• Journal of The Korean Association For Science Education
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• v.36 no.3
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• pp.423-434
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• 2016

The purpose of this study is to investigate preservice earth science teachers' mental models through applications of Coriolis force experiment apparatus. After the root of preconception was examined by face to face interviews based on the questionnaire, five preservice earth science teachers were finally selected for this study. The mental models about concept of Coriolis force was classified into naive mental model, static unstable mental model, dynamic unstable mental model, and scientific mental model through the result of individual interviews and their drawings. According to the mental model analysis about Coriolis' force conception, students C and M showed naive mental model about concept of Coriolis force before experiment. After the experiment, student M's model changed to static unstable mental model. Student C's model improved to dynamic unstable mental model. In adiition, students D and O's model improved from static unstable mental model to dynamic unstable mental model. In the case of student B, the dynamic unstable mental model was maintained after the experiment, however, student B's preconception changed to scientific concept. It turned out that a change occurred from low mental model level to integrated mental model after the application of the developed Coriolis' force experiment apparatus. According to the results, national curriculum is similar to static unstable mental model and the result of developed Coriolis' force experiment apparatus is similar to dynamic unstable mental model. It is suggested that it become the theoretical foundation to develop more comfortable and advanced Coriolis force experiment apparatus by improving the experiment apparatus.

• Journal of Environmental Impact Assessment
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• v.12 no.5
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• pp.383-393
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• 2003

IPCC(Intergovernmental Panel on Climate Change)는 향후 100년 동안 지구의 평균기온이 $1^{\circ}C$에서 $3.5^{\circ}C$ 상승할 경우, 각 기후대가 극방향으로 약 150~550km 이동할 것으로 예측하고 있으나, 과거 기후변동 연구결과들은 삼림의 이동속도를 100년간 4~200km로 추정하고 있어 식생이 기후대의 이동을 따라가지 못하여 사멸되는 지역이 발생할 것으로 예측되고 있다. 약 960km의 남북으로 긴 지형적 특성을 가진 한반도 역시 이러한 영향을 벗어나지 못할 것으로 예측되고 있어 기존의 기후변화 시나리오와 함께 삼림의 이동성을 고려한 영향연구가 요구된다. 본 연구는 IPCC의 새로운 기후변화 시나리오인 SRES 시나리오의 대기대순환모형(Global Climate Model, GCM) 결과와 AIM(Asia Integrated Model)/Impact[Korea] 모형을 이용하여 제작된 Holdridge 생물기후분류의 연구성과를 이용하여, CO2농도 배증시의 한반도지역의 자연식생 영향과 적응 가능성을 삼림의 이동성을 고려하여 평가하였다. 삼림의 이동속도를 0.25, 0.5, 1.0, 2.0(km/yr)로 변화시키며 2100년 한반도 자연식생의 기후 변화 영향을 평가한 결과, (1) 목본식물의 이동속도가 년간 1km 이상일 경우 삼림 피해가 미미하게 나타났으나 (2) 이동이 느린 0.25km/yr의 경우, 생육위험지역을 포함한 시나리오별 전체 피해규모는 A2(17.47%), A1(9.97%), B1(6.21%), B2(5.08%) 순으로 나타났으며, 삼림소멸의 경우는 A2, B2 시나리오에서 발생하며 A2 시나리오에서 한반도의 약 2.1%로 가장 크게 발생하였다. (3) 전반적인 생육위험 지역의 분포는 함흥만, 영흥만의 동해안지역에 집중되었으며, A2 시나리오의 극단적 소멸예상지역은 금오산, 가야산, 팔공산을 연결하는 지역에서 발생하는 것으로 나타났다.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.2
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• pp.343-350
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• 2009

