• Title/Summary/Keyword: anomaly score

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Anomaly Detection for User Action with Generative Adversarial Networks (적대적 생성 모델을 활용한 사용자 행위 이상 탐지 방법)

  • Choi, Nam woong;Kim, Wooju
    • Journal of Intelligence and Information Systems
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    • v.25 no.3
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    • pp.43-62
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    • 2019
  • At one time, the anomaly detection sector dominated the method of determining whether there was an abnormality based on the statistics derived from specific data. This methodology was possible because the dimension of the data was simple in the past, so the classical statistical method could work effectively. However, as the characteristics of data have changed complexly in the era of big data, it has become more difficult to accurately analyze and predict the data that occurs throughout the industry in the conventional way. Therefore, SVM and Decision Tree based supervised learning algorithms were used. However, there is peculiarity that supervised learning based model can only accurately predict the test data, when the number of classes is equal to the number of normal classes and most of the data generated in the industry has unbalanced data class. Therefore, the predicted results are not always valid when supervised learning model is applied. In order to overcome these drawbacks, many studies now use the unsupervised learning-based model that is not influenced by class distribution, such as autoencoder or generative adversarial networks. In this paper, we propose a method to detect anomalies using generative adversarial networks. AnoGAN, introduced in the study of Thomas et al (2017), is a classification model that performs abnormal detection of medical images. It was composed of a Convolution Neural Net and was used in the field of detection. On the other hand, sequencing data abnormality detection using generative adversarial network is a lack of research papers compared to image data. Of course, in Li et al (2018), a study by Li et al (LSTM), a type of recurrent neural network, has proposed a model to classify the abnormities of numerical sequence data, but it has not been used for categorical sequence data, as well as feature matching method applied by salans et al.(2016). So it suggests that there are a number of studies to be tried on in the ideal classification of sequence data through a generative adversarial Network. In order to learn the sequence data, the structure of the generative adversarial networks is composed of LSTM, and the 2 stacked-LSTM of the generator is composed of 32-dim hidden unit layers and 64-dim hidden unit layers. The LSTM of the discriminator consists of 64-dim hidden unit layer were used. In the process of deriving abnormal scores from existing paper of Anomaly Detection for Sequence data, entropy values of probability of actual data are used in the process of deriving abnormal scores. but in this paper, as mentioned earlier, abnormal scores have been derived by using feature matching techniques. In addition, the process of optimizing latent variables was designed with LSTM to improve model performance. The modified form of generative adversarial model was more accurate in all experiments than the autoencoder in terms of precision and was approximately 7% higher in accuracy. In terms of Robustness, Generative adversarial networks also performed better than autoencoder. Because generative adversarial networks can learn data distribution from real categorical sequence data, Unaffected by a single normal data. But autoencoder is not. Result of Robustness test showed that he accuracy of the autocoder was 92%, the accuracy of the hostile neural network was 96%, and in terms of sensitivity, the autocoder was 40% and the hostile neural network was 51%. In this paper, experiments have also been conducted to show how much performance changes due to differences in the optimization structure of potential variables. As a result, the level of 1% was improved in terms of sensitivity. These results suggest that it presented a new perspective on optimizing latent variable that were relatively insignificant.

ANNs on Co-occurrence Matrices for Mobile Malware Detection

  • Xiao, Xi;Wang, Zhenlong;Li, Qi;Li, Qing;Jiang, Yong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.7
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    • pp.2736-2754
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    • 2015
  • Android dominates the mobile operating system market, which stimulates the rapid spread of mobile malware. It is quite challenging to detect mobile malware. System call sequence analysis is widely used to identify malware. However, the malware detection accuracy of existing approaches is not satisfactory since they do not consider correlation of system calls in the sequence. In this paper, we propose a new scheme called Artificial Neural Networks (ANNs) on Co-occurrence Matrices Droid (ANNCMDroid), using co-occurrence matrices to mine correlation of system calls. Our key observation is that correlation of system calls is significantly different between malware and benign software, which can be accurately expressed by co-occurrence matrices, and ANNs can effectively identify anomaly in the co-occurrence matrices. Thus at first we calculate co-occurrence matrices from the system call sequences and then convert them into vectors. Finally, these vectors are fed into ANN to detect malware. We demonstrate the effectiveness of ANNCMDroid by real experiments. Experimental results show that only 4 applications among 594 evaluated benign applications are falsely detected as malware, and only 18 applications among 614 evaluated malicious applications are not detected. As a result, ANNCMDroid achieved an F-Score of 0.981878, which is much higher than other methods.

A Study about the Relationship between Maternal Attachment and Discharge Against Advice in High Risk Infants (모아 애착과 회복이 어려운 환아의 치료 포기와의 관계)

  • 김태임
    • Journal of Korean Academy of Nursing
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    • v.12 no.2
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    • pp.31-44
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    • 1982
  • The purpose of this study was to analyze the relationship between maternal attachment and discharge against advice in high risk infants and determine the factors which affect discharge against advice. Data of this study were collected by means of reviewing the medical records of 127 in-patients who were diagnosed as high risk infants in admission and interviewing of the mothers of these patients was done by telephone. The high risk categories were neonatal hyperbilirubinemia, congenital anomaly, congenital heart disease, blood disorder, neonatal infection and birth injury. Maternal attachment was measured by deviding the subjects into 2 groups, the one the continuing treatment group and the other the discharge against advice group. Maternal attachment is determined by an interplay of maternal attitude and specific infant behaviors. Maternal attachment developes through continuous physical and psychological contact between mother and infants. Later it developes into maternal love. The results were as follows: 1. There was a significant association between maternal attachment and discharge against advice, that is, the attachment score was higher in the continuing treatment group. 2. Inspite of controlling medical insurance, severity of disease and the length of stay, it was found that there continued to be either a partially significant or fully significant relationship between maternal attachment and discharge against advice. Stepwise multiple regression revealed that maternal attachment was second in importance as a predictor of discharge against advice, which indicates that maternal attachment was a significant predictor of discharge against advice. 3. Stepwise multiple regression revealed that in 32.3% of these cases the significant predictors of discharge against advice were length of stay, maternal attachment, delivery type, feeding type and income.

