• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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• pp.68-71
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• 2004

본 연구는 싱크로트론 방사광의 단색광 (monobeam)을 이용한 영상을 획득하였다. 영상센서로서 CMOS를 사용하였으며 센서 앞단에는 형광체 (phosphor)를 이용하여 방사광에 대한 빛의 신호로서 영상을 획득하였다. 사용된 싱크로트론 방사광의 beam size는 $5mm{\times}2mm$ 이며 ion chamber를 통한 beam intensity 는 $10{\times}10^{-7}$이다. 형광체는 각각 ZnS(Cu:Al), ZnS(Ag,Al), $BiTiO_3$, $Y_2O_2S(Tb)$로서 4가지를 사용하였으며 여기에 사용된 형광체는 기계식 스크린 프린팅 (Screen Printing) 방식으로 직접 제조하였다. 두께는 모두 동일하게 $10{\mu}m$이며 각각에 대한 PL(Photoluminescence)을 측정하여 분석하였다. object로는 물고기와 20linepair를 사용하였으며 CMOS센서를 이용하여 각각의 phosphor에 대하여 영상을 획득하였다. 영상의 평가는 20line pair 영상의 MTF를 이용하였다. 각각의 형광체에 대한 MTF는 5 lp/mm 에서는 0.5650, 0.2150, 0.7890, 0.3840 이며 10 lp/mm 은 0.4500, 0.0900, 0.2510, 0.1500이고 15 lp/mm 는 0.1900, 0.0300, 0.1430, 0.0500이며 마지막으로 20 lp/mm 은 0.0810, 0.004, 0.0500, 0.0320의 MTF 값을 나타내었다. $10{\mu}m$ 두께에 대하여 ZnS(Cu:Al)이 가장 좋은 MTF의 값을 나타내었다.

• Journal of Periodontal and Implant Science
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• 제47권3호
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• pp.174-181
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• 2017

Purpose: Epitope spreading is a phenomenon in which distinct subdominant epitopes become major targets of the immune response. Heat shock protein (HSP) 60 from Porphyromonas gingivalis (PgHSP60) and peptide 19 from PgHSP60 (Pep19) are immunodominant epitopes in autoimmune disease patients, including those with periodontitis. It remains unclear whether Pep19 is a dominant epitope in subjects without periodontitis or autoimmune disease. The purpose of this study was to determine the epitope spreading pattern and verify Pep19 as an immunodominant epitope in healthy teenagers using dot immunoblot analysis. The patterns of epitope spreading in age-matched patients with type 1 diabetes mellitus (type 1 DM) and healthy 20- to 29-year old subjects were compared with those of healthy teenagers. Methods: Peptide from PgHSP60, Mycobacterium tuberculosis HSP60 (MtHSP60), and Chlamydia pneumoniae HSP60 (CpHSP60) was synthesized for comparative recognition by sera from healthy subjects and patients with autoimmune disease (type 1 DM). Dot immunoblot analysis against a panel of peptides of PgHSP60 and human HSP60 (HuHSP60) was performed to identify epitope spreading, and a densitometric image analysis was conducted. Results: Of the peptide from PgHSP60, MtHSP60, and CpHSP60, PgHSP60 was the predominant epitope and was most consistently recognized by the serum samples of healthy teenagers. Most sera from healthy subjects and patients with type 1 DM reacted more strongly with PgHSP60 and Pep19 than the other peptides. The relative intensity of antibody reactivity to Pep19 was higher in the type 1 DM group than in the healthy groups. Conclusions: Pep19 is an immunodominant epitope, not only in autoimmune disease patients, but also in healthy young subjects, as evidenced by their robust immunoreactivity. This result suggests that the Pep19-specific immune response may be an initiator that triggers autoimmune diseases.

• 한국의학물리학회지:의학물리
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• 제29권2호
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• pp.66-72
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• 2018

The proper position of a multi-leaf collimator (MLC) is essential for the quality of intensity-modulated radiation therapy (IMRT) and volumetric modulated arc radiotherapy (VMAT) dose delivery. Task Group (TG) 142 provides a quality assurance (QA) procedure for MLC position. Our study investigated the QA validation of the mechanical leaf gap measurement and the maintenance procedure. Two $VitalBeam^{TM}$ systems were evaluated to validate the acceptance of an MLC position. The dosimetric leaf gaps (DLGs) were measured for 6 MV, 6 MVFFF, 10 MV, and 15 MV photon beams. A solid water phantom was irradiated using $10{\times}10cm^2$ field size at source-to-surface distance (SSD) of 90 cm and depth of 10 cm. The portal dose image prediction (PDIP) calculation was implemented on a treatment planning system (TPS) called $Eclipse^{TM}$. A total of 20 VMAT plans were used to confirm the accuracy of dose distribution measured by an electronic portal imaging device (EPID) and those predicted by VMAT plans. The measured leaf gaps were 0.30 mm and 0.35 mm for VitalBeam 1 and 2, respectively. The DLG values decreased by an average of 6.9% and 5.9% after mechanical MLC adjustment. Although the passing rates increased slightly, by 1.5% (relative) and 1.2% (absolute) in arc 1, the average passing rates were still within the good dose delivery level (>95%). Our study shows the existence of a mechanical leaf gap error caused by a degenerated MLC motor. This can be recovered by reinitialization of MLC position on the machine control panel. Consequently, the QA procedure should be performed regularly to protect the MLC system.

