• Spatial Information Research
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• v.16 no.3
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• pp.373-383
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• 2008

LiDAR, unlike satellite imagery and aerial photographs, which provides irregularly distributed three-dimensional coordinates of ground surface, enables three-dimensional modeling. In this study, urban area was classified based on 3D information collected by LiDAR. Morphological and spatial properties are determined by the ratio of ground and non-ground point that are estimated with the number of ground reflected point data of LiDAR raw data. With this information, the residential and forest area could be classified in terms of height and density of trees. The intensity of the signal is distinguished by a statistical method, Jenk's Natural Break. Vegetative area (high or low density) and non-vegetative area (high or low density) are classified with reflective ratio of ground surface.

• ETRI Journal
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• v.32 no.4
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• pp.630-633
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• 2010

In this letter, we propose a novel polygonal approximation of digital curves that preserve original shapes. The proposed method first detects break points, which have two different consecutive vectors, and sets an initial dominant point set. The approximation is then performed iteratively by deleting a dominant point using a novel distance, which can measure both the distance and the angle acuteness. The experimental results show that the proposed method can preserve original shapes and is appropriate for various shapes, including slab-sided shapes.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.3
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• pp.279-284
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• 2012

Purpose: We measured the amplitude of accommodation using the push-up and push-away tests and near point of convergence (NPC) and investigated the accommodative insufficiency (AI) and convergence insufficiency (CI) in elementary school children of 12~13 years old. Methods: 88 students who aged 12~13 $12.63{\pm}0.51$ years old with more than 1.0 spectacle best corrected visual acuity were examined using push-up and push-away tests. The break and recovery points of NPC also were measured. Results: Mean amplitudes of accommodations using push-up and push-away tests were $11.52{\pm}2.50D$ and $10.06{\pm}1.97D$, respectively in right eye (P<0.001). Mean break and recovery points in NPC were $8.66{\pm}1.99cm$ and $10.98{\pm}2.06cm$. AI and CI showed 28.75% and 30.00% each. 48.75% was within normal range in both amplitudes of accommodations according to their age expected and convergence. Students having both AI and CI were 7.50%. Conclusions: A high correlation between the push-up test and push-away test was found in elementary school children (r=0.6025; P<0.05). Students having normal amplitude of accommodation by their age expected and normal convergence were 71.25% and 70.00%, respectively.

• Journal of Technologic Dentistry
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• v.10 no.1
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• pp.185-193
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• 1988

손익분기점분석(break-even point analysis)이란 매출액의 변화에 따라 달라지는 고정비 변동비의 수준과 이익의 관계를 연구하여 이익의 계획통제를 하는데, 혹은 자본구성에 관한 주요결정을 합리적으로 수행하는데 이용되는 중요한 재무분석 기법이다. 이는 결국 원가 매출액(생산량) 이익의 상호관계를 분석하는 것으로 CVP분석(cost-volume-profit relationship analysis)이라고 부른다.

• Communications for Statistical Applications and Methods
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• v.4 no.1
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• pp.243-254
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• 1997

특정분포에 대한 P-P plot과 Q-Q plot의 특징을 분석하고 두 가지 그래프 사이의 관계를 비교해 보았다. NTV의 본질적인 특징을 알아보고 각 특정분포에 대한 NTV plot의 특징을 분석했다. 전형적인 bimodal 분포가 나타날 때 P-P 혹은 Q-Q plot은 뚜렷한 break-point를 갖는다는 것을 알아보고, 단지 skewed된 분포나 skewed된 것처럼 보이는 bimodal 분포 사이에서 발생하는 판단의 어려움에 대하여 여러 plot고찰해 보았다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2006.05a
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• pp.146-151
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• 2006

• The Korean Journal of Health Service Management
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• v.4 no.1
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• pp.145-156
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• 2010

