• 대한치과보철학회지
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• 제27권1호
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• pp.55-81
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• 1989

Recently the instantaneous center concept has been to understand the biomechanics by which a tissue derangement causes a mechanical derangement in human joint. Therefore, to understand the biomechanics of temporomandibular joint (T.M.J.) as a part of human joint, it is necessary to clarify the instantaneous center of rotation (I.C.R.) in the mandibular movement. Twenty male subjects without T.M.J. disorder and mandibular deviation during the mandibular movement were selected for this study. The habitual opening and closing paths were recorded on the paper of the sagittal metal plate by two pencil markers connected to the resin open clutch attached on the lower teeth, which was designed for this study. The coordinates of the 33-target points and the 109-anatomical landmarks were obtained using a Summagraphic digitizer connected to a 18AT computer. The original raw data of the opening and closing paths were smoothed by B-spline curve fitting technique and then the I.C.R. pathways were determined mathematically by the computer using algorithm for finding the I.C.R. of a planer rigid body model. Also the opening and closing movements of the mandible were simulated according to the determined I.C.R. The results obtained from this study were as follows. 1. At the early opening and the last closing, I.C.R's were almost distributed around the mastoid process outside the mandibular body without the presence in the region of the mandibular condyle. 2. The I.C.R. pathway showed variable patterns to each subject at the opening and closing movements. 3. The K constant with uniform pattern was obtained by the rotation angle times the radius, which was assumed to the index of the mandibular movement. 4. The opening and closing movements of the mandible were simulated by the I.C.R. pathways at the habitual opening and closing movements. 5. The mandibular condyle was rotated or translated accordng to the relative rotation angle and radius of the determinant factors of K contant.

• Journal of Periodontal and Implant Science
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• 제39권1호
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• pp.37-44
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• 2009

Purpose: Tetracycline and its chemically modified non-antibacterial analogues can inhibit certain host-derived tissue destructive collagenases such as matrix metalloproteinases. The purpose of this study was to evaluate clinical and microbiologic effects of the subantimicrobial dose of doxycycline(SDD) in conjunction with scaling and root planing. Materials and methods: A total of 30 patients with chronic periodontitis who were going to receive scaling and root planing were randomly allocated to receive either a doxycycline hyclate for 3 months or nothing. Clinical probing depth, clinical attachment level, gingival recession, and bleeding on probing were measured by one periodontist. After a periodontal examination, microbial samples were collected using sterile paper points. The effect of SDD in conjunction with scaling and root planing on alterations of the periodontal pathogens (Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Porphyromonas gingivalis) were also assessed using l6S rRNA polymerase chain reaction. Results: During the treatment period, clinical parameters for both treatment group and control group were improved. After 3 months, reductions in probing depth and gains in clinical attachment level were significantly greater for the SDD group than control group. Microbial analysis showed that there was no alteration of the periodontal pathogens and no difference between the groups. Conclusion: This study suggested that the subantimicrobial dose of doxycycline as an adjunct therapy with scaling and root planing might be effective and safe in the management of chronic periodontitis.

• Journal of electromagnetic engineering and science
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• 제14권3호
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• pp.267-272
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• 2014

Hyperthermia is a form of cancer treatment in which affected human tissue is exposed to $>40^{\circ}C$ temperature. In this paper, our goal is to assess the efficacy of fullerene agents to reduce heating time for cancer treatment. Such agents can accelerate heating of cancer cells and improve hyperthermia treatment efficacy. Typically, in vitro testing involves cancer cell culturing, heating cell cultures in accordance to specifications, and recording cancer cell viability after hyperthermia. To heat cell cultures, we design and evaluate a 2.4-GHz microwave cavity with controllable temperature. The cavity is comprised of a polystyrene cell culture dish (diameter = 54 mm, height = 13.5 mm) and a printed monopole antenna placed within the cavity for microwave heating. The culture temperature can be controlled through the intensity and duration of the antenna's microwave radiation. Heating experiments were carried out to validate the cavity's performance for F-12K culture medium (Kaighn's F-12K medium, ATCC). Importantly, fullerene agents were shown to reduce heating time and improve hyperthermia treatment efficacy. The culture medium temperature increased, on average, from $24.0^{\circ}C$ to $50.9^{\circ}C$ (without fullerene) and from $24.0^{\circ}C$ to $56.8^{\circ}C$ (with 3 mg/mL fullerene) within 15 minutes.