• 한국멀티미디어학회지
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• 제14권4호
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• pp.88-98
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• 2010

지금은 급속도로 발전하는 ICT(정보통신기술)뿐만 아니라 BT, CT, NT, ST 들이 컨버전스하는 고도의 통합기술이 활용되는 유비쿼터스시대이다. 이들 기술로 시간과 공간의 벽을 넘어 인간의 5감을 크게 도와주는 3차원 가상현실 시각화기술을 이해함은 최근에 매우 중요하게 되었다. 본 연구는 3차원 가상현실 시각화 기술을 살피고 향후의 발전 방향을 예측하고 전망과 제언을 하는 것이다. 가상현실 구현기술은 3차원 컴퓨터그래픽스 표현기술에 크게 종속되어 있어 몰입할 수 있는 3차원 영상 구현기술이 가능하였고, 또한 컴퓨터의 상호작용성을 이용하여 새로운 패러다임으로 영상을 증강시키는 PC와 디스플레이 장비를 기반으로 구현되고 있으며, 보다 인간성을 강조하는 방향으로 활발히 연구되고 있다. 이 기술은 초고속 인터넷 기술 등의 상위기술들의 해결로 명실상부한 21세기 유비쿼터스사회 구현에 큰 몫을 감당할 것이 확실하다.

• Journal of Korean Neurosurgical Society
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• 제53권5호
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• pp.312-315
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• 2013

Aspergillosis in the central nervous system (CNS) is a very rare disease in immune-competent patients. There was a case of a healthy man without a history of immune-compromised disease who had invasive aspergillosis with unusual radiologic findings. A 48-year-old healthy man with diabetes mellitus, presented with complaints of blurred vision that persisted for one month. Brain magnetic resonance imaging (MRI) showed multiple nodular enhancing lesions on the right cerebral hemisphere. The diffusion image appeared in a high-signal intensity in these areas. Cerebrospinal fluid examination did not show any infection signs. An open biopsy was done and intraoperative findings showed grayish inflammatory and necrotic tissue without a definitive mass lesion. The pathologic result was a brain abscess caused by fungal infection, morphologically aspergillus. Antifungal agents (Amphotericin B, Ambisome and Voriconazole) were used for treatment for 3 months. The visual symptoms improved. There was no recurrence or abscess pocket, but the remaining focal enhanced lesions were visible in the right temporal and occipital area at a one year follow-up MRI. This immune-competent patient showed multiple enhancing CNS aspergillosis in the cerebral hemisphere, which had a good outcome with antifungal agents.

• 한국멀티미디어학회논문지
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• 제7권1호
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• pp.35-43
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• 2004

본 논문에서는 고속도로나 도심 진입 차량의 무인 자동과금 및 주요시설 출입 차량의 통제와 관리를 위하여 차량번호판 인식뿐만 아니라 차량 표시 문자와 제조사 식별자 검출 분류하여 차량의 정보를 판독하는 차량정보인식 및 자동과금시스템을 제안하였다. 제안한 알고리즘은 차량 후면부에서 획득된 영상으로부터 잡음제거, 세선화 등의 전처리 과정을 수행하고 템플릿 마스킹 및 레이블링 연산처리를 수행하여 차량표시문자, 제조사 표식자 및 번호판 영역을 각각 검출하였다. 또한, 검출된 특징 영역으로부터 특징자의 구조적 특징 및 패턴정보를 이용하여 표시문자와 제조사 표식자를 분류하였고, 하이브리드 패턴벡터와 세븐세그먼트 패턴벡터를 사용하여 차량번호판의 문자 및 숫자를 각각 인식하였다. 실험에서는 실제 고속도로상에서 제안한 차량인식 시스템에서 획득된 실 영상을 사용하여 인식 성능을 수행하였다. 실험 결과 제안한 알고리즘이 잡음, 외부환경, 차량의 크기에 무관하게 차량 특징자를 정확히 검출 분류하였으며 제안한 시스템은 범죄차량 단속, 차량자동과금 및 관공서 등의 차량입출력 관리의 무인화에 적용이 가능하다.

