• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권5호
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• pp.1671-1686
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• 2022

Face manipulation tools represented by Deepfake have threatened the security of people's biological identity information. Particularly, manipulation tools with deep learning technology have brought great challenges to Deepfake detection. There are many solutions for Deepfake detection based on traditional machine learning and advanced deep learning. However, those solutions of detectors almost have problems of poor performance when evaluated on different quality datasets. In this paper, for the sake of making high-quality Deepfake datasets, we provide a preprocessing method based on the image pixel matrix feature to eliminate similar images and the residual channel attention network (RCAN) to resize the scale of images. Significantly, we also describe a Deepfake detector named Cascaded-Hop which is based on the PixelHop++ system and the successive subspace learning (SSL) model. By feeding the preprocessed datasets, Cascaded-Hop achieves a good classification result on different manipulation types and multiple quality datasets. According to the experiment on FaceForensics++ and Celeb-DF, the AUC (area under curve) results of our proposed methods are comparable to the state-of-the-art models.

• Journal of Information Processing Systems
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• 제20권2호
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• pp.215-225
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• 2024

With the rapid development of Internet of Things (IoT) and big data technology, a large amount of data will be generated during the operation of related industries. How to classify the generated data accurately has become the core of research on data mining and processing in IoT industry chain. This study constructs a classification model of IoT industry chain based on improved random forest algorithm and text analysis, aiming to achieve efficient and accurate classification of IoT industry chain big data by improving traditional algorithms. The accuracy, precision, recall, and AUC value size of the traditional Random Forest algorithm and the algorithm used in the paper are compared on different datasets. The experimental results show that the algorithm model used in this paper has better performance on different datasets, and the accuracy and recall performance on four datasets are better than the traditional algorithm, and the accuracy performance on two datasets, P-I Diabetes and Loan Default, is better than the random forest model, and its final data classification results are better. Through the construction of this model, we can accurately classify the massive data generated in the IoT industry chain, thus providing more research value for the data mining and processing technology of the IoT industry chain.

• 전기학회논문지
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• 제66권9호
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• pp.1392-1401
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• 2017

In this study, the design methodology of pattern classification is introduced for avoiding faults through partial discharge occurring in the power facilities and local sites. In order to classify some partial discharge types according to the characteristics of each feature, the model is constructed by using the Radial Basis Function Neural Networks(RBFNNs) and Particle Swarm Optimization(PSO). In the input layer of the RBFNNs, the feature vector is searched and the dimension is reduced through Principal Component Analysis(PCA) and PSO. In the hidden layer, the fuzzy coefficients of the fuzzy clustering method(FCM) are tuned using PSO. Raw datasets for partial discharge are obtained through the Motor Insulation Monitoring System(MIMS) instrument using an Epoxy Mica Coupling(EMC) sensor. The preprocessed datasets for partial discharge are acquired through the Phase Resolved Partial Discharge Analysis(PRPDA) preprocessing algorithm to obtain partial discharge types such as void, corona, surface, and slot discharges. Also, when the amplitude size is considered as two types of both the maximum value and the average value in the process for extracting the preprocessed datasets, two different kinds of feature datasets are produced. In this study, the classification ratio between the proposed RBFNNs model and other classifiers is shown by using the two different kinds of feature datasets, and also we demonstrate the proposed model shows superiority from the viewpoint of classification performance.

• 한국정보과학회논문지:데이타베이스
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• 제34권1호
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• pp.46-58
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• 2007

마이크로어레이 데이타는 동시에 수 만개 유전자의 발현 값을 포함하고 있기 때문에 질병의 발현 형질 분류에 매우 유용하게 쓰인다. 그러나 동일한 생물학적 주제라 할지라도 여러 독립된 연구 집단에서 생성된 마이크로어레이의 분석결과는 서로 다르게 나타날 수 있다. 이에 대한 주된 이유는 하나의 마이크로어레이 실험에 참여한 샘플의 수가 제한적이기 때문이다. 따라서 개별적으로 수행된 마이크로어레이 데이타를 통합하여 샘플의 수를 늘리는 것은, 보다 정확한 분석을 하는데 있어 매우 중요하다. 본 연구에서는 이에 대한 해결 방안으로 두 단계 접근방법을 제안한다. 제 1 단계에서는 개별적으로 생성된 동일주제의 마이크로어레이 데이타를 통합한 후 인포머티브(Informative) 유전자를 추출하고 제 2 단계에서는 인포머티브 유전자만을 이용하여 클래스 분류(Classification) 과정 후 분류자를 추출한다. 이 분류자를 다른 테스트 샘플 데이타에 적용한 실험결과를 보면 마이크로어레이 데이타를 통합하여 샘플의 수를 증가시킬수록, 비교 방법에 비해 정확도가 최대 24.19% 높은 분류자를 만들어 내는 것을 알 수 있다.

