• 제목/요약/키워드: Preprocessing method

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A Network Packet Analysis Method to Discover Malicious Activities

  • Kwon, Taewoong;Myung, Joonwoo;Lee, Jun;Kim, Kyu-il;Song, Jungsuk
    • Journal of Information Science Theory and Practice
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    • 제10권spc호
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    • pp.143-153
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    • 2022
  • With the development of networks and the increase in the number of network devices, the number of cyber attacks targeting them is also increasing. Since these cyber-attacks aim to steal important information and destroy systems, it is necessary to minimize social and economic damage through early detection and rapid response. Many studies using machine learning (ML) and artificial intelligence (AI) have been conducted, among which payload learning is one of the most intuitive and effective methods to detect malicious behavior. In this study, we propose a preprocessing method to maximize the performance of the model when learning the payload in term units. The proposed method constructs a high-quality learning data set by eliminating unnecessary noise (stopwords) and preserving important features in consideration of the machine language and natural language characteristics of the packet payload. Our method consists of three steps: Preserving significant special characters, Generating a stopword list, and Class label refinement. By processing packets of various and complex structures based on these three processes, it is possible to make high-quality training data that can be helpful to build high-performance ML/AI models for security monitoring. We prove the effectiveness of the proposed method by comparing the performance of the AI model to which the proposed method is applied and not. Forthermore, by evaluating the performance of the AI model applied proposed method in the real-world Security Operating Center (SOC) environment with live network traffic, we demonstrate the applicability of the our method to the real environment.

치아교정의 역학적 해석을 의한 유한요소 모델링 및 치아의 거동해석 (Finite Element Modeling and Mechanical Analysis of Orthodontics)

  • 허경헌;차경석;주진원
    • 대한기계학회논문집A
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    • 제24권4호
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    • pp.907-915
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    • 2000
  • The movement of teeth and initial stress associated with the treatment of orthodontics have been successfully studied using the finite element method. To reduce the effort in preprocessing of finite element analysis, we developed two types of three-dimensional finite element models based on the standard teeth model. Individual malocclusions were incorporated in the finite element The movement of teeth and initial stress associated with the treatment of orthodontics have been successfully studied using the finite element method. To reduce the effort in preprocessing of finite element analysis, we developed two types of three-dimensional finite element models based on the standard teeth model. Individual malocclusions were incorporated in the finite element models by considering the measuring factors such as angulation, crown inclination, rotation and translations. The finite element analysis for the wire activation with a T-loop arch wire was carried out. Mechanical behavior on the movement and the initial stress for the malocclusion finite element model was shown to agree with the objectives of the actual treatment. Finite element models and procedures of analysis developed in this study would be suitably utilized for the design of initial shape of the wire and determination of activation displacements.

경상도 별미김치의 표준화 연구 (Standardizations of Traditional Special Kimchi in Kyungsang Province)

  • 한지숙
    • 동아시아식생활학회지
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    • 제5권2호
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    • pp.27-38
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    • 1995
  • This study was conducted to standardize ingredient ratio and preparation method of mafor traditional special kimchies in kyungsang province, korea. There were about 35 varieties of special kimchi in Kyungsang province. Six varieties of them such as burdock kimchi, wild leek kimchi, green thread onion kimchi, perilla leaf kimchi, Godulbaegi(Korean wild lettuce) kimchi, and red pepper leaf kimchi were selected, because they tasted good and the physiological functions of their main ingredients were excellent. The ingredient ratios of the selected special kimchi were standardized through surveying hereditary preparation of some families in kyungsang province and using the literatures including cooking books. The standardized ingredient ratio of the burdock kimchi was 15.1 pickled anchovy juice, 6.8 red pepper powder, 5.7 garlic, 2.2 ginger, 18.0 rice flour paste, 13.5 green thread onion, and 1.2 sesame seed in proportion to 100 of burdock. The standardized preparation step of the selected special kimchies was similar except some preprocessing methods of main ingredients. The diagonally cut-up burdock ws usually parboiled or soaked in salted water, then it was mixed with the other ingredients. Wild leek and green thread onion were usually pickled with salt or pickled anchovy juice. Sometimes the green thread onion pickled was dried in the sun. General preprocessing of perilla leaf, Korean wild lettuce, and red pepper leaf was soaking them in salted water for about 5-10 days. Sometimes red pepper leaf was heated with steam and dried in the sun, then it was mixed with the other ingredients.

