• 동력기계공학회지
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• 제4권4호
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• pp.70-77
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• 2000

On the dynamic behavior of a simple beam the influences of the velocities and distance of two moving masses have been studied by numerical method. The instant amplitude of a simple beam is calculated and analyzed for each position of the moving masses represented by the time functions. As increasing the velocties of two moving masses on the simple beam, the amplitude of the transverse vibration of the simple beam is decreased and the frequency of the transverse vibration of the simple beam is increased. As the distance between two moving masses increase, the transverse displacement of the simple beam is decrease. The simple beam is very stable in second mode at $\bar{a}=0.5$ and in third mode at $\bar{a}=0.3$.

• 한국구조물진단유지관리공학회 논문집
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• 제17권3호
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• pp.20-27
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• 2013

본 논문에서는 고유진동수를 구하기 Simple Iteration Method을 제시하였다. 이 방법은 임의의 단면과 지점을 갖고 임의의 하중을 받는 보나 탑의 진동모드와 관련된 고유진동수를 간편하면서도 정확하게 계산할 수 있는 획기적인 방법이다. 이 방법에는 공진상태에서 관성력에 기인한 부재의 처짐 모드를 구하게 된다. 진동해석을 위하여 처짐의 영향을 고려한 다양한 방법이 검토되었다. 이러한 목적으로 본 논문에서는 유한차분법을 사용하였다. 고유진동수에 대한 $D_{22}$ 휨강성의 영향을 철저하게 검토하였다. 본 논문에서는 구조 요소의 하중 분포 또는 상이한 단면에 따른 고유진동수에 대한 영향을 연구하였으며 그 결과를 제시하였다. 이 방법은 첨단복합재료를 포함한 2차원 문제에도 적용할 수 있다.

• 한국전산유체공학회지
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• 제7권2호
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• pp.8-16
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• 2002

A numerical study on the use of the momentum interpolation method for flows with a large body force is presented. The inherent problems of the momentum interpolation method are discussed first. The origins of problems of the momentum interpolation methods are the validity of linear assumptions employed for the evaluation of the cell-face velocities, the enforcement of mass conservation for the cell-centered velocities and the specification of pressure and pressure correction at the boundary. Numerical experiments are performed for a typical flow involving a large body force. The numerical results are compared with those by the staggered grid method. The fact that the momentum interpolation method may result in physically unrealistic solutions is demonstrated. Numerical experiments changing the numerical grid have shown that a simple way of removing the physically unrealistic solution is a proper grid refinement where there is a large pressure gradient. An effective way of specifying the pressure and pressure correction at the boundary by a local mass conservation near the boundary is proposed, and it is shown that this method can effectively remove the inherent problem of the specification of pressure and pressure correction at the boundary when one uses the momentum interpolation method.

• 한국정보처리학회논문지
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• 제5권11호
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• pp.2835-2844
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• 1998

대부분의 데이터 병렬 언어들은 배열을 분배하는 방법을 제공하고 있다. 이들 중 블록-순환(block-cyclic) 분배가 가장일반적인 데이터 방법이다. 블록-순환 형태로 분할된 배열 구간 A(l:h:s) 중 각 프로세서가 자신의 메모리 영역에서 접근하는 A의 지역주소를 컴파일러 또는 실시간 시스템들이 생성하는 방안에 대한 연구가 이루어지고 있다. 이 논문에서는 블록-순환 분배된 배열에 대한 두 가지 지역 주소 생성 방법을 제안한다. 하나는 가상-블록 (virtual-block)을 변형한 simple scan 방법이고, 다른 하나는 지역 메모리 접근에 대한 정보를 포함하는 ${\Delta}M$테이블을 선형시간에 생성하는 알고리즘이다. ${\Delta}M$테이블 생성과 각 프로세서가 10,000개의 지역배열 원소를 접근하는데 소요된 시간을 측정하는 실험을 하였다. 실험결과 simple scan 방법은 성능이 좋지 못하였다. 하지만 ${\Delta}M$테이블을 구성하는 다른 방법들 보다 빠른 시간에 수행이 완료되었다.

• 한국측량학회지
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• 제31권1호
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• pp.49-55
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• 2013

데이터마이닝과 바이오인식 분야의 판별모델의 성능평가 방법을 이종의 공간 데이터 셋의 매칭에 적용함으로써 좋은 매칭결과를 보이는 판별모델을 도출하고자 한다. 이를 위하여 매칭 기준별 매칭 후보객체 쌍의 거리 값을 구하고, 이들 거리 값을 Min-Max 방법과 Tanh 방법으로 정규화하여 유사도를 산출한다. 산출된 유사도를 CRITIC 방법, Matcher Weighting 방법 그리고 Simple Sum 방법으로 결합하여 형상유사도를 도출하는 판별모델을 적용하였다. 각 판별모델을 PR곡선과 AUC-PR로 평가한 결과, Tanh 정규화와 Simple Sum 방법을 적용한 판별모델의 AUC-PR이 0.893으로 가장 높게 나타났다. 따라서 이종의 공간 데이터 셋의 매칭을 위해서는 Tanh 정규화를 이용하여 각 매칭기준별 유사도를 산출하고 Simple Sum 방법으로 형상유사도를 구하는 판별모델이 적합한 것으로 사료된다.