This study aimed to evaluate the anti-asthmatic effects of Samjajihwang-tang (SJT) using OVA-induced asthmatic mice model. Asthmatic mice model was conducted by repeated challenge of OVA using C57BL/6 mice. Each group was treated with distilled water, SJT (400 mg/kg and 200 mg/kg) extract or cyclosporin A (10 mg/kg) for the later 8 weeks, Penh (plethysmography and enhanced pause), immune cells subpopulation, eotaxin, IL-5, TNF-${\alpha}$, Anti-OVA-lgE in BALF (bronchoalveolar lavage), and lung tissue was analyzed, No cytotoxicity of SJT was shown on hFCs (human fibroblast cells). Administration of SJT significantly decreased Penh levels comparing to control group. SJT treatment significantly ameliorated the increase of total cells number and eosinophil including of immune cell subpopulation of $CD3^+/CD69^+$, $CCR3^+$, $B220^+/CD22^+$, $B220^+/CD45^+$, and $B220^+/lgE^+$ cells in BALF comparing to control group. Eotaxin, IL-5, TNF-${\alpha}$, and Anti-OVA-lgE level in BALF were significantly decreased by SJT treatment too. Histopathological finding verified the improvement of infiltration of inflammatory cells and collagen tissue in the SJT groups comparing to control group. These results strongly suggest that SJT would be a effective candidate for herbal-originated anti-asthmatic drug. However, this drug should be further studied for characterization of the accurate action and underlying mechanisms using variant disease model in the future.

• The KIPS Transactions:PartB
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• v.12B no.3 s.99
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• pp.265-272
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• 2005

In this paper, we propose a technique which is speedily searching for correspondent points of two images using Voronoi-Distance, as an image registration method for feature based image mosaics. It extracts feature points in two images by the SUSAN corner detector, and then create not only the Voronoi Surface which has distance information among the feature points in the base image using a priority based Voronoi distance algorithm but also select the model area which has the maximum variance value of coordinates of the feature points in the model image. We propose a method for searching for the correspondent points in the Voronoi surface of the base image overlapped with the model area by use of the partitive search algorithm using queues. The feature of the method is that we can rapidly search for the correspondent points between adjacent images using the new Voronoi distance algorithm which has $O(width{\times}height{\times}logN)$ time complexity and the the partitive search algerian using queues which reduces the search range by a fourth at a time.

• The KIPS Transactions:PartB
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• v.17B no.3
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• pp.233-238
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• 2010

In this paper, we propose a multiple classifier combination method based on image degradation modeling to improve recognition performance on low-quality images. Using an image degradation model, it generates a set of classifiers each of which is specialized for a specific image quality. In recognition, it combines the results of the recognizers by weighted averaging to decide the final result. At this time, the weight of each recognizer is dynamically decided from the estimated quality of the input image. It assigns large weight to the recognizer specialized to the estimated quality of the input image, but small weight to other recognizers. As the result, it can effectively adapt to image quality variation. Moreover, being a multiple-classifier system, it shows more reliable performance then the single-classifier system on low-quality images. In the experiment, the proposed multiple-classifier combination method achieved higher recognition rate than multiple-classifier combination systems not considering the image quality or single classifier systems considering the image quality.

• Korean Journal of Construction Engineering and Management
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• v.23 no.5
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• pp.98-107
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• 2022

The purpose of this study is to suggest a model for evaluation of a risk based value index for modular design alternatives in plant construction projects. Accordingly, 1) Setting the basic project cost and the scope to apply the module, 2) Evaluating the importance, easiness, and effectiveness index for Engineering, Procurement, Fabrication, transportation, and construction work, 3) Estimating the total project cost by analyzing the risk reserve Step, 4) Comparing the effectiveness index and total project cost for each modular design alternative, it was composed of the steps of deriving RVI. To verify such a model, Plan-A, which applied a module to one process, and Plan-B, which applied a module to three processes, were composed to evaluate RVI.

