• 대한건축학회논문집:계획계
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• 제34권7호
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• pp.89-98
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• 2018

Koolhaas' perspective on urbanism differs from the modern urbanism and typological urbanism. The Melun-Senart masterplan, La $D{\acute{e}}fense$ masterplan shows unique characteristic different from that of conventional urbanism. The roots of this creative approach can be found in the traits of his research with O.M. Ungers back in the 1970s. Koolhaas and Ungers have collaborated intimately from 1972 to 1977 to work on urban projects. This collaboration reaches its cilmax in their project City in the City, where many of Koolhaas' core concepts such as archipelago, void/solid, plurality, infrastructure, congestion, and social condenser are introduced. This thesis will explore the development of these concepts in their collaboration and shed new light on how this period has made a transition into Koolhaas' perspective on urbanism and architecture as well as his works. The purpose of this study is to investigate these core concepts of Koolhaas in City in the City, and to find the development and the meaning of these concepts in his projects.

• 한국지반공학회논문집
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• 제25권8호
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• pp.23-32
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• 2009

본 연구에서는 모래 다짐말뚝 공법의 설계 및 시공단계에서 침하거동 예측에 활용될 수 있는 합리적이고 간편한 해석기법을 제안하였으며, 모델 계수값들은 유전자 알고리즘에 근거한 최적화 과정을 통하여 구할 수 있다. 제안된 기법의 검증을 위하여 0(무치환), 20, 36 및 56%의 다양한 모래 치환율에 대한 SCP 복합지반의 침하거동에 관한 실내압밀실험이 수행되었다. 제안된 모델은 각 치환율에 대하여 간극비-대수응력 관계 및 시간-압축 관계에서 계측값과 매우 일치되는 경향성을 보였다.

• Structural Monitoring and Maintenance
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• 제3권4호
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• pp.335-347
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• 2016

One of major errors in flow rate measurement for two-phase flow using an Electrical Capacitance Sensor (ECS) concerns sensor sensitivity under temperature raise. The thermal effect on electrical capacitance sensor (ECS) system for air-water two-phase flow monitoring include sensor sensitivity, capacitance measurements, capacitance change and node potential distribution is reported in this paper. The rules of 12-electrode sensor parameters such as capacitance, capacitance change, and change rate of capacitance and sensitivity map the basis of Air-water two-phase flow permittivity distribution and temperature raise are discussed by ANSYS and MATLAB, which are combined to simulate sensor characteristic. The cross-sectional void fraction as a function of temperature is determined from the scripting capabilities in ANSYS simulation. The results show that the temperature raise had a detrimental effect on the electrodes sensitivity and sensitive domain of electrodes. The FE results are in excellent agreement with an experimental result available in the literature, thus validating the accuracy and reliability of the proposed flow rate measurement system.

• 한국세라믹학회지
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• 제30권4호
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• pp.332-338
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• 1993

TiN/Ti is the best buffer layer between PZT thin film and si substrate among the Ti, TiN, ZrN, TiN/Ti, ZrN/Ti. The amorphous PZT films deposited on TiN/Ti buffer layer directly transform into perovskite phase when rapid thermal annealed for 30sec above 55$0^{\circ}C$. As Rapid Thermal Annealing(RTA) temperature increased, the remanent polarization(Pr) and dielectric constant($\varepsilon$r) increased and then showed Pr=21 $\varepsilon$r=593 when rapid thermal annealed 80$0^{\circ}C$ for 30sec. On the contrary the leakage current increased with increasing RTA temperature due to the formation of void made by Pb evaporationand grain cohesion.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.375-378
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• 2001

This study was peformed to understand permeability characteristic of clays with various pH values. A serious of physical properties and permeability tests, consolidation tests was performed on a clay and a marine clay. Results of the study are as follows. As pH values were decreased, coefficient of permeability was increased because of increase in effective void caused by decrease in thickness of diffuse double layer besides change in soil structures and effective grain size. As pH values were increased, coefficient of permeability of marine clay was increased. Variation of coefficient of permeability of marine clay was increased. Variation of coefficient of permeability of marine clay was largely related because of higher clay contents.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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• pp.229-234
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• 1997

The dynamic behavior of underground structures is complex due to the effects of vibrational characteristics of the structure and the rock. In this study, dynamic displacement responses at the structure surface by the elastic stress waves are considered as the vibrational characteristics, and evaluated by the form of the frequency spectrum. The variation of the vibrational characteristic is simulated by numerical analysis at the case of the structure has internal defections. The results reveals the possibility of the experimental detection of void existence and size. Furthermore, the verification of the dynamic response can be used for rating the stability of a tunnel.

