• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.2
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• pp.47-61
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• 2000

Agroclimatic zoning was done for paddy rice culture in North Korea based on a simulation experiment. Daily weather data for the experiment were generated by 3 steps consisting of spatial interpolation based on topoclimatological relationships, zonal summarization of grid cell values, and conversion of monthly climate data to daily weather data. Regression models for monthly climatological temperature estimation were derived from a statistical procedure using monthly averages of 51 standard weather stations in South and North Korea (1981-1994) and their spatial variables such as latitude, altitude, distance from the coast, sloping angle, and aspect-dependent field of view (openness). Selected models (0.4 to 1.6$^{\circ}C$ RMSE) were applied to the generation of monthly temperature surface over the entire North Korean territory on 1 km$\times$l km grid spacing. Monthly precipitation data were prepared by a procedure described in Yun (2000). Solar radiation data for 27 North Korean stations were reproduced by applying a relationship found in South Korea ([Solar Radiation, MJ m$^{-2}$ day$^{-1}$ ] =0.344 + 0.4756 [Extraterrestrial Solar Irradiance) + 0.0299 [Openness toward south, 0 - 255) - 1.307 [Cloud amount, 0 - 10) - 0.01 [Relative humidity, %), $r^2$=0.92, RMSE = 0.95 ). Monthly solar irradiance data of 27 points calculated from the reproduced data set were converted to 1 km$\times$1 km grid data by inverse distance weighted interpolation. The grid cell values of monthly temperature, solar radiation, and precipitation were summed up to represent corresponding county, which will serve as a land unit for the growth simulation. Finally, we randomly generated daily maximum and minimum temperature, solar irradiance and precipitation data for 30 years from the monthly climatic data for each county based on a statistical method suggested by Pickering et a1. (1994). CERES-rice, a rice growth simulation model, was tuned to accommodate agronomic characteristics of major North Korean cultivars based on observed phenological and yield data at two sites in South Korea during 1995~1998. Daily weather data were fed into the model to simulate the crop status at 183 counties in North Korea for 30 years. Results were analyzed with respect to spatial and temporal variation in yield and maturity, and used to score the suitability of the county for paddy rice culture.

• Journal of dental hygiene science
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• v.16 no.2
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• pp.176-182
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• 2016

The purpose of this study was to evaluate the in-vitro efficacy of the active ingredients of dentifrice following treatment time. The whitening effect was evaluated by a change in lightness value relative to the contact time of hydrogen peroxide, by using artificially stained hydroxyapatite discs. The anti-calculus effect was assessed based on the amount of calcium eluted from the human dental calculus by sodium pyrophosphate. Remineralization was evaluated by the Vickers hardness test following the application of sodium fluoride to bovine enamel. In order to view dentinal tubules occlusion, the formation of insoluble calcium salts by bovine dentin specimens was observed using scanning electron microscopy. Change in lightness value (${\Delta}L$) was $5.50{\pm}1.51$ after 1 min of treatment, $5.73{\pm}0.43$ after 3 min, $8.64{\pm}0.24$ after 10 min, $18.93{\pm}0.76$ after 30 min, and $27.35{\pm}0.54$ after 60 min. The amount of calcium eluted from the human dental calculus was $4.23{\pm}0.14ppm$ after 1 min of treatment, $4.51{\pm}0.04ppm$ after 3 min, $12.12{\pm}0.16ppm$ after 10 min, $17.85{\pm}0.81ppm$ after 30 min, and $25.15{\pm}0.32ppm$ after 60 min. The Vickers hardness change value (${\Delta}VHN$) was $1.96{\pm}1.44$ after 1 min, $1.52{\pm}1.06$ after 3 min, $9.06{\pm}0.15$ after 10 min, $10.83{\pm}5.13$ after 30 min, and $12.55{\pm}2.09$ after 60 min. Partial dentinal tubules occlusion was observed at 10 min and complete occlusion was evident at 60 min. In summary, the use of patch type dentifrices for 10, 30, or 60 min were 1.57 to 8.26 times more effective than using the paste type dentifrices for 1 to 3 min. Based on these findings, it is reasonable to expect that the use of patch type dentifrices for 10 min would lead to remineralization, anti-calculus and dentinal tubules occlusion effects, and that use for 30 min would result in a whitening effect.

