• Computers and Concrete
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• 제19권4호
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• pp.405-411
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• 2017

Carbon Fiber Reinforced Plastic (CFRP) has commonly been used to strengthen existing RC structures. Wrapping the whole component with CFRP is an effective method and simple to execute. Besides, specific configuration of CFRP sheets (L, X and T shape) has also been considered in some experiments to examine CFRP effects in advance. This study aimed to provide an optimal CFRP configuration to effectively retrofit the beam-column connection using continuous material topology optimization procedure. In addition, Moved and Regularized Heaviside Functions and penalization factors were also considered. Furthermore, a multi-material procedure was also used to compare with the results from the single material procedure.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2000년도 추계학술대회 논문집(Proceeding of the KOSME 2000 Autumn Annual Meeting)
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• pp.143-151
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• 2000

Dissolved silica is make some critical trouble at steam turbine. And, we must measure it to ppb level. We were looking for the best measuring method of the silica. Via this study, we could found it in the N-IR spectroscopy technology. This dissertation have been discuss about system structure, system fundamentals and performance test. At the test, we were study in the spectral interference of $NH_3$. We know that existing system had some problem. It is structural frailties of single beam type. Therefore we were study for double beam type structure. And we obtain a good result. In the result, it have been discuss that conduct a test of $NH_3$ effect.

• Journal of Advanced Marine Engineering and Technology
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• 제30권8호
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• pp.919-926
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• 2006

To move in unknown or uncertain environment, a mobile robot must collect informations from various sensors and use it to construct a representation of the external world. Ultrasonic sensor can provide range data for this purpose in a simple cost-effective way. However conventional ultrasonic sensor system for a mobile robot are not sufficient for environment recognition because of their large beam opening angle, specular reflection. This paper describe on environmental perception algorithm which can solve these problems in case using ultrasonic sensor. The algorithm consist of two parts. One is to solve beam opening angle problem by fusion from multiple ultrasonic sensors. The other is to cope with specular reflection problem in wall line extract, which is based on Hough Transform. Experiments to verify the validity of the proposed algorithm are carried out, and the results are provided at last part in this paper.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.339-339
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• 2000

In this parer, a method of measuring the size of defects on the wall and restructing the defect image of 3-dimension is developed based on the tracking algorithm of a camera position which uses the inclination angle of line slit beam for overcoming the difficulty of the corresponding problem identifying the image point in the both image. In the experiments, an algorithm for estimating the horizontal angle of CCD camera is presented and validated by applying it to the measurement of area and length under the variations of both the distance and the angle of CCD camera. And its performance is compared to that of the rotating and mapping method of image which has the Euclidian distance.

• 비파괴검사학회지
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• 제29권3호
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• pp.242-247
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• 2009

The ability of time reversal techniques to focus ultrasonic beams on the source location is important in many aspects of ultrasonic nondestructive evaluation. In this paper, we investigate the time reversal beam focusing of ultrasonic array sensors on a defect in layered media. Numerical modeling is performed using the commercially available software which employs a time domain finite difference method. Two different time reversal approaches are considered - the through transmission and the pulse-echo. Linear array sensors composed of N elements of line sources are used for signal reception/excitation, time reversal, and reemission in time reversal processes associated with the scattering source of a side-drilled hole located in the second layer of two layer structure. The simulation results demonstrate the time reversal focusing even with multiple reflections from the interface of layered structure. We examine the focusing resolution that is related to the propagation distance, the size of array sensor and the wavelength.

• The Journal of the Acoustical Society of Korea
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• 제14권2E호
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• pp.87-90
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• 1995

측방향의 음장 모양이 sinc 함수 형태를 갖고 제한 깊이까지 그 모양을 유지하는 새로운 범의 수학적인 해석방법을 제안하였다. 물리적으로 이러한 음장의 형성은 각각 다른 파장을 갖는 파가 다른 방향으로 진행할 때 그 파장들이 합성되면서 나타난다. 이러한 제한회절빔은 초음파 영상에서 선형 어레이로 구현될 수 있으며 제한 깊이 내에서 균일한 측방향 해상도를 얻을 수 있다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.945-947
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• 2009

We developed a new laser irradiation (BLDA: Blue Multi-Laser-Diode Annealing) system. The system forms the uniform line beam, which is constructed by 48 pieces of semiconductor lasers. This new system has achieved high laser output stability and the highly accurate beam shape by adopting a reliable laser control, the auto-focus control in addition to an original laser photosynthesis technology and the beam homogenizing technology. It was confirmed to crystallize the Si films effectively with good quality.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권1호
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• pp.10-17
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• 2000

Recently, as the field of cyclotron application is to be wider, to inject the beam whree the user want to is getting more important. But since it is not the easy way to describe the model equation of cyclotron, it could be operated by only operator's experiences. In this paper, we suggest the cyclotron controller using the fuzzy logic and the genetic algorithm. The proposed controller was verified in useful by applying to the cyclotron's beam line. In the experiment the measured results were obtained by VXIbus and the control algorithm was performed by LabWindows/CVI.

• 대한전자공학회논문지
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• 제26권12호
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• pp.1995-2000
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• 1989

The ion beam system of 20keV C-W (Cockroft Walton) type composed of the AuGe alloy LMIS(Liquid Metal Ion Source) has been designed and constructed. For the fabrication of the ohmic contact to the n-GaAs, the ion beam extracted from the AuGe alloy source was implanted into the n-GaAs, and it was measured by contact resistivity. The stable AuGe ion beam(2.5\ulcorner/cm\ulcorner was obtained at the extraction voltage of 14.5kV. The measurements of the contact resistivity were done by the TLM (Transmission Line Model) method and the specific contact resistivity was found to be 2.4x10**-5 \ulcornercm\ulcornerfor the implanted sample by the 1.9x10**20/cm**3 and the annealed sample at 30\ulcorner for 2 min.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.455-458
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• 2002

Design methods are presented for an X-band traveling-wave slot array realized on a rectangular waveguide. An array of 21 longitudinal slots is realized on the broad wall of a rectangular waveguide. The squint of the antenna main beam is adjusted using the element spacing and the waveguide broad wall dimension. The excitation of the array is controlled by the slot offset from the waveguide center line Multiple I-plane steps are placed around last slot elements so that the second-order beam due to tile reflected wave Is minimized A waveguide-to-coaxial adapter Is designed for feeding the array antenna from a coaxial system. Results of the design show an outstanding performance of the antenna 17.1 dB gain. 36"beam 1111, and -21 dB maximum sidelobe level.evel.