlated well with local drillcore and water table observations. Incorporation of these two geophysical datasets yielded a synthetic section that resembled a simplified aquifer model, with the best-fitting seismic velocity, dielectric constant, and porosity of the saturated weathered layer being $v_{seismic}=1000m/s$, ${\varepsilon}_r=16$, and ${\phi}=0.32$, respectively.

• Journal of KIISE:Information Networking
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• v.37 no.4
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• pp.255-262
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• 2010

Recently, automated signature generation systems(ASGSs) have been developed in order to cope with zero-day attacks with malicious codes exploiting vulnerabilities which are not yet publically noticed. To enhance the usefulness of the signatures generated by (ASGSs) it is essential to identify signatures only with the high accuracy of intrusion detection among a number of generated signatures and to provide them to target security systems in a timely manner. This automated signature exchange, distribution, and update operations have to be performed in a secure and universal manner beyond the border of network administrations, and also should be able to eliminate the noise in a signature set which causes performance degradation of the security systems. In this paper, we present a system architecture to support the identification of high quality signatures and to share them among security systems through a scheme which can evaluate the detection accuracy of individual signatures, and also propose a set of algorithms dealing with exchanging, distributing and updating signatures. Though the experiment on a test-bed, we have confirmed that the high quality signatures are automatically saved at the level that the noise rate of a signature set is reduced. The system architecture and the algorithm proposed in the paper can be adopted to a automated signature sharing framework.

• Nutrition Research and Practice
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• v.14 no.4
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• pp.374-383
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• 2020

BACKGROUNDS/OBJECTIVES: To describe the data-based development of a food frequency questionnaire (FFQ) for dietary evaluation of Korean preschool children. SUBJECTS/METHODS: Development of the FFQ was based on the data from 2,766 preschool children aged 1-5 years, who had completed 24-hour dietary recalls in the 2009-2013 Korea National Health and Nutrition Examination Survey. We selected the food list based on the results of nutritional contribution and between-person variability for energy and 13 nutrients. We selected 88 foods with over 80% of total contribution to each nutrient and with over 80% of accumulated r² for each nutrient. A dish containing any of the 88 foods in the recipe was listed, and a total of 903 dishes were extracted. Among the 903 dishes, we selected 438 dishes contributing more than 1% of total consumption. RESULTS: FFQ included 116 dish items combined from 438 dishes based on nutrient profile and recipe. Quantities of dietary intake were assessed by nine categories of frequency and portion size option. In addition, when comparing the food portions of children with the reference portion size, subjects would be asked to select one of three response categories (less, similar, and more) and then to record the amount as a percentage for the reference portion. Percentages of coverage for energy, protein, fat, and carbohydrate were 89.2%, 88.4%, 88.2%, and 89.4%, respectively. CONCLUSIONS: The dietary intake of Korean preschool children can be assessed by this new data-based FFQ. In addition, the new instrument can be used to identify nutritional needs of target groups for planning nutrition education and strategies to improve diet. Further studies are warranted to evaluate the performance of the instrument.

• Progress in Medical Physics
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• v.30 no.4
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• pp.94-103
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• 2019

Purpose: To evaluate the clinical feasibility of knowledge-based planning (KBP) for volumetric-modulated arc radiotherapy (VMAT) in spine stereotactic body radiotherapy (SBRT). Methods: Forty-eight VMAT plans for spine SBRT was studied. Two planning target volumes (PTVs) were defined for simultaneous integrated boost: PTV for boost (PTV-B: 27 Gy/3fractions) and PTV elective (PTV-E: 24 Gy/3fractions). The expert VMAT plans were manually generated by experienced planners. Twenty-six plans were used to train the KBP model using Varian RapidPlan. With the trained KBP model each KBP plan was automatically generated by an individual with little experience and compared with the expert plan (closed-loop validation). Twenty-two plans that had not been used for KBP model training were also compared with the KBP results (open-loop validation). Results: Although the minimal dose of PTV-B and PTV-E was lower and the maximal dose was higher than those of the expert plan, the difference was no larger than 0.7 Gy. In the closed-loop validation, D_1.2cc, D_0.35cc, and D_mean of the spinal cord was decreased by 0.9 Gy, 0.6 Gy, and 0.9 Gy, respectively, in the KBP plans (P<0.05). In the open-loop validation, only D_mean of the spinal cord was significantly decreased, by 0.5 Gy (P<0.05). Conclusions: The dose coverage and uniformity for PTV was slightly worse in the KBP for spine SBRT while the dose to the spinal cord was reduced, but the differences were small. Thus, inexperienced planners could easily generate a clinically feasible plan for spine SBRT by using KBP.

• Journal of Ecology and Environment
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• v.33 no.4
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• pp.377-389
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• 2010

Understanding the factors relevant to endangerment and the patterns of habitat locations in relation to protected areas is critically important for the conservation of rare species. Although 64 plant species have recently been listed as endangered species in Korea, this information has, until now, not been available, making appropriate management and conservation strategies impossible to devise. Thus, we collected information on potentially threatening factors, as well as information on the locations in which these species were observed. The potentially threatening factors were classified into seven categories. National parks, provincial parks, ecosystem conservation areas, and wetland conservation areas were defined as protected conservation areas. Korean digital elevation model data, along with the maps of all protected areas were combined with the maps of endangered plant species, and analyzed via Geographic Information Systems (GIS). Excluding the category of "small population", endangered plant species in Korea were associated more frequently with extrinsic factors than intrinsic factors. Considering land surface only, all conservation areas in Korea totaled 4.9% of the land, far lower than International Union for Conservation of Nature and Natural Resources (IUCN)'s 10% coverage target. At the species level, 69% of the endangered plant species were detected in conservation areas, mostly in national parks. However, this result demonstrates that 31% of endangered species inhabit areas outside the conservation zones. Furthermore, at the habitat level, a large proportion of endangered species were found to reside in unprotected areas, revealing "gaps" in protected land. In the face of rapid environmental changes such as population increases, urbanization, and climate changes, converting these gap areas to endangered species' habitats, or at least including them in habitat networks, will help to perpetuate the existence of endangered species.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.23 no.1
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• pp.131-151
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• 2012