• 한국환경보건학회지
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• 제22권4호
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• pp.25-32
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• 1996

The Bioconcentration factor(BCF) is used as an important criterion in the risk assessment of environmental contaminants. Also it can be used as indicator of biomagnification of environmentally hazardous chemicals through food-chain as well as a tool for ranking the bioconcentration potential of the chemicals in the environment. This paper reports the measured BCF value on carbofuran in Carassius auratus(goldfish), under steady state, and examined corelation between the BCF value and the depuration rate constant. Carassius auratus(goldfish) was chosen as test organism and test periods were 1-day, 3-day and 5-day. Experimental concentrations were 0.05, 0.10 and 0.50 ppm. Carbofuran in fish tissue and in test water was extracted with n-hexane and acetonitril. GC-ECD was used to detect and quantitate carbofuran. The depuration rate of carbofuran from the whole body of goldfish is determined over the 24-h period after treatment. The obtained results were as follows: 1. It was possible to determine short term BCFs of carbofuran through relatively simple procedure in environmental concentrations. 2. $BCF_1$ of carbofuran in concentration of 0.05, 0.10 and 0.50 ppm were 1.66, 1.64 0.61, $BCF_3$ were 2.08, 2.14, 0.66 and $BCF_5$ were 2.21, 2.57, 0.86, respectively. 3. Carbofuran concentration in fish extract was increased as increasing test concentration and prolonging test period, but $BCF_s$ in concentration of 0.50 ppm was greately decreased. 4. Determined deputation rate constants of carbofuran in concentration of 0.05, 0.10, 0.50 ppm were 0.076, 0.082 and 0.089, respectively. 5. It is considered that great decrease of $BCF_s$ in concentration of 0.50 ppm is due to high water solubility and stability of carbofuran in testwater. 6. It is suggested that low BCF of carbofuran is due to its relatively high water solubility and depuration rate, compared to BPMC, carbaryl and chlorothalonil.

• 한국정보과학회논문지:소프트웨어및응용
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• 제31권4호
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• pp.525-536
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• 2004

유전발현 데이타는 생명체의 특정 조직에서 채취한 샘플을 microarray상에서 측정한 것으로, 유전자들의 발현 정도가 수치로 나타난 데이타이다. 일반적으로 정상조직과 이상조직에서 관련 유전자들의 발현정도는 차이를 보이기 때문에, 유전발현 데이타를 통하여 질병을 분류할 수 있다. 이러한 분류에 모든 유전자들이 관여하지는 않으므로 관련 유전자를 선별하는 작업인 특징선택이 필요하며, 선택된 유전자들을 적절히 분류하는 방법이 필요하다. 본 논문에서는 상관계수, 유사도, 정보이론 등에 기반을 둔 7가지 특징선택 방법과 대표적인 6가지 분류기에 대하여 특징-분류기 쌍의 최적 앙상블을 탐색하기 위한 유전자 알고리즘 기반 방법을 제안한다. 두 가지 암 관련 유전자 발현 데이타에 대하여 leave-one-out cross validation을 포함한 실험을 해본 결과, 림프종 데이타와 대장암 데이타 모두 단일 특징-분류기 쌍보다 훨씬 우수한 성능을 보이는 앙상블들을 발견할 수 있었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권12호
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• pp.545-552
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• 2003

When a Si PIN diode is exposed to fast neutrons, it results in displacement damage to the Si lattice structure of the diode. Defects induced from structural dislocation become effective recombination centers for carriers which pass through the base of a PIN diode. Hence, increasing the resistivity of the diode decreases the current for the applied forward voltage. This paper involves the development of a neutron sensor based on the phenomena of the displacement effect damaged by neutron exposure. The neutron effect on the semiconductor was analyzed. Several PIN diode arrays with various thickness and cross-section area of the intrinsic layer(I layer) were fabricated. Under irradiation tests with a neutron beam, the manufactured diodes have a good linearity to neutron dose and show that the increase of thickness of I layer and the decrease of cross-section of PIN diodes improve the sensitivity. Newly developed PIN diodes with thicker I layer and various cross section, were retested and then showed the best neutron sensitivity at the condition that the I layer thickness was similar to a side length. On the basis of two test results, final discrete PIN diodes with a rectangular shape were manufactured and the characteristics as neutron detectors were analyzed through the neutron beam test using on-line electronic dosimetry system. Developed PIN diode shows a good linearity as dosimetry in the range of 0 to 1,000cGy(Tissue) and its neutron sensitivity is 13mV/cGy at constant current of 5mA, that is three times higher than that of commercially available neutron detectors. And the device shows little dependency on the orientation of the neutron beam and a considerable stability in annealing test for a long period.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권5호
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• pp.551-555
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• 2010

