• Journal of Periodontal and Implant Science
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• 제27권2호
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• pp.291-303
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• 1997

Periodontal ligament cells may have a role in the regulation of hard and soft periodontal tissues, but their specific function has not yet to be determined. To evaluate further their role in periodontal regeneration, they were examined for osteoblast-like behavior. Periodontal ligament cells and gingival fibroblasts were primarily cultured from extracted premolar with non-periodontal diseases. Cells were cultured with DMEM at $37^{\circ}C$, 5% $CO_2$, 100% humidity incubator, and as a measure of cell characterization, it was examined that the morphology, alkaline phosphatase activity, collagen synthesis, and immunocytochemistry for osteonectin, osteocalcin, and collagen type I. Healthy periodontal ligament cells has more osteoblastic-like cell property in alkaline phosphatase activity. and collagen synthesis than gingival fibroblast. Immunocytochemistry localization explained that calcitonin were expressed in periodontal ligament cells only, and osteonectin and type I collagen were produced in both cells simultaneously. This results indicate that the growth characteristics of periodontal ligament cells and gingival fibroblasts exhibit some differences in proliferative rates and biochemical synthesis. The differences may help to calrify the role such cells play in the regenearation of periodontal tissues.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.110-115
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• 2014

The nuclear power plant was launched by Kori unit 1 in 1978 years. Currently, 23 nuclear power plants have been operating in Korea since 1978 years. The localization was completed for most of the reactor facility from Hanbit(Youngkwang) unit 3&4. However, RCP(Reactor Coolant Pump) and MMIS(Man Machine Interface System) is an important technology that has been excluded from the scope of the technical transfer has been dependent on a specific overseas vendor. Recent success in RCP development through co-operation with government and industries. Developed RCP will be applied to Shin-Hanul unit 1&2 nuclear power plants. The RCP operates in high speed and high pressure condition and only rotating component in the NSSS(Nuclear Steam Supply System). Therefore, the problem of vibration has arisen caused by the hydraulic forces of the working fluid. These forces can influence on the stability characteristics for entire RCS(Reactor Coolant System) loop, and can act as significant destabilizing forces. In this study, vibration evaluation of the pump shaft of development RCP estimated under normal operation and over speed conditions. In order to predict the vibration characteristics and dynamic behavior, modal analysis, critical speed analysis and unbalance response spectrum analysis were performed.

• 한국시뮬레이션학회논문지
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• 제26권1호
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• pp.39-46
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• 2017

은밀하게 침투하여 아군의 핵심자산으로 접근하는 표적 잠수함을 상시 감시하기 위하여 수중 해저면 위치에 최적의 고정형 수동탐지소나를 배치하는 것을 고려 할 수 있다. 수동탐지소나 배치 최적화를 위한 효과도 지수는 넓은 탐지영역과 위치추정가능성의 함수로 적용할 수 있는데 계절적인 요인, 해상상태, 표적 잠수함의 침투심도 등의 다양한 확률적 변이를 포함하고 있어서 효과도지수가 배치의 입력에 대하여 확률적으로 나타나는 특성을 갖는다. 본 논문에서는 다양한 파라메타의 입력조건에 대하여 확률적인 출력을 갖는 수동탐지소나의 배치에 대한 최적화 문제를 정의하였으며, DPSO(Discrete binary version of PSO) 방법을 사용하여 최적 배치 안을 도출하기 위한 모의기반의 절차를 제시하고 고찰하였다.

• 한국지반공학회논문집
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• 제32권3호
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• pp.49-60
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• 2016

일반적으로 흙의 파괴는 전단 변형이 집중되는 영역인 전단면의 형성과 발달에 의해 발생한다. 정규압밀 점성토의 파괴거동을 확인하기 위해 시료 내부의 변형거동 분포에 대해 평가가 필요하다. 본 연구에선 재성형된 카올리나이트 시료에 대해 평면변형률 시험을 수행하였으며, 전단 과정에서 일정 변형률 간격에서 디지털 이미지 해석을 수행하였다. 시험 결과로 도출된 응력-변형률 결과를 통해 4개의 단계를 결정하여 시료의 변형거동과 전단면 특성을 평가하였다.