Recently scholarly information service institutes as well as public institutes have provided their holding resources to the other institutes and end users in order to reuse the information and create new value. Information providing subjects should stipulate the dissemination policy of digital contents for ensuring its consistent and efficient service. This study aims to establish the dissemination policy of digital contents for scholarly information service institutes focusing on NDSL. This study researches and analyzes the cases of the digital contents service policy and the dissemination policy to draw main components of the policy for NDSL. As a result, this study suggests goals and objectives, target users, coverage, dissemination methods, requests, agreement and MOU of utilization for the dissemination policy of NDSL.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.4
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• pp.434-441
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• 2014

Recently, a mutual interference threat has been increasing among the radar systems due to the rapid growth of the military radar operation. In this paper, the radar interference protection criteria is presented for interoperability in terms of the radar coverage and target detection probability in association with the international recommendation on the interference spectrum by ITU-R. The required criteria for the minimum allowable interference is also presented in terms of INR. In order to ensure the maximum detection probability of the radar under the mutual interference situation, only 5 % of detection range loss is allowed for the case of INR of -6 dB, and required SNR is presented at each INR in terms of the detection range and detection probability. This result will be useful for establishing the interference protection criteria in the combined military radar systems.

• Korean Journal of Health Education and Promotion
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• v.26 no.1
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• pp.93-104
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• 2009

Objectives: Although Asian immigrants have lower rates of smoking and binge drinking than other ethnics in the US, Korean Americans have the highest rate of Asian immigrants. This study, therefore, compared with the rates and examined the predictors of smoking and binge drinking by gender and ethnicity among Asian immigrants in California. Methods: In 2001 and 2003, California Health Interview Survey (CHIS) were conducted in English and their original languages with Asian immigrants residing in 58 Counties and 3 Cities, California. We performed analysis to find out the differences of smoking and binge drinking rates using the secondary data, CHIS 2001 and 2003. Multiple logistic regression analysis for survey data identified predictors of smoking and binge drinking behaviors by gender and ethnicity. Results: Korean American males (35.4%) and Japanese American females (15.4%) had higher rates of smoking prevalence compared with other Asian immigrants in California. In binge drinking, 26.5% of male and 8.1% of female among Korean Americans were binge drinker, and the rates were the top with Asian Americans who had lived in California. It showed the remarkable gap between gender of smoking and binge drinking among Vietnamese immigrants, whereas not the striking difference among Japanese Americans. In multiple regression models, age, educational level, occupation, marital status, English proficiency, and health insurance coverage remained significant for smoking and binge drinking behaviors(P<0.05). Even though the time in the US was not significant, it seemed to be related to educational level and English proficiency. In particular among female, smoking and binge drinking behaviors were associated with acculturation. Conclusion: Although Asian Americans had shared with American culture since they had immigrated in the US, they had significantly different prevalence rates of smoking and binge drinking based on gender and ethnicity. Therefore, future efforts should be focused on understanding differences by ethnicity and target at high-risk subgroups. To achieve this, it needs to develop the educational materials in Korean and their original languages.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7A
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• pp.776-785
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• 2008

Compared with the existing cellular base station whose radio parameters are configured manually, the small base station named as self-configurable base station configures its radio parameters automatically by the central controller. When installing the self-configurable base station, it should be considered primarily that the seamless coverage for the target area is secured while the signal interference to the existing cellular service area must to be minimized. In order to achieve this, it is very important to select the correct radio parameters, e.g., transmission power and working frequency. In this work, we formulate and solve the optimization problem by using mixed integer programming to optimize the air parameter for the self-configurable base stations.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.3
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• pp.101-109
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• 2009

Objectives : This study aimed to investigate the present status of physical therapies provided in the Korean medicine clinics, and to find out the priorities among and the estimated fees of physical therapies for the National Health Insurance plan. Methods : We administered nationwide survey to Korean medicine doctors using the on-line survey system. 16 physical therapies were listed in the Web-based questionnaires, and responders were asked to mark the therapies they used for their patients, and, for each therapy they marked, to fill in the form including the frequencies of service, service fees, target diseases, and priorities for health insurance coverage, etc. Results : Of 488 respondents, 93.7% provide more than one physical therapy for their patients, and each responder uses 5.9 physical therapies on average. 60-90% of physical therapies are being given to patients for free because they are not covered by the National Health Insurance. There is little evidence that the specialties of Korean medicine doctors are related with the use of physical therapies, but, in some therapies, the doctors with longer career years use the physical therapy more frequently. Most physical therapies are applied to the patients with musculoskeletal diseases, cardiovascular diseases, and nervous diseases, etc. Conclusions : Physical therapies are widely used among Korean medicine doctors without proper compensation. This could be the one of the main factors distorting the profit structure of Korean medicine clinics, and it encourages the National Health Insurance to cover physical therapies provided in the Korean medicine clinics.