• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.1
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• pp.40-48
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• 2015

In this paper, we suggest a measurement modeling of the RF seeker using the ISAR(Inverse Synthetic Aperture Radar) image. Reference scattering points are extracted first from ISAR images which are changed according to target attitude. And then uncertainties included in RF seeker measurement such as noise strength, blink, and boresight error are added to the reference scattering points. The proposed measurement model of the RF seeker can be used to develop various kinds of target tracking algorithms.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.8
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• pp.579-584
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• 2016

When surgical instruments are tracked in an image-guided surgical navigation system, a stereo vision system with high accuracy is generally used, which is called optical tracker. However, this optical tracker has the disadvantage that a line-of-sight between the tracker and surgical instrument must be maintained. Therefore, to complement the disadvantage of optical tracking systems, an internal vision sensor is attached to a surgical instrument in this paper. Monitoring the target marker pattern attached on patient with this vision sensor, this surgical instrument is possible to be tracked even when the line-of-sight of the optical tracker is occluded. To verify the system's effectiveness, a series of basic experiments is carried out. Lastly, an integration experiment is conducted. The experimental results show that rotational error is bounded to max $1.32^{\circ}$ and mean $0.35^{\circ}$, and translation error is in max 1.72mm and mean 0.58mm. Finally, it is confirmed that the proposed tool tracking method using an internal vision sensor is useful and effective to overcome the occlusion problem of the optical tracker.

• The Journal of the Korean dental association
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• v.20 no.9 s.160
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• pp.753-758
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• 1982

선천이상 중에서도 순열과 구개열은 특상한 성질의 것으로서 안모의 변형, 발음장애, 신체타부와의 관계기형, 이비인후과질환을 병발하기 쉽고, 호흡기, 소화기 질환에 이환되기 쉬으며 환자는 정신적, 사회적으로도 매우 불리한 위치에 놓여 있는 신체장애자로, Fogh-Anderson은 순열과 구개열은 열성반성유전(recessive sexlinked heredity)을 한다고 보고했다. 그러나 구개열은 유전적추적이 불가능하기 때문에 그 발생원인으로 물리적원인을 우선적으로 들고있다. 발생기전은 태생 8~12조경의 제2차구개형성기에 어떤 이유로 양측의 구개돌기(palatine process)와 비중격이 분리되있는 채로 있든가, 접근해서도 유합되지 않고 있든가의 조해요인으로 태아의 모태내에 있어서의 자세, 특히 흉부에 의한 하악골압박에 의해 발생하는 소악증(micromandible), 설하수(glossoptosis)를 동반하는 Pierr Robin syndrome, 태생 8~10조경까지의 혀의 만기정유, 지, 제대의 원시구강내로의 미입등을 들수있다. 순열 및 구개열환자의 치료에 있어서 종래에는 전과정이 외과의사에게만 맡겨졌었으나, 구순, 비부의 추형등의 문제, 특징적으로 발생되는 하악의 열성장, 이별궁이 왜형, 발음장애등의 문제점해결을 위하여 필연적으로 이에 관계있는 명기다른 전문분야의 전문의가 시술에 임하게되는 multidiscipline approach로서 종합진단, 장기치료계획의 입안, 전문적 의견의 교환을 통해서 치료시기, 치료순서의 결정으로 성공적인 순열및 구개열의 치료목표를 달성하리라고 생각한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.358-363
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• 2017

The high intercept probability depends on optimization of the system, which consists of target detection, tracking system, missile system and so on. To reduce the complexity of global optimization of the system performance, simplification of the relative dependances of each sub-system is done and design parameters for DACS configuration are identified. The conceptual design process is addressed based on the requirement of the design parameters and new methodology is suggested for higher performance.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1563-1566
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• 2015

보안과 관련된 기술이 발전하여 대규모의 장소에 적합한 보안시스템들이 많이 개발되었다. 특히 CCTV를 이용한 감시카메라의 형태도 다양화되었다. 스마트폰의 어플리케이션이나 웹을 통해서 어디서든 감시할 수도 있어, 이를 통해 보안사고 시에 빠른 대처가 가능하다. 하지만 대규모 시스템이 아닌 경우에는 침입자 발견이 늦고, 뒤늦은 대처로 인해 큰 피해가 발생할 수 있다. 라즈베리파이, 실드 보드 등 기타 하드웨어들을 통하여 침입자를 스스로 감지하여 사용자에게 즉시 알림을 전송함으로써 보안사고에 대한 대처를 빠르고 효율적으로 할 수 있는 보안카메라를 구현하였다. 본 보안 시스템은 소리의 방향을 계산하고 정확한 방향으로의 보정을 통하여 최초 침입자를 인식한다. 이후 이미지트래킹을 통하여 침입자를 추적한다. 무선 네트워크를 이용하기 때문에 네트워크가 지원되는 어느 장소에서든지 사용이 가능하다. 대규모 보안시스템을 설치할 여건이 되기 어려운 작은 공장, 상가, 사무실 등에서 보안시스템으로 사용되면 유용할 것이다. 자세한 개발 내용은 본문에 기술한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.549-552
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• 2022

