• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(1)
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• pp.35-38
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• 2004

In this paper, we aim to implement the embedded VoIP Phone based on EISC core Microcontroller. EISC is recently new microprocessor architecture, which contains both advantage of RISC and CISC. This advantages are desirably resulted in high code density, high performance and 16/32/64bit scalable instruction length. Also, we select the embedded system which can be guaranteed performance and economical efficiency for implementation that system. As the step of this research, we first study basic system for implementation of target system. Next, we construct the structure of embedded VoIP Phone based on 32bit EISC MCU efficiently. And then we realize that constructed system and verify the performance of that realized system by the test of voice communication in field.

• Structural Engineering and Mechanics
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• 제24권2호
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• pp.247-268
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• 2006

The parts of pile, above the soil and embedded in the soil are called the first region and second region, respectively. The forth order differential equations of both region for critical buckling load of partially embedded pile with shear deformation are obtained using the small-displacement theory and Winkler hypothesis. It is assumed that the behavior of material of the pile is linear-elastic and that axial force along the pile length and modulus of subgrade reaction for the second region to be constant. Shear effect is included in the differential equations by considering shear deformation in the second derivative of the elastic curve function. Critical buckling loads of the pile are calculated for by differential transform method (DTM) and analytical method, results are given in tables and variation of critical buckling loads corresponding to relative stiffness of the pile are presented in graphs.

• Journal of the Optical Society of Korea
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• 제15권3호
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• pp.305-309
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• 2011

We present an efficient design approach for a plasmonic slot waveguide using a genetic algorithm. The analyzed structure consists of a nanometric slot in a thin metallic film embedded within a dielectric. To achieve high confinement without long propagation length, the thickness and width of the slot are optimally designed in order to optimize the figures of merit including mode confinement and propagation length. The optimized design is based on the finite element method and enhances the guiding and focusing of light power propagation.

• Structural Engineering and Mechanics
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• 제35권2호
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• pp.191-203
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• 2010

To investigate the critical buckling load and post-buckling behavior of an axially loaded pile entirely embedded in soil, the non-linear large deflection differential equation for a pinned pile, based on the Winkler-model and the discretionary distribution function of the foundation coefficient along pile shaft, was established by energy method. Assuming that the deflection function was a power series of some perturbation parameter according to the boundary condition and load in the pile, the non-linear large deflection differential equation was transformed to a series of linear differential equations by using perturbation approach. By taking the perturbation parameter at middle deflection, the higher-order asymptotic solution of load-deflection was then found. Effect of ratios of soil depth to pile length, and ratios of pile stiffness to soil stiffness on the critical buckling load and performance of piles (entirely embedded and partially embedded) after flexural buckling were analyzed. Results show that the buckling load capacity increases as the ratios of pile stiffness to soil stiffness increasing. The pile performance will be more stable when ratios of soil depth to pile length, and soil stiffness to pile stiffness decrease.

• International Journal of Concrete Structures and Materials
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• 제11권2호
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• pp.301-313
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• 2017

This paper presents the fibre-matrix interfacial properties of hooked end steel fibres embedded in ultra-high performance mortars with various water/binder (W/B) ratios. The principle objective was to improve bond behaviour in terms of bond strength by reducing the (W/B) ratio to a minimum. Results show that a decrease in W/B ratio has a significant effect on the bond-slip behaviour of both types of 3D fibres, especially when the W/B ratio was reduced from 0.25 to 0.15. Furthermore, the optimization in maximizing pullout load and total pullout work is found to be more prominent for the 3D fibres with a larger diameter than for fibres with a smaller diameter. On the contrary, increasing the embedded length of the 3D fibres did not result in an improvement on the maximum pullout load, but increase in the total pullout work.

• Steel and Composite Structures
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• 제51권5호
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• pp.529-543
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• 2024

The bonding efficacy of steel I-section embedded in metakaolin-fly ash-based geopolymer concrete (MK-FA-GC) was investigated in this study. Push-out tests were conducted on nine column specimens to evaluate the influence of compressive strength of concrete, embedded length of steel I-section, thickness of concrete cover, and stirrup ratio on the bond performance. Failure patterns, load-slip relationships, bond strength, and distribution of bond stress among the specimens were analyzed. The characteristic bond strength of geopolymer concrete (GC) increased with higher compressive strength, longer embedded steel section length, thicker concrete cover, and larger stirrup ratio. Empirical formulas for bond strength at the loading end were derived based on experimental data and a bond-slip constructive model for steel-reinforced MK-FA-GC was proposed. The calculated bond-slip curves showed good agreement with experimental results. Furthermore, numerical simulations using ABAQUS software were performed on column specimens by incorporating the suggested bond-slip relationship into connector elements to simulate the interface behavior between MK-FA-GC and the steel section. The simulation results showed a good correlation with the experimental findings.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
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• pp.199-202
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• 2002

