• 한국산학기술학회논문지
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• 제11권6호
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• pp.2240-2245
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• 2010

심근영상의 SPECT(Single Photon Emission Computed tomography)검사는 감마선을 방출하는 방사성의약품을 환자에게 정맥주사한 후 이 의약품이 심장에 고루 퍼지면 관심부위를 촬영하여 질병으로 인한 변화를 컴퓨터를 이용하여 진단하는 검사법이다. 기능적인 정보를 담고 있는 심근관류 영상은 비침습적인 심근질환 검사에 유용한 방법이지만, 물리적 인자들에 의해 잡음과 낮은 해상도는 판도하는데 어려움을 주게 된다. 본 논문은 심근영상을 레벨 셋 알고리즘을 이용하여 영상을 분할하고 분할된 영역을 3차원으로 구현하여 판독에 도움을 주는 방안을 제안하였다. 판독의 어려움을 해결하기 위하여 레벨 셋을 이용하여 관심부위인 좌심실 영역을 분할하였고 분할된 영역을 3차원영상으로 모델링 하였다.

• 미생물학회지
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• 제19권3호
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• pp.128-136
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• 1981

In order to investigate early identification of species of the wood-decaying fungi in the the mycelial stage, the authors isolated of 41 species, 28 genus, 9 family at 8 locations in Korea and cultivated these isolates on the various kinds of solid media. After investigating such cultural characteristics as oxidase reactions with tannic and gallic acid, various morphological features of colony and growth grade, appeared on the various media, the authors obtained the following results : 1. The oxidase reactions with tannic and gallic acid in the PDTA, DTA, PDGA and DGA media are available for identificantion of the wood-decaying fungi. 2. The oxidase reactions with guaiacol, pyrogallol and hydroquinone in the PDGUA, PDPA and PDHA media are not so much available for identification of the wood-decaying fungi. 3. Morphological features of colonies such as mycelium color, floccose, floccose-powdery, mycelloid, powdery-mycelloid, velvet, radiate, contoured, rosulate and growth grade on the PDA, PSA and PXA media are useful for identification of wood-decaying fungi. 4. It is believed that early identification in species level of wood-decaying fungi using cultural characteristics in the mycelial stage is possible. 5. The key for the identification of 41 species of wood-decaying fungi is proposed by the cultural characteristics using several solid media.

• Nuclear Engineering and Technology
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• 제37권3호
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• pp.245-258
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• 2005

This paper addresses two types of uncertainty: stochastic uncertainty and subjective uncertainty in probabilistic accident consequence assessments. The off-site consequence assessment code OSCAAR has been applied to uncertainty and sensitivity analyses on the individual risks of early fatality and latent cancer fatality in the population outside the plant boundary due to a severe accident. A new stratified meteorological sampling scheme was successfully implemented into the trajectory model for atmospheric dispersion and the statistical variability of the probability distributions of the consequence was examined. A total of 65 uncertain input parameters was considered and 128 runs of OSCAAR with 144 meteorological sequences were performed in the parameter uncertainty analysis. The study provided the range of uncertainty for the expected values of individual risks of early and latent cancer fatality close to the site. In the sensitivity analyses, the correlation/regression measures were useful for identifying those input parameters whose uncertainty makes an important contribution to the overall uncertainty for the consequence. This could provide valuable insights into areas for further research aiming at reducing the uncertainties.

• Journal of Nutrition and Health
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• 제37권9호
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• pp.801-808
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• 2004

Benign prostatic hyperplasia (BPH) is the most common prostate disease in middle aged and elderly men. Therefore, identifying risk factors for BPH is crucial for understanding the etiology and for undertaking interventions or targeting strategies. The survey was carried out in two steps: first, pilot study was conducted prior to the main study in order to estimate baseline characteristics. Second, main study investigated prevalence and risk factors of BPH by clinical diagnostic tests and questionnaire. A total of 641 male aged 50-79 years participated in this community-based cross-sectional study. Using 24 hour recall of food consumption, we found that animal fat intakes increased the risk of BPH with adjusted for age, chronic bronchitis, PSA level, drinking frequency, and excercise frequency (odds ratio 1.84,95% confidence interval 1.10-3.06) . Although BPH has been considered as unavoidable disease with advancing age, if these dietary risk factors are clearly identified, it can be prevented effectively by laying special emphasis on those at risk.

