• 도시과학
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• 제9권2호
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• pp.45-50
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• 2020

The formation characteristics of calcium carbonates are closely related to the durability and mechanical properties of cement-based materials. In this regard, a deep understanding of the reaction pathway of calcium carbonates is critical. Recently, non-classical nucleation theory was summarized and it was presumed that prenucleation clusters are present. The formation of the prenucleation cluster at undersaturated condition (≈ 0.1 ml) in the present study was investigated via electrical characteristics of an electrolytic solution. Calcium chloride dihydrate (CaCl2·2H2O) and sodium carbonate (Na2CO3) were used as starting materials to supply calcium and carbonate sources, respectively. Furthermore, the reaction pathway of calcium carbonates was investigated by time-resolved polarization and depolarization characteristics of the electrolytic solution. The time-resolved polarization and depolarization tests were conducted by switching polarity with an interval of 20 seconds for 1 hr and by measuring the variation of electrical resistance. It can be inferred from the results obtained in the present study that the reactive constituent for the formation of calcium carbonates was mostly consumed in the period possibly associated with the prenucleation and the reaction pathways may be governed by the monomer-addition mechanism.

• 융합경영연구
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• 제10권3호
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• pp.21-36
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• 2022

Purpose: The purpose of this study is to compare and analyze the enterprise's score index calculated from atypical data and corrected data. Research design, data, and methodology: In this study, news articles which are non-financial information but qualitative data were collected from 2,432 SMEs that has been extracted "square proportional stratification" out of 18,910 enterprises with fixed data and compared/analyzed each enterprise's score index through text mining analysis methodology. Result: The analysis showed that qualitative data can be quantitatively evaluated by region, industry and period by collecting news from SMEs, and that there are concerns that it could be an element of alternative credit evaluation. Conclusion: News data cannot be collected even if one of the small businesses is self-employed or small businesses has little or no news coverage. Data normalization or standardization should be considered to overcome the difference in scores due to the amount of reference. Furthermore, since keyword sentiment analysis may have different results depending on the researcher's point of view, it is also necessary to consider deep learning sentiment analysis, which is conducted by sentence.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.601-607
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• 2022

In recent years, monitoring of spent nuclear fuel inside dry cask storage has become an important area of national security. Muon tomography is a useful method for monitoring spent nuclear fuel because it uses high energy muons that penetrate deep into the target material and provides a 3-D structure of the inner materials. We designed a muon tomography system consisting of four 2-D position sensitive detector and characterized and optimized the system parameters. Each detector, measuring 200 × 200 cm², consists of a plastic scintillator, wavelength shifting (WLS) fibers and, SiPMs. The reconstructed image is obtained by extracting the intersection of the incoming and outgoing muon tracks using a Point-of-Closest-Approach (PoCA) algorithm. The Geant4 simulation was used to evaluate the performance of the muon tomography system and to optimize the design parameters including the pixel size of the muon detector, the field of view (FOV), and the distance between detectors. Based on the optimized design parameters, the spent fuel assemblies were modeled and the line profile was analyzed to conduct a feasibility study. Line profile analysis confirmed that muon tomography system can monitor nuclear spent fuel in dry storage container.

• 대한조선학회논문집
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• 제59권5호
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• pp.330-337
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• 2022

Research on object detection algorithms using 2D data has already progressed to the level of commercialization and is being applied to various manufacturing industries. Object detection technology using 2D data has an effective advantage, there are technical limitations to accurate data generation and analysis. Since 2D data is two-axis data without a sense of depth, ambiguity arises when approached from a practical point of view. Advanced countries such as the United States are leading 3D data collection and research using 3D laser scanners. Existing processing and detection algorithms such as ICP and RANSAC show high accuracy, but are used as a processing speed problem in the processing of large-scale point cloud data. In this study, PointNet a representative technique for detecting objects using widely used 3D point cloud data is analyzed and described. And RandLA-Net, which overcomes the limitations of PointNet's performance and object prediction accuracy, is described a review of detection technology using point cloud data was conducted.