• 산업경영시스템학회지
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• 제44권4호
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• pp.193-207
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• 2021

As Deepfakes phenomenon is spreading worldwide mainly through videos in web platforms and it is urgent to address the issue on time. More recently, researchers have extensively discussed deepfake video datasets. However, it has been pointed out that the existing Deepfake datasets do not properly reflect the potential threat and realism due to various limitations. Although there is a need for research that establishes an agreed-upon concept for high-quality datasets or suggests evaluation criterion, there are still handful studies which examined it to-date. Therefore, this study focused on the development of the evaluation criterion for the Deepfake video dataset. In this study, the fitness of the Deepfake dataset was presented and evaluation criterions were derived through the review of previous studies. AHP structuralization and analysis were performed to advance the evaluation criterion. The results showed that Facial Expression, Validation, and Data Characteristics are important determinants of data quality. This is interpreted as a result that reflects the importance of minimizing defects and presenting results based on scientific methods when evaluating quality. This study has implications in that it suggests the fitness and evaluation criterion of the Deepfake dataset. Since the evaluation criterion presented in this study was derived based on the items considered in previous studies, it is thought that all evaluation criterions will be effective for quality improvement. It is also expected to be used as criteria for selecting an appropriate deefake dataset or as a reference for designing a Deepfake data benchmark. This study could not apply the presented evaluation criterion to existing Deepfake datasets. In future research, the proposed evaluation criterion will be applied to existing datasets to evaluate the strengths and weaknesses of each dataset, and to consider what implications there will be when used in Deepfake research.

• 대한원격탐사학회지
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• 제38권4호
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• pp.395-409
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• 2022

The purpose of this study is to evaluate the classification performance and applicability when land cover datasets constructed for AI training are cross validation to other areas. For study areas, Gyeongsang-do and Jeolla-do in South Korea were selected as cross validation areas, and training datasets were obtained from AI-Hub. The obtained datasets were applied to the U-Net algorithm, a semantic segmentation algorithm, for each region, and the accuracy was evaluated by applying them to the same and other test areas. There was a difference of about 13-15% in overall classification accuracy between the same and other areas. For rice field, fields and buildings, higher accuracy was shown in the Jeolla-do test areas. For roads, higher accuracy was shown in the Gyeongsang-do test areas. In terms of the difference in accuracy by weight, the result of applying the weights of Gyeongsang-do showed high accuracy for forests, while that of applying the weights of Jeolla-do showed high accuracy for dry fields. The result of land cover classification, it was found that there is a difference in classification performance of existing datasets depending on area. When constructing land cover map for AI training, it is expected that higher quality datasets can be constructed by reflecting the characteristics of various areas. This study is highly scalable from two perspectives. First, it is to apply satellite images to AI study and to the field of land cover. Second, it is expanded based on satellite images and it is possible to use a large scale area and difficult to access.

• 스마트미디어저널
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• 제11권1호
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• pp.17-30
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• 2022

기존 컴퓨터 비전의 연구 동향과 마찬가지로, 위성영상을 이용한 연구도 GPU 기반의 컴퓨터 연산능력과 이미지 처리와 관련된 딥러닝 방법론의 발전으로 많이 이루어지고 있다. 그로 인해 다양한 분야에 위성영상이 활용되고 있고, 위성 영상을 활용에 관한 연구도 증가하고 있다. 본 연구에서는 위성영상의 연구 활용 분야와 위성영상을 활용한 연구에 이용할 수 있는 데이터셋에 대해 소개하도록 한다. 먼저, 위성영상을 활용한 연구를 수집하여 연구 방법에 따라 분류하였다. 크게 분류 기반 연구와 회귀 기반 연구로 분류하였고, 그 이외의 방법으로 활용한 논문들을 정리하였다. 다음으로 위성영상을 활용한 연구들에서 이용한 데이터셋을 정리하였다. 본 연구에서는 데이터셋의 정보와 연구에서의 활용 방법에 대해 제안한다. 이와 함께 최근 AI hub에서 개방한 국내 위성영상 데이터셋의 정리와 활용 방안에 대해 소개한다. 마지막으로, 위성 이미지 관련 연구의 한계점과 앞으로의 동향을 간략하게 제시하였다.

