• Design & Manufacturing
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• 제2권1호
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• pp.33-38
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• 2008

As consumer in optics, electronics, aerospace and electronics industry grow, the demand for ultra precision aspherical surface lens increases higher. Precision turning with single-diamond tools has a long history of development for fabrication of optical quality surfaces since the advent of aerostatic rotary spindles and precise linear motion guide ways. To enhance the precision and productivity of ultra precision aspherical surface micro lens, the following specification of ultra precision grinding system is required: the highest rotational speed of the grinder is 100,000rpm and its turning accuracy is $0.1{\mu}m$, positioning accuracy is $0.1{\mu}m$. The development process of the grinding system for the ultra precision aspherical surface micro lens for optoelectronics industry is introduced. In the work reported in this paper, an intelligent grinding system for ultra precision aspherical surface machining was designed by considering the factors affecting the surface roughness and profiles accuracy. An aerostatic form was adopted to build the spindle of the workpiece and the spindle of grinder and ultra precision LM guide way was adopted in this system. And this paper deals with mirror grinding of an aspheric surface micro lens by resin bonded diamond wheel and spherical lens of BK7. It results was that a form accuracy of $0.6{\mu}m$ P-V and a surface roughness of $0.006{\mu}m$ Rmax.

• 한국정밀공학회지
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• 제20권12호
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• pp.64-72
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• 2003

This paper presents a small loading and positioning device using VCM (voice coil motor). The developed device consists of a VCM-based linear actuating system, a capacitance displacement sensor and a cantilever deflection sensing system. The trust force of the VCM proportional to applied current moves the column supported on two pairs of parallel leaf springs. The infinitesimal displacement of moved column is detected by capacitance displacement sensor with a resolution of 0.1nm and a repeatability of 1nm. Also, a micro cantilever with known stiffness (200N/m), which is mounted on the end of the column, is used as a force sensor to detect the load applied to a specimen. After the cantilever contacts with the specimen, the deflection of cantilever and the load applied to the specimen are measured by using an optical lever system which consists of a diode laser, a mirror and a PSD (position sensitive detector). In this paper, an experimental system was constructed and its actuator and sensing parts were tested and calibrated. Also, the constructed system was applied to the indentation experiment and the load-displacement curve of aluminum was obtained. Experimental results showed that the developed device can be applied for performing nano indentation.

• 한국정밀공학회지
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• 제17권1호
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• pp.21-26
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• 2000

This paper describes a positioning system for ultra-precision that will be utilized in semiconductor manufacturing field and precision machinery. This system is composed with laser scale unit with 10nm resolution, ball screw with LM guide, brushless DC servo motor, vibration isolator and is equipped in chamber for continuous measuring environment. The dynamic of table, the problem of servo control and the traceability for micro step motion are described. These data will be applied for getting more stable system with 50nm resolution.

• Nuclear Medicine and Molecular Imaging
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• 제42권5호
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• pp.401-409
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• 2008

목적: 최근 들어, 분자 영상에서 다중 영상 기법이 널리 보급되고 있다. 우리는 PET/MR 융합 영상을 얻기 위해 쉽게 이용 가능한 점토와 순간 고형제를 이용하여 동물 특이적 자세 고정 틀을 제작하였다. 동물 특이적 자세 고정 틀은 동물의 고정과 재현성 있는 자세 연출이 가능하도록 한다. 여기에서 우리는 실험 동물의 틀을 제작하는데 있어 점토와 순간 고형제를 비교해 보았다. 재료 및 방법: MicroPET의 받침대와 잘 맞는 바닥이 둥근 아크릴 받침대를 먼저 제작하였다. 실험 동물은 마취 후, 자세 고정을 위해서 틀 위에 올려놓았다. 틀 제작을 위하여 순간 고형제와 점토가 사용되었다. 순간 고형제와 점토를 사용한 두 가지 경우 모두, 실험 동물의 자세 고정을 위하여 부드럽게 실험 동물을 눌러 위치를 잡았다. 위치가 잡혔으면, 쥐를 들어내고, 점토로 뜬 틀은 $60^{\circ}C$ 건조기에 넣어 두어 완전히 경화시켰다. 그리고 $[^{18}F]FDG$용액이 든 밀봉된 4개의 파이펫 팁을 기준 마커로 사용하였다. 실험 동물의 꼬리에 $[^{18}F]FDG$를 정맥 주사하여 microPET 스캔을 실시한 후, 동일한 실험동물을 순차적으로 MRI 스캔하였다. 결과: 다중 영상을 위하여 점토와 순간 고형제로 동물 특이적 자세 고정 틀을 제작하였다. MicroPET과 MRI를 통하여 기능적이고 해부학적인 영상을 얻었다. PET/MR 융합 영상은 무료로 이용 가능한 AMIDE 프로그램을 사용하여 획득할 수 있었다. 결론: 쉽게 이용 가능한 점토, 순간 고형제와 일회용 파이펫 팁을 사용하여 성공적으로 동물 특이적 자세 고정 틀을 제작할 수 있었다. 동물 특이적 자세 고정 틀 덕택으로, 적은 오차 범위 내에서 PET/MR 융합 영상을 얻을 수 있었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1099-1104
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• 2004