• Asian Journal of Innovation and Policy
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• 제10권1호
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• pp.39-67
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• 2021

This study investigated the policy instruments pertinent to the establishment of a regional innovation system in the Mekong Delta that facilitates the development of a countermeasure towards various issues of industrial and technological nature. First, we conducted the research with regard to the status and environment of the region. Second, a field visiting survey was implemented to analyze the results of international efforts and regional capacity to solve the problems attendant upon introducing technologies related to the Fourth Industrial Revolution. Third, we derived the key policy issues and challenges from the results of the field visiting survey and experts' conference with a deep focus on technological transfer and international cooperation to enhance the capability in the science and technology field. Fourth, we conducted the opinion survey of the experts from Korea and Vietnam to converge local opinions from both countries and analyzed the results. The range of research subjects is responding to climate change, managing water resources, coordinating energy and industrial structure, making a resilient Mekong regional ecosystem, smartification of local cities, and improving the life quality of citizens, and so on. The results of this study are expected to be the beginning of fundamental research in the mid to long-term view of the Mekong Delta region innovation system of Korea and Vietnam and to evaluate the master plan.

• 한국멀티미디어학회논문지
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• 제25권9호
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• pp.1356-1366
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• 2022

In the display of virtual space, the degree of space virtualization cannot be judged only by the degree of material technology. Based on the non-material relationship, the virtual space that this research focuses on is a conceptual and ontological point of view (based on the conceptual and ontological viewpoints of non-material relations), including practical technical issues. The research on the characteristics of virtual space ontology not only has an impact on the space design of science fiction movies, but also becomes a powerful medium that brings changes to the world. In the future, there will be a large number of cases where fantasy things in science fiction movies are actualized. From this perspective, based on the study of several science fiction movies using virtual reality scenes, this paper puts forward a study on the representation characteristics of virtual space ontology. In addition, the study of the virtual reality is of great significance for verifying the possibility of virtual reality in the application of deep space technology in the future. At the same time, it provides reference value for the development of special effects film field from montage theory-based to Bazin theory-based expression, and contributes to the theoretical system of film space.

• Asia pacific journal of information systems
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• 제32권4호
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• pp.770-802
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• 2022

With the development of deep learning techniques, text mining is producing breakthrough performance improvements, promising future applications, and practical use cases across many fields. Likewise, even though several attempts have been made in the field of financial information, few cases apply the current technological trends. Recently, companies and government agencies have attempted to conduct research and apply text mining in the field of financial information. First, in this study, we investigate various works using text mining to show what studies have been conducted in the financial sector. Second, to broaden the view of financial application, we provide a description of several text mining techniques that can be used in the field of financial information and summarize various paradigms in which these technologies can be applied. Third, we also provide practical cases for applying the latest text mining techniques in the field of financial information to provide more tangible guidance for those who will use text mining techniques in finance. Lastly, we propose potential future research topics in the field of financial information and present the research methods and utilization plans. This study can motivate researchers studying financial issues to use text mining techniques to gain new insights and improve their work from the rich information hidden in text data.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권1호
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• pp.15-29
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• 2024

A fetoscope is an optical endoscope, which is often applied in fetoscopic laser photocoagulation to treat twin-to-twin transfusion syndrome. In an operation, the clinician needs to observe the abnormal placental vessels through the endoscope, so as to guide the operation. However, low-quality imaging and narrow field of view of the fetoscope increase the difficulty of the operation. Introducing an accurate placental vessel segmentation of fetoscopic images can assist the fetoscopic laser photocoagulation and help identify the abnormal vessels. This study proposes a method to solve the above problems. A novel encoder-decoder network with a dual-path structure is proposed to segment the placental vessels in fetoscopic images. In particular, we introduce a channel attention mechanism and a continuous convolution structure to obtain multi-scale features with their weights. Moreover, a switching connection is inserted between the corresponding blocks of the two paths to strengthen their relationship. According to the results of a set of blood vessel segmentation experiments conducted on a public fetoscopic image dataset, our method has achieved higher scores than the current mainstream segmentation methods, raising the dice similarity coefficient, intersection over union, and pixel accuracy by 5.80%, 8.39% and 0.62%, respectively.

