• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.40-44
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• 2002

Precision correction is the process of geometrically aligning images to a reference coordinate system using GCPs(Ground Control Points). Many applications of remote sensing data, such as change detection, mapping and environmental monitoring, rely on the accuracy of precision correction. However it is a very time consuming and laborious process. It requires GCP collection, the identification of image points and their corresponding reference coordinates. At typical satellite ground stations, GCP collection requires most of man-powers in processing satellite images. A method of automatic registration of satellite images is demanding. In this paper, we propose a new algorithm for automatic precision correction by GCP chips and RANSAC(Random Sample Consensus). The algorithm is divided into two major steps. The first one is the automated generation of ground control points. An automated stereo matching based on normalized cross correlation will be used. We have improved the accuracy of stereo matching by determining the size and shape of match windows according to incidence angle and scene orientation from ancillary data. The second one is the robust estimation of mapping function from control points. We used the RANSAC algorithm for this step and effectively removed the outliers of matching results. We carried out experiments with SPOT images over three test sites which were taken at different time and look-angle with each other. Left image was used to select UP chipsets and right image to match against GCP chipsets and perform automatic registration. In result, we could show that our approach of automated matching and robust estimation worked well for automated registration.

• Journal of KIISE:Information Networking
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• v.36 no.4
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• pp.263-274
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• 2009

Decentralized group key management mechanisms offer beneficial solutions to enhance the scalability and reliability of a secure multicast framework by confining the impact of a membership change in a local area. However, many of the previous decentralized solutions reveal the plaintext to the intermediate relaying proxies, or require the key distribution center to coordinate secure group communications between subgroups. In this study, we propose a decentralized group key management scheme that features a mechanism allowing a service provider to deliver the group key to valid members in a distributed manner using the proxy cryptography. In the proposed scheme, the key distribution center is eliminated while data confidentiality of the transmitted message is provided during the message delivery process. The proposed scheme can support a secure group communication in dynamic network environments where there is no trusted central controller for the whole network and the network topology changes frequently.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.32-32
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• 2016

정부는 1999년 제정된 연안관리법에 따라 2000년부터 시행 중인 '연안정비계획' 등을 통하여 연안 침식 대응사업을 지원하고 있다. 그러나 연안의 개발은 지속적으로 일어나고 있으며 그 중 동해항 3단계 북방파제 축조공사가 내년 3월 중으로 착공할 것으로 예상된다. 동해항 3단계 개발사업은 동해항을 환동해권 물류 중심 거점 항만으로 육성하기 위해, 오는 2020년까지 대규모 항만개발과 방파제 등이 축조될 예정이다. 이에 따라 본 연구에서는 동해항 3단계 개발사업의 추진에 따른 인근해변의 해안침식 저감대책 방안으로 해안선 및 수심 변화를 예측하고자 한다. 동해항 인근의 추암 해수욕장부터 삼척 해수욕장까지 대상지역 N-line 모델 적용 및 Case분석을 실시한다. 해안선 변화는 Polar coordinate에서 개발된 One-line 모델에 회절 효과를 반영하고 해빈 경사와 쇄파고에 따라 횡단 방향으로 발생하는 표사로 인한 추가적인 해안선 변화 효과를 반영하여 입사파고 변동에 따른 단기적인 해안선 변화의 변동 폭을 제공한다. 연평균 입사 파고에 따라 형성되는 연안방향 표사로부터 해안선이 변동하며 이 해안선을 기준으로 연평균 파고에 따른 전진 폭과 최고 파고에 따른 침식 폭을 제시한다. 동해항 개발 전 변화 예측 모델링과 동해항 개발 후 변화 예측 모델링을 통해 개발에 따른 장래 해안선의 변화 예측 모델링 결과 분석 및 검토를 실시, 동해항 인근 지역에 적합한 해안선 유지관리 방법 결정 및 제안을 하는데 도움을 줄 것이라 기대된다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.2
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• pp.84-88
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• 2021

The change of the photoluminescence properties of La2O3-CaF2-Al2O3-SiO2 glass-ceramics doped with rare earth material, that is used as laser and optical sensors, was analyzed according to heat treatment temperature. The heat treatment conditions for fabricating glass-ceramics were obtained through non-isothermal thermal analysis, and X-ray diffraction analysis was performed to determine the degree of crystal growth and kinds of crystal phases generated according to the heat treatment temperature. Using Scherrer's equation, it was predicted that crystals with a size of 25~40 nm would be generated inside the glass-ceramics. Photoluminescence (PL) analysis showed that the specimens heat-treated at 660℃ to 670℃ for 1 hour had the highest PL intensity. Also, from the CIE color coordinate analysis, all glass-ceramics specimens emitted red-orange light regardless of the heat treatment condition.

• Cross-Cultural Studies
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• v.33
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• pp.407-459
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• 2013

The paper pragmatically analyzes ellipsis in Russian and Polish colloquial and informal texts. The famous Polish writer Sławomir $Mro{\dot{z}}ek^{\prime}s$ "Exit to the South", written in Polish and Russian is used as a material for the analysis. Russian and Polish ellipsis in colloquial and informal texts have in common that the givenness and subjecthood of the elliptical co-referent play a crucial role. However, the ellipsis in two languages also has differences in many ways. Above all, in the Polish texts of colloquial and informal style, a theme is likely to be elliptical and the coreferential relation reaches to an extra-sentential antecedent, while the ellipsis in analysed Russian texts in most cases requires coordinate, subordinate or relative clauses, and the elliptical co-referent tends to have an intra-sentential antecedent. The ellipsis of the theme-subject is unmarked in Polish, where every verbal form has an ending denoting person. Unlike formal style which often allows explicit noun subject, Polish text of colloquial and informal style prefer null form of the subject in most cases. If Polish sentences have explicit theme-subjects, they disambiguate intervening and main themes, and indicate the contrast, the focus, the introduction of new narratives or the change of speaker's point of view. Sometimes direct speeches and deictic pronouns also need explicit theme-subjects in Polish sentences. On the other hand, the ellipsis of the theme-subject is marked in Russian even in colloquial and informal texts. The theme-subject can be deleted in Russian colloquial and informal texts, if the subject is a form of the first or the second person, or if the aspect and the tense of the antecedent sentence's verb are the same as those of the given sentence's verb and both the antecedent and the coreferential word have the nominative case.

