• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.755-758
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• 2000

Rapid prototyping is one of the most important technology for 21th century industry. To overcome the limitation of the material and function, Functional Prototype Development(FPD) concept is newly proposed. Wide function is necessary such as mechanical, optical, chemical and electrical property in order to solve broad requirements of the industry. The process of FPD has more than two conventional processes based on fusion technology and the FPD system is integrated with the interdisciplinary, interfacing and intelligent concepts. This paper shows some representative achievements such as optic coloring prototypes, electric multi layer printed circuit broad(MLB) and MEMS using electrostrictive polymer. Finally, we confirmed that FPD has a great possibility which can be applied in broad industry and will be a powerful tool in near future.

• 한국정밀공학회지
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• 제24권7호
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• pp.69-74
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• 2007

The paper proposes a new sonic resonance test for a elastic modulus measurement which is based on time-average electronic speckle pattern interferometry(TA-ESPI) and Euler-Bernoulli equation. Previous measurement technique of elastic constant has the limitation of application for thin film or polymer material because contact to specimen affects the result. TA-ESPI has been developed as a non-contact optical measurement technique which can visualize resonance vibration mode shapes with whole-field. The maximum vibration amplitude at each vibration mode shape is a clue to find the resonance frequencies. The dynamic elastic constant of test material can be easily estimated from Euler-Bernoulli equation using the measured resonance frequencies. The proposed technique is able to give high accurate elastic modulus of materials through a simple experiment set up and analysis.

• 한국공작기계학회논문집
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• 제13권6호
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• pp.56-63
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• 2004

The real-time NURBS interpolation method using 2-stage interpolation is studied. The 2-stage interpolation method that compensates for interpolation errors within machine BLU is proposed. The interpolation result was filtered by an Acceleration/Jerk limitation equation. Through this 2-stage interpolation, both the interpolation error condition and the motion kinematics could be satisfied. Using computer simulation in which interpolation results are evaluated by a numerical iteration method, it is shown that the 2-stage interpolation algerian could interpolate target curves precisely with geometric and dynamic contentment. The proposed algorithm was implemented in the CNC simulator system and an experimental un was conducted to identify the real-time adaptation.

• 한국생산제조학회지
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• 제26권3호
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• pp.313-319
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• 2017

This study presents a genetic algorithm (GA) to design a PID controller systematically for an inchworm operated by piezoelectric actuators. The performance index considering overshoot and settling time is adopted to search an optimal PID gain using GA. The piezoelectric actuator shows nonlinear characteristics including hysteresis and residual displacement. The PID feedback system combined with an integrator is used to improve the ability of tracking the complex input signals and suppressing the steady state error. The PID controller tuned by GA can track the various motion contours effectively. However, the PID controller shows an improper residual vibration under the application of high-frequency square input. The input shaper combined with the feedback system can overcome this limitation of the PID controller.

• Nuclear Medicine and Molecular Imaging
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• 제42권sup1호
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• pp.126-129
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• 2008

Renal cell carcinoma is the most common histological type of renal malignancy, predominant in men and the primary treatment modality of this tumor is surgery. The role of diagnostic imaging in the management of this tumor is the evaluation of extent of disease as well as the detection and characterization of renal mass. US has long been a routine screening tool for kidney but tomographic imaging modalities such as CT and MRI begin to be also commonly used these days. On the other hand, the sensitivity of $^{18}F-FDG-PET$ in detection of renal mass is relatively low because of inherent limitation caused by FDG excretion pathway despite avid uptake of FDG to tumor cell per se. Many studies revealed FDG PET scan could play an important role in detection of metastatic lesions although the sensitivity for the detection of primary lesion is not so high. Furthermore, development of PET/CT scanner will make it possible to expand the indication of FDG PET scan in this malignancy.

• 한국소음진동공학회논문집
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• 제15권3호
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• pp.329-333
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• 2005

This paper is concerned with the measurement of low-frequency vibrations of structures using the image processing method. To measure the vibrations visually, the measurement system consists of a camera, an image grabber board, and a computer. The specific target installed on the structure is used to calculate the vibration of structure. The captured image is then converted into a pixel-based data and then analyzed numerically. The limitation of the system depends on the image capturing speed and the size of image. In this paper, we propose the methodology for the vibration measurement using the image processing method. The method enables us to measure the displacement directly without any contact. The current resolution of the vibration measurement is limited to sub centimeter scale. However, the frequency bandwidth and resolution can be enhanced by a high-speed and high-resolution image processing system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.821-825
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• 2008

Requirements of wireless sensor are increasing in machine condition monitoring. But, the limitation of battery power, self-power wireless sensor is necessary for the purpose of stand-alone operation. To overcome this problem, energy harvester is developed by the vibration energy. The purpose of this study is to develop a high efficiency energy harvester with high precision tuning.

• 대한후두음성언어의학회지
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• 제18권2호
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• pp.102-107
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• 2007

Laryngopharyngeal reflux disease (LPRD) is the result of retrograde flow of gastric contents to the laryngopharynx. Laryngoscopic findings and special questionnaires are first step of diagnosis of LPRD. Empiric trials of Proton pump inhibitor' test (PPI test) is recommended as treatment and diagnosis. However confirmation of reflux is then recommended primarily in patients with persistent symptoms despite acid-suppressive therapy. The 24 hour ambulatory double pH monitoring has been a gold standard method in diagnosis of LPRD even though it has some limitation. The combined multichannel intraluminal impedance and pH monitoring is a new-rising test tool. It can detect acid/non-acid, liquid/gaseous reflux and clearance of refluxate. The water siphon test is also used for diagnosis of LPRD.

• 한국화재소방학회논문지
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• 제22권2호
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• pp.108-115
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• 2008

본 연구는 우리나라의 구급제도에 대한 문제점을 도출하고 개선방안을 제시하는데 중점을 두었다. 현재 구급제도는 전문성의 미흡, 재정확보의 한계 등의 여러 가지 문제점이 도출되고 있다. 이를 개선하기 위해 구급인프라가 지속적으로 확충 개선되어야 하며 응급의료 전문의사의 배치, 구급업무의 질 향상을 위한 충분한 노력이 필요하다. 또한 구급제도에 유료화를 단계적으로 도입하여 재원확보와 전문성을 살리고 병원, 보험회사 등과 민관파트너십을 구성하여 119구급서비스의 통합운영체제를 구축하여야 한다.

• 한국터널지하공간학회 논문집
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• 제10권1호
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• pp.81-90
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• 2008

TBM 장비에서 최적의 커터간격을 결정하는 것은 매우 중요하다. 실제로 이러한 최적 커터간격은 커터간격을 변화시켜가며 수 회의 선형절삭시험(LCM시험)을 수행하여 이를 통해 얻어진 절삭 비에너지를 비교함으로써 도출될 수 있다. 본 연구에서는 AUTODYN-3D를 이용하여 실제 선형절삭시험을 수행하지 아니하더라도 최적 커터간격을 예측할 수 있는 수치해석적 기법을 제시하였으며, 본 기법을 황등화강암에 적용하여 최적 커터간격을 예측하였다.