• 대한기계학회논문집
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• 제17권2호
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• pp.248-256
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• 1993

본 연구에서는 연속계의 진동모드를 구하여 일반질량(generalize mass)을 유 동하였으며 집중, 분포질량 변경에 따른 일반질량 변화량을 산출하여 감도계수를 구하 는 새로운 연속계 감도해석 방법을 제안하였고, 타당성을 검증하기 위해 외팔보, 계단 보에 적용하여 감도계수, 고유진동수, 진동모드, 전달함수의 변화량을 예측하고 이론 치와 비교하였다. Fig.1은 본 연구의 흐름도를 나타낸다.

• 설비공학논문집
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• 제15권9호
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• pp.744-750
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• 2003

The performance of adiabatic capillary tubes are measured to provide the database for a generalized correlation. Test conditions and capillary tube geometries are selected to cover a wide range typically observed in air-conditioning and heat pump applications. Based on extensive experimental data for R22, R290, and R407C measured in this study, a generalized correlation for refrigerant flow rate in adiabatic capillary tubes is developed by implementing dimensionless parameters for tube inlet conditions, capillary tube geometry, and refrigerant properties. The correlation yields good agreement with the present data for R22, R290, and R407C with average and standard deviations of 0.9% and 5.0%, respectively. In addition, approximately 97% of the data for Rl2, R134a, R152a, R410A, and R600a obtained in the open literature are correlated within a relative deviation of $\pm$ 15%.

• 한국생산제조학회지
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• 제9권5호
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• pp.40-46
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• 2000

This study predicts the modified structural eigenvector and eigenvalue due to the change in the mass and stiffness of 2-dimesional continuous system by iterative calculation of the sensitivity coefficient using the original dynamic characteristic. The method is applied to examples of a crank shaft by modifing the mass and stiffness. The predicted dynamics characteristics are in good agreement with these from the structural analysis using the modified mass and stiffness. The predicted dynamic characteristics are in good agreement with these from the structural analysis using the modified mass and stiffness.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1648-1653
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• 2003

This paper predicts the modified proportional damping structural eigenvectors and eigenvalues due to the change in the mass and stiffness of a proportional damping structure by iterative calculation of the sensitivity coefficient using the original dynamic characteristics. The method is applied to examples of a cantilever and 3 degree of freedom lumped mass model by modifing the mass and stiffness. The predicted dynamic characteristics are in good agreement with these from the structural reanalysis using the modified mass and stiffness.

• 한국공작기계학회논문집
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• 제14권4호
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• pp.7-12
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• 2005

This study predicts the modified eigenvectors and eigenvalues of the damped structure due to the change in the mass, damping and stiffness of structure by calculation of the sensitivity coefficient using the original dynamic characteristic. The method is applied to examples of the damped 3 degree of freedom system by modifing the mass, damping and stiffness. The predicted dynamic characteristics are in good agreement with these from the structural reanalysis using the modified mass, damping and stiffness.

• 대한기계학회논문집A
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• 제26권4호
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• pp.739-744
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• 2002

This study predicts the modified structural eigenvectors and eigenvalues due to the change in the mass and stiffness of a structure by iterative calculation of the sensitivity coefficient using the original dynamic characteristics. The method is applied to examples of a cantilever and 3 degree of freedom lumped mass model by modifing the mass and stillness. The predicted dynamic characteristics are in good agreement with these from the structural reanalysis using the modified mass and stiffness.

• Structural Engineering and Mechanics
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• 제60권3호
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• pp.529-545
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• 2016

In this article, the generalized coupled non-Fickian diffusion-thermoelasticity analysis is carried out using an analytical method. The transient behaviors of field variables, including mass concentration, temperature and displacement are studied in a strip, which is subjected to shock loading. The governing equations are derived using generalized coupled non-Fickian diffusion-thermoelasticity theory, which is based on Lord-Shulman theory of coupled thermoelasticity. The governing equations are transferred to the frequency domain using Laplace transform technique and then the field variables are obtained in analytical forms using the presented method. The field variables are eventually determined in time domain by employing the Talbot technique. The dynamic behaviors of mass concentration, temperature and displacement are studied in details. It is concluded that the presented analytical method has a high capability for simulating the wave propagation with finite speed in mass concentration field as well as for tracking thermoelastic waves. Furthermore, the obtained results are more realistic than that of others.

• 대한기계학회논문집A
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• 제30권7호
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• pp.750-756
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• 2006

This study predicts the modified eigenvectors and eigenvalues of the non-proportional damped structure due to the change in the mass, damping and stiffness of structure by iterative method of the sensitivity coefficient using the original dynamic characteristic. The method is applied to the non-proportional damped 3 degree of freedom system by modifying the mass, damping and stiffness. The predicted dynamic characteristics are showed a good agreement with these from the structural reanalysis using the modified mass, damping and stiffness.

• 설비공학논문집
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• 제16권10호
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• pp.895-900
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• 2004

With the phaseout of CFC and HCFC refrigerants, refrigeration and heat pump systems must be redesigned to match and improve system performance with alternative refrigerants. A generalized flow model for predicting mass flow rate through short tube orifices is derived from a power law form of dimensionless parameters generated by Pi-theorem. The database for developing the correlation includes extensive experimental data for R12, R22, R134a, R407C, R410A, and R502 from the open literature. The correlation yields an average deviation of $0.3\%$ and a standard deviation of $6.1\%$ based on the present database. In addition, rating charts for predicting refrigerant flow rate through short tube orifices are generated for R12, R22, R134a, R407C, R410A, and R502.

• Journal of Chest Surgery
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• 제26권7호
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• pp.548-551
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• 1993

Calcified right ventricular thrombi are very rare.One case of large clacified thrombus in right ventricle being seen in a 65-year old man, is presented. He had dyspnea and generalized edema.The chest film showed a large calcified mass in cardiac shadow especially in lateral view.On echocardiography and chest computed tomography, large calcified mass density occupied nearly entire right ventricular outflow tract.The mass removal was performed through right ventriculotomny.The mass was whitish, stony hard, measured 4 cm x 4.5 cm x 8 cm, tightly attached to right ventricular infundibular septum and ventriculoinfundibular fold.