• Korean Journal of Geomatics
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• 제2권1호
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• pp.25-29
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• 2002

The calculation of earthwork plays a major role in plan or design of many civil engineering projects, and thus it has become very important to improve the accuracy of earthwork calculation. In this paper, we propose an algorithm for finding a cubic spline surface with the free boundary conditions, which interpolates the given three dimensional data, by using B-spline and an accurate method to estimate pit-excavation volume. The proposed method should be of interest to surveyors especially concerned with accuracy of volume computations. We present some computational results showing that our proposed method provides good accuracy.

• 한국산학경영학회:학술대회논문집
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• 한국산학경영학회 2006년도 추계학술발표대회 발표논문집
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• pp.107-120
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• 2006

This thesis examines the relationship between the trading volume and price return in the korean stock Index Futures until June 2005. First, the volume of KOSPI200 futures doesn't play a primary role with the clear explanation of return model. Second, an unexpected volume shocks are negatively associated with the return in case of the KOSPI200 futures, but it is a meaningless relation in the KOSDAQ50 futures. In the case of open interest, it's difficult to find any mean in a both futures. Third, The changes in the trading volumes by foreign investors are positively associated with the return and the volatility, but individuals and domestic commercial investors are negatively associated with the return. This empirical result seems that foreign investors are initiatively trading the korean stock index futures, individuals and domestic commercial investors follow the lead made by foreign investors.

• 한국조리학회지
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• 제23권8호
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• pp.1-10
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• 2017

This study investigated the quality characteristics of muffins by the amount of addition of suchero (0%, 25%, 50%, 75%, 100%) as there is increasingly higher interest in functional alternative sweetener. The effects of suchero were evaluated in terms of height, volume, weight, specific volume, baking loss rate, colorimeter, and sensory evaluation. Texture and moisture contents of muffins during storage (1, 2, 3 days) were measured. As the ratio of suchero increased, the volume, specific volume, and weight increased, whereas the volume and specific volume was not significant. During storage, moisture content of muffins decreased significantly. The moisture content of the sample containing suchero was higher than S0(control group). The addition of suchero increased L value of crust and crumb decreased, whereas a value and b value increased. The muffin with 100% of suchero (S100) in test group showed the lowest hardness. According to the sensory evaluation, the muffin with 50% of suchero (S50) showed the highest score in terms of appearance, color, flavor, taste, and overall acceptance, S50 showed the best result and the optimum addition of suchero.

• Imaging Science in Dentistry
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• 제53권2호
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• pp.91-99
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• 2023

Purpose: This systematic review aimed to investigate the correlation between chronological age and dental pulp volume in cone-beam computed tomography (CBCT). Materials and Methods: The literature was searched in 4 databases(PubMed, Scopus, Web of Science, and Google Scholar). Within each study, the outcome of interest was the correlation (r) between chronological age and pulp volume. A random-effect meta-analysis was conducted. Subgroup analysis was carried out according to sex and tooth type. Results: Of 5,693 identified studies, 27 fulfilled the inclusion criteria and were selected for meta-analysis. These articles focused on single-rooted teeth (n=21), multi-rooted teeth (n=6), maxillary teeth (n=14), mandibular teeth (n=6), and maxillary and mandibular teeth (n=12). The relationship between chronological age and dental pulp volume was examined in the entire population (r= -0.67), men (r= -0.75), and women (r= -0.77) in single- and multi-rooted teeth. The results of the total population analysis showed a relatively strong negative relationship between age and pulp volume. Conclusion: This study suggested that CBCT is a reliable and repeatable tool for dental age estimation. A strong inverse relationship was observed between pulp chamber volume and age. Further studies on the correlation between chronological age and pulp volume of multi-rooted teeth may be beneficial.

• 문화기술의 융합
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• 제4권4호
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• pp.155-160
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• 2018

본 연구는 미국의 실질실효환율과 단기금리가 중국의 수출과 수입에 미치는 영향을 EGARCH-GED 모형을 이용하여 분석하였다. 미국이 금리의 인상을 추진하고 중국과의 무역 전쟁이 심화되는 시점에서 미국 주요 경제변수의 중국 수출과 수입에 대한 효과를 분석하였다. 분석결과, 첫째 중국의 교역량에는 미국 실질실효환율은 유의한 영향을 미치지 않고 미국 단기금리만이 유의한 양의 영향을 미치는 것으로 나타났다. 중국 수출의 경우에도 미국 실질 실효환율은 유의한 영향을 미치지 않고 미국 단기금리만이 유의한 양의 영향을 미쳤다. 그러나 중국 수입의 경우에는 수출과는 반대로 미국 단기금리는 유의한 영향을 미치지 않고 미국 실질실효환율은 유의한 양의 영향을 미치는 것으로 나타났다. 한편 중국 정책금리는 중국 수출에만 유의한 양의 영향을 미치는 것으로 나타났다.

