• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.1
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• pp.79-88
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• 1997

Very stiff floor system in a residential-commercial building causes some problems in the numerical analysis procedure due to significant difference in stiffness with adjacent elements. Static analysis of structure with a stiff transfer-floor can be performed approximately in two steps for upper and lower parts for the structure. However, it is impossible to perform dynamic analysis in two steps with separate models. An efficient method for dynamic analysis of a structure with a right floor system is proposd in this study. The matrix condensation technique is employed to reduce the degree of freedom for upper and lower parts of the structure and a beam elements with rigid bodies at both ends are introduce to model the rigid floor system. Efficiency and accuracy of the proposed method are verified through analysis of several example structures.

• Transactions of The Korea Fluid Power Systems Society
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• v.3 no.2
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• pp.21-26
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• 2006

With the increasing concerns on noise and vibration in hydraulic fluid power systems, it is important to find better way to reduce noise and vibration. In this study, the authors survey former researches on hose(viscoelastic tube) modeling in advance. And a summary of several existing methods for measuring the speed of sound in the fluid in pipes is presented. Their basic principles, advantages and limitations are compared. And The authors suggest a far simple identification procedure to obtain wave speed in hose by just using an experimental pressure data for the object tube with hose. In the new procedure, flow in hose is basically modeled by transfer matrix method, and wave speed in hose is obtained as data in frequency series. The wave speed in hose as data in frequency series will be used to compute the pressure pulsation attenuation in hydraulic pipe systems. The computed results are compared with the experimental ones, and the validity of the new procedure to obtain wave speed in hose is confirmed

• The Journal of the Acoustical Society of Korea
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• v.9 no.2
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• pp.14-24
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• 1990

A Study is made on shrink fit shaft in which its part is modelled and spring stiffness per unit length is estimated, then obtained transfer matrix. Transfer matrix of shaft is found by Myklestad's method and natural frequency is found by shrink fit tolerance on shrink fit shaft, too. In order to verify effectiveness of shrink fit effect, hollow shaft of the same size is compared with shrink fit shaft which will verified on experiment. As a result of this study, the more shrink fit tolerance increases, the more spring stiffness per unit length increases. It is obvious from the above results that shrink fit shaft due to shrink fit tolerances decreases natural frequency.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.391-398
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• 1998

The intake noise, a major source of vehicle noises, has rapidly become a noticeable, and has been studied to reduce the level. Traditionally, the intake system has been developed through the road test and the experiment using a engine dynamo, namely, the trial and error process. This approach require very high cost and long time consuming to develop the system. In this study, the simulator which had a speaker in the cylinder head was presented. It was easy to analyze the acoustic characteristic of the intake system in laboratory environment. This study presented a improvement to reduce the level of the intake noise using the Transfer Matrix Method and NIT/SYSNOISE, FE analysis commercial software. It was to select optimum position of a resonator and verified by the simulator. This simulator can be used early in the design stage of development of the intake system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.9
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• pp.4568-4584
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• 2016

Steganography based on text generation has become a hot research topic in recent years. However, current text-generation methods which generate texts of normal style have either semantic or syntactic flaws. Note that texts of special genre, such as poem, have much simpler language model, less grammar rules, and lower demand for naturalness. Motivated by this observation, in this paper, we propose a text steganography that utilizes Markov chain model to generate Ci-poetry, a classic Chinese poem style. Since all Ci poems have fixed tone patterns, the generation process is to select proper words based on a chosen tone pattern. Markov chain model can obtain a state transfer matrix which simulates the language model of Ci-poetry by learning from a given corpus. To begin with an initial word, we can hide secret message when we use the state transfer matrix to choose a next word, and iterating until the end of the whole Ci poem. Extensive experiments are conducted and both machine and human evaluation results show that our method can generate Ci-poetry with higher naturalness than former researches and achieve competitive embedding rate.