본 논문에서는 가상현실에서 헤드 마운티드 디스플레이(Head mounted display, HMD) 사용자와 Non-HMD 사용자에게 사용자의 걷기, 뛰기, 절름발이 움직임을 몰입감 있게 표현하기 위한 새로운 가상현실(VR, Virtual Reality) 인터페이스를 제안한다. 가상현실에서는 몰입감을 높이기 위해 시각적 감각을 활용한 HMD와 사용자의 자세나 움직임을 추적하는 장비를 활용하지만, 일반적인 사용자들에게 HMD 보급은 많이 이루어져 있지 않으며, 비용적인 측면과 멀미로 인해 가상현실 콘텐츠에 몰입하기 어렵다. 본 논문에서는 효율적으로 몰입도를 높이고 비용적인 부담을 줄여주기 위해 아두이노를 활용한 새로운 보행 인터페이스 장치를 제안한다. 보행 인터페이스 장치는 사용자의 다리 가속도 정보를 기반으로 사용자의 상태 변화에 맞게 패턴을 설정하여 사용자의 걷기, 뛰기, 절름발이 움직임을 통해 사용자 캐릭터의 움직임을 제어하고 표현할 수 있는 새로운 결과를 보여준다.

• Progress in Medical Physics
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• v.10 no.2
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• pp.63-71
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• 1999

For the purpose of utilization in 3-D conformal radiotherapy and whole body radiosurgery, the Whole Body 3-Dimensional Topographic Radiation Therapy System has been developed. Whole body frame was constructed in order to be installed on the couch. Radiopaque catheters were engraved on it for the dedicated coordinate system and a MeV-Green immobilizer was used for the patient setup by the help of side panels and plastic rods. By designing and constructing the whole body frame in this way, geometrical limitation to the gantry rotation in 3-D conformal radiotherapy could be minimized and problem which radiation transmission may be altered in particular incident angles was solved. By analyzing CT images containing information of patient setup with respect to the whole body frame, localization and coordination of the target is performed so that patient setup error may be eliminated between simulation and treatment. For the verification of setup, the change of patient positioning is detected and adjusted in order to minimize the setup error by means of comparison of the body outlines using 3 CCTV cameras. To enhance efficiency of treatment procedure, this work can be done in real time by watching the change of patient setup through the monitor. The method of image subtraction in IDL (Interactive Data Language) was used to visualize the change of patient setup. Rotating X-ray system was constructed for detecting target movement due to internal organ motion. Landmark screws were implanted either on the bones around target or inside target, and variation of target location with respect to markers may be visualized in order to minimize internal setup error through the anterior and the lateral image information taken from rotating X-ray system. For CT simulation, simulation software was developed using IDL on GUI(Graphic User Interface) basis for PC and includes functions of graphic handling, editing and data acquisition of images of internal organs as well as target for the preparation of treatment planning.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.93-99
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• 2010

