• 제목/요약/키워드: control surface damage

검색결과 226건 처리시간 0.027초

CMOS 소자를 위한 NiSi의 Surface Damage 의존성 (The Dependency of Surface Damage to NiSi for CMOS Technology)

  • 지희환;안순의;배미숙;이헌진;오순영;이희덕;왕진석
    • 한국전기전자재료학회논문지
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    • 제16권4호
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    • pp.280-285
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    • 2003
  • The influence of silicon surface damage on nickel-silicide (NiSi) has been characterized and H$_2$ anneal and TiN rapping has been applied to suppress the electrical, morphological deterioration phenomenon incurred by the surface damage. The substrate surface is intentionally damaged using Ar IBE (Ion beam etching) which can Precisely control the etch depth. The sheet resistance of NiSi increased about 18% by the surface damage, which is proven to be mainly due to the reduced silicide thickness. It is shown that simultaneous application of H: anneal and TiN capping layer is highly effective in suppressing the surface damage effect.

표면피복재 종류에 따른 철근콘크리트의 철근 부식특성에 관한 실험적 연구 (An Experimental Study on the Corrosion Characteristics of Reinforcement Concrete According to Types of Surface Covering Material)

  • 김갑수;장종호;김재환;김용로;오시덕;김무한
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2003년도 학술.기술논문발표회
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    • pp.39-43
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    • 2003
  • Chloride ions are considered to be the major cause of steel corrosion in concrete structures exposed to seashore environments and also permeation of chloride is controlled by chloride diffusion. Therefore, the study on chloride diffusion of concrete have been done so far by many researchers. It is reported that coating material as surface covering material is effect about deterioration of salt damage and carbonation, therefore these materials are important in durability of concrete structure. In this study, corrosion characteristics of reinforcement concrete according to types of surface covering material were evaluated by water-cement ratio, chloride penetration by age on the corrosion area rate and mass decrement of reinforcement. And it is considered that the result of this study on application of the corrosion characteristics of reinforcements under salt damage environmental will be suggested as fundamental data of control performance of salt damage. It is performed that comparison and examination of control performance of salt damage by the corrosion characteristics under salt damage environmental.

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신경회로망을 이용한 이산 비선형 재형상 비행제어시스템 (Nonlinear Discrete-Time Reconfigurable Flight Control Systems Using Neural Networks)

  • 신동호;김유단
    • 제어로봇시스템학회논문지
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    • 제10권2호
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    • pp.112-124
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    • 2004
  • A neural network based adaptive reconfigurable flight controller is presented for a class of discrete-time nonlinear flight systems in the presence of variations of aerodynamic coefficients and control effectiveness decrease caused by control surface damage. The proposed adaptive nonlinear controller is developed making use of the backstepping technique for the angle of attack, sideslip angle, and bank angle command following without two time separation assumption. Feedforward multilayer neural networks are implemented to guarantee reconfigurability for control surface damage as well as robustness to the aerodynamic uncertainties. The main feature of the proposed controller is that the adaptive controller is developed under the assumption that all of the nonlinear functions of the discrete-time flight system are not known accurately, whereas most previous works on flight system applications even in continuous time assume that only the nonlinear functions of fast dynamics are unknown. Neural networks learn through the recursive weight update rules that are derived from the discrete-time version of Lyapunov control theory. The boundness of the error states and neural networks weight estimation errors is also investigated by the discrete-time Lyapunov derivatives analysis. To show the effectiveness of the proposed control law, the approach is i]lustrated by applying to the nonlinear dynamic model of the high performance aircraft.

화포에 의해 손상된 날개의 공력특성에 관한 연구 (A Study on the Aerodynamic Characteristic of Gunfire Damaged Airfoil)

  • 이기영;정형석;김시태
    • 한국군사과학기술학회지
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    • 제11권2호
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    • pp.144-151
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    • 2008
  • An experimental study has been conducted to investigate the effects of circular damage hole on the characteristics of airfoil performance. The damage on a wing created from a hit by anti-air artillery was modeled as a circular hole. Force balance measurements and static pressure measurements on the wing surface were carried out for the cases of having damage holes of 10% chord size at quarter chord and/or half chord positions. All experiments were conducted at Reynolds number of $2.85\times10^5$ based on the chord length. The surface pressure data show big pressure alterations near the circular damage holes. This abnormal surface pressure distribution produces shear stress that could lead to the acceleration of the structural degradation of the wing around the circular damage hole. However, in spite of the existence of circular damage holes, the measured force data indicated the only a slight decrease in lift accompanied by increase in drag compared to the results of undamaged one. The influence of damage hole on the aerodynamic performance was increased as the location of damage moved to the leading edge. The effect on the control force was insignificant when the damaged size was not large.