As consumer in optics, electronics, aerospace and electronics industry grow, the demand for ultra precision aspherical surface lens increases higher. To enhance the precision and productivity of ultra precision aspherical surface micro lens, the following specification of ultra precision grinding system is required: the highest rotational speed of the grinder is 100,000rpm and its turning accuracy is $0.1{\mu}m$, positioning accuracy is $0.1{\mu}m$. The development process of the grinding system for the ultra precision aspherical surface micro lens for optoelectronics industry is introduced. In the work reported in this paper, an intelligent grinding system for ultra precision aspherical surface machining was designed by considering the factors affecting the surface roughness and profiles accuracy. An aerostatic form was adopted to build the spindle of the workpiece and the spindle of grinder and ultra precision LM guide way was adopted in this system.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2006년도 학술대회 1부
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• pp.638-646
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• 2006

유비쿼터스 시대가 도래함에 따라 사회적으로 실내 위치 추적 시스템에 대한 관심이 증가되었다. 하지만 기존 실내 위치 추적 시스템은 실내 환경의 빈번한 변화에 능동적으로 대응하지 못하고, 실내 환경의 NLOS 특성으로 인하여 이동 객체의 정확한 위치 측정이 어려운 문제점이 있다. 본 연구의 목적은 앞으로 유비쿼터스 시대가 도래함에 따라 다양한 사용자의 요구를 만족시키기 위한 서비스를 제공하는데 필수 요소인 실내 이동 객체의 위치를 효과적으로 파악하고, 이동 객체의 위치 정확도를 향상시킨 환경 적응형 위치 추적시스템을 제안한다.

• Journal of Positioning, Navigation, and Timing
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• 제2권1호
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• pp.67-74
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• 2013

In this study, a remote controller was designed using localization technique. The designed remote controller system consists of infrared transmit/receive module for time synchronization, ultrasonic transmit/receive module for measuring the TOA value, and micro-controller for processing the measured data value. For the position estimation method of remote controller, the Savarese method was used which does not have a problem of diverging solution depending on initial value. The noise included in the measured value was removed by separating the signal and noise with the use of EMD method which is the non-stationary signal analysis technique. The designed system was tested by constructing a simulation environment, and the improvement of accuracy and precision for the application of EMD method was examined.

• 한국정밀공학회지
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• 제20권7호
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• pp.99-104
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• 2003

A precision displacement measurement system of 3-DOF micro motions is proposed in this paper. The measurement system is composed of two diode lasers, two quadratic PSDs, two beam splitters and a sphere whose surface is highly reflective. In this measurement system, the sphere reflector is mounted on the platform of positioning devices whose 3-DOF translational motions are to be measured, and the sensitive areas of two PSDs are oriented toward the center point of the sphere reflector. Each laser beam emitted from two diode laser sources is reflected at the surface of sphere and arrives at two PSDs. Each PSD serves as a 2-dimensional sensor, providing the information on the 3-dimensional position of the sphere. In this paper, we model the relationship between the outputs of two PSDs and 3-DOF translational motions of the sphere mounted on the object. Based on a deduced measurement model, we perform measurement simulation and evaluate the performance of the proposed measurement system: linearity, sensitivity, and measurement error. The simulation results show that the proposed measurement system can be valid means of precision displacement measurement of 3-dimensional micro motions.

• 대한의용생체공학회:의공학회지
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• 제44권2호
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• pp.125-138
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• 2023

The development of AI systems for radiation therapy is important to improve the accuracy, effectiveness, and safety of cancer treatment. The current system has the disadvantage of monitoring patients using CCTV, which can cause errors and mistakes in the treatment process, which can lead to misalignment of radiation. Developed the PMRP system, an AI automation system that uses depth cameras to measure patient's fine movements, segment patient's body into parts, align Z values of depth cameras with Z values, and transmit measured feedback to positioning devices in real time, monitoring errors and treatments. The need for such a system began because the CCTV visual monitoring system could not detect fine movements, Z-direction movements, and body part movements, hindering improvement of radiation therapy performance and increasing the risk of side effects in normal tissues. This study could provide the development of a field of radiotherapy that lags in many parts of the world, along with the economic and social importance of developing an independent platform for radiotherapy devices. This study verified its effectiveness and efficiency with data through phantom experiments, and future studies aim to help improve treatment performance by improving the posture correction mechanism and correcting left and right up and down movements in real time.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.873-877
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• 1997

This paper presents experimental results to know the charcteristics of machined surface due to cutter runout. Cutter runout is a common but undesirable phenomenon in multi-tooth machining such as end-milling process because it introduces variable chip loading to insert which results in a accelerated tool wear, amplification of force variation and hence enargement vibration amplitude. To develop in-proess cutter runout compensation system, set-up the micro-positoning mechanism which is based on piezoelectric translator embeded in the work holder to manipulate the depth of cut in real-time. And feasibility test of system was done under the various experimental cutting conditions. This results provide lots of information to build-up the precision machining technology.