• 제어로봇시스템학회논문지
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• 제7권11호
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• pp.962-966
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• 2001

The major problem at a branch point for point-to-multipoint available bit rate(ABR) services in asynchronous transfer mode (ATM) networks is how to consolidate backward resource management(BRM) cells from each branch for a multicast connection. In this paper, we propose an efficient feedback consolidation algorithm based on an adaptive dynamic threshold(ADT) to eliminate the consolidation noise and the reduce the consolidation delay. The main idea of the ADT algorithm lies in that each branch point estimates the ABR traffic condition of the network through the virtual queue estimation and the transmission threshold of the queue level in branch points is adaptively controlled according to the estimation. Simulation results show that the proposed ADT algorithm can achieve a faster response in congestion status and a higher link utilization compared with the previous works.

• Geomechanics and Engineering
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• 제4권4호
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• pp.243-249
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• 2012

In the companion paper, the nonlinear consolidation of soft clays subjected to cyclic loading was analytically investigated. This paper reports the results of an experimental program conducted to verify some critical assumptions made in the analytical study. It, also, includes a numerical study carried out to examine the capability of the proposed theory to determine the consolidation characteristics of soft clays subjected to cyclic loading. Results show that the permeability of the soft clays does not significantly change during the cyclic loading. It is also shown that, compared to the Terzaghi's solution for a linear clay, the inherit nonlinearity of the clay tends to decrease the degree of consolidation due to the smaller rate of dissipation in the excess pore water pressure.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.151-154
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• 2003

This paper reviews depositional environments and consolidation characteristic of Soft Dredged Clay fill and then analytical solution of self-weight consolidation is made to find consolidated state. It's known that Soft Dredged Clay Ground is in the under-consolidated state under $U{\fallingdotseq}30%$ from analytical solution. It is effective for higher consolidation rate that the time of Dredge is shorter ani the time of leave is longer. It is conclude that the under-consolidated state should be considered in prediction of consolidation settlement.

• 산업기술연구
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• 제21권A호
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• pp.317-327
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• 2001

For soils with high void ratios, the inverse method of utilizing results obtained from centrifuge model test was used to find the constitutive relation of effective stress - void ratio - permeability whereas conventional oedometer test and constant rate of strain consolidation test were also used to fine its relation at ranges of relatively low void ratio. Results of column test about settlement of interface and pore pressure and distribution with time were compared with numerically estimated values to confirm such a constitutive relation as obtained from the inverse method. Consolidational settlement in dredged and reclaimed ground, where the consolidation was in progress, was predicted by using the numerical technique implemented with the finite strain consolidation theory.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.91-96
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• 2000

Glass fiber reinforced thermoplastic composites were manufactured by Rapid Press Consolidation Technique(RPCT) as functions of temperature, pressure and time in pre-heating, consolidation and solidification sections during the manufacturing processing. It was found that the material property is greatly affected by pre-heating temperature under vacuum, mold temperature and molding pressure. Among them, the temperature In the mold was the most critical factor in determining the mechanical properties and the molded conditions of specimen. The crystallinity of PET matrix was also investigated by differential scanning calorimetry(DSC) measurements for various processing conditions. The level of crystallinity($X_c$) depended strongly on the mold temperature, cooling rate and the type of composite. The difference in $X_c$ is believed to be one of important factors in characterizing the mechanical properties.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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• pp.141-146
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• 2010

To investigate the effect of drainage spacing and smear on the rate of consolidation, a large consolidation chamber and mandrel insertion device were developed. After the occurrence of smear by installation of sand drain, model ground was consolidated in either overconsolidated or normally consolidated state. As smear effect increases and thus drain spacing decreases, total settlement increase in overconsolidated state but has no effect in normally consolidated state. Efficiency of vertical drain decreases and consequently consolidation time increases in all tests as smear effect becomes significant.