• Convergence Security Journal
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• v.17 no.5
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• pp.11-18
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• 2017

Now the ways in which information is exchanged by computers are changing, a variety of this information exchange method also requires corresponding change of responding to an illegal attack. Among these illegal attacks, the IP spoofing attack refers to the attack whose process are accompanied by DDoS attack and resource exhaustion attack. The way to detect an IP spoofing attack is by using traceback information. The basic traceback information analysis method is implemented by comparing and analyzing the normal router information from client with routing information existing in routing path on the server. There fore, Such an attack detection method use all routing IP information on the path in a sequential comparison. It's difficulty to responding with rapidly changing attacks in time. In this paper, all IP addresses on the path to compute in a coordinate manner. Based on this, it was possible to analyze the traceback information to improve the number of traceback required for attack detection.

• Journal of Science and Technology Studies
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• v.18 no.3
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• pp.255-289
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• 2018

The social problem-solving R&D is different from the goal and process in comparison with research aimed at scientific excellence and industrial innovation. It pursues social values and active participation of the end-user civil society. In this study, we try to derive its characteristics by analyzing the cases that are evaluated as successful social problem solving R&D project. In order to analyse the social problem-solving R & D case, these four variables are selected; 1) social and technological planning for problem solving 2) participatory technological development 3) law, system and delivery system development for innovation deployment 4) scale-up of new R&D process. Those are important issues identified through case studies: 1) the tools and support services needed to carry out social and technical planning effectively, 2) the role of the Living Lab to coordinate opinions with experts and users, 3) the legislative and institutional improvement activities as important as technological development, 4) researcher's change through interaction with end user.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.443-451
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• 2021

Finger millet (Eleusine coracana) is widely cultivated in tropical regions worldwide owing to its high nutritional value. Finger millet is more tolerant against biotic and abiotic stresses such as pests, drought, and salt than other millet crops; therefore, it was proposed as a candidate crop to adapt to climate change in Korea. In 2019, we used expressed sequence tag simple sequence repeat (EST-SSR) markers to evaluate the genetic diversity and structure of 102 finger millet accessions from two geographical regions (Africa and South Asia) to identify appropriate accessions and enhance crop diversity in Korea. In total, 40 primers produced 116 alleles, ranging in size from 135 to 457 bp, with a mean polymorphism information content (PIC) of 0.18225. Polymorphism was detected among the 40 primers, and 13 primers were found to have PIC values > 0.3. Principal coordinate and phylogenetic analyses, based on the combined data of both markers, grouped the finger millet accessions according to their respective collection areas.Therefore, the 102 accessions were classified into two groups, one from Asia and the other from Africa. We have conducted an in-depth study on the finger millet landrace pedigree. By sorting out and using the molecular characteristics of each pedigree, it will be useful for the management and accession identification of the plant resource. The novel SSR markers developed in this study will aid in future genetic analyses of E. coracana.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.11
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• pp.4084-4104
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• 2021

Visual place recognition (VPR) is a fundamental yet challenging task of mobile robot navigation and localization. The existing VPR methods are usually based on some pairwise similarity of image descriptors, so they are sensitive to visual appearance change and also computationally expensive. This paper proposes a simple yet effective four-step method that achieves adaptive convolutional neural network (CNN) landmark matching for VPR. First, based on the features extracted from existing CNN models, the regions with higher significance scores are selected as landmarks. Then, according to the coordinate positions of potential landmarks, landmark matching is improved by removing mismatched landmark pairs. Finally, considering the significance scores obtained in the first step, robust image retrieval is performed based on adaptive landmark matching, and it gives more weight to the landmark matching pairs with higher significance scores. To verify the efficiency and robustness of the proposed method, evaluations are conducted on standard benchmark datasets. The experimental results indicate that the proposed method reduces the feature representation space of place images by more than 75% with negligible loss in recognition precision. Also, it achieves a fast matching speed in similarity calculation, satisfying the real-time requirement.

• The Mathematical Education
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• v.62 no.3
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• pp.417-433
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• 2023

In the 2022 revised mathematics curriculum, a new content on 'Movement of a point' was added. Therefore, this study analyzed the contents of the movement of a point presented in Finnish mathematics textbooks as elements of spatial orientation. Analysis was conducted by dividing it into direction, distance, and route. As a result of the study, in Finnish textbooks, directions were expressed in various ways, such as linguistic, visual, and coded expressions. In the case of distance, activities to move as much as the distance or compare the distance were presented using the number of cells, length, steps, coordinate points, ratio, etc. In the case of routes, activities such as moving according to instructions, making routes, finding the route, and modifying the route were presented using unconditional movement and conditional movement. In particular, the movement of a point could be linked not only to various mathematical content areas such as 'number and arithmetic' and 'change and relationship', but also to digital literacy and programming education. Knowing that the movement of a point can be presented in various ways according to the direction, distance, and route, it is expected that it can be used to organize the contents of the 2022 revised mathematics textbook.