Interfacial properties and electrical sensing for fiber fracture in carbon and SiC fibers/epoxy composites were investigated by the electrical resistance measurement and fragmentation test. As fiber-embedded angle increased, interfacial shear strength (IFSS) of two-type fiber composites decreased, and the elapsed time was long to the infinity in electrical resistivity. The initial slope of electrical resistivity increased rapidly to the infinity at higher angle, whereas electrical resistivity increased gradually at small angle. Furthermore, both fiber composites with small embedded angle showed a fully-developed stress whitening pattern, whereas both composites with higher embedded angle exhibited a less developed stress whitening pattern. As embedded angle decreased, the gap between the fragments increased and the debonded length was wider for both fiber composites. Electro-micromechanical technique can be a feasible nondestructive evaluation to measure interfacial sensing properties depending on the fiber-embedded angle in conductive fiber reinforced composites.

• 말소리와 음성과학
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• 제2권1호
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• pp.127-133
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• 2010

The purpose of the present study was to examine the relationship between sentence repetition and sentence production in school-age children. The participants included 120 school-age children through 1st to 6th grades who were then divided into three grade groups (lower grade: 1st to 2nd grades, intermediate grade: 3th to 4th grades, and higher grade: 5th to 6th grades). The repetition task consisted of 32 sentences that were classified by sentence length (5, 6, 7, and 8 words) and structure (conjunctive and embedded sentences). The sentence production task utilized Lee's (2007) grammaticality judgement and sentence combining task. The findings of present study were as follows. (1) The higher grade performed significantly better than the lower and intermediate grades. (2) The participants performed significantly worse when imitating longer sentences than when imitating shorter ones. In addition, there were interaction effects between grade groups and sentences length. (3) The participants performed significantly better when imitating conjunctive rather than embedded sentences. (4) There was significantly positive correlation between the sentence repetition and sentence production task.

• 한국응용과학기술학회지
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• 제33권3호
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• pp.428-434
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• 2016

본 연구에서는 알킬체인의 길이가 서로 다른 benzyltrialkylammonium chloride계 화합물을 합성하여 리포좀 제조에 응용하였다. 제조된 리포좀의 평균 입도분포, 제타전위, 방출거동 및 항균성을 조사하였으며, 사슬 길이에 따른 특성을 비교하였다. 리포좀의 평균 입도는 120~140 nm의 크기분포를 가졌으며 소수성 사슬의 길이가 증가할수록 큰 입자크기를 가졌다. 리포좀 용액의 제타전위는 양이온성 계면활성제인 benzyltrialkylammonium chloride를 첨가함에 따라 +80~90 mV의 값을 가지며 향상된 분산 안정성을 보였다. 방출거동에서는 사슬 길이에 따라 방출 속도를 조절할 수 있었으며 긴 사슬의 계면활성제를 첨가한 리포좀은 증가된 서방형 방출특성을 보였다. 또한, 리포좀의 포집효율은 25.9~27.5% 이었다.

• Structural Engineering and Mechanics
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• 제68권1호
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• pp.103-119
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• 2018

In the present research, an attempt is made to obtain a semi analytical solution for both nonlinear natural frequency and forced vibration of embedded functionally graded double layered nanoplates with all edges simply supported based on nonlocal strain gradient elasticity theory. The interaction of van der Waals forces between adjacent layers is included. For modeling surrounding elastic medium, the nonlinear Winkler-Pasternak foundation model is employed. The governing partial differential equations have been derived based on the Mindlin plate theory utilizing the von Karman strain-displacement relations. Subsequently, using the Galerkin method, the governing equations sets are reduced to nonlinear ordinary differential equations. The semi analytical solution of the nonlinear natural frequencies using the homotopy analysis method and the exact solution of the nonlinear forced vibration through the Harmonic Balance method are then established. The results show that the length scale parameters give nonlinearity of the hardening type in frequency response curve and the increase in material length scale parameter causes to increase in maximum response amplitude, whereas the increase in nonlocal parameter causes to decrease in maximum response amplitude. Increasing the material length scale parameter increases the width of unstable region in the frequency response curve.