• 대한수학회지
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• 제34권1호
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• pp.237-245
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• 1997

The fixed point index plays an important role in solving the positive solutions of nonlinear equations in ordered Banach spaces ([7], [10], [11], [14], [15]). Many authors have studied the existence problems of positive solutions of nonlinear equations for nonlinear mappings ([1]-[5], [7], [9], [10], [14], [15]).

• Smart Structures and Systems
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• 제18권2호
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• pp.197-216
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• 2016

The increased speed of a train causes increased loads that act on the track substructures. To ensure the safety of the track substructures, proper maintenance and repair are necessary based on an accurate characterization of strength and stiffness. The objective of this study is to develop and apply a cone penetrometer incorporated with the dynamic cone penetration method (CPD) for investigating track substructures. The CPD consists of an outer rod for dynamic penetration in the ballast layer and an inner rod with load cells for static penetration in the subgrade. Additionally, an energy-monitoring module composed of strain gauges and an accelerometer is connected to the head of the outer rod to measure the dynamic responses during the dynamic penetration. Moreover, eight strain gauges are installed in the load cells for static penetration to measure the cone tip resistance and the friction resistance during static penetration. To investigate the applicability of the developed CPD, laboratory and field tests are performed. The results of the CPD tests, i.e., profiles of the corrected dynamic cone penetration index (CDI), profiles of the cone tip and friction resistances, and the friction ratio are obtained at high resolution. Moreover, the maximum shear modulus of the subgrade is estimated using the relationships between the static penetration resistances and the maximum shear modulus obtained from the laboratory tests. This study suggests that the CPD test may be a useful method for the characterization of track substructures.

• 한국지반공학회논문집
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• 제23권12호
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• pp.13-23
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• 2007

풍화토는 암석으로부터 풍화되어 그 산물로 나타난다. 또한, 풍화정도에 따라 연암, 풍화암, 잔적토에 이르기까지 그 산물은 다양하다. 일반적으로 풍화정도의 결정은 화학적 방법이나 표준관입시험의 N-value를 이용한다. 그러나 이러한 방법은 약간의 단점을 가지고 있으며, 이에 본 연구에서는 교란시료와 물리적인 방법인 Fall cone test를 이용하여 풍화정도를 결정할 수 있는 방법을 제시하였다. Fall cone test 결과, 동일한 지역에서 풍화정도의 차이를 확인할 수 있었으며, 관입량에 따른 화학적풍화지수(CWI)와 함수비의 관계는 하나의 방정식으로 표현할 수 있었다.

• Journal of Computational Design and Engineering
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• 제3권3호
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• pp.198-214
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• 2016

Oval substrates are widely used in automobiles to reduce the exhaust emissions in Diesel oxidation Catalyst of CI engine. Because of constraints in space and packaging Oval substrate is preferred rather than round substrate. Obtaining the flow uniformity is very challenging in oval substrate comparing with round substrate. In this present work attempts are made to optimize the inlet cone design to achieve the optimal flow uniformity with the help of CATIA V5 which is 3D design tool and CFX which is 3D CFD tool. Initially length of inlet cone and mass flow rate of exhaust stream are analysed to understand the effects of flow uniformity and pressure drop. Then short straight cones and angled cones are designed. Angled cones have been designed by two methodologies. First methodology is rotating flow inlet plane along the substrate in shorter or longer axis. Second method is shifting the flow inlet plane along the longer axis. Large improvement in flow uniformity is observed when the flow inlet plane is shifted along the direction of longer axis by 10, 20 and 30 mm away from geometrical centre. When the inlet plane is rotated again based on 30 mm shifted geometry, significant improvement at rotation angle of $20^{\circ}$ is observed. The flow uniformity is optimum when second shift is performed based on second rotation. This present work shows that for an oval substrate flow, uniformity index can be optimized when inlet cone is angled by rotation of flow inlet plane along axis of substrate.

• 한국기계가공학회지
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• 제20권11호
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• pp.92-99
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• 2021

Agricultural tractors drive and operate both off-road and on-road. Tire-road interaction significantly affects the tractive performance of a tractor, which is difficult to predict numerically. Many empirical models have been developed to predict the tractive performance of tractors using the cone index, which can be measured through simple tests. However, a magic formula model that can determine the tractive performance without a cone index can be used instead of traditional empirical models as the cone index cannot be measured on asphalt roads. The aim of this study was to predict the tractive performance of a tractor using the magic formula tire model. The traction force of the tires on an asphalt road was measured using an agricultural tractor. The dynamic wheel load was calculated to derive the coefficients of the traction-slip curve using the measured static wheel load and drawbar pull of the tractor. Curve fitting was performed to fit the experimental data using the magic formula. The parameters of the magic formula tire model were well identified, and the model successfully determined the coefficient of traction of the tractor.