• 한국비블리아학회지
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• 제18권2호
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• pp.39-59
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• 2007

데이터베이스시스템을 활용하여 데이터를 수집 처리하는 분야가 급속도로 확대됨에 따라 데이터세트에 대해서도 일반기록물과 같이 수집 평가 보존 활용해야 할 필요성이 증대되고 있다. 그럼에도 불구하고 국내 기록관리 분야에서의 데이터세트에 대한 관심은 매우 미흡한 수준이다. 이에 본고에서는 데이터세트를 기록물로 인식하고 체계적인 관리를 하기 위한 기본항목을 제시하고자 한다. 국제표준인 ISAD(G)를 준용하여 RAD, MAD와 데이터세트를 기록물로 인정하여 서비스를 제공하고 있는 NDAD의 기술요소를 세밀히 조사 분석하여, ISAD(G)의 기술영역을 기준으로 국내 데이터세트 기술에 필요한 각 기술영역과 영 역별 내 주요 기술요소안을 제시하였다.

• Genomics & Informatics
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• 제21권3호
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• pp.40.1-40.11
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• 2023

Microbial community profiling using 16S rRNA amplicon sequencing allows for taxonomic characterization of diverse microorganisms. While amplicon sequence variant (ASV) methods are increasingly favored for their fine-grained resolution of sequence variants, they often discard substantial portions of sequencing reads during quality control, particularly in datasets with large number samples. We present a streamlined pipeline that integrates FastP for read trimming, HmmUFOtu for operational taxonomic units (OTU) clustering, Vsearch for chimera checking, and Kraken2 for taxonomic assignment. To assess the pipeline's performance, we reprocessed two published stool datasets of normal Korean populations: one with 890 and the other with 1,462 independent samples. In the first dataset, HmmUFOtu retained 93.2% of over 104 million read pairs after quality trimming, discarding chimeric or unclassifiable reads, while DADA2, a commonly used ASV method, retained only 44.6% of the reads. Nonetheless, both methods yielded qualitatively similar β-diversity plots. For the second dataset, HmmUFOtu retained 89.2% of read pairs, while DADA2 retained a mere 18.4% of the reads. HmmUFOtu, being a closed-reference clustering method, facilitates merging separately processed datasets, with shared OTUs between the two datasets exhibiting a correlation coefficient of 0.92 in total abundance (log scale). While the first two dimensions of the β-diversity plot exhibited a cohesive mixture of the two datasets, the third dimension revealed the presence of a batch effect. Our comparative evaluation of ASV and OTU methods within this streamlined pipeline provides valuable insights into their performance when processing large-scale microbial 16S rRNA amplicon sequencing data. The strengths of HmmUFOtu and its potential for dataset merging are highlighted.

• 대한원격탐사학회지
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• 제39권5_3호
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• pp.967-978
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• 2023

본 연구에서는 다양한 드론 영상 데이터셋을 효과적으로 학습하여 의미론적 분할의 정확도를 향상시키기 위한 combined segmentation network (CSN)를 제안하고 검증하였다. CSN은 세 가지 드론 데이터셋의 다양성을 고려하기 위하여 인코딩 영역의 전체를 공유하며, 디코딩 영역은 독립적으로 학습된다. CSN의 경우, 학습 시 모든 데이터셋에 대한 손실값을 고려하기 때문에 U-Net 및 pyramid scene parsing network (PSPNet)으로 단일 데이터셋을 학습할 때보다 학습 효율이 떨어졌다. 그러나 국내 자율주행 드론 영상에 CSN을 적용한 결과, CSN이 PSPNet에 비해 초기 학습 없이도 영상 내 화소를 적절한 클래스로 분류할 수 있는 것을 확인하였다. 본 연구를 통하여 CSN이 다양한 드론 영상 데이터셋을 효과적으로 학습하고 새로운 지역에 대한 객체 인식 정확성을 향상시키는 데 중요한 도구로써 활용될 수 있을 것으로 기대할 수 있다.