• Journal of the Optical Society of Korea
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• 제10권3호
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• pp.124-129
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• 2006

We have developed a compact and cost-effective camera module on the basis of wafer-scale-replica processing. A multiple-layered structure of several aspheric lenses in a mobile-phone camera module is first assembled by bonding multiple glass-wafers on which 2-dimensional replica arrays of identical aspheric lenses are UV-embossed, followed by dicing the stacked wafers and packaging them with image sensor chips. This wafer-scale processing leads to at least 95% yield in mass-production, and potentially to a very slim phone with camera-module less than 2 mm in thickness. We have demonstrated a VGA camera module fabricated by the wafer-scale-replica processing with various UV-curable polymers having refractive indices between 1.4 and 1.6, and with three different glass-wafers of which both surfaces are embossed as aspheric lenses having $230{\mu}m$ sag-height and aspheric-coefficients of lens polynomials up to tenth-order. We have found that precise compensation in material shrinkage of the polymer materials is one of the most technical challenges, in orderto achieve a higher resolution in wafer-scaled lenses for mobile-phone camera modules.

• Imaging Science in Dentistry
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• 제32권3호
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• pp.159-165
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• 2002

Purpose: The aim of this study was to introduce a method of obtaining the oscillation graphs of the dental x-ray tube heads relative to time using an accelerometer. Materials and Methods: An Accelerometer, Piezotron type 8704B25 (Kistler Instrument Co., Amherst, NY, USA) was utilized to measure the horizontal oscillation of the x-ray tube head immediately after positioning the tube head for an intraoral radiograph. The signal from the sensor was transferred to a dynamic signal analyzer, which displayed the magnitude of the acceleration on the Y-axis and time lapse on the X -axis. The horizontal oscillation of the tube head was measured relative to time, and the settling time was also determined on the basis of the acceleration graphs for 6 wall type, 5 floor-fixed type, and 4 mobile type dental x-ray machines. Results : The oscillation graphs showed that tube head movement decreased rapidly over time. The settling time varied with x-ray machine types. Wall-type x-ray machines had a settling time of up to 6 seconds, 5 seconds for fixed floor-types, and 1 I seconds for the mobile-types. Conclusion: Using an accelerometer, we obtained the oscillation graphs of the dental x-ray tube head relative to time. The oscillation graph with time can guide the operator to decide upon the optimum exposure moment after x-ray tube head positioning for better radiographic resolution.

• 방사성폐기물학회지
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• 제9권1호
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• pp.41-48
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• 2011

한국원자력연구원 내 지하 처분 연구시설(KURT)에서 채취한 지하수에 존재하는 나노 콜로이드 입자의 크기 및 농도를 현상에서 조사하기 위해 이동식 레이저 유도 파열 검출 장치를 개발하였다. 제작한 장치는 CCD 카메라를 이용하여 레이저 유도 플라즈마가 발생한 위치를 2-차원 영상으로 기록함으로써 광학적으로 입자의 크기를 결정할 수 있다. 크기가 정확히 알려진 폴리스틸렌 표준 입자를 이용하여 입자 크기 측정용 검정 곡선 (calibration curve)을 구했고, 이를 이용하여 지하 처분 연구시설에서 채취한 지하수 내 콜로이드 입자의 크기를 측정하였다. 지하수 내 존재하는 콜로이드 입자의 평균 크기는 $108{\pm}26$ nm 임을 보였고, 농도는 50 ppb 이하인 것으로 추정하였다.

• 전기전자학회논문지
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• 제24권1호
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• pp.293-301
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• 2020

Consultation with the patient and doctor is very important in the examination. However, if the consultation cannot be done directly, such as corona virus, it is difficult for the doctor to determine the patient's condition more accurately. Recently, an image counseling system has been developed based on the Internet, but in the case of heart disease, remote medical counseling cannot be performed because it is not possible to stethoscope the heart sounds remotely. In order to solve this problem, it is necessary to develop an interactive mobile robot capable of remote medical consultation, and a doctor and a patient should be able to set a planting sound during consultation and transmit it in real time. In this paper, we developed a robot that can remotely control a medical counseling robot to move to a hospital room where patients are hospitalized, and to consult a patient in the room remotely from a doctor's office. A remote medical imaging stethoscope system for real-time heart sound transmission is presented. The proposed system is a kind of P2P communication that transmits video information, audio information, and control signal independently through webRTC platform, so that there is no data loss. Consults and sees doctors in real time and finds it more effective than traditional methods for patient security. The system implemented in this paper will be able to perform remote medical care in the place where the spread of diseases between humans like the recent corona 19 as well as the remote medical care of heart disease patients in the future.