• Applied Biological Chemistry
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• v.19 no.3
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• pp.172-183
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• 1976

RNA, DNA and other phosphorus fractions were determined in the leaf and root of soybean plants different in phosphorus sensitivity grown in $NH_4-N,\;NO_3-N$ and urea medium. The phosphorus sensitive cultivars contained higher ASIP (acid soluble inorganic phosphorus) than the tolerant cultivars with all nitrogen sources. ASIP was highest in the urea treated plants and lowest in the nitrate treated plants. Total phosphorus content was mostly affected with increase in ASIP. When ASIP increased, acid solsuble organic phosphorus(ASOP), phospholipids (L-P), RNA-P, residual phosphorus (R-P) tended to increase, while DNA-P showed little change. The percent RNA-P or DNA-P of total phosphorus in the nitrate treated plant was twice that in the ammonium treated plant, which were also higher in tolerant cultivars regardless of nitrogen sources. The percent ASOP in total acid soluble phosphorus $(ASOP/ASP{\times}100)$ decreased as phosphorus sensitivity decreased. Indications are that phosphorus sensitivity depends on the relative sizes of phosphorus metabolic pools. Total dry matter yield was negatively correlated with total phosphorus (r=0.84 significant at 0.01P), ASIP (0.84 significant at 0.01P) and residual phosphorus (0.69 significant at 0.05P). ASOP showed positive correlation with L-P, RNA-P and DNA-P but negative with R-P. RNA-P was significanly correlated only with L-P (0.63 at P=0.01). There was significant interaction (0.01) among nitrogen sources, cultivars and phosphorus metabolic pools. Phosphorus sensitivity and ammonium toxicity appear to be same in view of energy metabolism, that is, the former inhibits the conversion of ATP to ADP (energy releasing) through phosphate potential while the latter inhibits ATP formation (energy storing).

• Journal of the Korea Concrete Institute
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• v.27 no.2
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• pp.185-193
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• 2015

Ultra high performance concrete (UHPC) has been developed to overcome the low tensile strengths and brittleness of conventional concrete. Considering that UHPC, owing to its composition and the use of steel fibers, develops a compressive strength of 180 MPa as well as high stiffness, the top flange of the steel girder may be superfluous in the composite beam combining a slab made of UHPC and the steel girder. In such composite beam, the steel girder takes the form of an inverted-T shaped structure without top flange in which the studs needed for the composition of the steel girder with the UHPC slab are disposed in the web of the steel girder. This study investigates experimentally and analytically the flexural behavior of this new type of composite beam to propose details like stud spacing and slab thickness for further design recommendations. To that goal, eight composite beams with varying stud spacing and slab thickness were fabricated and tested. The test results indicated that stud spacing running from 100 mm to 2 to 3 times the slab thickness can be recommended. In view of the relative characteristic slip limit of Eurocode-4, the results showed that the composite beam developed ductile behavior. Moreover, except for the members with thin slab and large stud spacing, most of the specimens exhibited results different to those predicted by AASHTO LRFD and Eurocode-4 because of the high performance developed by UHPC.

• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.507-516
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• 1999

Background : Patients with lung cancer and their relatives often ask the advice of relative or friends who are doctors on the treatment and prognosis of the disease. Therefore a doctor's opinion may play a role in determining the treatment modality and affect therapeutic compliance of patients. The purpose of this study was to find the opinion of general practitioners on lung cancer treatment. Method : A mail survey for general practitioners in Taegu City and Northern Kyungsang Province was performed. Each individual was sent a written questionnaire in which he or she was asked for ten questions about management and prognosis of lung cancer. Results : Two hundred and twenty eight doctors filled in the questionnaire. Of the respondents, 68% had the experience of being asked about lung cancer by their friends or relatives. About 52% replied that it was better to tell the patient of his or her disease. And about 22% considered it better to follow the relatives' opinion. On the question about choosing the treatment modality, following the doctors' plan was most appropriate in 86.9%, showing that most respondents favored actively recommending doctors. Nonsurgical treatment was preferable in patients over 80 years old with resectable lung cancer and with an increase in age, significant increase was observed in respondents recommending nonsurgical treatment. Most respondents said that they would actively recommend or advise following the doctors' plan about radiotherapy and chemotherapy. But a large percent of the respondents had a negative view on the effect of radiotherapy and chemotherapy. Conclusion : The opinions of general practitioners on the treatment and prognosis of lung cancer was variable. And they did not prefer active treatment for patients with old age or advanced lung cancer.