• Journal of Korean Neurosurgical Society
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• 제52권5호
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• pp.491-494
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• 2012

We report a rare complication of iatrogenic spinal intradural following minimally invasive extradural endoscopic procedues in the lumbo-sacral spines. To our knowledge, intradural cyst following epiduroscopy has not been reported in the literature. A 65-year-old woman with back pain related with previous lumbar disc surgery underwent endoscopic epidural neuroplasty and nerve block, but her back pain much aggravated after this procedure. Postoperative magnetic resonance imaging revealed a large intradural cyst from S1-2 to L2-3 displacing the nerve roots anteriorly. On T1 and T2-weighted image, the signal within the cyst had the same intensity as cerebrospinal fluid. The patient underwent partial laminectomy of L5 and intradural exploration, and fenestration of the cystic wall was accomplished. During operation, the communication between the cyst and subarachnoid space was not identified, and the content of the cyst was the same as that of cerebrospinal fluid. Postoperatively, the pain attenuated immediately. Incidental durotomy which occurred during advancing the endoscope through epidural space may be the cause of formation of the intradural cyst. Intrdural cyst should be considered, if a patient complains of new symptoms such as aggravation of back pain after epiduroscopy. Surgical treatment, simple fenestration of the cyst may lead to improved outcome. All the procedures using epiduroscopy should be performed with caution.

• 방송공학회논문지
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• 제18권2호
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• pp.167-177
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• 2013

이 논문에서는 향상된 움직임 적응적 디인터레이싱 알고리듬을 제안한다. 정확한 움직임 정보탐색을 위하여 세 가지 부분으로 구성된다 : (1) Modified Edge-based Line Average(MELA) 기법, (2) 연속된 5개의 필드에서의 움직임 탐색, 그리고 (3) 블록기반의 지역적 특성을 포함한다. 움직임 검출부분에서는 FIR 필터를 이용한다. 이것은 물체의 움직임의 내부를 정확하게 탐색 할 뿐만 아니라, 영상에 포함된 잡음도 줄일 수 있는 향상된 기법을 이용함으로써 계산 할 수 있다. 검출된 움직임의 정도에 따라서 가중치를 구하여 공간적 기법과 시간적 기법을 결합시킨다. 제안된 방법의 영상 시퀀스에 대한 실험 결과는 기존의 방법들에 비하여 주관적, 객관적인 비교에서 우수함을 보여준다.

• 대한기계학회논문집A
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• 제27권2호
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• pp.317-326
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• 2003

The influence of cyclic bending moment on the delamination and the fatigue crack propagation behavior in Al/GFRP laminate such as the wing section was investigated. The main objective of this study was to evaluate the relationship between crack profile and delamination behavior. And a propose parameter on the delamination growth rate(d $A_{D}$/da) of Al/GFRP laminates with a saw-cut using relationship between delamination area( $A_{D}$) and cycles(N), crack length(a), stress intensity factor range($\Delta$K). Also, the fiber bridging effect factor( $F_{BE}$ ) was propose that the fiber bridging modification factor($\beta$$_{fb}$ ) to evaluate using the delamination growth rate(d $A_{D}$/da). The shape and size of the delamination zone formed along the fatigue crack between aluminum alloy sheet. Class fiber-adhesive layer were measured by an ultrasonic C-scan image. The shape of delamination zone turns out to be semi-elliptic with the contour decreased non-linearly toward the crack tip. It represents that relationship between crack length and delamination growth rate(d $A_{D}$/da) were interdependent by reciprocal action, therefore it's applicable present a model for the delamination growth rate(dA/sib D//da) in Al/GFRP laminates.minates.s.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.362-367
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• 2003

It is shown that the effect of variable parameters on flame structures and NOx emissions in the laminar partially premixed methane-air flames with a co-axial Bunsen burner. Objectives of this paper is to understand the effects of flow variables on NOx emissions and the flame structure with OH chemiluminescence, including reconstructed image by abel inversion processing at each conditions. A fuel flowrate of 200 [cc/min] was fixed and the amount of air was varied from 400 to 1200 [cc/min]. The experimental variables were equivalence ratio(${\Phi}$ fuel split percentage(${\sigma}$ and inner tube recess(x/D). Flow conditions were ranged from $1.36{\sim}4.76$(equivalence ratio), $50{\sim}100$(fuel split percentage) and $0{\sim}20$(inner tube recess). NOx analyzer and ICCD camera with a OH filter were used as a main experimental apparatus. In addition, Abel inversion, which is a kind of tomography and valuable to estimate a two-dimensional structure of co-axial flames from cubical information, was employed for combustion diagnostics. Results from this study indicate that the main effects depend on equivalence ratio and next sigma, x/D for NOx production and OH formation. Throughout Abel inversion, we could affirm the maximum position and the tendency of OH radical intensity by variants at five axial heights above the burner exit.