단백질 2-DE 이미지 분석에서 단백질 자체가 가지고 있는 불안정성과 2-DE 실험이 가지고 있는 근본적인 문제점으로 인하여 이미지 스팟 매칭 분석의 정확도가 낮아지게 된다. 이 논문에서는 다중 참조이미지를 사용하여, 스팟 매칭 패턴의 정확도에 큰 영향을 주는 이미지 찌그러짐을 보완하고, 그에 따른 노이즈 스팟 제거와 참조 이미지 품질에 의한 정확도 저하를 최소화하는 방법을 제안하였다. 또한 2-DE 이미지의 데이터 특성에 의하여 이미지 수가 증가할 때 성능이 급격히 떨어지는 문제를 해결하기 위하여, 다중 참조이미지를 사용하여 구축한 스팟 매칭 데이터베이스를 이미지의 생물학적 특성에 의하여 "분할 및 확장" 방법을 사용하여, 정확도를 향상시키는 동시에 패턴 길이를 보장하는 스팟 매칭 패턴을 효과적으로 생성하였다. 실험에서는 실제 인간 2-DE 이미지 데이터를 사용하여 제안한 방법의 타당성을 보여준다.

• 한국산학기술학회논문지
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• 제12권4호
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• pp.1770-1774
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• 2011

본 논문은 리포포린에 의해 디아실글리세리드(DAG)가 Manduca sexta 유충 지방체로 운반되는 과정을 조사하였다. $[^3H]$-DAG 표지 리포포린($[^3H]$-DAG-Lp)을 시간별로 유충 지방체와 배양하여 지방체로 운반되는 DAG의 방사능을 결정하였다. $[^3H]$-DAG-Lp와 지방체를 배양하면 지방체에 DAG가 축적되며 이의 일부는 지방체에서 트리아실글리세리드(TAG)로 전환되는 것을 알 수 있었다. Suramin과 표지되지 않은 리포포린(unlabeled Lp)의 존재 하에서는 지방체로 운반되는 DAG가 억제되는 데, 이는 DAG를 운반하는 데 리포포린 수용체가 관여한다는 사실을 알 수 있었다. Suramin의 효과는 다소 복잡하지만 리포포린 수용체에 결합하여 막의 특성을 변화시켜 DAG 운반속도에 영향을 주는 것 같다. 지질 운반과정이 수용체-매개 내포작용이라는 사실을 조사하기 위하여 내포작용 억제자인 ammonium chloride와 chloroquine을 처리하였다. 그 결과 리포포린과 지방체사이에서의 지질 운반 기작이 수용체-매개 과정이라는 사실을 보여준다.

• 정보처리학회논문지D
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• 제15D권5호
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• pp.681-690
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• 2008

단백질체학에서 특정 조건 하에서 단백질의 기능 이상 및 구조 변형 유무를 규명하고 질병 과정을 추적하는 것은 중요한 연구이다. 일반적으로 단백질의 발현량 변화 분석에는 통계적 방법이 많이 사용되고 있으며 단백질 상용 이미지 분석 소프트웨어에서 제공하는 그래픽을 이용한 방법들도 있으나, 이 방법들은 많은 조직 내에 존재하는 수많은 단백질을 수동으로 비교해야 하는 어려움이 있다. 본 논문에서는 데이터베이스와 데이터마이닝 기법을 이용하여 OLAP 데이터 큐브와 Discovery-driven 탐색의 응용 방법을 제안한다. 데이터 큐브의 특성을 이용함에 의해서, 질병에 의해 발현량이 변하는 단백질 뿐 아니라 임상적 특성과 단백질의 영향 관계를 분석하는 것이 가능하다. 데이터 큐브에서 단백질의 발현량 변화 분석에 적합한 데이터 큐브의 척도와Discovery-driven 탐색을 위한 예외 지표를 제안하고, 특히 In-exception을 계산하는데 있어서의 계산량 감소 방안을 제시한다. 실험을 통해 폐암 2-DE 데이터에서 데이터 큐브와 Discovery-driven 방법이 유용함을 보인다.

• 대한방사선기술학회지:방사선기술과학
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• 제40권4호
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• pp.621-626
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• 2017

본 논문에서는 방사선치료 시 용적 선량 평가에 응용할 수 있는 광 도시메트리 시스템을 구축하고 100 MeV 고선속 양성자 빔에 대한 특성 평가를 수행하였다. 광 도시메트리 시스템은 액체 유기 섬광체와 카메라 렌즈, 고감도 저잡음 화상(complementary metal-oxide-semiconductor; CMOS) 카메라로 구성되며, 2 m 거리에 영상의 화각(field of view; FOV)이 15 cm가 되도록 설계 및 제작하였다. 구축된 광 도시메트리 시스템은 100 MeV 양성자 빔에 대하여 1~40 Gy 선량 범위에서 선량-출력의 직선성을 확인하였으며, 심부선량백분율 데이터와 등선량 곡선을 획득하였다. 본 연구에서는 용매의 인체조직등가성에 제한점이 있지만 광 도시메트리 절차를 확립하였으며, 새로운 용적 선량 평가법의 제안으로 그 의미가 있다.