• Management & Information Systems Review
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• v.35 no.1
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• pp.51-68
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• 2016

In this paper, we aim to analyze the effect of accounting policy change subsequent to the adoption of K-IFRS in Korea, whereby the firms are required to recognize impairment losses on goodwill on a periodic basis rather than to amortize over a specific period. As a principle-based accounting standard, the K-IFRS expands the scope of fair value measurement with a view to enhance the relevance and timeliness of accounting information. In the same vein, intangibles with indefinite useful life, of which goodwill is an example, are subject to regulatory impairment tests at least once a year. Related literature on the impact of mandatory change in goodwill policy document that impairment recognition is more likely to be practiced opportunistically, mainly because managers have a greater discretion to conduct the tests under K-IFRS. However, existing literature examined the frequency and/or magnitude of the goodwill impairment before versus after the K-IFRS adoption, failing to notice the impairment symptoms at individual firm level. Borrowing the definition of impairment symptoms suggested by Ramanna and Watts(2012), this study performs a series of tests to determine whether the goodwill impairment recognition achieves the goal of communicating timelier information under the K-IFRS regime. Using 947 firm-year observations from domestic companies listed in KRX and KOSDAQ markets from 2008 to 2011, we document overall delays in recognizing impairment losses on goodwill after the adoption of K-IFRS relative to prior period, based on logistic and OLS regression analyses. The results are qualitatively similar in robustness tests, which use alternative proxy for goodwill impairment symptom. Afore-mentioned results indicate that managers are likely to take advantage of the increased discretion to recognize the impairment losses on goodwill rather than to provide timelier information on impairment, inconsistent with the goal of regulatory authority, which is in line with the improvement of timeliness and relevance of accounting information in conjunction with the full implementation of K-IFRS. This study contributes to the extant literature on goodwill impairment from a methodological viewpoint. We believe that the method employed in this paper potentially diminishes the bias inherent in researches relying on ex post impairment recognition, by conducting tests based on ex ante impairment symptoms, which allows direct examination of the timeliness changes between before and after K-IFRS adoption.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.4
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• pp.389-403
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• 2008

In Angle's Class III malocclusion, which has higher incidence in Korean than Western, depressed midfacial profile with protruded lower lips and mandible may give rise to many functional, esthetic, psychological, social problems. Due to the different malocclusion incidence according to racial differences, many previous studies focused on the relationship between Class II malocclusion and nasal airway obstruction. Previous studies used lateral cephalography which has limitations of 2 dimensional image with projection error and identification error. Therefore, the purpose of this study was to analyze morphologic differences in the nasal airway between normal occlusion and Angle's Class III malocclusion patients using 3-dimensional facial computed tomography. Thirteen normal occlusion(7 men and 6 women) and sixteen skeletal Class III(7 men and 9 women) patients were selected and 3-dimensional facial computed tomography taking was performed. Comparison between two group in volume and sectional area of nasal airway were carried out. The results were followed. 1. In the comparison of absolute nasal airway volume, oropharyngeal space of experimental group were larger than control group but there are no significant difference in other. 2. In the comparison of relative nasal airway volume, oropharyngeal space of experimental group were larger than control group but there are no significant difference in other. 3. In the oropharyngeal space width on frontal and lateral view, the similar tendency was revealed between two groups. 4. In the lateral curvature of nasal airway, the similar tendency was revealed between two groups.