• Corrosion Science and Technology
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• 제13권6호
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• pp.209-213
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• 2014

Due to the increasing of interest about the eco-friendly concrete, it is increased to use concretes containing by-products of industry such as fly ash(FA), ground granulated blast furnace slag(GGBFS), silica fume(SF), and etc. Especially, these are well known for improving the resistances to reinforcement corrosion in concrete and decreasing chloride ion penetration. The purpose of this experimental research is to evaluate the resistance against corrosion of reinforcement of high volume fly ash(HVFA) concrete which is replaced with high volume fly ash for cement volume. For this purpose, the concrete test specimens were made for various strength level and replacement ratio of FA, and then the compressive strength and diffusion coefficient for chloride ion of them were measured for 28, 91, and 182 days, respectively. Also, corrosion monitoring by half cell potential method was carried out for the made lollypop concrete test specimens to detect the time of corrosion initiation for reinforcement in concrete. As a result, it was observed from the test results that the compressive strength of HVFA concrete was decreased with increasing replacement ratio of FA but long-term resistances against reinforcement corrosion and chloride ion penetration of that were increased.

• Journal of International Society for Simulation Surgery
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• 제1권1호
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• pp.27-31
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• 2014

In this paper, an overview of segmentation and 3D visualization methods are presented. Commonly, the two kinds of methods are used to visualize organs and vessels into 3D from medical images such as CT(A) and MRI - Direct Volume Rendering (DVR) and Iso-surface Rendering (IR). DVR can be applied directly to a volume. It directly penetrates through the volume while it determines which voxels are visualizedbased on a transfer function. On the other hand, IR requires a series of processes such as segmentation, polygonization and visualization. To extract a region of interest (ROI) from the medical volume image via the segmentation, some regions of an object and a background are required, which are typically obtained from the user. To visualize the extracted regions, the boundary points of the regions should be polygonized. In other words, the boundary surface composed of polygons such as a triangle and a rectangle should be required to visualize the regions into 3D because illumination effects, which makes the object shaded and seen in 3D, cannot be applied directly to the points.

• 한국의류학회지
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• 제46권5호
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• pp.868-889
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• 2022

Fashion companies are using a big data approach as a key strategic analysis to predict and forecast sales. This study investigated the effectiveness of the past sales, web search volume, information amount, brand promotion, and the advertising endorser on the sales forecasting model. The study conducted the autoregressive distributed lag (ARDL) time series model using the internal and external social big data of a national fashion brand. Results indicated that the brand's past sales, search volume, promotion, and amount of advertising endorser information amount significantly affected the sales forecast, whereas the brand's advertising endorser search volume and information amount did not significantly influence the sales forecast. Moreover, the brand's promotion had the highest correlation with sales forecasting. This study adds to information-searching behavior theory by measuring consumers' brand involvement. Last, this study provides digital marketers with implications for developing profitable marketing strategies on the basis of consumers' interest in the brand and advertising endorser.

• 한국과학교육학회지
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• 제30권5호
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• pp.594-608
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• 2010

이 연구는 중학생의 생명현상 관찰활동에서 과학적 흥미가 발생하는 요인을 추출하고, 추출한 요인이 과학적 흥미의 발생에 영향을 주는 정도를 검증한 것이다. 흥미발생요인을 추출하기 위해 중학교 3학년을 대상으로 4차시 분량의 관찰활동 프로그램을 투입하였고, 관찰활동에 참여한 학생 중 과학적 흥미가 높았던 학생을 대상으로 면담을 실시하였다. 면담 결과를 응답 유형별로 분류하여 21가지의 흥미발생요인을 추출하였다. 추출한 흥미발생요인은 크게 관찰대상의 특성, 관찰활동의 특성, 관찰결과의 특성, 관찰자의 특성, 외적 요인의 특성 등 5가지로 범주화하였다. 이렇게 추출한 흥미발생요인이 관찰활동에서 과학적 흥미의 발생에 영향을 주는지 검증해 보았다. 우선, 추출한 흥미발생요인이 관찰활동에서 흥미의 발생에 영향을 준 정도를 확인하기 위하여 흥미발생요인 조사지를 작성하였다. 중학교 3학년을 대상으로 4차시 분량의 관찰활동 프로그램을 실시한 후 흥미발생요인 조사지를 투입하였다. 흥미발생요인 조사지의 응답 결과를 분석하여 각각의 요인이 흥미의 발생에 영향을 준 정도의 차이를 확인해 보았다. 그 결과, 추출한 21개의 요인은 과학적 흥미의 발생에 유의미한 영향을 주는 것을 확인하였다. 이 연구의 결과는 흥미롭지 않은 관찰활동에 대한 원인 분석이 가능하며 흥미로운 관찰활동 프로그램을 개발하는데 매우 중요한 역할을 할 것이다.

• 한국자동차공학회논문집
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• 제3권6호
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• pp.112-122
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• 1995

As an alternative fuel producing less exhaust emissions, natural gas is of interest for use both in SI and CI engines. The potential of natural gas fuelled dual-fuel engine is considered high enough. However, much effort has to be made so that gaseous fuel is used efficiently with simultaneous minimum use of pilot oil. Hence, a simplified three-dimensional model, using a finite volume method in cylindrical coordinates, has been developed to facilitate an understanding of the dual-fuel combustion phenomena and to predict the complex interactions between the pilot distillate and natural gas. The computer model was calibrated by comparing it with the experimental results obtained from diesel engine like combustion bomb tests. In the pre-mixed natural gas combustion, the fuel burning was highly reliant on the injection condition and subsequent burning nature of the pilot distillate.