• Korean Chemical Engineering Research
• /
• 제50권2호
• /
• pp.334-342
• /
• 2012

새로 개발된 '고액분리 통합이론'의 핵심 개념인 '케이크 첫 입자층이 받는 압력 $p_d$'의 역할을 인식하기 위해, 고압축성 케이크에 대해 다음과 같은 세 가지 고액분리 분야를 새로운 개념으로 분석하였다. 첫째, 침전된 플럭의 케이크 여과에서 여과 대상이 되는 침전 플럭의 두께 계산에서 $p_d$의 역할과, 케이크의 형성 두께 계산에서의 $p_d$의 역할. 둘째, 압착 과정에서의 $p_d$의 역할, 그리고 마지막으로 간섭침전 결과 쌓이는 높이에 미치는 $p_d$의 역할과 간섭침전 과정에서의 $p_d$의 중요성을 보였다. 이로써 고액분리 통합이론의 적용 가능성과, 그에 있어 $p_d$의 중요성을 밝힐 수 있었다. 이 과정을 통하여 케이크 여과, 압착, 간섭침전의 이론적인 새로운 정의가 가능해졌다.

• Bulletin of the Korean Chemical Society
• /
• 제35권8호
• /
• pp.2311-2316
• /
• 2014

Conformations and vibrational frequencies of the racemic (2RS,3RS)-5-amino-3-(4-phenylpiperazin-1-yl)-1,2,3,4-tetrahydronaphthalen-2-ol-(I) [(2RS,3RS)-(I)], a precursor of benzovesamicol analogues, have been carried out using various DFT methods (M06-2X, B3LYP, B3PW91, PBEPBE, LSDA, and B3P86) with basis sets of 6-31G(d), 6-31+G(d,p), 6-311+G(d,p), 6-311++G(d,p), cc-pVTZ, and TZVP. The LSDA/6-31G(d) level of theory shows the best performance in reproducing the X-ray powder structure. However, the PBEPBE/cc-pVTZ level of theory is the best method to predict the vibrational frequencies of (2RS,3RS)-(I). The potential energy surfaces of racemic pairs (2RS,3RS)-(I) and -(II) are obtained at the LSDA/6-31G(d) level of theory in the gas phase and in water. The results indicate that (2RS,3RS)-(I) are more stable by ~0.75 kcal/mol in energy than (2RS,3RS)-(II) in water, whereas conformer AIIg and BIIg are more stable by ~0.04 kcal/mol than AIg in gas phase. In particular, the hydrogen bond distances between the N of piperazine and the OH of tetrahydronaphthalen become longer in gas, compared with those in the water phase. Vibrational frequencies calculated at the PBEPBE/cc-pVTZ level of theory in the gas phase are larger than those in water, whereas their intensities in the gas phase are weaker than those in water.

• 대한원격탐사학회지
• /
• 제21권2호
• /
• pp.145-162
• /
• 2005

SAR 자료의 분류에서 토지 피복 구분 분류 정확도의 향상을 위해 이 논문은 다중 시기 SAR 자료를 이용한 분류에서의 특징 추출과 정보 융합 방법론을 제시하였다. 다중 시기 SAR 센서의 산란 특성을 고려하여 평균 후방 산란계수, 시간적 변이도와 긴밀도를 특징으로서 추출하였다. 이렇게 추출된 특징의 효율적인 응합을 위해 Dempster-Shafer theory of evidence(D-S 이론)와 퍼지 논리를 적용하였다. 특히 D-S 이론의 적용시 특징 기반 mass function 할당을 제안하였고, 퍼지 논리의 적용시 다양한 퍼지 결합 연산자의 결과를 비교하였다. 다중 시기 Radarsat-1 자료에의 적용 결과, 추출된 특징들은 서로 상호 보완적인 정보를 제공할 수 있으며 수계, 논과 도심지를 효율적으로 구분할 수 있었다. 그러나 산림과 밭은 구분이 애매한 경우가 나타났다. 정보 융합 방법론 측면에서, D-S 이론과 퍼지 Max와 Algebraic Sum 연산자를 제외한 다른 퍼지 연산자는 서로 유사한 분류 정확도를 나타내었다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제15권7호
• /
• pp.2631-2649
• /
• 2021

Device-to-Device (D2D) communication is one of the enabling technologies for 5G networks that support proximity-based service (ProSe) for wireless network communications. This paper proposes a power control algorithm based on the Nash equilibrium and game theory to eliminate the interference between the cellular user device and D2D links. This leadsto reliable connectivity with minimal power consumption in wireless communication. The power control in D2D is modeled as a non-cooperative game. Each device is allowed to independently select and transmit its power to maximize (or minimize) user utility. The aim is to guide user devices to converge with the Nash equilibrium by establishing connectivity with network resources. The proposed algorithm with pricing factors is used for power consumption and reduces overall interference of D2Ds communication. The proposed algorithm is evaluated in terms of the energy efficiency of the average power consumption, the number of D2D communication, and the number of iterations. Besides, the algorithm has a relatively fast convergence with the Nash Equilibrium rate. It guarantees that the user devices can achieve their required Quality of Service (QoS) by adjusting the residual cost coefficient and residual energy factor. Simulation results show that the power control shows a significant reduction in power consumption that has been achieved by approximately 20% compared with algorithms in [11].