• 전기학회논문지P
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• 제61권4호
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• pp.180-185
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• 2012

Tidal power is one of new and renewable energy sources. The seawater is stored inside a tidal embankment built at the mouth of a river or bay, where tides ebb and flow. The water turbine-generators produce power by exploiting the gap in the water level between the water outside and inside the embankment. Tidal power plant is a large plant that is installed on the sea. And then, the facility's operations and a separate control system for monitoring and maintenance is required. However, this plant predictive control of building systems and technologies have been avoided the transfer of technology from advanced global companies. Accordingly, the control system for core technology development and localization is urgently needed. This paper presents modeling and simulation using by PSS/E about generator, governor, exciter, and power system stabilizer for control system in Sihwa tidal power plant to improve the efficiency and develope of core technology. And the dynamic characteristics of governor and exciter were analyzed.

• 대한원격탐사학회지
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• 제19권1호
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• pp.61-70
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• 2003

This paper proposes an autonomous approach to localize the center of fiducial marks included in aerial photographs without precise geometric information and human interactions. For this localization, we present a conceptual model based on two assumptions representing symmetric characteristics of fiducial area and fiducial mark. The model makes it possible to locate exact center of a fiducial mark by checking the symmetric characteristics of pixel value distribution around the mark. The proposed approach is composed of three steps: (a) determining the symmetric center of fiducial area, (b) finding the center of a fiducial mark with unit pixel accuracy, and finally (c) localizing the exact center up to sub-pixel accuracy. The symmetric center of the mark is calculated tv successively applying three geometric filters: simplified ${\nabla}^2$G (Laplacian of Gaussian) filter, symmetry enhancement filter, and high pass filter. By introducing a self-diagnosis function based on the self-similarity measurement, a way of rejecting unreliable cases of center calculation is proposed, as well. The experiments were done with respect to 284 samples of fiducial marks composed of RMK- and RC-style ones extracted from 51 scanned aerial photographs. It was evaluated in the visual inspection that the proposed approach had resulted the erroneous identification with respect to only one mark. Although the proposed approach is based on weak constraints, being free from the exact geometric model of the fiducial marks, experimental results showed that the proposed approach is sufficiently robust and reliable.

• Journal of Electrochemical Science and Technology
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• 제15권2호
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• pp.220-241
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• 2024

Due to its unique advantages, electrochemical machining (ECM) is playing an increasingly significant role in the manufacture of difficult-to-machine materials. Most of the current ECM research is conducted at room temperature, with studies on ECM in a cryogenic environment not having been reported to date. This study is focused on the electrochemical dissolution characteristics of typical iron and nickel base alloys in NaNO₃ solution at low temperature (-10℃). The polarization behaviors and passive film properties were studied by various electrochemical test methods. The results indicated that a higher voltage is required for decomposition and more pronounced pitting of their structures occurs in the passive zone in a cryogenic environment. A more in-depth study of the composition and structure of the passive films by X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy showed that the passive films of the alloys are modified at low temperature, and their capacitance characteristics are more prominent, which makes corrosion of the alloys more likely to occur uniformly. These modified passive films have a huge impact on the surface morphologies of the alloys, with non-uniform corrosion suppressed and an improvement in their surface finish, indicating that lowering the temperature improves the localization of ECM. Together with the cryogenic impact of electron energy state compression, the accuracy of ECM can be further improved.

• 문화기술의 융합
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• 제7권1호
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• pp.377-382
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• 2021

《牧羊哀話, 목양애화》는 중국현대문학사상 최초의 한인제재 소설로 알려져 있으며, 저자가 직접 한국을 방문하고 영감을 얻어 창작한 소설로 유명하다. 《목양애화(牧羊哀話)》의 번역본은 꾸준히 재번역(4종)되고 있다. 이러한 번역본은 시기별 특성도 반영하고 있으며, 활용한 번역 전략도 각기의 특징을 가지고 있다. 본 연구를 통해 4종의 번역본을 비교 분석한 결과는 다음과 같다. A역은 일제시기 출판된 작품으로 검열을 피하기 위해서 역자의 의도에 따라 일정부분이 축소, 생략되었으며 이국화 번역 전략을 사용하였다. B역, C역, D역은 많은 부분 자국화 번역 전략을 활용하여 내용적 등가를 구현해 내었으며, 독자의 이해를 돕기 위해서 부분적으로 보충설명을 덧붙여 놓았다. 번역은 의사소통의 과정이므로 단순히 원천 텍스트를 목표 텍스트로의 전환하는 것이 아니라, 작품에 대한 목표어 독자들의 반응이 출발어 독자들의 반응과 같아야만 한다. 때문에 번역은 시대 환경과 독자층을 감안해야만하며, 가능한 모든 방법을 동원하여 독자로 하여금 원문을 읽은 것과 같은 감동과 공감을 이끌어내야 한다. 그러므로 번역자는 목표어와 도착어 국가의 정치, 경제, 역사, 문화 등에 대한 이해를 바탕으로 자(이)국화 전략은 동시에 적절히 활용할 필요가 있다.

