• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1352-1355
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• 1987

This Paper proposed the modified binary n-gram algorithm for the contextual post processing system in English sentence. Backward gram was used to correct the first position error in a word. It is not requires additional storage but more times of comparison it allows interactive correction routine. Experiments were implemented using PASCAL language on a micro computer, IBM PC/XT. This algorithm improves the correction rate around $4{\sim}5%$ on a limited experimental environments.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.553-556
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• 2006

Generally, concrete is one of the most widely used construction materials, because of its good durability to cost ratio. However, when subjected to severe environments its durability can significantly decline due to various harmful conditions. In this article, we would like to investigate a chloride ion diffusion of cement matrix with inert filler, which ground calcium carbonate(GCC). For the experimental results of the chloride ion diffusion, as the addition of GCC makes decreasing the permeability by micro-filler effect, the matrix of 5-15% ratio of replacement are superior to the GCC0 mortar matrix with respect to durability of cement matrix in this scope.

• 한국레이저가공학회지
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• 제11권1호
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• pp.12-18
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• 2008

Laser micromachining is a promising technique to fabricate the micro-scale devices. However, there remains important challenges to reducethe redeposition of ablated materials around the laser irradiated zone and to get a smooth surface, especially for metal and semiconductor materials. To achieve the high-quality micromachined devices, various methods have been developed. Liquid-assisted micromachining can be a good solution to overcome the previously mentioned problems. During the laser ablation process, the liquid around the solid sample dramatically changes the ablation characteristics, such as ablation rate, surface profile, formation of debris, and so on. In this investigation, we conducted the laser micromachining of Si in various liquid environmental conditions, such as liquid types, liquid thickness. In addition, using nanoscale time-resolved shadowgraphy technique, we observed the ablation process in liquid environments to understand the mechanism of liquid-assisted laser micromachining.

• 전기학회논문지
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• 제64권7호
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• pp.1074-1080
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• 2015

In the last decades, the increasing interest in unmanned aerial vehicle(UAV) for military, surveillance, and rescue applications made necessary the development of flight control theory and body structure more and more efficient and fast. In this paper, we describe the design and performance of a prototype hexarotor UAV platform featuring an inertial measurement unit(IMU) based autonomous-flying for use in bluetooth communication environments. The proposed system comprises the construction of the test hexarotor platform, the implementation of an IMU, dynamic modeling and simulation in the hexarotor helicopter. Furthermore, the hexarotor helicopter with implemented IMU is connected with a micro controller unit(ARM-cortex) board. The P-PD control algorithm was used to control the hexarotor. We used the Matlab software to help us to tune the P-PD control parameters for quick response and minimizing the fluctuation. The control simulation and experiment on the real system are implemented in the test platform, evaluated and compared against each other.

• 전기학회논문지
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• 제57권5호
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• pp.741-747
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• 2008

This paper proposes a new concept of IDSP(Intelligent Digital Switchgear Panel) which can solve the problem of the safety, the reliability and the convenience to correspond to the requirement of the general electric customer or electric power company under the ubiquitous-based home automation environments. By analyzing their requirement functions, a 32-bit micro processor is adopted as main controller to support the designed functions efficiently. The DSP-based single phase power management device is utilized to collect the electric power information and the ethernet convertor to communicate through internet among the IDSPs and the remote computer system. In the proposed IDSP, the several functions are implemented such as the earth leakage level display and waveform transmission, the electric fee display, the voltage management, the load management and the load control function. Finally, the prototype of the IDSP is made experimently based on the designed results, and then the effectiveness is verified by testing its basic functions.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2003년도 추계학술발표논문집 (중)
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• pp.903-906
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• 2003

EHMIPv6(Enhanced Hierarchical Mobile Ipv6)는 호스트의 로컬 이동성을 제공해주기 위해 제시된 EHMIPv6(Hierarchical Mobile Ipv6)를 이동 네트워크 환경에 맞게 변형한 이동 관리 방법이다. EHMIPv6 를 통해 AR(Access Router)내의 MR(Mobile Router)들의 이동성(Macro mobility)과 MR 내의 MN(Mobile Node)의 이동성(Micro mobility)을 동시에 제공함으로써 매끄러운 이동성을 제공해준다. 따라서 EHMIPv6 를 통해 이동 네트워크 상에서 인터넷 서비스를 지속적으로 제공함과 동시에 패킷손실과 지연을 줄여 보다 나은 인터넷 서비스를 제공한다.

• 한국자동차공학회논문집
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• 제22권2호
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• pp.134-140
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• 2014

The paper presents an overview of the present state of study on the fatigue behaviors at very high number of cycles ($N_f$ > $10^7$). A classification of materials with typical S-N curves and influencing factors such as notches, residual stresses, temperatures, corrosion environments and stress ratios are given. The microstructural inhomogeneities of materials and micro-cracks played an important roles in very high cycle fatigue behaviors. The failure mechanisms for the fatigue design of materials and components are mentioned.

• Advances in nano research
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• 제8권4호
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• pp.283-292
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• 2020

In the present research, differential quadrature (DQ) method has been utilized for investigating free vibrations of porous functionally graded (FG) micro/nano beams in thermal environments. The exact location of neutral axis in FG material has been assumed where the material properties are described via porosity-dependent power-law functions. A scale factor related to couple stresses has been employed for describing size effect. The formulation of scale-dependent beam has been presented based upon a refined beam theory needless of shear correction factors. The governing equations and the associated boundary conditions have been established via Hamilton's rule and then they are solved implementing DQ method. Several graphs are provided which emphasis on the role of porosity dispersion type, porosity volume, temperature variation, scale factor and FG material index on free vibrational behavior of small scale beams.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.202-203
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• 2018

Chemistry and microstructure of steel reinforcement bars play an important role to control the corrosion in concrete environments. In present study, we have chosen two different microstructure of steel rebars produced from companies and assessed their corrosion characteristics in simulated concrete pore (SCP) solution with prolonged exposure periods. Hot rolled steel rebar showed more corrosion resistance compare to thermo-mechanically treated (TMT) one. The growth of passive is greater in hot rolled (A) than TMT (B) due to orientation of microstructure. TMT steel rebar exhibit distorted microstructure with many micro cells which enhances the galvanic coupling and induce the deterioration while on the other hand hot rolled rebars exhibit fine grain boundary which responsible in growth of uniform, adherent and protective passive film resultant improved impedance was observed.

• Computers and Concrete
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• 제15권2호
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• pp.183-198
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• 2015

Chloride ingress implies a complex interaction between physical and chemical process, in which heat, moisture and chloride ions transport through concrete cover. Meanwhile, reinforced concrete structure itself undergoes evolution due to variation in temperature, relative humidity and creep effects, which can potentially change the deformation and trigger some micro-cracks in concrete. In addition, all of these process show time-dependent performance with complex interaction between structures and environments. In the present work, a time-dependent behavior of chloride transport in reinforced concrete beam subjected to flexural load is proposed based on the well-known section fiber model. The strain state varies because of stress redistribution caused by the interaction between environment and structure, mainly dominated by thermal stresses and shrinkage stress and creep. Finally, in order to clear the influence of strain state on the chloride diffusivity, experiment test were carried out and a power function used to describe this influence is proposed.