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컨테이너 식별자 영상 인식 시스템에서 다중 임계영역을 이용한 영상 전처리 (Image Preprocessing in Container Identifier Recognition System Using Multiple Threshold Regions)

  • 우종호
    • 한국멀티미디어학회논문지
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    • 제16권5호
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    • pp.549-557
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    • 2013
  • 본 논문에서는 컨테이너 식별자 영상 인식 시스템의 전처리 과정에 다중 임계 영역을 사용하는 방안을 제안한다. 컨테이너 영상의 특징을 이용해서, 설정된 여러 개의 후보 임계 영역들을 사용해서 영상을 각각 이진화하고, 각각의 이진 영상에 대해서 라벨링, 패널링 등을 함께 진행하면서 최종적으로 최적의 문자 영역을 추출한다. 또한 유사한 방법을 적용해서 잡음을 제거하고 개별 문자를 분리한다. 영상 162장을 사용한 실험에서 문자 영역 분리와 개별 문자 분리의 성공률이 각각 99.04%와 98.09%가 되었다.

Correction of Signboard Distortion by Vertical Stroke Estimation

  • Lim, Jun Sik;Na, In Seop;Kim, Soo Hyung
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제7권9호
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    • pp.2312-2325
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    • 2013
  • In this paper, we propose a preprocessing method that it is to correct the distortion of text area in Korean signboard images as a preprocessing step to improve character recognition. Distorted perspective in recognizing of Korean signboard text may cause of the low recognition rate. The proposed method consists of four main steps and eight sub-steps: main step consists of potential vertical components detection, vertical components detection, text-boundary estimation and distortion correction. First, potential vertical line components detection consists of four steps, including edge detection for each connected component, pixel distance normalization in the edge, dominant-point detection in the edge and removal of horizontal components. Second, vertical line components detection is composed of removal of diagonal components and extraction of vertical line components. Third, the outline estimation step is composed of the left and right boundary line detection. Finally, distortion of the text image is corrected by bilinear transformation based on the estimated outline. We compared the changes in recognition rates of OCR before and after applying the proposed algorithm. The recognition rate of the distortion corrected signboard images is 29.63% and 21.9% higher at the character and the text unit than those of the original images.

A Sentiment Classification Approach of Sentences Clustering in Webcast Barrages

  • Li, Jun;Huang, Guimin;Zhou, Ya
    • Journal of Information Processing Systems
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    • 제16권3호
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    • pp.718-732
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    • 2020
  • Conducting sentiment analysis and opinion mining are challenging tasks in natural language processing. Many of the sentiment analysis and opinion mining applications focus on product reviews, social media reviews, forums and microblogs whose reviews are topic-similar and opinion-rich. In this paper, we try to analyze the sentiments of sentences from online webcast reviews that scroll across the screen, which we call live barrages. Contrary to social media comments or product reviews, the topics in live barrages are more fragmented, and there are plenty of invalid comments that we must remove in the preprocessing phase. To extract evaluative sentiment sentences, we proposed a novel approach that clusters the barrages from the same commenter to solve the problem of scattering the information for each barrage. The method developed in this paper contains two subtasks: in the data preprocessing phase, we cluster the sentences from the same commenter and remove unavailable sentences; and we use a semi-supervised machine learning approach, the naïve Bayes algorithm, to analyze the sentiment of the barrage. According to our experimental results, this method shows that it performs well in analyzing the sentiment of online webcast barrages.

Building Hybrid Stop-Words Technique with Normalization for Pre-Processing Arabic Text

  • Atwan, Jaffar
    • International Journal of Computer Science & Network Security
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    • 제22권7호
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    • pp.65-74
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    • 2022
  • In natural language processing, commonly used words such as prepositions are referred to as stop-words; they have no inherent meaning and are therefore ignored in indexing and retrieval tasks. The removal of stop-words from Arabic text has a significant impact in terms of reducing the size of a cor- pus text, which leads to an improvement in the effectiveness and performance of Arabic-language processing systems. This study investigated the effectiveness of applying a stop-word lists elimination with normalization as a preprocessing step. The idea was to merge statistical method with the linguistic method to attain the best efficacy, and comparing the effects of this two-pronged approach in reducing corpus size for Ara- bic natural language processing systems. Three stop-word lists were considered: an Arabic Text Lookup Stop-list, Frequency- based Stop-list using Zipf's law, and Combined Stop-list. An experiment was conducted using a selected file from the Arabic Newswire data set. In the experiment, the size of the cor- pus was compared after removing the words contained in each list. The results showed that the best reduction in size was achieved by using the Combined Stop-list with normalization, with a word count reduction of 452930 and a compression rate of 30%.