Purpose: Currently, PET/CT scan has been known to provide useful information to both preoperative and postoperative examination of cancer patients. Contracted stomach by the long fasting could cause difficulties of interpretation because of its size on reconstructed image data. To solve this problem, after the whole body PET/CT scan, patients were administrated in drinking 300 mL of water to expand stomach and performed additional scan on stomach region. Not only PET/CT scan but also CT performs this water-administration, and patients were take oral solution to make stomach expand for stomach cancer. When this scan performed, patients lay supine position. In this study, we evaluated the capacity of stomach through PET/CT scan with drinking water performed in supine and prone position so that we can distinguish exact location of cancer around pylorus and inferior wall of stomach. Furthermore, image data from supine and prone positions were analyzed the difference of volume of stomach through the change of standardized uptake values. Materials and Methods: From July 2009 to January 2010 in severance hospital, 30 patients who were diagnosed as early gastric cancer or advanced gastric cancer were chosen. All patients had PET/CT scan before the operation and have had follow-up PET/CT. The patients fast for at least 8 hours, and had an injection intravenously with $^{18}F$-FDG, 7.4 MBq (0.2 mCi/kg) per kilogram. They were rested for 60 minutes. Before the examination, all patients were administrated to drink water for 300 mL Patients had PET/CT scan with supine position around the region of stomach, whole body, and around the region of stomach with prone position after drinking another 300 mL of water respectively. Results: As a results of comparison between stomach capacity of 30 patients in supine and prone position, the study draw results that average capacity of stomach body was 460.29 $mm^2$ in supine position, and 641.39 $mm^2$ in prone position for 30 patients. The change of capacity shows 41.3% expanded in prone position. And there was no noticeable difference at maximum standardized uptake values in supine position and prone position. Conclusion: As results, stomach would have more expanded capacity in prone position than supine position. For patients who have physical disabilities to move freely, additional scan in prone position will be obstacle to perform. However, if additional scan in supine position add with the scan in prone position, it will be easier to diagnose stomach cancer. Moreover, we believe that this study will help the research for inventing support tools for patients who have physical disabilities in prone position.

• Clinical and Experimental Pediatrics
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• v.50 no.3
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• pp.241-247
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• 2007

Purpose : Congenital muscular torticollis (CMT) is a common and benign congenital disorder of the musculoskeletal system in neonates and infants. The pathophysiology is that the sternocleidomastoid muscle (SCM) is shortened on the involved side by fibrosis, leading to ipsilateral tilt and contralateral rotation of the face and chin. In this study, we investigated the clinical features of CMT, the role of ultrasonography (USG) in prediction of prognoses and the clinical significance of early detection and treatment. Methods : Forty seven patients (M:F=31:16) were diagnosed as a CMT between March 2003 and May 2006. We reviewed age at diagnosis, physical findings, USG findings, treatment and therapeutic outcome from their medical records. Results : The median age at diagnosis was 90 days (18 days-9 years, 7 months) and the right side of neck was affected in more patients (right : left=26:21). Of 24 patients with a palpable neck mass, 21 had USG; 19 cases showed sternocleidomastoid tumor (SMT). In cases with no neck mass, USG was performed in 11 patients; seven had postural torticollis (POST), three had SMT and one had muscular torticollis (MT). Among 40 patients with follow-up, 36 had total resolution. There was negative correlation between the age at diagnosis and the recovery time, whereas the final outcome was not correlated with USG findings. However, the patients without positive findings in USG had earlier resolution (1 month vs 2.6 months, P=0.0008). The patients with SMT had earlier diagnosis and excellent outcomes. The patients with MT were delayed to diagnosis and had the longest time to resolve. Lastly, the patients with POST had delayed diagnoses, but they had excellent outcomes. Conclusion : Since the patients with delayed diagnoses, in despite of benign courses, may take a long time to resolve and rarely need surgical treatment, it is important to diagnose and treat early. This study showed that USG findings of the SCM may be used as predictive factors.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.161-169
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• 2008

Since measuring the size of kidney with sonography becomes an important index for diagnosis, treatment, and prognostic prediction in kidney disease, the accurate measurement and evaluation on this are clinically very important. Accordingly, the purpose of this study was to increase reproducibility and objectivity in measuring the size of kidney by enumerating factors that have an impact for measurement. It targeted 44 adults in Korea at the age of 21-27. It measured in order for both kidneys to be seen most largely while changing a subject-examiner's position in a state of fasting for 8 hours and a transducer's approaching direction. It compared a size of kidney by measuring, respectively, with the same method in 30 minutes and in 1 hour after drinking water in 700-1,000cc. In case of the lateral approach scan in decubitus position, the average length of the kidney both to the right and the left and the deviation of measurement to be the largest. In NPO(None Per Oral) state, the average length in the right kidney was 10.19cm, and the average length in the left kidney was 10.33cm. In 60 minutes after taking moisture, the average length in the right kidney was 10.94cm, and the average length in the left kidney was 11.13cm. In comparing the average length of the kidney in NPO state and its average length in 60 minutes after taking moisture, the size swelled by 7.3% for the length in the right kidney and by 7.7% in the left, thereby having been indicated to be statistically significant(P<0.003). The measurement in a size of kidney by using ultrasound may be measured differently depending on a patient's state of taking moisture and a transducer's approaching direction. It is thought that when the measurement in a size of kidney is especially important clinically, the intake and intake time in moisture need to be considered and that measuring with the posterior approach in prone position is a good method aiming to increase reproducibility in measuring length of the kidney.