• 정보처리학회논문지B
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• 제18B권4호
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• pp.193-200
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• 2011

본 논문은인간-컴퓨터 인터페이스, 가상현실의 의학 응용, 환자의 원격 모니터링과 같은 실시간 응용 분야에 적합한 인체 운동의 시각적 해석 알고리즘 (visual analyzer algorithm)을 제안한다. 본 알고리즘을 사용할 때의 비용을 줄이기 위해서, 단수의 카메라를 사용하도록 설계한다. 그리고 제안한 알고리즘을 좀 더 편리하게 사용할 수 있도록 하기 위해서 광학적 표시자의 사용을 피한다. 제안하는 알고리즘이 실시간 사용에 편리하도록 하기 위해서, 폐쇄적 형태가 되도록 설계한다. 폐쇄적 형태의 알고리즘을 설계하기 위해서, 인체의 각 관절을 기존의 3차원 관절 모델 대신 어떤 형태의 근사화도 사용하지 않고도 2차원 관절 모델로 공식화하는 아이디어를 제안한다. 그리고 이 폐쇄적 형태의 알고리즘이 높은 정확도를 갖게 하기 위해서, 계산 알고리즘을 최적화 문제로 공식화한다. 이렇게 해서 설계된 알고리즘을 인체의 각 관절에 차례대로 적용한다.

• 대한산업공학회지
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• 제17권2호
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• pp.87-95
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• 1991

The exact solution of the closed queueing networks(CQN) is known only for the product form (BCMP) queueing networks. Various computational algorithms are available to derive system throughput(the rate at which a system completes units of computational work) of the networks. However, the computational expense of an exact solution is often excessive when there are multiple classes of cutomers. Instead of computing the exact values, it may be sufficient to derive bounds on the performance measures. Techniques for obtaining bounds on BCMP queueing networks have appeared in the past years. This paper also presents bounds on throughput in CQN models with multiple classes of customers.

• Steel and Composite Structures
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• 제50권2호
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• pp.135-148
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• 2024

This paper analytically investigates the free vibration analysis of functionally graded-carbon nanotube reinforced composite (FG-CNTRC) plates by dynamic stiffness method (DSM). The properties of CNTRC are determined with the extended rule of mixture. The governing differential equations of motion based on the first-order shear deformation theory of CNTRC plate are derived using Hamilton's principle. The FG-CNTRC plates are studied for a uniform and two different distributions of carbon nanotubes (CNTs). The accuracy and performance of the DSM are compared with the results obtained from closed closed-form and semi-analytical solution methods in previous studies. In this study, the effects of boundary condition, distribution type of CNTs, plate aspect ratio, plate length to thickness ratio, and different values of CNTs volume fraction on the natural frequencies of the FG-CNTRC plates are investigated. Finally, various natural frequencies of the plates in different conditions are provided as a benchmark for comparing the accuracy and precision of the other analytical and numerical methods.

• 한국전자파학회논문지
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• 제19권5호
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• pp.547-555
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• 2008

본 논문에서는 linear amplification with nonlinear components(LINC) 시스템의 두 신호 경로에 발생하는 크기와 위상 오차를 자동으로 검출하여 보상하는 알고리즘을 제안하였다. LINC 시스템은 첨두 대 평균 전력비가 큰 non-constant envelop 신호를 constant envelop 신호로 바꿔주어 고효율 전력 증폭기를 사용할 수 있는 장점이 있다. 그러나 LINC 시스템은 두 전력 증폭기의 경호에서 발생하는 매우 작은 경로 오차에 민감하게 성능이 열화된다는 단점이 있다. 본 논문에서는 4개의 테스트 신호를 이용하여 두 경로의 크기와 위상 오차를 검출하는 알고리즘을 제안하였다. 제안된 오차 검출 기법은 닫힌 해(closed form solution)를 가지며, 반복 계산이 필요하지 않아, 빠르고 효율적으로 오차를 검출할 수 있다. 본 논문에서는 제안된 기법을 적용하여 오차 검출과 검출된 결과를 반영하여 신호의 왜곡을 보상하는 digital-IF 형태를 갖는 LINC 시스템을 구현하였다. 구현된 LINC 시스템은 7 MHz 채널 대역을 갖고 16-QAM으로 변조된 IEEE 802.16 WiMAx 기저 대역 신호를 이용하여 성능을 분석하였으며, 제안된 기법을 이용하여 EVM이 -37.37 dB까지 개선되었으며, 이로서 LINC 시스템 구현시 제안된 오차 검출 및 보상 기법의 적용 타당성을 확인하였다.