• Nuclear Engineering and Technology
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• 제42권6호
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• pp.670-679
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• 2010

In this paper, a new approach using a pixel-based correction method was developed to fix the non-uniform responses of flat-bed type scanners used for radiochromic film dosimetry. In order to validate the method's performance, two cases were tested: the first consisted of simple dose distributions delivered by a single port; the second was a complicated dose distribution composed of multiple beams. In the case of the simple individual dose condition, ten different doses, from 8.3 cGy to 307.1 cGy, were measured, horizontal profiles were analyzed using the pixel-based correcton method and compared with results measured by an ionization chamber and results corrected using the existing correction method. A complicated inverse pyramid dose distribution was made by piling up four different field shapes, which were measured with GAFCHROMIC$^{(R)}$EBT film and compared with the Monte Carlo calculation; as well as the dose distribution corrected using a conventional method. The results showed that a pixel-based correction method reduced dose difference from the reference measurement down to 1% in the flat dose distribution region or 2 mm in a steep dose gradient region compared to the reference data, which were ionization chamber measurement data for simple cases and the MC computed data for the complicated case, with an exception for very low doses of less than about 10 cGy in the simple case. Therefore, the pixel-based scanner correction method is expected to enhance the accuracy of GAFCHROMIC$^{(R)}$EBT film dosimetry, which is a widely used tool for two-dimensional dosimetry.

• 전기학회논문지
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• 제57권5호
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• pp.839-844
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• 2008

A novel state of health estimation method for hybrid electric vehicle lithium battery using sliding mode observer has been presented. A simple R-C circuit method has been used for the lithium battery modeling for the reduced calculation time and system resources due to the simple matrix operations. The modeling errors of simple model are compensated by the sliding mode observer. The design methodology for state of health estimation using dual sliding mode observer has been presented in step by step. The structure of the proposed system is simple and easy to implement, but it shows robust control property against modeling errors and temperature variations. The convergence of proposed observer system has been proved by the Lyapunov inequality equation and the performance of system has been verified by the sequence of urban dynamometer driving schedule test. The test results show the proposed observer system has superior tracking performance with reduced calculation time under the real driving environments.

• Transactions on Electrical and Electronic Materials
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• 제7권4호
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• pp.210-214
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• 2006

In this paper, two sampling methods which are Latin hypercube sampling (LHS) and simple random sampling were. compared to improve the modeling speed of neural network model. Sampling method was used to generate initial weights and bias set. Electrical characteristic data for $HfO_2$ thin film was used as modeling data. 10 initial parameter sets which are initial weights and bias sets were generated using LHS and simple random sampling, respectively. Modeling was performed with generated initial parameters and measured epoch number. The other network parameters were fixed. The iterative 20 minimum epoch numbers for LHS and simple random sampling were analyzed by nonparametric method because of their nonnormality.

• 소성∙가공
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• 제29권6호
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• pp.316-322
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• 2020

The flow stress curve is usually determined via uniaxial tensile or simple compression test. However, the flow stress curve up to high strain cannot be obtained using these two tests. This study presents a simple method for obtaining the flow stress curve up to high strain via FE analysis, a simple compression test, and an indentation test. In order to draw the flow stress curve up to high strain, the indentation test was carried out with the pre-stained specimen using the simple compression test. The flow stress curve of Al6110 was evaluated up to high strain using the proposed method, and the result was compared with the flow stress curve of the uniaxial tensile test of the initial material.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 추계 학술발표회논문집
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• pp.117-124
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• 2003

Long span structures with low natural frequencies such as shopping malls, large offices, and assembly rooms may experience signification dynamic responses due to human activities. In this study, equations to estimate the magnitudes of group walking loads are derived and a simple procedure to estimate and evaluate the corresponding response of the existing and new building structures subjected to human loads is proposed. The effectiveness of the proposed method is verified analytically using a simple floor and experimentally on a footbridge measuring the structural response induced by group pedestrians. Results indicate that the amplitudes of group walking loads can be easily estimated if the mode shapes are available, and that the corresponding structural responses can be estimated easily by the simple response measurement using the proposed method.