• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.3
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• pp.349-356
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• 1986

For the extension of application in flash method measuring the thermophysical properties of materials, the heat diffusion equation with the heat transfer loss from front, rear, and circumferential surfaces of two layer cylinderical sample is mathematically analyzed by means of Green's function for axially symmetric pulse heating on the front of samples. The solutions are applied to determine the unknown thermal diffusivity of the two materials and analyzed the measurement error due to heat loss and finite pulse time effects.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05d
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• pp.119-121
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• 2003

열을 발생하는 부품에 있어서 효과적으로 열방출 향상시키는 것은 부품의 신뢰성을 위해 중요한 사항이며, LTCC와 같은 고밀도 회로기판을 설계하는데 있어서 필수적으로 고려할 사항이다. 본 연구에서는 열전달을 향상시키기 위한 구조를 설계하였다. 또한, 열전달 효과를 조사하기 위해서 LTCC 기판 내에 열 비아 및 패드를 위치시킨 기판을 제작하였다. Laser Flash Method를 통해 재료의 열전도도 분석을 수행 하였다. 열비아 및 열방출을 위한 패드로 구성된 LTCC 기판의 열전도 특성은 순수 Ag 재료의 44%인 103 W/mK 특성 값을 나타내었다.

• 한국연소학회:학술대회논문집
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• 2001.06a
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• pp.106-118
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• 2001

A rigorous study of single droplet vaporization under quiescent high pressure atmosphere is attempted adopting method of flash evaporation calculation for vapor-liquid equilibrium. Results due to flash method shows excellent agreement with measurement. Also shown is the present model fairly capable of depicting transients of droplet vaporization under high pressure environment, such as ambient gas solubility, property variation, and multicomponent transports. Systematic treatment of these effects with emphasis on vapor-liquid phase equilibrium revealed; conventional treatment for subcritical droplet vaporization, such as $d^2$-law, leads to erroneous prediction of droplet history, augmented gas solubility is significant under supercritical pressure, and vaporization rate proportionally increase with pressure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.311-313
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• 2012

Many efforts have been made and many tools have been developed in order to manage construction projects by a smart device such as a smart phone and smart pad. This research proposed a method to manage construction schedules via a smart device using Flash. The interactive and graphic property of Flash enables a field manager to manage schedules easily and efficiently. A prototype was implemented by Adobe Flex Builder, and it applied a sample network in a smart pad. Further studies would develop network diagrams such as CPM(Critical Path Method).

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.380-385
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• 2000

In this study, geometric shape and crack in welded interface of the air cooled heat exchanger Fin-Tube of Dissimilar Meterials was analysed. The object of study is to understand the behavior of Stress Intensity Factor for fin length, flash thickness, flash length, symmetric and asymmetric cracks of comming from the manufacturing process. Stress Intensity Factor was analysed by BEM. Kelvin's solution was used as a fundamental solution in BEM analysis and stress extrapolation method was used to determine Stress Intensity Factor.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.3
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• pp.423-426
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• 2015

Current verification methods for on-chip memory have been implemented using coverpoints that are generated based on a single operation. These coverpoints cannot consider the influence of other memory banks in a busy state. In this paper, we propose a method in which the coverpoints account for all operations executed on different memory banks. In addition, a new constrained random vector generation method is proposed to reduce the required random vectors for the multi-operation-based coverpoints. The simulation results on NAND flash memory show 100% coverage with 496,541 constrained random vectors indicating a reduction of 96.4% compared with conventional random vectors.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.709-712
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• 2017

Liquid nitrogen jet has been imaged by using backlight method. In addition to the images, simultaneously measured temperature by thermocouples has been used to investigate the role of 'Pseudo-flash-boiling' in breakup of the supercritical jet. The backlight image can provide qualitative appearance of the jet, but not the density profile for the high density of injected fluid.

• Journal of the Korean Society of Radiology
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• v.15 no.1
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• pp.1-7
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• 2021

In order to acquire an image in a positron emission tomography, it is necessary to draw the position coordinates of the scintillation pixels of the detector module measured at the same time. To this end, in a detector module using a plurality of scintillation pixels and a small number of photosensors, it is necessary to obtain a flood image and divide a region of each scintillation pixel to obtain a position of a scintillation pixel interacting with a gamma ray. Alternatively, when the number of scintillation pixels and the number of photosensors to be used are the same, the position coordinates for the position of the scintillation pixels can be directly acquired as digital signal coordinates. A method of using a plurality of scintillation pixels and a small number of photosensors requires a process of obtaining digital signal coordinates requires a plurality of photosensors and a signal processing system. This complicates the signal processing process and raises the cost. To solve this problem, in this study, we developed a method of obtaining digital signal coordinates without performing the process of separating the planar image and region using a plurality of flash pixels and a small number of optical sensors. This is a method of obtaining the position coordinate values of the flash pixels interacting with the gamma ray as a digital signal through a look-up table created through the signals acquired from each flash pixel using the maximum likelihood function. Simulation was performed using DETECT2000, and verification was performed on the proposed method. As a result, accurate digital signal coordinates could be obtained from all the flash pixels, and if this is applied to the existing system, it is considered that faster image acquisition is possible by simplifying the signal processing process.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.517.2-517
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• 2001

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.2
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• pp.30-37
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• 2014

In this study, we studied how to perform the structural analysis which need a large-capacity flash memory with the computer program when the flash memory storage of a personal computer has no enough room for the analysis of structure. As one of the solutions of this problem, the blocking method of stiffness matrix, which is a method that stiffness matrix is divided by a few blocks and each block is sequentially used for the calculation of matrix decomposition, is proposed and an algorithm available in computer program is derived on the method. Finally, A structural analysis program (sNs) based on this study is developed and the correctness and efficiency of the algorithm is founded through some examples which are fundamental in structural analysis.