• 펄프종이기술
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• 제37권3호
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• pp.1-8
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• 2005

Increase in the utilization rate of recycled paper and closing level of papermaking system increased the problem associated with stickies that include decrease in process runnability and product quality. It is required to establish a process for removing the micro stickies to solve the problems associated with stickies. In this study, the application of flotation process as a method to remove micro stickies was examined. Model micro stickies (MMS) were prepared using microcrystalline cellulose (MCC) and pressure sensitive adhesives (PSA), and the influence of three nonionic surfactants on the removal efficiency of MMS from flotation process was examined. Also the effect of surfactants on the deposition of micro stickies that remaining in the papermaking wet end onto wire was examined. Removal efficiency of MMS by flotation was increased when the proportion of nonionic surfactant with propylene oxide (PO) type hydrophilic tail was increased and stock pH was 7. It was suggested that this nonionic surfactant minimized the increase of surface energy of hydrophobic MMS. The MMS with high hydrophobicity remaining in the papermaking system, however, would cause more serious deposition problems on papermaking wet end. Therefore, it is of great importance to increase the removal efficiency of MMS in flotation process for the prevention of papermaking system contamination caused by stickies deposition.

• Nuclear Engineering and Technology
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• 제48권3호
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• pp.684-701
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• 2016

The Gaussian process model (GPM) is a flexible surrogate model that can be used for nonparametric regression for multivariate problems. A unique feature of the GPM is that a prediction variance is automatically provided with the regression function. In this paper, we estimate the safety margin of a nuclear power plant by performing regression on the output of best-estimate simulations of a large-break loss-of-coolant accident with sampling of safety system configuration, sequence timing, technical specifications, and thermal hydraulic parameter uncertainties. The key aspect of our approach is that the GPM regression is only performed on the dominant input variables, the safety injection flow rate and the delay time for AC powered pumps to start representing sequence timing uncertainty, providing a predictive model for the peak clad temperature during a reflood phase. Other uncertainties are interpreted as contributors to the measurement noise of the code output and are implicitly treated in the GPM in the noise variance term, providing local uncertainty bounds for the peak clad temperature. We discuss the applicability of the foregoing method to reduce the use of conservative assumptions in best estimate plus uncertainty (BEPU) and Level 1 probabilistic safety assessment (PSA) success criteria definitions while dealing with a large number of uncertainties.

• 한국안전학회지
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• 제26권5호
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• pp.99-104
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• 2011

An ILRT Interval for a nuclear power plant in Korea was extended from once in five years to once in ten years. Therefore, it is necessary to evaluate risk impact for ILRT interval extensions. In this paper, input data were generated for the reference plants, KSNP, using raw data such as meteorological data, population distribution data and source term data. And, using MACCS II code the risk impact assessment was performed based on the two methodologies of NUREG-1493 and NEI Interim Report. The risk impact derived from an ILRT interval extension was identified not to be significant. It is considered to apply this study and results to making an accident management plan and safety goal, and to the field of public acceptance.

• 한국초지조사료학회지
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• 제22권1호
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• pp.51-58
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• 2002

식물의 광합성에 관여하는 광계 I의 protein subunit들의 연구는 최근까지도 극히 미약한 실정이며, 각각의 subunit들의 특성 또한 일부만이 밝혀져 있다. 본 연구진은 배추의 cDNA library로부터 식물에만 존재하는 subunit 중의 하나인, PSI-H subunit을 암호화하는 유전자인 bpsaH를 분리하였다. 이 유전자는 총 633 bp의 염기로 구성되어 있으며, 염기서열로부터 추정되는 분자량은 약 15,400이었고 등전점은 9.91이었다. 배추 PSI-H subunit의 아미노산 서열을 다른 식물체 유래의 단백질들과 비교분석한 결과, 시금치의 PSI-H와 가장 높은 유사성 (79.3%)을 나타내었다. 또한 bpsaH의 조직 특이적 발현 양상을 조사한 결과, 광합성 조직인 잎에서는 강하게 발현된 반면 꽃봉우리에서는 약하게 발현되었으며, 비광합성 조직인 뿌리에서는 전혀 발현되지 않았다.