• Journal of Oral Medicine and Pain
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• 제34권1호
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• pp.81-90
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• 2009

2005년부터 2007년까지 진주 OOO치과의원 턱관절/구강안면통증클리닉에 내원한 측두하악장애환자 95명, 190개의 관절을 대상으로 한 명의 검사자가 측두하악관절장애 분석검사와 파노라마영상검사를 엄격히 시행하고, CBCT영상을 촬영하여 구강내과 전문의와 치과방사선과 전문의가 각각 영상진단 하였으며, 임상적 진단과 CBCT영상의 결과를 비교하여 다음과 같은 결과를 얻었다. 1. 구강내과 전문의와 치과방사선과 전문의에 의한 CBCT의 영상진단의 일치도(Kappa: 0.681)가 높았다. 2. 파노라마영상과 CBCT의 영상진단과의 일치도(Kappa: 0.169)가 낮으며, 파노라마영상에서 골변화의 위음성이 높았다. 3. 임상적으로 비퇴행성골관절염으로 진단된 관절 중 CBCT의재진단시 54.2%에서 골변화가 관찰되었으며, 퇴행성골관절염으로 진단된 관절 중 CBCT의 재진단시 15.3%에서 골변화가 없는 것으로 관찰되었다. 4. 관절통은 침식성 골변화에서 높게 나타났으며, 골증식체의 골변화에서 염발음이 가장 많이 나타났으며 병력기간도 가장 길었다.

• 한국산림과학회지
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• 제79권4호
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• pp.424-430
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• 1990

소나무, 잡종(雜種)소나무 및 곰솔의 수지구지수(樹脂溝指數)의 변화(變化)에 따라 침엽(針葉), 구과(毬果) 및 종자(種子)의 형태적(形態的) 특성(特性)과 동위효소(同位酵素) ADH, ME, PGI의 대립유전자빈도(對立遺傳子頻度)의 변이(變異)를 조사(調査)한바 다음과 같다. 1. 수지구지수(樹脂溝指數)가 증가(增加)암에 따라 침엽(針葉)의 길이, 엽초장, 구과(毬果)의 크기, 종자(種子)의 크기, 종자(種子)날개의 크기, 종자(種子) 1000립중(粒重)은 증가(增加)하고 침엽(針葉)의 기공열수(氣孔列數)는 감소하는 경향을 나타내고 있다. 2. 침엽(針葉), 구과(毬果) 및 종자(種子)의 형태적(形態的) 특성(特性)을 판별분석(判別分析) 결과(結果) 수지구지수(樹脂溝指數)와 대채로 일치(一致)하는 경향을 보이고 있으나 개체(個體) 따라 일치(一致)하지 않는 개체(個體)도 있다. 소나무 및 잡종(雜種)소나무에서는 10-25% 정도는 일치(一致)하지 않았고 곰솔에서는 거의 일치(一致)하였다. 3. 각(各) 형태적(形態的) 특성(特性)에 의한 정준판별함수(正準判別函數)의 결과 소나무, 이입교잡종(移入交雜種), 잡종(雜種)소나무, 곰솔의 양적형질중(量的形質中) 수지구지수(樹脂溝指數), 종자(種子)의 1000립중(粒重), 구과(毬果)의 크기 및 엽초장이 각수종(各樹種)의 특성(特性)을 가장 잘 나타내고 있다. 4. 수지구지수(樹脂溝指數)가 증가(增加)함에 따라 잡종도지수(雜種度指數)도 증가(增加)하는 경향을 나타내고 잡종도지수(雜種度指數)와 판별분석(判別分析)의 결과(結果)는 거의 같은 경향을 나타내고 있다. 5. 수지구지수(樹脂溝指數) 증가(增加)함에 따라 동위효소(同位酵素) ADH-$B_2$, ME-$A_2$, 및 PGI-$B_1$, $B_2$ 대립유전자(對立遺傳子)의 빈도(頻度)는 증가(增加)하고 ADH-$B_3$, ME-$A_4$, PGI-$B_3$는 감소하는 경향을 나타내고 있다. ADH-$B_2$, ME-$A_2$ 및 PGI-$B_1$, $B_2$의 인자(因子)는 곰솔에서 소나무로 유입(流入)된 것으로 간주되며 이러한 인자(因子)가 유입(流入)됨에 따라 ADH-$B_3$, ME-$A_4$, 및 PGI-$B_3$는 감소하는 것으로 생각된다.

• Molecules and Cells
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• 제26권4호
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• pp.373-379
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• 2008

Recently, we reported the existence of AII "rod" amacrine cells in the retina of the greater horseshoe bat Rhinolophus ferrumequinum (Jeon et al., 2007). In order to enhance our understanding of bat vision, in the present study, we report on a quantitative analysis of cone and rod photoreceptors. The average cone density was $9,535cells/mm^2$, giving a total number of cones of 33,538 cells/retina. The average rod density was $368,891cells/mm^2$, giving a total number of rods of 1,303,517 cells. On average, the total populations of rods were 97.49%, and cones were 2.51% of all the photoreceptors. Rod: cone ratios ranged from 33.85:1 centrally to 42.26:1 peripherally, with a mean ratio of 38.96:1. The average regularity index of the cone mosaic in bat retina was 3.04. The present results confirm the greater horseshoe bat retina to be strongly rod-dominated. The rod-dominated retina, with the existence of AII cells discovered in our previous study, strongly suggests that the greater horseshoe bat retina has a functional scotopic property of vision. However, the existence of cone cells also suggests that the bat retina has a functional photopic property of vision.

• 대한수학회보
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• 제38권4호
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• pp.643-655
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• 2001

We discuss the existence of positive solutions to a certain nonlinear elliptic system representing a competition interaction with self-diffusion. The method used here is a fixed point index theory in a positive cone. We give a sufficient condition for the existence of positive solutions.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2006년도 하계 학술대회 논문집
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• pp.24-27
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• 2006