• 한국소음진동공학회논문집
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• 제11권8호
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• pp.357-363
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• 2001

This paper presents the application of the technique Q( differential transformation to the vibration analysis of beams resting on variable two-parameter elastic foundations. The closed form series solutions for beams are obtained for various boundary conditions. Numerical calculations are carried out and compared with previously published results. The results obtained by the present method agree very well with those reported in the previous works. The present analysis shows the usefulness and validity of differential transformation in solving nonlinear problem of the free vibration.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권12호
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• pp.3166-3181
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• 2012

Localization of mobile station (MS) has now gained considerable attention. Since the hybrid measurements can help to improve the positioning accuracy, several hybrid localization methods have been proposed in the literature. However, the high performance estimator with the closed-form solution and complete performance analysis for time-of-arrival/signal strength (TOA/SS) localization technique is still an opening issue. Two TOA/SS localization algorithms with the closed-form solutions are proposed for the cases with or without uncertainty in the positions of base stations. Furthermore, performance analysis for the TOA/SS localization technique is presented. Both the theoretical variances and Cramer-Rao lower bounds (CRLBs) are derived and the relationship between the cases with or without uncertainty is given. The paper also proves that the TOA/SS scheme has a lower CRLB than the TOA (or SS) scheme. Theoretical analysis and simulations show that the proposed method can reach its CRLB.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권3호
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• pp.1016-1033
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• 2016

In this paper, we present a joint relay-and-antenna selection and power allocation strategy for multiple-input multi-output (MIMO) amplify-and-forward (AF) two-way relay networks (TWRNs). In our approach, we select the best transmit and receive antennas at the two sources, a best relay and a best transmit and receive antenna at the selected relay based on maximizing the minimum of the end-to-end received signal-to-noise-ratios (SNRs) under a total transmit power constraints. We obtained the closed-form solution for the optimal power allocation firstly. Then with the optimal allocation solution we found, we can reduce the joint relay-and-antenna selection to a simpler problem. Besides, the overall outage probability is investigated and a tight closed-form approximation is derived, which provides a method to evaluate the outage performance easily and fast. Simulation results are presented to verify the analysis.

• Structural Engineering and Mechanics
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• 제70권5호
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• pp.535-549
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• 2019

This study aimed to develop a high-order shear deformation theory to predict the free vibration of hybrid cross-ply laminated plates under different boundary conditions. The equations of motion for laminated hybrid rectangular plates are derived and obtained by using Hamilton's principle. The closed-form solutions of anti-symmetric cross-ply and angle-ply laminates are obtained by using Navier's solution. To assess the validity of our method, we used the finite element method. Firstly, the analytical and the numerical implementations were validated for an antisymmetric cross-ply square laminated with available results in the literature. Then, the effects of side-to-thickness ratio, aspect ratio, lamination schemes, and material properties on the fundamental frequencies for different combinations of boundary conditions of hybrid composite plates are investigated. The comparison of the analytical solutions with the corresponding finite element simulations shows the good accuracy of the proposed analytical closed form solution in predicting the fundamental frequencies of hybrid cross-ply laminated plates under different boundary conditions.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.238-242
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• 1994

Shuster's algorithm for spin-axis determination is extended to include sensor bias and mounting angle as its solve-for parameters. The relation between direct and derived measurements bias is obtained by linearizing their kinematic equations. A one-step least-square estimation technique referred to as the 'closed form' solution is used, and the solution provides a more refined and decent initial guess for the subsequent filtering process contained within the differential correction module. The modified algorithm is applied for attitude determination of a GEO communication satellite in transfer orbit, and its results are presented.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3443-3446
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• 2014

We present the solution of Klein Gordon equation with new generalized Morse-like potential using SUSYQM formalism. We obtained approximately the energy eigenvalues and the corresponding wave function in a closed form for any arbitrary l state. We computed the numerical results for some selected diatomic molecules.