GAF 변환을 사용한 딥 러닝 기반 단일 리드 ECG 신호에서의 수면 무호흡 감지 (Sleep apnea detection from a single-lead ECG signal with GAF transform feature-extraction through deep learning)

  • 주우;이승은;강경태
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2022년도 제66차 하계학술대회논문집 30권2호
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    • pp.57-58
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    • 2022
  • Sleep apnea (SA) is a common chronic sleep disorder that disrupts breathing during sleep. Clinically, the standard for diagnosing SA involves nocturnal polysomnography (PSG). However, this requires expert human intervention and considerable time, which limits the availability of SA diagnoses in public health sectors. Therefore, ECG-based methods for SA detection have been proposed to automate the PSG procedure and reduce its discomfort. We propose a preprocessing method to convert the one-dimensional time series of ECG into two-dimensional images using the Gramian Angular Field (GAF) algorithm, extract temporal features, and use a two-dimensional convolutional neural network for classification. The results of this study demonstrated that the proposed method can perform SA detection with specificity, sensitivity, accuracy, and area under the curve (AUC) of 88.89%, 81.50%, 86.11%, and 0.85, respectively. Our experimental results show that SA is successfully classified by extracting preprocessing transforms with temporal features.

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Gabor 필터를 이용한 지문 인식 (Fingerprint Recognition using Gabor Filter)

  • 심현보;박영배
    • 정보처리학회논문지B
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    • 제9B권5호
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    • pp.653-662
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    • 2002
  • 지문인식은 입력지문이 데이터베이스 내에 있는 특성인의 지문과 일치하는지 여부를 확인하는 것이다. 이를 위해 대형 지문 데이터베이스에서는 여러 가지 전처리 과정과 분류 및 매칭을 하고 소형 지문데이터 인식에서는 분류를 하지 않고 바로 매칭을 한다. 매칭 방법은 특징점 (단점, 분기점)에 기초한 매칭이 주를 이루고 있는데, 특징점에 기초한 매칭은 지문의 변환, 회전, 비선형 변형, 가짜 특징점 등이 발생하는 문제로 특징점 추출 및 특징점들 간의 정확한 매칭에 매우 복잡한 계산을 필요로 하고, 지문의 품질향상을 위해 많은 전처리 과정이 필요한 문제점이 있다. 본 논문에서는 이러한 문제점을 해결하기 위하여 지문인식에 특징점을 이용하지 않고, Gabor 필터에 지문을 통과시켜 얻은 지문의 융선에서 Gabor 특징값을 산출하여 이 특징값을 지문인식에 이용하는 간단한 새로운 방법을 제안하고 이 방법이 지문인식 실행에 가능성을 가지고 있음을 실험으로 증명하였다.

분수계 기반 영상 분할의 속도 개선을 위한 새로운 전처리 방법 (A New Preprocessing Method for the Seedup of the Watershed-based Image Segmentation)

  • 조상현;최흥문
    • 대한전자공학회논문지SP
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    • 제37권2호
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    • pp.50-59
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    • 2000
  • 본 논문에서는 분수계 기반 영상 분할의 속도 개선을 위한 새로운 전처리 방법을 제안하였다 영상 분할을 위한 분수계 변환에 있어서, 단순히 단일척도 또는 다중척도의 형태학적 기울기 연산자를 사용하여 만드는 기존의 기준 영상과는 달리, 제안한 방법에서는 원 영상에 라플라시안 연산을 수행해 램프 에지의 위치와 에지 폭을 구한후 이로부터 램프 에지 기울기 보정값을 구하였다 그런후, 단일척도 기울기 연산자를 사용한 영상에 이들 램프 에지의 위치에만 보정값을 더하여 기준 영상을 만들었다 여기에 마커 영상을 만들어 부식에 의해 재구성하여 얻은 영상을 분수계 변환함으로써, 단일 또는 다중 척도 기울기 연산에 의한 기준 영상을 사용한 경우보다 과분할을 방지할 수 있어서, 분수계 기반 영상 분할 처리 시간의 대부분을 차지하는 영역 병합을 대폭 줄여 총 영상 분할 시간을 단축하였다 기존의 방법들과의 비교 실험을 통하여 제안한 방법은 램프 에지나 에지 밀집 지역의 주요 에지들의 소실 없이 과분할을 줄여 전체 영상 분할 속도를 약 2배 가까이 향상시킬 수 있음을 확인하였다

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