• Nuclear Engineering and Technology
• /
• 제54권1호
• /
• pp.19-29
• /
• 2022

The 2D/1D method has become the mainstream of the direct transport calculation considering the balance of accuracy and efficiency. However, the 2D/1D method still suffers from stability issues. Recently, a quasi-3D method has been proposed with axial Legendre expansion. Analysis and comparison of the 2D/1D and quasi-3D method is conducted in theory from the equation derivation. Besides, the C5G7 benchmark, the KUCA benchmark and the macro BEAVRS benchmark are calculated to verify the theory comparisons of these two methods with the direct transport code SHARK. All results show that the quasi-3D method has better stability and accuracy than the 2D/1D method with worse efficiency and memory cost. It provides a new option for direct transport calculation with the quasi-3D method.

• Advances in nano research
• /
• 제12권2호
• /
• pp.117-137
• /
• 2022

Effect of thickness stretching on free vibration, bending and buckling behavior of carbon nanotubes reinforced composite (CNTRC) laminated nanoplates rested on new variable elastic foundation is investigated in this paper using a developed four-unknown quasi-3D higher-order shear deformation theory (HSDT). The key feature of this theoretical formulation is that, in addition to considering the thickness stretching effect, the number of unknowns of the displacement field is reduced to four, and which is more than five in the other models. Two new forms of CNTs reinforcement distribution are proposed and analyzed based on cosine functions. By considering the higher-order nonlocal strain gradient theory, microstructure and length scale influences are included. Variational method is developed to derive the governing equation and Galerkin method is employed to derive an analytical solution of governing equilibrium equations. Two-dimensional variable Winkler elastic foundation is suggested in this study for the first time. A parametric study is executed to determine the impact of the reinforcement patterns, nonlocal parameter, length scale parameter, side-t-thickness ratio and aspect ratio, elastic foundation and various boundary conditions on bending, buckling and free vibration responses of the CNTRC plate.

• 디자인학연구
• /
• 제15권1호
• /
• pp.49-58
• /
• 2002

컴퓨터 기술의 발달함에 따라 일선 교사들로 하여금 애니메이션과 같을 다양한 시각도구를 이용하여 멀티미디어 교육자료를 고안, 개발하는 것이 가능하게 되었다. 화려한 3D 애니메이션 기법을 도입한 게임, 또는 영화의 특수효과들과는 달리 멀티미디어를 이용한 교육자료들의 경우 정지된 영상이나 2D 애니메이션을 이용한 것들이 대부분이다. 컴퓨터 애니메이션이 학습효과에 도움을 준다는 것은 누추나 인식하고 있는 사실이지만 3D 애니떼이션을 이용한 멀티미디어 교육이 얼마나 학생들에게 효과 있는지에 대한 연구는 미흡한 실정이다. 본 논문에서는 1차 색상을 혼합하여 2차 색상을 얻는 기본적인 색채이론 과정을 3D 컴퓨터 애니메이션으로 표현하는 방법을 기술하고 본 시청각 교육자료를 통하여 이루어진 색채교육의 결과가 기존의 방법들을 보완하면서도 어린이들로 하여금 색채이론의 이해도를 제고하는데 미치는 효과를 알아보았다.

• 대한화학회지
• /
• 제53권1호
• /
• pp.7-16
• /
• 2009

Bz-$H_2O$와 [Bz-$H_2O]^+$의 가능한 구조(N-1, N-2, C-1, C-2, 그리고 TS)에 대하여 여러 이론 수준에 서 분자구조를 최적화 하였으며, 조화 진동주파수를 계산하여 IR 스펙트럼을 예측하였다. 분자 구조의 최적화에서 가장 높은 이론 수준은 B3LYP/cc-pVQZ이며, 보다 정확한 결합에너지를 구하기 위하여 MP2 수준에서 한 점(single point) 에너지 계산을 하였다. 또한 영점 진동에너지(zero-point vibrational energy) 보정을 하여 실험값과 비교하였다. 결합에너지는 N-1 구조에 대하여 MP2/cc-pVQZ//B3LYP/cc-pVQZ 이론 수준에서 $D_e$ 값이 3.92 kcal/mol, 그리고 $D_0$ 값은 3.11 kcal/mol로 계산되었으며, 같은 이론 수준에서 [Bz-$H_2O]^+$의 C-1 구조에 대해서 $D_e$ 값은 9.06 kcal/mol 그리고 $D_0$ 값은 7.82 kcal/mol로 계산되어 실험값 과 비교적 잘 일치하는 것으로 나타났다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권6호
• /
• pp.1996-2013
• /
• 2015

This paper considers a scenario that more D2D users exist in the cell, they compete for cellular resources to increase their own data rates, which may cause transmission interference to cellular users (CU) and the unfairness of resource allocation. We design a resource allocation scheme for selfish D2D users assisted by cooperative relay technique which is used to further enhance the users' transmission rates, meanwhile guarantee the QoS requirement of the CUs. Two transmission modes are considered for D2D users: direct transmission mode and cooperative relay transmission mode, both of which reuses the cellular uplink frequency resources. To ensure the fairness of resource distribution, Nash bargaining theory is used to determine the transmission mode and solve the bandwidth allocation problem for D2D users choosing cooperative relay transmission mode, and coalition formation game theory is used to solve the uplink frequency sharing problem between D2D users and CUs through a new defined "Selfish order". Through theoretical analysis, we obtain the closed Nash bargaining solution under CUs' rate constraints, and prove the stability of the formatted coalition. Simulation results show that the proposed resource allocation approach achieves better performance on resource allocation fairness, with only little sacrifice on the system sum rates.

• Korean Journal of Mathematics
• /
• 제24권2호
• /
• pp.235-271
• /
• 2016

By using the Heckman-Opdam theory on ${\mathbb{R}}^d$ given in [20], we define and study in this paper, the generalized wavelets on ${\mathbb{R}}^d$ and the generalized wavelet transform on ${\mathbb{R}}^d$, and we establish their properties. Next, we prove for the generalized wavelet transform Plancherel and inversion formulas.