• 한국구조물진단유지관리공학회 논문집
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• 제5권2호
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• pp.183-190
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• 2001

A sub-structure is uplift if the floating greater than dead load of a structure. When such occasion arise, a structure sustain damage. In general, the measures for floating prevention of structure are a permanent anchor method and a drainage method. The primary construction cost of a permanent anchor method is heavy. And a drainage method is needed maintenance management long term. At this point, the measures for floating prevention of a notion being requires the other days. Therefore, at this study a simple construction and a economic vertical drainage system was developed. The findings be used in the in-situ and gave careful consideration to an application. The result of examination, this system considering a characteristic of coefficient of permeability for the ground controls occurrence of floating despite the water level rise of the ground, which a period of construction get shorter compared with other methods, which understood that measures satisfactory in the financial aspect. Especially, A structure occurring effects of flatting under the course of construction made use of it. As the result of the effect of it was confirmed by construction.

• 한국해안·해양공학회논문집
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• 제34권6호
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• pp.275-289
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• 2022

최근 연안에서 해상관광레저, 플로팅 건축 등의 사업발굴이 활발히 진행 중에 있어 해상조건에 적합한 부유식 구조물의 필요성이 대두되고 있다. 본 연구에서는 육상 이동이 가능한 단위 모듈의 수직 및 수평 적층으로 확장된 하이브리드 부유식 구조물의 안정성을 향상시키기 위해 수평감쇠판을 적용하였다. 적용된 수평감쇠판의 길이 변화에 따른 하이브리드 부유식 구조물의 거동 특성을 상용 프로그램인 ANSYS AQWA를 이용하여 분석하였다. 하지만 제안된 하이브리드 부유식 구조물의 경우 구조물에 의해 둘러싸인 유체영역이 존재하고 이로 인해 특정 주기에서 공진이 발생할 가능성이 있다. 따라서 구조물에 의해 둘러싸인 유체영역에 ANSYS AQWA에서 제공되는 감쇠존 효과를 고려하여 부유식 구조물의 거동 특성을 주파수 영역 수치해석을 통해 면밀하게 분석하였다.

• 한국컴퓨터산업학회논문지
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• 제6권5호
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• pp.783-790
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• 2005

In this paper, we have simulated a Symmetric Dual-gate Single-Si TFT which has three split floating n+ zones. This structure reduces the kink-effect drastically and improves the on-current. Due to the separated floating n+ zones, the transistor channel region is split into four zones with different lengths defined by a floating n+ region, This structure allows an effective reduction of the kink-effect depending on the length of two sub-channels. The on-current of the proposed dual-gate structure is 0.9mA while that of the conventional dual-gate structure is 0.5mA at a 12V drain voltage and a 7V gate voltage. This result shows a 80% enhancement in on-current. Moreover we observed the reduction of electric field in the channel region compared to conventional single-gate TFT and the reduction of the output conductance in the saturation region. In addition, we also confirmed the reduction of hole concentration in the channel region so that the kink-effect reduces effectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.14-15
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• 2009

Insulated Gate Bipolar Transistor(IGBTs) are widely used in power device industry. However, to improve the breakdown voltage, IGBTs are suffered from increasing on-state voltage drop due to structural design. In this paper, the new structure is proposed to solve this problem. The proposed structure has double p-floating layer inserted in n-drift layer. The p-floating layers improve the breakdown voltage compared to conventional IGBT without change of other electrical characteristics such as on-state voltage drop and threshold voltage. this is because the p-floating layers expand electric field distribution at blocking state. A electrical characteristic of proposed structure is analyzed by using simulators such as TSUPREM and MEDICI. As a result, on-state voltage drop and threshold voltage are same to a conventional TIGBT, but breakdown voltage is improved to 16%.