• Journal of the Korea Concrete Institute
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• v.26 no.6
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• pp.761-769
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• 2014

Ultra high performance concrete (UHPC) has been developed to overcome the low strengths and brittleness of conventional concrete. Considering that UHPC, owing to its composition and the use of steel fibers, develops a compressive strength of 180 MPa as well as high stiffness, the top flange of the steel girder may be superfluous in the composite beam combining a slab made of UHPC and the steel girder. In such composite beam, the steel girder takes the form of an inverted-T shaped structure without top flange in which the studs needed for the composition of the steel girder with the UHPC slab are disposed in the web of the steel girder. This study investigates experimentally and analytically the flexural behavior of this new type of composite beam to propose details like stud spacing and slab thickness for further design recommendations. To that goal, eight composite beams with varying stud spacing and slab thickness were fabricated and tested. The test results indicated that stud spacing running from 100 mm to 2 to 3 times the slab thickness can be recommended. In view of the relative characteristic slip limit of Eurocode-4, the results showed that the composite beam developed ductile behavior. Moreover, except for the members with thin slab and large stud spacing, most of the specimens exhibited results different to those predicted by AASHTO LRFD and Eurocode-4 because of the high performance developed by UHPC.

• Restorative Dentistry and Endodontics
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• v.30 no.1
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• pp.38-48
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• 2005

The purpose of this study was to compare and evaluate the shaping ability of the three different Ni-Ti file systems used by undergraduate students. Fifty undergraduate students prepared 150 simulated curved root canals in resin blocks with three Ni-Ti file systems - $ProFile^{(R)}$ (PF), Manual $ProTaper^{(R)}$ (MPT), Rotary $ProTaper^{(R)}$ (RPT). Every student prepared 3 simulated root canals with each system respectively. After root canal preparation, the Ni-Ti files were evaluated for distortion or breakage Assessments were made according to the presence of various types of canal aberrations. The pre- and post-instrumented canal images were attained and superimposed. The instrumented root canal width were measured and calculated for the net transportation (deviation) and the centering ratio. Under the condition of this study, both $ProTaper^{(R)}$ systems allowed significantly more removal of root canal wall than the $ProFile^{(R)}$ system. In the important other aspects such as the centering ratio, there was no significant differences between the systems. Novice dental students were able to prepare curved root canals with any kinds of Ni-Ti file systems with little aberration and great conservation of tooth structure. Students want to learn effective methods and at the same time simple rotary procedures. The rotary $ProTaper^{(R)}$ systems were one of the most compatible to these students from the point of view of cutting ability The $ProFile^{(R)}$ system was also compatible in safe and gentle shaping.

• Korean Journal of Remote Sensing
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• v.14 no.3
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• pp.213-222
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• 1998

Electro-Optical Camera(EOC) is the main payload of the KOrea Multi-Purpose SATellite(KOMPSAT) with the mission of cartography to build up a digital map of Korean territory including a Digital Terrain Elevation Map(DTEM). This instalment which comprises EOC Sensor Assembly and EOC Electronics Assembly produces the panchromatic images of 6.6 m GSD with a swath wider than 17 km by push-broom scanning and spacecraft body pointing in a visible range of wavelength, 510~730 nm. The high resolution panchromatic image is to be collected for 2 minutes during 98 minutes of orbit cycle covering about 800 km along ground track, over the mission lifetime of 3 years with the functions of programmable gain/offset and on-board image data storage. The image of 8 bit digitization, which is collected by a full reflective type F8.3 triplet without obscuration, is to be transmitted to Ground Station at a rate less than 25 Mbps. EOC was elaborated to have the performance which meets or surpasses its requirements of design phase. The spectral response, the modulation transfer function, and the uniformity of all the 2592 pixel of CCD of EOC are illustrated as they were measured for the convenience of end-user. The spectral response was measured with respect to each gain setup of EOC and this is expected to give the capability of generating more accurate panchromatic image to the users of EOC data. The modulation transfer function of EOC was measured as greater than 16 % at Nyquist frequency over the entire field of view, which exceeds its requirement of larger than 10 %. The uniformity that shows the relative response of each pixel of CCD was measured at every pixel of the Focal Plane Array of EOC and is illustrated for the data processing.