• Computers and Concrete
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• 제9권1호
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• pp.1-19
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• 2012

The size-effect study of various fracture parameters obtained from two parameter fracture model, effective crack model, double-K fracture model and double-G fracture model is presented in the paper. Fictitious crack model (FCM) for three-point bend test geometry for cracked concrete beam of laboratory size range 100-400 mm is developed and the different fracture parameters from size effect model, effective crack model, double-K fracture model and double-G fracture model are evaluated using the input data obtained from FCM. In addition, the fracture parameters of two parameter fracture model are obtained using the mathematical coefficients available in literature. From the study it is concluded that the fracture parameters obtained from various nonlinear fracture models including the double-K and double-G fracture models are influenced by the specimen size. These fracture parameters maintain some definite interrelationship depending upon the specimen size and relative size of initial notch length.

• 자원ㆍ환경경제연구
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• 제19권1호
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• pp.45-80
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• 2010

본 연구는 우리나라의 기후변화 대응 정책 입안에 있어 조세중립적 세제개편을 통한 탄소세의 도입에 따른 이중배당가설이 성립하는지를 연산가능일반균형모형을 이용하여 검토해 보았다. 법인세율 감경과 법정복리비 감경을 통한 조세중립적 세제개편과 병행한 탄소세 도입을 실험하여 본 결과, 우리나라의 경우 소득의 척도로 이중배당 효과를 측정할 때, 두 경우 모두 약이중배당 효과가 발견되고 있다. 그러나 소비 척도로 측정한 이중배당 효과는 법인세 감경을 통한 조세중립적 탄소세 도입의 경우 이중배당 효과가 전혀 나타나지 않았으며, 고용으로 측정한 이중배당 효과는 법정복리비 감경을 통한 조세중립적 탄소세 도입을 할 경우 강이중배당 효과도 발견되었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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• pp.691-694
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• 2003

Density gradient method is used to analyze the quantum effect in MOSFET, Quantization effect in the poly gate leads to a negative threshold voltage shift, which is opposed to the positive shift caused by quantization effect in the channel. Quantization effects in the poly gate are investigated using the density gradient method, and the impact on the short channel effect of double gate device is more significant.

• 설비공학논문집
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• 제17권2호
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• pp.191-199
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• 2005

Double pane window system, in which an air layer with a finite width is filled between glasses, is used in order to increase the insulation efficiency. In the present study, a conjugate heat transfer problem of a double pane window system has been studied numerically in order to investigate the effect of an air layer on the heat transmittance of the double pane window system using a finite element method based on P2P1 basis function. In this study on the conjugate heat transfer of a double pane window system, numerically predicted Nusselt numbers with or without conjugate heat transfer effect have been compared with an available existing empirical formula. It has been found that a Nusselt number from an existing formula for an enclosed space is different from that obtained from the present conjugate heat transfer analysis mainly due to the effects of a very high aspect ratio and conjugate heat transfer mechanism. Furthermore, it has been shown that the numerically estimated optimal air thickness of the double pane window system with conjugate heat transfer effect is a little bit longer than that obtained without considering conjugate heat transfer effect.

• 대한치과기공학회지
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• 제8권1호
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• pp.85-90
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• 1986

The effect of splinting on aqbutment tooth distal movement was performed in vitro study. An acrylic resin mandibular model with missing 2nd premolars, molars and a removable partial denture framework were constructed. The roots of the canines, 1st premolars and edentulous ridges were coated with silicone rubber. A modified Ney Surveyor was used for vertical load appkication, and abutment tooth distal movement were measured with a dial gauge with four conditions of splinting methods were tested by applying unilateral vertical loadings. The results are follows; 1. The magnitude of abutment tooth distal movement on the non-load side was less 40$\sim$69% than that occurred on the load side. 2. On the load side, reducing effect of splinting on abutment tooth movement in the condition of load side double abutment(30%), non-load side double abutment(10%), double abutments of both sides(40%) was compared with single abutments of both sides. 3. On the non-load side, reducing effect of splinting on abutment tooth movement in the condition of load side double abutment(5%), non-load side double abutment(22%), double abutments of both sides(59%) was compared with single abutments of both sides. 4. The magnitude of abutment tooth distal movement in the condition of double abutments of both sides was less 40$\sim$59% than that in the condition of single abutments of both sides.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.749-755
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• 2023

A new approximation method was proposed for treating the non-resonant spatial self-shielding effects of double heterogeneous region such as the double heterogeneous effect of VHTR fuel compact in the thermal energy range and that of BP compact with BISO. The method was developed based on the effective homogenization method and a spherical unit cell model with explicit coated layers and a matrix layer. The self-shielding factor was derived from the relation between the collision probabilities for a double heterogeneous compact and the effective cross section for the homogenized compact. First, the collision probabilities and transmission probabilities for all layers of the spherical model were calculated using conventional collision probability solver. Then, the effective cross section for the homogenized sphere cell representing the homogenized compact was obtained from the transmission probability calculated using the probability density function of a chord length. The verification calculations revealed that the proposed method can predict the self-shielding factor with a maximum error of 2.3% and the double heterogeneous effect with a maximum error of 200 pcm in the typical VHTR problems with various packing fractions and BP compact sizes.

