• Journal of The Korean Astronomical Society
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• v.49 no.3
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• pp.93-107
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• 2016

Augmenting the Wide Field Infrared Survey Telescope (WFIRST) microlensing campaigns with intensive observations from a ground-based network of wide-field survey telescopes would have several major advantages. First, it would enable full two-dimensional (2-D) vector microlens parallax measurements for a substantial fraction of low-mass lenses as well as planetary and binary events that show caustic crossing features. For a significant fraction of the free-floating planet (FFP) events and all caustic-crossing planetary/binary events, these 2-D parallax measurements directly lead to complete solutions (mass, distance, transverse velocity) of the lens object (or lens system). For even more events, the complementary ground-based observations will yield 1-D parallax measurements. Together with the 1-D parallaxes from WFIRST alone, they can probe the entire mass range M ≳ M_⊕. For luminous lenses, such 1-D parallax measurements can be promoted to complete solutions (mass, distance, transverse velocity) by high-resolution imaging. This would provide crucial information not only about the hosts of planets and other lenses, but also enable a much more precise Galactic model. Other benefits of such a survey include improved understanding of binaries (particularly with low mass primaries), and sensitivity to distant ice-giant and gas-giant companions of WFIRST lenses that cannot be detected by WFIRST itself due to its restricted observing windows. Existing ground-based microlensing surveys can be employed if WFIRST is pointed at lower-extinction fields than is currently envisaged. This would come at some cost to the event rate. Therefore the benefits of improved characterization of lenses must be weighed against these costs.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.22 no.4
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• pp.433-441
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• 2015

Purposes: This study was done to identify factors associated with uncontrolled hemoglobin A1c among patient with diabetes mellitus. Method: The sample was 412 Koreans with diagnosed diabetes aged 40 years or older who participated in the Fifth Korea Health and Nutrition Examination survey, which was a nationwide, cross-sectional survey. Data was analyzed using logistic regression. Uncontrolled hemoglobin A1c rate was 55%. Results: There was a difference between controlled and uncontrolled group in hemoglobin A1c as follows: duration of diabetes, BMI(Body Mass Index), hypertriglyceridemia, vitamin D, sleep duration. After adjusting for confounding factor, longer duration of diabetes (>7 years vs. ${\leq}7$)(Adjusted OR=2.277, 95% CI [1.277-4.060]), presence of hypertriglyceridemia (Adjusted OR=4.019, 95% CI [1.871-8.634]), lower vitamin D level (<20ng/mL vs. ${\geq}20$)(Adjusted OR=2.487, 95% CI[1.411-4.381]), longer sleep duration (6-8 hours vs >8 hours)(Adjusted OR=6.831, 95% CI [1.877-24.855]) were significantly associated with increased odds of uncontrolled hemoglobin A1c. Conclusions: Results show that duration of diabetes, hypertriglyceridemia, vitamin D and sleep duration are significantly related to hemoglobin A1c. Therefore, considering these factors it would be helpful to develop strategies to improve blood glucose control in patients with diabetes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.4
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• pp.229-239
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• 2013

Recently, device-to-device (D2D) communications have been highlighted to improve the spectral efficiency and offer various user experiences in cellular networks. In this paper, we survey standards and literatures related to the D2D technology and address various advantages of D2D technology, and the problems to be resolved before practically implemented. Especially, by considering an important interference issue between cellular and D2D links, five resource allocation and interference management scenarios are provided and their performances are evaluated through the system level simulations. The simulation results show that the use of D2D significantly improve the cell capacity and the D2D user rate due to the effects of frequency reuse and data off-loading. Notably, it is also shown that an optimal D2D communication range exists to maximize the system performance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5D
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• pp.655-662
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• 2009

The monitoring for analyzing coastline variations throughout many years is conducted in this study. Haeundae Beach is selected as a test area. We have collected RTK-GPS survey data, airborne LiDAR survey data from Sept. 2008 to 2005. We've done airborne LiDAR survey 2009 to 2006 and we would analyze coastline changes time series through interactive comparison analysis. The mean coastline distance of Haeundae shore is 1,347m (RTK-GPS) by airborne LiDAR survey (2 times). Coastline distance is decreased approximately 4.5% than mean distance in the November survey of 2008. We know right and left sides of the coastline are eroded and the center section shows us the littoral deposit of 3~7m toward sea. It turns out that the sand both sides is transported to the center section by a wave and tide and we know the coastline distance is getting smaller but the coastline width is getting longer like 2~7m.

• Restorative Dentistry and Endodontics
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• v.6 no.1
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• pp.123-132
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• 1980

The author conducted a dental survey of a college girl students and compared with that of E college students 10 years ago which based on the same criteria. The items of this survey included the prevalence of dental caries, DMFT and the kinds of restored material. All college students 1,414 were examined in May 1978, with the recommended criteria and method of W.H.O.. Among them, the data of 1,393 were analyzed for this study. The following results were obtained: 1. The average number of present teeth were 28.97${\pm}$1.64. 2. The prevalence of dental caries was 84.92% and D.M.F. index was 15.51. Average D.M.F. teeth were 4.49${\pm}$3.69. 3. The average number of decayed (D) teeth were 2.09${\pm}$2.16. 4.30% of the present decayed teeth was secondary decay, and 2.44% of the decayed teeth was indicated for extraction. 4. The average number of missing(M) teeth were 0.32${\pm}$0.79. It included 8.56% of root fragements. 5. Average number of filled(F) teeth were 2.09${\pm}$3.17. F-ratio of this group was 46.45%. The analysis revealed 50.88% of amalgam alloy, 31.41% of gold inlays, and 1.20%, the least among the filling materials, silicate cement or composite resin. 6. While the prosthodontic treatment, such as crown and bridge has reduced than that of 10 years ago, the fillings and inlays as the conservative means has increased.