• 한국농림기상학회지
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• 제25권4호
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• pp.337-345
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• 2023

벼의 출수기를 추정하는 것은 농업생산성과 관련된 중요한 과정 중 하나이지만 세계적인 이상기후의 증가로 벼의 출수기를 추정하는 것이 어려워지고 있다. 본 연구에서는 CNN 분류모델을 사용하여 다양한 영상데이터에서 벼의 출수기를 추정하려고 시도하였다. 드론과 타워형 영상관측장치 그리고 일반 RGB 카메라로 촬영된 직하방과 경사각 영상을 수집하였다. 수집한 영상은 CNN 모델의 입력데이터로 사용하기 위해서 전처리를 진행하였고, 사용된 CNN 아키텍처는 이미지 분류 모델에서 일반적으로 사용되는 ResNet50, InceptionV3 그리고 VGG19 를 사용하였다. 각각의 아키텍처는 모델의 종류, 영상의 유형과 관계없이 0.98 이상의 정확도를 나타내었다. 또한 CNN 분류 모델이 영상의 어떤 특징을 보고 분류하였는지 시각적으로 확인하기 위해서 Grad-CAM 을 사용하였다. Grad-CAM 결과 CNN 분류 모델은 벼의 출수를 이삭의 형태에 높은 가중치를 두어 분류 하는 것을 확인하였다. 다음으로 작성된 모델이 실제 논 포장 모니터링 이미지에서 벼의 출수기를 정확하게 추정하는지 확인하였다. 각각 다른 지역 4 개의 벼 포장에서 벼의 출수기를 약 하루정도의 차이로 추정하는 것을 확인하였다. 이 방법을 통해서 다양한 논 포장의 모니터링 이미지를 활용하여 자동적이고 정량적으로 벼의 출수기를 추정 할 수 있다고 판단된다.

• 방사성폐기물학회지
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• 제6권1호
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• pp.65-72
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• 2008

사용후핵 연료 심지층 처분의 목적은 그 독성이 인간 및 자연환경에 영향을 미치지 않도록 장기간 동안 격리하고, 방사성물질의 누출을 지연시키는 것이다. 이러한 심지층 처분장 설계시 주요한 요건은 처분시스템의 건전성 유지를 위하여 폐기물로부터 발생된 열로 인하여 완충재의 온도가 $100\;^{\circ}C$를 넘지 않도록 하는 것이다. 따라서, 원자력 발전소에서 방출된 후의 사용후핵연료 냉각기간은 심지층 처분장 설계시 효율 및 경제성을 위한 중요한 고려인자이다. 본 연구에서는 가장 적절한 사용후핵연료 냉각기간 설정을 위하여 처분시스템 온도요건을 만족하는 심지층 처분장 배치에 필요한 처분터널-처분공 간격 및 그에 따른 면적, 열하중에 대한 분석을 수행하였다. 이를 위하여, 기준 처분개념을 바탕으로 사용후핵연료의 냉각기간 및 처분터널/처분공 간격을 다양하게 설정하여, 처분시스템에서의 열적 안정성을 해석하고 그 결과를 비교분석하였다. 그리고 분석 결과를 바탕으로 처분면적 측면에서 효율적인 사용후핵연료 냉각기간을 도출하였다. 그 결과, 사용후핵연료의 냉각기간이 짧을수록 처분장에서 설계온도 제한치 범위내 최고온도에 이르는 시간은 빨라지고, 사용후핵연료 냉각기간이 길수록 처분장에서 온도상승 및 하강속도는 완만해지는 것으로 나타났다. 또한, 본 연구에서 고려대상으로 삼은 처분장 규모와 사용후핵연료를 심지층에 처분한다고 할 때 그 냉각기간을 40-50년으로 함이 적합한 것으로 나타났다.