• 한국세라믹학회지
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• 제33권5호
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• pp.590-601
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• 1996

This study aims at developing the double cantilever beam (DCB) method in order to calculate the bridging stress distribution in polycrystalline aluminas with different grain sizes. In the already existing DCB methods the measured crack opening displacement (COD) in coarse-grained aluminas deviates generally from the calcula-ted one because of the grain-interface bridging in the crack wake. In the current DBC method developed in the present study the effect of the bridging stress was considered in the DCB analysis. whereas the only effect of applied point-loading at the end of DCB specimen was taken into account in the existing DCB analysis The crack closure due to bridging stress was calculated using the power-law relation and the theoretical model developed in Part I of the present paper as bridging stress function and then compared analytically. The limitations of the current DCB methods such as specimen dimensions applied loads and elastic modulus were discussed in detail to provide a reliability of the newly developed DCB analysis for the bridging stress distribu-tion in polycrystalline aluminas.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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• pp.615-622
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• 2002

In this paper, the modification of double projection method for the adaptive analysis of Element-free Galerkin(EFG) method were proposed. As results of the double projection method, the smoothed error profile that is adequate for adaptive analysis was obtained by re-projection of error that means the differences of EFG stress and projected stress. However, it was found that the efficiency of double projection method is degraded as increase of the numerical integration order. Since, the iterative refinement to single step error estimation made the same effect as increasing of integration order, the application of the iterative refinement base on double projection method could be produced the inadequately refined analysis model. To overcome this defect, a modified scheme of double projection were proposed. In the numerical example, the results did not show degradation of double projection effect in iterative refinement and the efficiency of proposed scheme were proved.

• 대한한방내과학회지
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• 제19권2호
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• pp.159-184
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• 1998

The aim of the study was the experiment of the effect that Kami-Daesihotang had on the essential hypertension and hyperlipidemia. Rats were orally administered with Kami-Daesihotang for 30days and the constituent of the plasma and serum were analysed at the 10th, 20th and 30th day from the first day of experiment, respectively. The heart rate, blood pressure, plasma renin activity, plasma level of aldosterone, catecholamine, sodium and angiotensin II were measured after an oral administration of Kami-Daesihotang in SHR. In addition, serum levels of total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol and total lipid were measured with cholesterol-fed rats. The results were summarized as following ; 1. Single-dosage Kami-Daesihotang & double-dosage Kami-Daesihotang remarkably decreased the blood pressure in SHR. 2. Double-dosage Kami-Daesihotang were recognized as having the effect on the decreased of the pulse rate in SHR. 3. Plasma renin activity was significantly decreasd in SHR after single-dosage Kami-Daesihotang & double-dosage Kami-Daesihotang treatment. 4. Double-dosage Kami-Daesihotang considerably reduced the plasma angiotensin level in SHR. 5. Noticeable decreased of plasma norepinephrine level was showed in SHR, after single-dosage Kami-Daesihotang & double-dosage Kami-Daesihotang treatment. 6. Single-dosage Kami-Daesihotang & double-dosage Kami-Daesihotang noticeable reduced body weight in hyperlipidemia rats which had fed with 1% cholesterol. 7. Single-dosage Kami-Daesihotang & double-dosage Kami-Daesihotang had a significantly decreasing effect on serum total cholesterol in hyperlipidemia rats which had fed with 1% cholesterol. 8. Serum triglyceride level was importantly decreased in hyperlipidemia rats which had fed with 1% cholesterol, after single-dosage Kami-Daesihotang & double-dosage Kami-Daesihotang treatment. 9. Remarkable decreased of serum low density lipoprotein cholesterol level was found in hyperlipidemia rats which had fed with 1% cholesterol, after single-dosage Kami-Daesihotang & double-dosage Kami-Daesihotang treatment. 10. Double-dosage Kami-Daesihotang was showed a significantly decreasing effect on serum total lipid level in hyperlipidemia rats which had fed with 1% cholesterol. 11. Single-dosage Kami-Daesihotang noticeably reduced organ weight of liver, kidney, spleen and testis in hyperlipidemia rats which had fed with 1% cholesterol. Double-dosage Kami-Daesihotang significantly decreased organ weight of liver, kidney and spleen in hyperlipidemia rats. These Findings suggest a possible anti-hypertensive and hyperlipidemic effect of Kami-Daesihotang.

• 대한전자공학회논문지SD
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• 제45권10호
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• pp.15-22
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• 2008

기존의 MOSFET는 단채널 현상의 증가로 인하여 스케일링에 한계를 가지고 있다. Double-Gate MOSFET (DG-MOSFET)는 소자의 길이가 축소되면서 나타나는 단채널 현상을 효과적으로 제어하는 차세대 소자이다. DG-MOSFET으로 소자를 축소시키면 채널 길이가 10nm 이하에서 게이트 방향뿐만 아니라 소스와 드레인 방향에서도 양자 효과가 발생한다. 또한 게이트 길이가 매우 짧아지면 ballistic transport 현상이 발생한다. 따라서 본 연구에서는 2차원 양자 효과와 ballistic transport를 고려하여 DG-MOSFET의 특성을 분석하였다. 또한 단채널 효과를 줄이기 위해서 $t_{si}$와 underlap 그리고 lateral doping gradient를 이용하여 소자 구조를 최적화하였다.