들민달팽이의 생활사와 인삼의 피해 및 약제 방제 (Life History, Ginseng Damage and Chemical Control of the Field Slug, Deroceras varsans A, Adams)

  • 김기황;오승환
    • Journal of Ginseng Research
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    • 제14권3호
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    • pp.421-426
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    • 1990
  • Field and laboratory works were conducted to Investigate the life history, ginseng damage and chemical control effect of the field slug, Deroceras varians A. Adams. D. varians laid eggs from April to June, but a small number of eggs were also found from July to September in the field. Most young slugs grew through the slimmer months to maturity by October. overwintered beneath the moist soil surface, and began feeding and egg-laying in the following April. indicating that D varians have a life cycle in a year. Damage of ginseng plants by D. varina occurred mainly from late April to mid May in the 3rd to 5th year ginseng fields with rice-straw mulching. It seems that this damage is caused by the adults in oviposition periods and related to rice-straw mulching of ginseng fields. In the experiment, ethoprop 5% granule and metaldehyde 6% bait showed relatively high effectiveness in the control of D. varians adults. Bordeaux mixture was more effective when the chemical was sprayed after infestation of the slug than before the infestation and when the 6-12 mixture was used.

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원자층식각시스템을 이용하여 이황화 몰리브뎀을 층간 컨트롤 (Layer by Layer Control of MoS2 Film through Atomic Layer Etching System)

  • 임태철;전민환;염근영
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2014년도 추계학술대회 논문집
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    • pp.12-12
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    • 2014
  • Atomic layer etching system를 이용하여 $MoS_2$를 layer by layer control를 하였다. 이 방법이 전통적인 에칭에 비해서 low damage 층간 식각이 가능하였다.

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백스테핑기법과 신경회로망을 이용한 적응 재형상 비행제어법칙 (Reconfigurable Flight Control Law Using Adaptive Neural Networks and Backstepping Technique)

  • 신동호;김유단
    • 제어로봇시스템학회논문지
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    • 제9권4호
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    • pp.329-339
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    • 2003
  • A neural network based adaptive controller design method is proposed for reconfigurable flight control systems in the presence of variations in aerodynamic coefficients or control effectiveness decrease caused by control surface damage. The neural network based adaptive nonlinear controller is developed by making use of the backstepping technique for command following of the angle of attack, sideslip angle, and bank angle. On-line teaming neural networks are implemented to guarantee reconfigurability and robustness to the uncertainties caused by aerodynamic coefficients variations. The main feature of the proposed controller is that the adaptive controller is designed with assumption that not any of the nonlinear functions of the system is known accurately, whereas most of the previous works assume that only some of the nonlinear functions are unknown. Neural networks loam through the weight update rules that are derived from the Lyapunov control theory. The closed-loop stability of the error states is also investigated according to the Lyapunov theory. A nonlinear dynamic model of an F-16 aircraft is used to demonstrate the effectiveness of the proposed control law.

정상상태 압연공정의 유한요소 해석에 관한 연구 (A Study on Eulerian Finite Element Analysis for the Steady State Rolling Process)

  • 이용신
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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    • pp.184-196
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    • 2004
  • An Eulerian finite element analysis for the steady state rolling process is addressed. This analysis combines the crystal plasticity theory fur texture development as well as the continuum damage mechanics for growth of micro voids. Although an Eulerian analysis for steady state rolling has many advantages, it needs an initial assumption about the shape of control volume. However, the assumed control volume does not match the final shapes. To effectively predict the correct shape in an assumed control volume, a free surface correction algorithm and a streamline technique are introduced. Applications to plate rolling, clad rolling, and shape rolling will be given and the results will be discussed in detail.

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폐(肺)와 피부(皮膚)의 관계(關係)에 대(對)한 문헌적(文獻的) 고찰(考察) (The investigation of literature about relation of lung and skin)

  • 이한구;정승기;이형구
    • 대한한방내과학회지
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    • 제11권1호
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    • pp.141-146
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    • 1990
  • The skin is related the lung as follows ; 1. The lung control skin and give a nutrition to skin. The skin and hair 'hab' (合) the lung. 2. As a damage of lung is a damage of skin, skin and hair 'chi-lag' (聚落) 3. A defensive energy of lung give a nutrition to skin, and strengthen the body surface. 4. Dryness damage the lung, and so damage the skin. According to the above findings, we know the body surface are closely related to the lung functionally.

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전기화학적 가속 부식 평가법에서 강재의 부식 손상에 미치는 인가전류밀도의 영향 (Effect of Applied Current Density on the Corrosion Damage of Steel with Accelerated Electrochemical Test)

  • 이정형;박일초;박재철;김성종
    • 한국표면공학회지
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    • 제49권5호
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    • pp.423-430
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    • 2016
  • In this study, we investigated the corrosion damage characteristics of steel for offshore wind turbine tower substructure using an accelerated electrochemical test. The galvanostatic corrosion test method was employed with a conventional 3 electrode cell in natural sea water, and the steel specimen was served as a working electrode to induce corrosion in an accelerated manner. Surface and cross-sectional image of the damaged area were obtained by optical microscope and scanning electron microscope. The weight of the specimens was measured to determine the gravimetric change before and after corrosion test. The result revealed that the steel tended to suffer uniform corrosion rather than localized corrosion due to active dissolution reaction under the constant current regime. With increasing galvanostatic current density, the damage depth and surface roughness of surface was increased, showing approximately 25 times difference in damage depth between the lowest current density ($1mA/cm^2$) and the highest current density ($200mA/cm^2$). The gravimetric observation showed that the weight loss was proportionally increased with increment of current density that has 75 times different according by experimental conditions. Consequently, uniform corrosion of the steel specimen was conveniently induced by the electrochemically accelerated corrosion technique, and it was possible to control the extent of the corrosion damage by varying the current density.