• 한국지반공학회논문집
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• 제16권6호
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• pp.15-21
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• 2000

본 논문은 체적이 변하는 흙에 대하여 새로운 흙-수분 특성곡선 이론을 제시하고 이를 실험적으로 규명하였다. 그 결과, 점토와 같이 불포화되는 과정중 체적변형이 발생하는 흙의 흙-수분 특성곡선은 간극비와 흡인력의 함수이므로 체적변화를 무시할 수 없음이 밝혀졌다. 따라서 본 논문에서는 체적변화가 있는 경우 흙-수분특성곡선을 구하기 위하여 두가지 실험법을 채택하였다. 그 첫째는 전통적인 압력판 추출시험과, 중량함수비와 간극비와의 관계를 알 수 있는 수축한계시험을 실시하여 조합하는 방법이며, 둘째 방법은 압력판 셀을 새로인 고안하여 추출시험시에 체적 수축도 측정할 수 있는 수정된 압력판 셀 시험방법을 이용하는 것이다. 이 시험결과를 3차원 상의 면(surface)에서 표현하여, 체적변형을 고려한 흙-수분 특성을 규명할수 있도록 하였다.

• The Korean Journal of Ceramics
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• 제3권3호
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• pp.163-168
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• 1997

Most of heteroepitaxial $\beta$-SiC thin films have been successfully grown on Si(100) adapting a carburizing process, by which a few atomic layers of substrate surface is chemically converted to very thin SiC layer using hydrocarbon gas sources. Using an organo-silicon precursor, bis-trimethylsilymethane (BTMSM, [$C_7H_{20}Si_2$]), heteropitaxial $\beta$-SiC thin films were successfully grown directy on Si substrate without a carburized buffer layer. The defect density of the $\beta$-SiC thin films deposited without a carburized layer was as low as that of $\beta$-SiC films deposited on carburized buffer layer. In addition, void density was also reduced by the formation of self-buffer layer using BTMSM instead of carburized buffer layer. It seems to be mainly due to the characteristic bonding structure of BTMSM, in which Si-C was bonded alternately and tetrahedrally (SiC$_4$).

• 한국농공학회:학술대회논문집
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• 한국농공학회 2000년도 학술발표회 발표논문집
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• pp.484-489
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• 2000

This study was performed to examine the characteristic of creep behavior by reinforced clayey soil. So, it was carried out measurement of compressive strain and poisson's ratio by the reinforced soil mixtures. At each specimen was made by added calcium carbonate and 19mm length monofilaments into soil at designated ratio, and it was measured during the age of 30 days right after manufacturing the specimens. Because monofilaments controled increase of friction and dry shrinkage of soil into soil, compressive strain of monfilments reinforced soil with mixing rate of 0.3% is low value. And Because void was formed by compressive, vertical strain and horizontal strain of calcium carbonate reinforced soil with rate of 9% is high value.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.589-592
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• 2006

The durability of concrete involves resistance to freeze-thaw action, corrosion, permeation, carbonation, chemical attack and so on. Generally, properties of concrete have been well understood under the separate action of these deterioration mechanisms. However, in practice, the degradation of concrete usually is the result of combined action of physical and chemical attack and can be accelerated by the combined action of several deterioration mechanisms. In the present study, to evaluate the combined deterioration by freeze-thaw action and seawater attack, ground granulated blast-furnace slag or silica fume concrete with water or seawater as mixing water was exposed to 300 cycles of freeze-thaw action. Tests were conducted to determined the relative dynamic modulus of elasticity and compressive strength. Furthermore, The MIP analysis were performed on the deteriorated part of concrete due to freeze-thaw action and seawater attack.