• 한국실내디자인학회논문집
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• 제20권6호
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• pp.262-271
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• 2011

The purpose of this study was to classify types of family visitors' behaviors more concretely, which could be useful in planning of exhibition spaces in a science museum, with given priority to their behaviors according to interaction between them, and to understand characteristics of the behaviors. With this view, the scope of this study was restricted to subjects, who were family visitors of Gwacheon National Science Museum, consisting of parents and their one elementary school child per family unit. For understanding their behaviors, itinerary tracking and observation method of behavior were conducted. Moreover, for understanding substantial types and characteristics of family visitors' behaviors, multivariate analysis was applied. Accordingly, the results of the study are as follows. First, as a result of factor analysis, two main factors were derived. In other words, they were 'Durability of viewing' as the first and 'Interactivity between family members' as the second, which were shown valid in classification of the types of their behaviors. Second, according to the factors derived, the types of their behaviors were classified into in-depth cooperative viewing, selective independent viewing, interest concentration child-led viewing and consideration parent-led viewing. They were shown valid in topological localization and classification, as a result of analysis of the main factors. Third, in view of common characteristics of the types, it is judged that active orientation prior to regular viewing could encourage visitors coming to the museum for the first time to feel more friendly to unfamiliar exhibition environments, during the initial seek time, and to reduce visual supersaturation. Fourth, it is judged that distributed arrangement of exhibits, which result in continuous standby, could avoid confused visitor circulation by the estimated time required for viewing.

• Asian Pacific Journal of Cancer Prevention
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• 제17권5호
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• pp.2679-2681
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• 2016

Background: Gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NEN) are relatively rare tumors, not equally distributed in gastro-intestinal system. In 2010, a revised version of the WHO classification of GEP-NENs was published. This study reports for the first time the distribution and characteristics of GEP-NEN in a Lebanese population. Materials and Methods: This descriptive retrospective study concerns all the digestive neuroendocrine tumors with their characteristics diagnosed in $H\hat{o}tel$ Dieu de France in Beirut, Lebanon from 2001 to 2012, all the pathology reports being reanalyzed according to the latest WHO 2010 classification. The characteristics and features of GEP-NEN analyzed in this study were age, gender, grade and site. Results: A total of 89 GEP-NENs were diagnosed, representing 28.2% of all neuroendocrine tumors. The mean age of GEP-NEN patients was 58.7 years and the M/F sex ratio was 1.2. The primary localization was as follows: 21.3%(19) pancreatic, 18% (16) gastric, 15.7% (14) duodenal, 11.2% (10) appendix, 10.1% (9) intestinal, 10.1% (9) colorectal (7.9% colonic and 2.2% rectal), 5.6% (4) hepatic, 2.2% (2) ampulla, 1.1% (1) esophageal and 7.9%(5) NOS digestive (metastatic with unknown primary). Of the 89 patients with GEP-NEN, 56.2% (50) were diagnosed as grade I, 11.2% (10) as grade II, 20.2% (18) as grade III and 12.4% (11) were considered as mixed adeno-neuroendocrine carcinomas (MANEC). Conclusions: This study, one of the rare examples based on the 2010 WHO classification of neuroendocrine tumors in the literature, indicates that in the Lebanese population, all duodenal and appendicular tumors are G1 and the majority of MANEC tumors are gastric and pancreatic tumors. Moreover, more duodenal tumors and fewer rectal tumors were encountered in our study compared to European reports.