• Korean Journal of Acupuncture
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• 제38권4호
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• pp.267-274
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• 2021

Objectives : Acupoints education is important in that it can determine the clinical competency of Korean Medicine Doctors (KMDs). Accordingly, we aimed to develop a practical simulator for acupoints education, acupoints training, acupoints practice, and acupoints evaluation. Methods : Korean Medicine (KM) SMART Table can be divided into hardware, server and components, and is organically linked. We develop KM SMART Table that combines the hardware of a human-sized table with a UHD display capable of multi-touch in two cases and software that can teach acupoints. We make Augmented Reality (AR) contents linked with KM SMART Table contents and develop applications that can use contents using mobile devices. By developing an AR image tracking module to react with KM SMART Table, it enables acupoint learning according to the mobile device platform and human anatomy. Results : The current system is a prototype where some 3D technology has been implemented, but the AR function will be produced later. New learning using 3D and AR will be required during acupoints education and acupoints practice. It will be used a lot in OSCE (Objective Structured Clinical Examination) practices for strengthening the competency of KMDs, and it will be of great help not only in KM education as a unique simulator of KM, but also in the practice of acupuncture and chuna for musculoskeletal diseases. Conclusions : The KM SMART Table is a technology that combines 3D and AR to learn acupoints, and to conduct acupoints OSCE practice, and we suggest that it can be usefully used for educational evaluation.

• 대한방사선치료학회지
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• 제25권1호
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• pp.57-67
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• 2013

목 적: 방사선 치료 중 정확한 환자의 셋업 확인과 선량 측정용으로 사용되었던 film을 대신 하여 현재는 전자포탈영상장치(EPID)가 장착된 장비가 증가하고 있다. 이에 본 논문은 전자포탈영상장치 사용 시 자세확인의 정확성과 선량측정의 유용성을 평가해 보고자 한다. 대상 및 방법: 대한방사선치료학회, 대한방사선종양학회, Pubmed에서 "EPID", "Portal dosimetry", "Portal image", "Dose verification", "Quality control", "Cine mode", "Quality - assurance", "In vivo dosimetry"와 같은 용어로 검색하여 획득한 50개의 자료(1997~2012)를 대상으로 EPID의 역사와 선량측정(dosimetry), 자세확인(set-up verification), EPID 특성으로 구분하여 EPID의 유용성을 분석 하였다. 결 과: EPID는 1세대 Liquid-filled ionization chamber, 2세대 Camera based fluroscopic, 3세대 Amorphous-silicon 순으로 발전하였으며, EPID 촬영 모드에는 크게 EPID mode, Cine mode, Integrated mode로 나뉜다. 필름과 EPID의 절대선량정확성 평가를 한 결과 EPID는 1%, EDR2 필름은 3% 이내로 나타나 오차 측정 정확도가 필름에 비해 EPID가 우수하다는 것을 알 수 있었고, 치료계획 시스템으로부터 계산된 기준 조사면과 EDR2 필름, EPID로 측정한 기준 조사면의 선량 분포를 중첩하여 감마 분석한 결과 필름과 EPID 모두 허용기준 3%/3 mm와 2%/2 mm에서 감마값이 1을 초과하는 화소(r%>1)가 전체 화소의 2% 이내였다. 또한 업무 부하 비교에 있어 세기조절방사선 치료에서 전 과정 QA를 수행하는데 소요되는 시간은 EDR2 필름이 약 110분, EPID가 약 55분으로 측정되었다. 결 론: 전자포탈영상장치의 이용은 선량측정과 자세확인에 있어 기존의 복잡하고 번거로웠던 film과 전리조(Ionization chamber)를 대체하기에 충분하였으며, 특히 세기조절방사선치료의 정도관리에 있어 매우 유용하고 효율적이며 정확한 선량 측정 장치임을 알 수 있었다. 또한, 전자포탈영상장치를 이용한 Cine mode 촬영은 횡격막의 움직임에 따라 유동성이 큰 폐와 간의 경우나 자세의 안정성이 불안한 직장암 환자의 경우 추가 선량 없이 실시간으로 종양의 위치를 확인 할 수 있다는 장점이 있어 최적의 방사선 치료 구현이 가능하리라 사료된다.