• Journal of Korea Entertainment Industry Association
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• v.13 no.5
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• pp.139-143
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• 2019

The aim of this study was to assess the association of vitamin D and urine microalbumin/creatinine (uACR) and obesity. The study subjects were Korean adults 20 years or older (n = 4,948) who participated in the Korea National Health and Nutrition Examination Survey 2012. Analysis of covariance test adjusted for covariates were performed for uACR levels in relation to vitamin D status [vitamin D deficient, 25(OH)D < 10 ng/dL; vitamin D insufficient, 25(OH)D ≥ 10, < 20 ng/dL; vitamin D sufficient, 25(OH)D ≥ 20 ng/dL]. The key study results were as follows: First, in the populations without obesity (BMI < 25 kg/m²), uACR levels were decreased with the increasing of vitamin D status (p < 0.001) after adjusting for relevant variables. Second, in the populations with obesity (BMI ≥ 25 kg/m²), the association between uACR levels and vitamin D status was not significant (p = 0.659). In conclusion, urine microalbumin/creatinine levels were inversely associated with vitamin D status in Korean adults without obesity, but not in Korean adults with obesity.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4D
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• pp.561-567
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• 2008

In this study, shoreline change was analyzed by RTK-GPS and advanced airborne LiDAR survey. For extraction of coastline, first of all, tide correction was conducted at all RTK-GPS points through the comparing with the corresponding tidal height, and cross section providing coastline was produced using Autocad Civil3D program. Comparing with two results of RTK-GPS (first, 29 Aug 2007; second, 6 Oct 2007) surveys, coastline of the first result had been decreased about 21m compare with that of the second. And it was also demonstrated that the length of coastline by the first RTK-GPS was 15m shorter than that by the airborne LiDAR survey (Dec. 2006). In addition, we recoquized that the erosion appeared in the top right-hand (dock area); the sediment in the bottom left-hand (Chosun beach area) of the Haeundae beach. As a result, therefore, it was learned that artificial sand filling for beach open and natural effects such as a typhoon, current drift, wind direction gave cause for area changes and coastline.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.390-397
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• 2003

A three-dimensional (3D) inversion technique has been developed for interpretation of magnetotelluric (MT) data. The inversion method is based on the linearized least-squares (Gauss-Newton) method with smoothness regularization. In addition to the underground 3D resistivity distribution, static shifts are also treated as unknown parameters in the inversion. The forward modeling is by the staggered-grid finite difference method. A Bayesian criterion ABle is applied to search the optimum trade-off among the minimization of the data misfit, model roughness and static shifts. The method has been applied to several MT datasets obtained at geothermal fields in Japan and other Asian countries. In this paper, two examples will be discussed: one is the data at the Ogiri geothermal area, southwestern Japan, and the other is at the Pohang low-enthalpy geothermal field, southeastern Korea. The inversion of the Ogiri data has been performed stably, resulting in a good fitting between the observed and computed apparent resistivities and phases. The recovered 3D resistivity structure is generally similar to the two-dimensional (2D) inversion models, although the deeper portion of the 3D model seems to be more realistic than that of the 2D model. The 3D model is also in a good agreement with the geological model of the geothermal reservoirs. 3D interpretation of the Pohang MT data is still preliminary. Although the fitting to the observed data is very good, the preliminary 3D model is not reliable enough because the station coverage is not sufficient for a 3D inversion.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.521-530
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• 2021

Objectives: This was to examine and explore the elements of Size Korea 6th 3D head anthropometric database and to provide basic information for the selection of respirators in Korea. Methods: This was a pilot study for the first year of work in a two-year-project initiated at KOSHA in 2021. 3D head dimensions data were obtained from the Size Korea Center managing the Size Korea 6th 3D national anthropometry survey databases. The 3D head dimensions data, including 45 dimensions, were used in line with ISO standards (e.g., ISO/TS 16976-2) for examinations, comparisons, statistical analyses, etc. Results: A total of 3,088 subjects were finally determined in this study. The main features were: Male subjects were 52.5%; the highest age group was 15-29 at 36.7%; unhealthy weight group based on BMI was 31.7%; and survey area was the capital region. For the 6th 3D head dimensions data with 45 items, the means and standard deviations for 'Face length' were 115.9±7.5 cm for males and 107.3±6.9 cm for females respectively while those for 'Face width' item were not available since there was no such item in the data. Numerous findings were discussed accordingly. Conclusions: This study showed that there were likely requirements for improvements in the 6th 3D head anthropometric data as follows: Standardization of Korean and English terms; addition of head dimensions items missed in the Size Korea survey; and reliability of generalizability for subjects, suggesting that the study results can be used for further studies or improvement of respirator selection in Korea.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.38.1-38.1
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• 2010

We present the results of the survey for submillimeter galaxies in the MS0451 (04h 54m 10.8s, -03d 00m 57.0s) at z = 0.55 and PKS1138-262 (11h 40m 48.25s, -26d 29m 10.1s) at z = 2.16 with the 1.1mm bolometer array AzTEC at the James Clerk Maxwell Telescope. The samples were centered on a prominent large-scale structure overdensity. Submillimeter galaxies seem to be starburst galaxies at high redshift ($z\;\geq\;1$) with high starformation rates ($\sim1000M\odot\;yr^{-1}$) or active galactic nuclei (AGN). We have obtained AzTEC images using the AzTEC data reduction pipeline with the IDL language. Through a bayes' theorem, we determined the extragalaxy catalogue, containing the false-detection rate, completeness, flux deboosting correction, and the source positional uncertainty in this region. We compared the catalogue with HST, DSS, 2MASS observations.