The purpose of this study is one of high price medical equipment wished to grasp propriety factor about the MRI introduction, analyzing payability through cost accounting into compensation. It was investigated from January 1 to December 31, 2007 about the MRI of a General Hospital. Expectation availability was 23.2 cases, but actual availability did achievement more than 196.1% with 45.5 items. It is estimated that there are a lot of occurrence cases because great reasons that actual availability increases more than expectation availability is excellent resolving power than a CT, and is device that prefer to reason back that radiation damage is less in person body. The followings show the main results of this study. 1. The MRI was construed in order of cost accounting, wave and personnel expenses 45.4%, administrative expenses 53.0%, and material costs 1.6%. 2. According to CVP (Cost-volume-profit) analysis, BEP (Break Even Point) profit is 173,931,428 won for 11 months, and break even usage number of items are 37.5 cases, and separation usage number of items were confirmed by 1.4 cases. Therefore, was construed that can achieve BEP within 11 months though usage number of items keeps 1.4 items day to create the MRI's hospital operation profit. 3. Estimated limit profitability appears high by 96.7%, exceed fixed charges even if when is non-benefit and when it is benefit consider variable, is judged that the MRI's addition induction helps in hospital management enhancing earning rates.

• Nuclear Engineering and Technology
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• v.38 no.7
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• pp.639-656
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• 2006

In order to apply the leak before break (LBB) concept to nuclear piping systems, the dynamic strain aging effect of low carbon steel materials has to be taken into account, in compliance with the requirements of the Korean Standard Review Guide (KSRG) 3.6.3-1. For this goal, J-R tests are needed for a range of various temperatures and loading rates, including dynamic loading conditions. In the dynamic loading J-R test, the unloading compliance method can not be applied to measure the crack growth and direct current potential drop (DCPD) method; this method also has a problem defining the crack initiation point. The normalization method is known as a very useful method to determine the J-R curve under dynamic loading because it does not need additional equipment or complicated loading sequences such as electric current or unloading. This method was accepted by the American Society for Testing and Materials (ASTM) as a standard test method E1820 A15 in 2001. However, it has not yet been clearly verified yet if the normalization method is sufficiently reliable to be applied to LBB. In this study, the basic background of the J-integral, LBB and dynamic loading J-R test are explained, and the current status for dynamic loading J-R test methods are reviewed from the view point of LBB for nuclear piping. In particular, the theoretical and historical background of the normalization method which has received attention recently, is summarized. Recent studies for this method are introduced and future works are suggested that may improve the reliability of LBB for nuclear piping.

• The Korean Journal of Physiology
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• v.27 no.2
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• pp.227-232
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• 1993

The temperature dependence of $Na^+-dependent$ succinate uptake was studied in brush border (BBMV) and basolateral (BLMV) membrane vesicles isolated from the rabbit kidney cortex. The succinate uptake was markedly altered by temperature in a similar fashion in both membranes. The temperature dependence was characterized by a nonlinear Arrhenius plot with a break point at 22 and $25^{\circ}C$ for BBMV and BLMV, respectively. The activation energy was 3.91 and 17.09 kcal/mole at above and below the break point respectively, far BBMV; 2.65 and 14.05 kcal/mole, respectively, for BLMV. When temperature increased f개m 20 to $35^{\circ}C$, the Vmax of succinate transport increased from $3.49{\pm}0.11\;to\;5.90{\pm}0.86\;nmole/mg/5\;sec$ for BBMV and from $2.86{\pm}0.25\;to\;3.63{\pm}0.32\;nmole/mg/5\;sec$ for BLMV, with no change in Km in both membranes. These results suggest that renal dicarboxylate transport is similarly sensitive to a change in membrane physical state in BBMV and BLMV.

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1460-1464
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• 2014

The substituent effects on the pyridinolysis (XC5H4N) of Y-aryl ethyl chlorophosphates are investigated in acetonitrile at $35.0^{\circ}C$. The two strong ${\pi}$-acceptor substituents, X = 4-Ac and 4-CN in the X-pyridines, exhibit large positive deviations from the Hammett plots but little positive deviations from the Br$\ddot{o}$nsted plots. The substituent Y effects on the rates are really significant and the Hammett plots for substituent Y variations in the substrates invariably change from biphasic concave downwards via isokinetic at X = H to biphasic concave upwards with a break point at Y = 3-Me as the pyridine becomes less basic. These are interpreted to indicate a mechanistic change at the break point from a stepwise mechanism with a rate-limiting bond formation (${\rho}_{XY}$ = -6.26) for Y = (4-MeO, 4-Me, 3-Me) to with a rate-limiting leaving group expulsion from the intermediate (${\rho}_{XY}$ = +5.47) for Y = (4-Me, H, 3-MeO). The exceptionally large magnitudes of ${\rho}_{XY}$ values imply frontside nucleophilic attack transition state.