• 한국광학회지
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• 제4권3호
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• pp.338-346
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• 1993

시간 상관 단일 광자 계수법을 사용하여 rhodamine 6G 분자의 회전 재배열 시간을 측정하였다. 알코올 용매에서 유체 역학 모델이 예측하는 것보다 회전 재배열 시간이 느린 현상으로 이해하기 위해 유전 마찰 효과를 고려하였으며, 유전 마찰과 정적 분광학 데이터로부터 바닥 및 여기 상태의 전이 쌍극자 모멘트 크기를 계산하였다.

• 소성∙가공
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• 제16권4호
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• pp.229-233
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• 2007

The present work focuses on the prediction of birefringence in injection-molded part and its improvement by rapid mold heating. To calculate birefringence, flow-induced residual stress is computed through a fully three-dimensional injection molding analysis. Then the stress-optical law is applied from which the order of birefringence can be evaluated and visualized. The birefringence patterns are predicted for a rectangular plate with a variation of mold temperature, which shows that the amount of molecular orientation and birefringence level decreases with an increase of mold temperature. The effect of mold temperature on the order of birefringence is also studied for a thin-walled rectangular strip, and the relevant results are compared with experimental measurements. Both predicted and experimental patterns of birefringence are in agreements on the observation that the birefringence level diminishes significantly when the mold temperature is raised over the glass transition temperature.

• 디지털산업정보학회논문지
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• 제16권1호
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• pp.93-98
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• 2020

Research on underwater sensor networks is increasing due to such reasons as marine resource management, maritime disaster prediction and military protection. Many underwater sensor networks performs wireless communication using an acoustic sound wave band signal having a relatively low frequency. So the digital part of their modem can take charge of carrier band signal processing. To enable this, the sampling rate of the baseband band signal should be increased to a sampling rate at which carrier band signal processing is possible. In this paper, we designed a sampling rate increasing circuit based on a CIC interpolator for underwater sensor nodes. The CIC interpolator has a simple circuit structure. However, since the CIC interpolator has a large attenuation of the pass band and a wide transition band, an inverse sinc LPF is added to compensate for frequency response of the CIC interpolator. The proposed interpolator was verified in time domain and frequency domain using ModelSim and Matlab.

• 설비공학논문집
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• 제7권1호
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• pp.20-29
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• 1995

A theoretical model for film condensation of a vapor including a relatively lighter noncondensable gas on a horizontal tube has been formulated on the basis of the conservation laws and other fundamental physical principles. The model is applied to the prediction of the condensation heat transfer characteristics for the Freon vapor in the presence of air on a horizontal tube. Calculated results for the mean heat transfer coefficient, which is shown to depend strongly on the bulk concentration of air, are in good agreement with the available experimental results for a range of operating conditions. The distributions of physical quantities along the surface of tube are also calculated, such as the boundary layer thickness and local heat transfer coefficient. The present model is readily reduced to the Nusselt model as the bulk concentration of air decreases to zero. Therefore, the transition from the condensation of pure vapor to that of vapor-air mixture occurs continuously not abruptly.

• 한국정보과학회 언어공학연구회:학술대회논문집(한글 및 한국어 정보처리)
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• 한국정보과학회언어공학연구회 2004년도 제16회 한글.언어.인지 한술대회
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• pp.191-199
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• 2004

본 논문에서는 텍스트에 나타난 감정상태를 인지하는 모델을 제안하고, 이러한 모델을 활용하여 현재문장에서 나타난 감정 및 이후에 나타나게 될 감정상태들을 예측하는 시스템에 대하여 다룬다. 사용자의 감정을 인지하고 이에 대한 자연스러운 메시지, 행동 등을 통해 인간과 상호작용 할 수 있는 컴퓨터시스템을 구현하기 위해서는 현재의 감정상태뿐만 아니라 사용자 개개인의 정보 및 시스템과 상호작용하고 있는 상황의 정보 등을 통해 이후에 사용자가 느낄 수 있는 감정을 예측할 수 있는 감정모델이 요구된다. 본 논문에서는 파악된 이전의 감정상태 및 실제 감정과 표현된 감정간의 관계, 그리고 감정에 영향을 미친 주변대상의 특징 및 감정경험자의 목표와 행동이 반영된 상태-전이형태의 감정모델인 감정망(Emotion Network)을 제안한다. 감정망은 각 감정을 나타내는 상태(state)와 연결된 상태들 간의 전이(transition), 그리고 전이가 발생하기 위한 조건(condition)으로 구성된다. 본 논문에서는 텍스트 형태의 상담예시에 감정망을 활용하여 문헌의 감정어휘에 의해 직접적으로 표출되지 않는 감정을 예측할 수 있음을 보인다.