• 반도체디스플레이기술학회지
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• 제14권2호
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• pp.41-45
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• 2015

From 20nm technology node, the finFET has become standard device for ULSI's. However, the finFET process made stacking gate non-volatile memory obsolete. Some reported capacitor-less DRAM structure by utilizing the FBE. We present possible non-volatile memory device structure similar to the dual gate MOSFET. One of the gates is left floating. Since body of the finFET is only 40nm thick, control gate bias can make electron tunneling through the floating gate oxide which sits across the body. For programming, gate is biased to accumulation mode with few volts. Simulation results show that the programming electron current flows at the interface between floating gate oxide and the body. It also shows that the magnitude of the programming current can be easily controlled by the drain voltage. Injected electrons at the floating gate act similar to the body bias which changes the threshold voltage of the device.

• Journal of Advanced Research in Ocean Engineering
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• 제1권1호
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• pp.55-62
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• 2015

Floating structure such as tension leg platform, semi-submersible and spar are widely used in field of oil exploration and renewable energy system. All of these structures have the base cylinder support structure which have effective rule in overall dynamic of response. So the accurate and reliable modeling is needed for optimum design and understanding the physical background of these systems. The aim of this article is an analytical discussion on stochastic modeling of floating cylinder based support structure but an applicable one. Due to this a mathematical mass-damper-spring system of a floating cylinder of HAWAII WTG offshore wind as an applicable and innovative system is adopted to model a coupled degrees using random vibration in analytical way. A fully develop spectrum is adopted to solve the stochastic spectrum analytically by a proper approximation. Some acceptable assumption is adopted. The simplified but analytical and innovative hydrodynamic analysis of this study not only will help researcher to concentrate more physically on hydrodynamic analysis of floating structures but also can be useful for any quick, simplified and closed form analysis of a complicated problem in offshore engineering.

• 한국해양공학회지
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• 제10권3호
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• pp.125-137
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• 1996

Experimental wind tunnel tests have been attempted to investigate the aerodynamic characteristics of floating offshore structure using some types of scaled mldels. The static behaviors of lift, drag forces and pitching moment of its models are measured to exammine the relationship between wind loads and incidence angle, wind velocity, shape of models. The effect of solid ground has been obtained also.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.258-264
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• 2007

Floating floors, which are mainly used for reducing interior noise levels of railway vehicle, are known to be superior to single structure in respect to sound transmission loss and vibration reduction performances. The stiffness of isolator is one of the important design variables in floating floors. From modal tests, modal properties of underframe, top floor and isolators are derived. They are used as input parameters for predicting structure-borne noise using AUTOSEA.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2011년도 춘계학술대회
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• pp.187-188
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• 2011

Independent component analysis (ICA) is a method separating the mixture of signals into statistically and mutually independent ones. It has been applied to not only the Cocktail-party problem but also EEG analysis using the EEG waveform, digital signal processing, image processing and cognitive technique field actively. This study aims to propose a procedure to estimate the modal responses and mode shapes of a floating structure by using the ICA method from measured responses of the floating structure.

• 한국해양공학회지
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• 제20권6호
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• pp.101-107
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• 2006

Recently, with the increase in requirements for marine development, a marine urbanism is being visualized, with more and more huge-scale structures at the scope of the ocean space utilization. In particular, a pontoon-type structure has attracted attention, since The Floating Structures Association of Japan proposed a new concept as the most suitable one of floating airports. The Very Lage Floating Structure (VLFS) is considered a flexible structure, for a quite large length-to-breadth ratio and its geometrical flexibility. The main objective of this study is to makean exact and convenient prediction about the hydro-elastic response on very large offshore structures in waves. The numerical approach for the hydro-elastic responses is based on the combination of the three dimensional source distribution method and the dynamic response analysis method, which assumed a dividing pontoon type structure, as many rigid bodies connected elastic beam elements. The established hydo-elastic theory was applied to the radiation forces caused by motions of a whole structure, formulated using the global coordinate system, which has the origin at the center of the structure. However, in this paper, we took radiation forces, occurred by individual motions of floating bodies, into consideration. The calculated results show good agreement with the experimental and calculated results by Yago.