• 한국농공학회지
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• 제24권3호
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• pp.84-91
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• 1982

This study was conducted to investigate the consolidation characteristics of repeated increasing and decreasing load m marine clay. Consolidation test was performed by the whole repetition of increasing and decreasing load and the partial repetition of increasing and decreasing load. The results obtained were as follows: 1. The void ratio e was decreased according to the increase of preloading and the repe- tition of increasing and decreasing load. 2. In case of the partial repetition of increasing and decreasing load the compression index Cc was decreased with the increase of preloading and the repetition of increa- sing and decreasing load 3. The expansion rate was greatly increased with the whole repetition of increasing and decreasing load and it was inclined to be increased with the increase of preloading in case of the partial repetition. 4. The coefficient of volume compressibility were decreased according to the repetition of increasing and decreasing load 5. The secondary consolidation coefficient was decreased with the repetition of increasing and decreasing load. Especially in case of the partial repetition, the peaks of secon- dary consolidation curves could be found to move toward the vicinity of preloading.

• 한국지반공학회지:지반
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• 제11권4호
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• pp.13-24
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• 1995

5가지의 토질을 대상으로 하여 심지배수가 존재하는 경우와 그렇지 않은 경우에 있어서 진공압밀실험을 실시하여 진공압밀에서의 시간에 따른 침하량을 측정하였다. 이에 앞서 기초실험을 통하여 토질의 특성을 파악하고 아울러 일차원 압밀실험을 행하여 심지배수가 존재하지 않은 경우의 진공압밀이 진행되는 동안 기존의 압밀 실험이 토질의 거동을 예측할 수 있는지를 검토하여 보았다. 본 연구결과 기존의 일차원 압밀실험은 심지배수가 존재하지 않는 경우의 진공압밀 실험과정을 예측하는데 부적절하였으나 최종침하량은 적절하게 예측하였음이 밝혀졌다. 진공압밀의 실험결과에서는, 실트질토에 있어서 심지배수의 존재가 압밀의 속도에는 커다란 영향을 미쳤으나 최종 침하량은 심지배수의 존재에 상관없이 동일하였음이 밝혀졌으며 심지배수의 존재는 시료의 깊이에 대해 함수비와 밀도를 일정하게 한다는 것은 규명되었으나 점토질토에서의 심지배수의 존재는 압밀의 속도 뿐만 아니라 최종침하량도 증가시킴이 밝혀졌다.

• 한국지반공학회지:지반
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• 제13권1호
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• pp.137-146
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• 1997

A Study on the 본 연구에서는 플라스틱드레인을 이용하여 진공수평배수에 의해 개량된 준설 점토 지반의 압밀거동을 파악하기 위하여 대형 압밀시험을 실시하였으며, 실험 결과가 포텐결중공원주의 압밀이론을 이용한 수치해석에 의해 비교 검토되었다. 본 연구 실험결과에 의하면 수평배수진공압밀시험은 점토층 내부의 함수비 및 간극수압과 드레인 배수 속도 등이 진공압밀 시간 경과에 따라 감소되어 압밀이 급속하게 진행되고 있음이 확인되었다. 점토층 중공원주의 방사류에 대한 선형포텐샬압밀이론을 이용하여 수치 압밀해석 결과 간극수압은 확산 형태보다 흙의 변형과 투수에 의해 크게 좌우되고 있으므로, 지표면 부근에서의 실측 침하량은 압밀응력증가율 a가 -0.5정도에서 수치해석과 일치하며 또한 드레인 설치 부근에서의 점토층 침하량은 Baryon 압밀이론과 유사한 거동을 나타내고 있다. 최종적으로 수평 배수에 대한 적당한 선택과정을 포함한 설계 및 시공관리가 시험결과에 의하여 설명 되었으며 포텐셜압밀이론은 진공배수시 수평드레인에 의한 압밀거동을 정확하게 예측할 수 있다.

• 한국지반공학회논문집
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• 제21권5호
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• pp.25-32
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• 2005

일반적으로 압밀계수는 일차원 압밀이론에 근거한 표준압밀시험을 이용하여 평가된다 하지만 실제 현장에서는 압밀 중 3차원적으로 응력 및 변형이 발생하게 된다. 본 연구에서는 실제 현장에서 발생 가능한 다양한 응력-변형 조건을 고려한 새로운 압밀계수 평가방법을 제안하였다. 제안된 방법에 의한 과잉간극수압 소산양상 예측 결과는 실측치와 매우 잘 일치하였으며, 따라서 본 연구에서 제안된 방법을 이용하는 경우 지반의 압밀 속도를 보다 정확하게 예측할 수 있을 것으로 판단된다.