• Journal of Korean Society of Forest Science
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• v.107 no.2
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• pp.184-192
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• 2018

In this study was implemented to develop tree stem weight prediction equation of Larix kaempferi in central region by selecting a standard site, taking into account of diameter and position of the local trees. Fifty five sample trees were selected in total. By utilizing actual data of the sample trees, 11 models were compared and analyzed in order to estimate four different kinds of weights which include fresh weight, ovendry outside bark weight, ovendry inside bark weight and merchantable weight. As to estimate its weight, the study has classified its model according to three parameters: DBH, DBH and height, and volume. The optimal model was chosen by comparing the performance of model using the fit index and standard error of estimate and residual distribution. As a result, the formula utilizing DBH (Variable 1) is $W=a+bD+cD^2$ (3) and its fit index was 90~92%. The formula for DBH and height (Variable 2) is $W=aD^bH^C$ (8) and its fit index was 97~98%. In summation, Variable 2 model showed higher fitness than Variable 1 model. Moreover, fit index of formula for total volume and merchantable volume (W=aV) showed high rate of 98~99%, as well as resulting 7.7-17.5 with SEE and 8.0-10.0 with CV(%) which lead to predominately high fitness in conclusion. This study is expected to provide information on weights for single trees and furthermore, to be used as a basic study for weight of stand unit and biomass estimation equations.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.2
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• pp.74-82
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• 2009

In order to make successful oral cancer treatment, we need to understand about tumor biology and effective chemotherapeutic agents. To achieve these studies, it is necessary to develope a proper in-vivo model. Therefore the author will make try to develop more improved animal model of more applicable in various method of cancer study. In this study, the author induced in-vivo tumorigenesis in nude mice by $YD-10B_{mod}$ cell line used by YD-10B cell line originated from oral tongue squamous cell carcinoma and observed tumor formations and invasiveness of surrounding tissue, and found some results as follows : 1. The experimental group($YD-10B_{mod}$, subcutaneous injection) produced tumors 13 out of 15 mice, while the control group produced none of 5 mice. 2. The inoculation of $1{\times}10^6$cells/mouse produced tumors 3 out of 5 mice and inoculation of $1{\times}10^7$cells/mouse, $2{\times}10^7$cells/mouse produced tumors in every 5 mice. 3. In the histopathologic studies, the inoculation of $1{\times}10^6$cells/mouse group showed the characteristic features of well-differentiated squamous cell carcinoma and demarcated expansile growth, while the inoculation of $1{\times}10^7$cells/mouse, $2{\times}10^7$cells/mouse group showed the expansile growth with partial central necrosis and invasive growth to surrounding fat & connective tissue. These findings suggest that atopic xenograft of $YD-10B_{mod}$ cell line in nude mice has a improved productivity of tumors, produced tumors showed the characteristics feature of human tumor and invasive growth to surrounding tissue in histopathologic appearance. These atopic nude mouse model of tongue carcinoma might assist in studying oral cancer biology and effective choice of chemotherapeutic agents.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.4
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• pp.14-21
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• 2001

To estimate crack growth rate and cycle ratio uniquely, many investigators have developed various kinds of mechanical parameters and theories. But, thes have produced local solution space through single parameter. Neural Networks can perform patten classification using several input and output parameters. Fatigue damage model by neural networks was used to recognize the relation between da/dN/N/N(sub)f, and half-value breadth ratio B/Bo, fractal dimension D(sub)f, and fracture mechanical parameters in 2024-T3 aluminium alloy. Learned neural networks has ability to predict both crack growth rate da/dN and cycly ratio /N/N(sub)f within engineering estimated mean error(5%).

• Transactions of Materials Processing
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• v.23 no.3
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• pp.139-144
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• 2014

In the current study, we present a new model for predicting width spread of a slab with a dog-bone shaped cross section during rolling in the roughing train of a hot strip mill. The approach is based on the extremum principle for a rigid plastic material and a three dimensional admissible velocity field. The upper bound theorem is used for calculating the width spread of the slab. The prediction accuracy of the proposed model is examined through comparison with the predictions from 3-D finite element (FE) process simulations.