• Architectural research
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• 제18권1호
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• pp.13-20
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• 2016

Smart Home has achieved remarkable developments over the past few decades. In the ICT(Information and Communications Technology) field, 'app ecosystem'-a collection of multiple devices such as mobile phones and tablets, software (operating system and development tools), companies (manufacturers, carriers, app-stores, etc.) and the process through which data is transferred/shared by a user from one device to another device or by the device itself-has come into wide use since the advent of the smart phone. Due to the synergy effect of the 'app ecosystem', it has been applied to various fields such as televisions and automobile industries. As a result, both the Smart TV and connected vehicle have developed their own ecosystem. Although much research has been conducted on these two ecosystems, there is a lack of research regarding 'App Ecosystem based Smart Home' (AESH). This research focuses on the building scenarios based on 'Tracking, Analyzing, Imaging, Deciding, and Acting (T.A.I.D.A), a future prediction method process. Rather than taking an approach from the perspective of providing and applying advanced technology for research on building future scenarios, this paper focuses on research from the perspective of architectural planning. As a result, two future scenarios of AESH are suggested.

• 디지털융복합연구
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• 제12권1호
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• pp.319-324
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• 2014

최근 들어 고성능 비행 드론이 주목받고 있다. 특히, 다중 로터를 장착한 헬기 형태의 비행 드론은 항공촬영, 방송영상제작, 항공구조, 물류배송, 감시, 측량, 방역 방제, 군사용 등으로 그 활용범위를 확장해가고 있다. 그러나 이를 조종하는 제어기의 형태는 매우 단순하다. 따라서 본 연구에서는 모바일 기기에 탑재된 G-센서를 이용하여 사용자의 직관적인 동작으로 비행 드론을 조종할 수 있는 향상된 제어기를 구현한다. 구현된 제어기는 신경망 알고리즘을 사용하여 동작 인식 성능을 향상시켰다.

• 한국항공운항학회지
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• 제22권1호
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• pp.130-135
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• 2014

FOD(Foreign Object Debris) has the potential threat to damage aircraft during critical phases of take-off and landing roll with some objects including metal on the runway. FOD can be found anywhere on an airport's air operation areas such as runway, taxiway and apron. It can lead to catastrophic loss of life and airframe, and increased maintenance and operating costs. In this paper, we defined FOD and surveyed its riskiness and necessity of automatic FOD detection system. We compared the requirements of the environment in Korea to the FAA advisory circular. Also we analyzed operation methods of FOD detection systems already installed at some airports. Based on the surveys mentioned above, we propose hybrid type of FOD detection system considering the environment in Korea which uses millimeter wave radar, optical camera and thermal imaging camera to detect FOD efficiently. In management approach, fixed type of the system should be installed for real-time monitoring, and mobile type of the system can be used additionally.

• 대한골관절종양학회지
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• 제13권1호
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• pp.14-21
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• 2007

Bone is a common site for metastatic spread from many kinds of malignancies. The morbidity associated with this metastatic spread can be significant, including severe pain. When it comes to spinal metastasis, occupying nearly 40% of skeletal metastases, the risks of complications, such as vertebral body collapse, nerve root impingement, or spinal cord compression, are also significant. Because of the necessity of preserving the integrity of the spinal column and the proximity of critical structures, surgical treatment has limitations when durable local control is desired. Radiotherapy, therefore, is often used as an adjunct treatment or as a sole treatment. A considerable limitation of standard radiotherapy is the reported recurrence rate or ineffective palliation of pain, either clinically or symptomatically. This may be due to limited radiation doses to tumor itself because of the proximity of critical structures. CyberKnife is an image-guided robotic radiosurgical system. The image guidance system includes a kilovoltage X-ray imaging source and amorphous silica detectors. The radiation delivery device is a mobile X-band linear accelerator (6 MV) mounted on a robotic arm. Highly conformal fields and hypofractionated radiotherapy schedules are increasingly being used as a means to achieve biologic dose escalation for body tumors. Therefore, we can give much higher doses to the targeted tumor volume with minimizing doses to the surrounding critical structures, resulting in more effective local control and less severe side effects, compared to conventional fractionated radiotherapy. A description of this technology and a review of clinical applications to bone metastases are detailed herein.