• Journal of Embryo Transfer
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• v.8 no.2
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• pp.83-90
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• 1993

To investigate the effect of extracellular matrix proteins on the in vitro development of ethanol-induced parthenogenetic eggs of ICR strain mice, those were cultured in vitro in fibronectin, gelatin, or collagen precoated culture dishes containing 1.5 ml of NaH-C03$_3$-BMOC-3 medium at 37$^{\circ}C$ for 96 hrs. under the atmosphere of 5% $CO_2$ and 95% air. Fibronectin, gelatin, or collagen significantly(P$\pm$1.4, 45.4i1.4, and 44.8$\pm$O.9, respectively. And the diameter of those eggs ranged 104.6$\pm$1.9, 102.8$\pm$2.3, and 103.4$\pm$O.8 $\mu$m, respectively.

• Journal of Embryo Transfer
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• v.26 no.4
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• pp.287-296
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• 2011

Mammalian fertilization is a complex cascade process consisting of sperm migration through the female reproductive tract, physiological changes to sperm such as sperm capacitation and acrosome reaction, and sperm-egg interaction in the oviduct in vivo. On the other hand, in vitro fertilization (IVF) is a process by which egg cells are fertilized by sperm outside the body: in vitro. IVF has been used for a variety of purposes in reproductive biotechnology for human and animals. The discovery of sperm capacitation in 1951 promoted the development of IVF technology. In the initial stage of IVF, sperm capacitation in preincubation medium was shown to be essential to fuse with eggs. Besides, sperms should detour some of the in vivo regulations for IVF. This review introduces a general mammalian fertilization process, including sperm capacitation, removal of cumulus matrix, acrosome reaction, and sperm-egg fusion and focuses on the roles of key biochemical molecules, signal mechanisms, and genes involved during IVF and novel results of sperm-oocyte interaction elucidated in various gene-knockout mice models.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.112-116
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• 2007

We have investigated the hysteresis phenomenon of a hydrogenated amorphous silicon thin film transistor (a-Si:H TFT) and analyzed the effect of hysteresis phenomenon when a-Si:H TFT is a pixel element of active matrix organic light emitting diode (AMOLED). When a-Si:H TFT is addressed to different starting gate voltages, such as 10V and 5V, the measured transfer characteristics with 1uA at $V_{DS}$ = 10V shows that the gate voltage shift of 0.15V is occurred due to the different quantities of trapped charge. When the step gate-voltage in the transfer curve is decreased from 0.5V to 0.05V, the gate-voltage shift is decreased from 0.78V to 0.39V due to the change of charge do-trapping rate. The measured OLED current in the widely used 2-TFT pixel show that a gate-voltage of TFT in the previous frame can influence OLED current in the present frame by 35% due to the change of interface trap density induced by different starting gate voltages.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.09a
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• pp.57-71
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• 1995

A simple mathematical model for gacilitated mass transport with a fixed site carrier membrane was derived by assuming an instantaneous, microscopic concentration (activity) fluctuation, The concentration fluctuation, developed due to reversible chemical reaction between carrier and solute, could acuse the higher chemical potential gradient and the facilitated transport. For mathematical formulation, an analogy was employed between the mass transfer for the facilitated transport with fixed site carrier membrane and the electron transfer in a parallel resistor-capacitor (RC) circuit. For the single RC model, it was assumed that a single capacitor represented the total carrier and a solute could not inter-diffuse between matrix and carrier, allowing only two diffusional pathways, This assumption was relaxed by adopting a serial combination of the parallel RC circuit. Here, a solute diffuses in two elements (matrix or carrier) can exchange its pathway, exhibiting four diffusional pathways. The current models were examined against experimental data and the agreement was exceptional.

• 연구논문집
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• s.27
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• pp.127-139
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• 1997

Two-for-one twister is a kind of textile machine and makes special fancy yarn which is twisted two times per one revolution in order to increase tensile strength and wear resis-tance of yarn. Spindle mechanism has to be stable and continuous motion in high speed revolution, and then optimal design is necessary to analyze dynamic characteristics of spindle unit. Spindle unit is consist of blade and rotary disc that are cylindrical body of revolution. For analysis of the dynamic characteristics of spindle unit, transfer matrix method is used and a numerical code SPINDLE also. Torsion and natural bending frequency of the spindle unit are examined. Its displacement mode is studied in function of variable revolutions.