• 한국군사과학기술학회지
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• 제8권3호
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• pp.24-32
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• 2005

This paper describes the tracking filter performance for Naval Gun Ballistic Computation Unit(BCU). BCU needs tracing filter for gun firing. Using data of tracking sensor, BCU calculates the future position of Target and Gun order in the time of flight. In this paper, tracing filter is designed with interacting multiple model(IMM). The tracking algorithm based on the IMM requirers a considerable number of sub-model for the various maneuvering target in order to have a good performance. But, in the case of ship target, the maneuvering is restricted compared with the air target. Considering the maneuvering properties and adjusting the mode transition probabilities and the process noise of sub-model, We designed the IMM3 algorithm for Naval tracking filter with three sub-model.

• Structural Engineering and Mechanics
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• 제22권1호
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• pp.17-32
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• 2006

The application of cellular materials in load-carrying and security-relevant structures requires the exact prediction of their mechanical behavior, which necessitates the development of robust simulation models and techniques based on appropriate experimental procedures. The determination of the yield surface requires experiments under multi-axial stress states because the yield behavior is sensitive to the hydrostatic stress and simple uniaxial tests aim only to determine one single point of the yield surface. Therefore, an experimental technique based on a uniaxial strain test for the description of the influence of the hydrostatic stress on the yield condition in the elastic-plastic transition zone at small strains is proposed and numerically investigated. Furthermore, this experimental technique enables the determination of a second elastic constant, e.g., Poisson's ratio.

• Nuclear Engineering and Technology
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• 제42권4호
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• pp.426-433
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• 2010

The characteristic X-rays emitted from materials after gamma ray exposure was simulated and measured. A CdTe semiconductor detector and a $^{57}Co$ radiation source were used for energy spectroscopy. The types of materials could be identified by comparing the measured energy spectrum with the theoretical X-ray transition energy of the material. The sample composition was represented by the $K_{\alpha1}$-line (Siegbahn notations), which has the highest intensity among the characteristic X-rays of each atom. The difference between the theoretic prediction and the experimental result of K-line measurement was < 0.61% even if the characteristic X-rays from several materials were measured simultaneously. 2D images of the mixed materials were acquired with very high selectivity.

• Journal of the Korean Physical Society
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• 제73권10호
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• pp.1550-1554
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• 2018

The spin cutoff parameters of $^{50-57}Cr$ isotopes have been calculated using a superconducting Hamiltonian with the inclusion of the pairing effect. Their energy and temperature dependences have been studied through comparison with some well-known semi-empirical formulae. This study shows that the microscopic calculation results converge to the Fermi gas model prediction at higher energies. Also, an even-odd effect is evident in the spin cutoff parameters at low temperatures and disappears after the pairing phase transition.

• Structural Engineering and Mechanics
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• 제89권6호
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• pp.571-578
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• 2024

The bistable thin cylindrical shell is developable structure with the ability to transition between its two stable configurations. This structure offers significant potential applications due to its excellent deformability. In this paper, the composite thin cylindrical shell consisting of the composite layer and the piezoelectric layer was investigated. The material and geometric parameters of the shell were found to influence its stable characteristics. The analysis model of the composite thin cylindrical shell incorporating the piezoelectric layer was developed, and the expressions for its strain energy were derived. By applying the minimum energy principle, the impact of the electric field intensity on the bi-stable behaviors of the cylindrical shell was analyzed. The results showed that the shell exhibited the bistability only under the appropriate electric field strength. And the accuracy of the theoretical prediction was verified by simulation experiments. This study provides an important reference for the application of deployable structures.