• Journal of Korean Medical Science
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• 제33권47호
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• pp.303.1-303.10
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• 2018

Background: Cell division cycle 6 (CDC6) is an essential regulator of DNA replication and plays important roles in the activation and maintenance of the checkpoint mechanisms in the cell cycle. CDC6 has been associated with oncogenic activities in human cancers; however, the clinical significance of CDC6 in prostate cancer (PCa) remains unclear. Therefore, we investigated whether the CDC6 mRNA expression level is a diagnostic and prognostic marker in PCa. Methods: The study subjects included 121 PCa patients and 66 age-matched benign prostatic hyperplasia (BPH) patients. CDC6 expression was evaluated using real-time polymerase chain reaction and immunohistochemical (IH) staining, and then compared according to the clinicopathological characteristics of PCa. Results: CDC6 mRNA expression was significantly higher in PCa tissues than in BPH control tissues (P = 0.005). In addition, CDC6 expression was significantly higher in patients with elevated prostate-specific antigen (PSA) levels (> 20 ng/mL), a high Gleason score, and advanced stage than in those with low PSA levels, a low Gleason score, and earlier stage, respectively. Multivariate logistic regression analysis showed that high expression of CDC6 was significantly associated with advanced stage (${\geq}T3b$) (odds ratio [OR], 3.005; confidence interval [CI], 1.212-7.450; P = 0.018) and metastasis (OR, 4.192; CI, 1.079-16.286; P = 0.038). Intense IH staining for CDC6 was significantly associated with a high Gleason score and advanced tumor stage including lymph node metastasis stage (linear-by-linear association, P = 0.044 and P = 0.003, respectively). Conclusion: CDC6 expression is associated with aggressive clinicopathological characteristics in PCa. CDC6 may be a potential diagnostic and prognostic marker in PCa patients.

• 접착 및 계면
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• 제24권3호
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• pp.77-85
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• 2023

본 연구에서는 연속교반탱크반응기(CSTR)를 이용하여 다양한 분자량과 산가의 고분자 음이온 유화제를 합성하였다. CSTR은 회분식 및 반회분식 반응기에 비해 생산 속도가 빠르고 제품 특성이 더 일정하다는 장점이 있다. 고분자 유화제는 소수성 그룹으로 부틸 아크릴레이트를 사용하고 친수성 그룹으로 아크릴산을 공중합하여 제조되었다. 합성된 고분자 유화제는 알칼리 수용액을 통해 이온화하여 음이온성 유화제로 사용하였다. 제조된 고분자 유화제의 유화물성을 알아보기 위해 산가, 임계미셀농도(CMC), 분자량 등의 물성을 측정하였다. 이 결과 고분자 유화제의 산가는 60~380, 수 평균 분자량은 8,000~13,000 g/mol이었다. 또한 CMC는 0.01 g/ml로 상용 유화제와 비슷한 값을 나타내었다. 제조된 고분자 유화제의 유화성능을 알아보기 위해 아크릴계 에멀젼 점착제를 합성하여 점착물성을 측정하였다. 이때 고분자 유화제의 산가 150과 분자량 8,500 g/mol일 때 최대 박리강도 21.24 N/25mm를 나타내었다. 이 값은 상용 음이온 유화제인 SDS (Sodium Dodecyl Sulfate)혹은 상용 음이온/비이온 유화제 조합인SDS/TRX(Triton X-100) 조합을 사용한 점착제보다 더욱 우수한 점착 특성을 보였다.