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Outcomes for Patients with Submucous Cleft Palate Accompanying Hypernasality Treated with Double Opposing Z-plasty (과대비성을 동반한 점막하구개열 환자에 대한 Double Opposing Z-plasty를 통한 수술적 치료 결과)

  • 김현준;김진영;배정호;김광문;최홍식
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.11 no.1
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    • pp.81-86
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    • 2000
  • Submucous cleft palate is a relatively uncommon congenital anomaly accompanying velopharyngeal incompetence(VPI). Double opposing Z-plasty has many advantages including prolongation of soft palate, normal midfacial growth, midline scar. We analyzed postoperative results comparing with those of preoperative evaluation by several variables(nasometer, endoscopy, satisfactory scale) in 14 patients treated with double opposing Z-plasty due to submcous cleft palate. Nasalance score in Ah sound, Ma phrase, and Pa phrase decreased 20.23%, 3.25%, and 23.26% in the average, respectively. As a result, hypernasality improved significantly. Closure rate in velum evaluated by endoscopy was increased from 0.44 to 0.76. In objective satisfactory scale checked by each patient's guardian at the postoperative period, much improved in 3, improved in 6, minimally improved in 1, and no difference in 1 was reported. (n=11 patients) Double opposing B-plasty is a good surgical modality in patients accompanying VPI with submucous cleft palate or incomplete cleft palate and will be used more usefully and widely.

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The Development of Ensemble Statistical Prediction Model for Changma Precipitation (장마 강수를 위한 앙상블 통계 예측 모델 개발)

  • Kim, Jin-Yong;Seo, Kyong-Hwan
    • Atmosphere
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    • v.24 no.4
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    • pp.533-540
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    • 2014
  • Statistical forecast models for the prediction of the summertime Changma precipitation have been developed in this study. As effective predictors for the Changma precipitation, the springtime sea surface temperature (SST) anomalies over the North Atlantic (NA1), the North Pacific (NPC) and the tropical Pacific Ocean (CNINO) has been suggested in Lee and Seo (2013). To further improve the performance of the statistical prediction scheme, we select other potential predictors and construct 2 additional statistical models. The selected predictors are the Northern Indian Ocean (NIO) and the Bering Sea (BS) SST anomalies, and the spring Eurasian snow cover anomaly (EUSC). Then, using the total three statistical prediction models, a simple ensemble-mean prediction is performed. The resulting correlation skill score reaches as high as ~0.90 for the last 21 years, which is ~16% increase in the skill compared to the prediction model by Lee and Seo (2013). The EUSC and BS predictors are related to a strengthening of the Okhotsk high, leading to an enhancement of the Changma front. The NIO predictor induces the cyclonic anomalies to the southwest of the Korean peninsula and southeasterly flows toward the peninsula, giving rise to an increase in the Changma precipitation.

Subseasonal-to-Seasonal (S2S) Prediction of GloSea5 Model: Part 2. Stratospheric Sudden Warming (GloSea5 모형의 계절내-계절 예측성 검정: Part 2. 성층권 돌연승온)

  • Song, Kanghyun;Kim, Hera;Son, Seok-Woo;Kim, Sang-Wook;Kang, Hyun-Suk;Hyun, Yu-Kyung
    • Atmosphere
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    • v.28 no.2
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    • pp.123-139
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    • 2018
  • The prediction skills of stratospheric sudden warming (SSW) events and its impacts on the tropospheric prediction skills in global seasonal forecasting system version 5 (GloSea5), an operating subseasonal-to-seasonal (S2S) model in Korea Meteorological Administration, are examined. The model successfully predicted SSW events with the maximum lead time of 11.8 and 13.2 days in terms of anomaly correlation coefficient (ACC) and mean squared skill score (MSSS), respectively. The prediction skills are mainly determined by phase error of zonal wave-number 1 with a minor contribution of zonal wavenumber 2 error. It is also found that an enhanced prediction of SSW events tends to increase the tropospheric prediction skills. This result suggests that well-resolved stratospheric processes in GloSea5 can improve S2S prediction in the troposphere.

Anomaly Detection using VGGNet for safety inspection of OPGW (광섬유 복합가공 지선(OPGW) 설비 안전점검을 위한 VGGNet 기반의 이상 탐지)

  • Kang, Gun-Ha;Sohn, Jung-Mo;Son, Do-Hyun;Han, Jeong-Ho
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2022.01a
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    • pp.3-5
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    • 2022
  • 본 연구는 VGGNet을 사용하여 광섬유 복합가공 지선 설비의 양/불량 판별을 수행한다. 광섬유 복합가공 지선이란, 전력선의 보호 및 전력 시설 간 통신을 담당하는 중요 설비로 고장 발생 전, 결함의 조기 발견 및 유지 관리가 중요하다. 현재 한국전력공사에서는 드론에서 촬영된 영상을 점검원이 이상 여부를 점검하는 방식이 주로 사용되고 있으나 이는 점검원의 숙련도, 경험에 따른 정확성 및 비용과 시간 측면에서 한계를 지니고 있다. 본 연구는 드론에서 촬영된 영상으로 VGGNet 기반의 양/불량 판정을 수행했다. 그 결과, 정확도 약 95.15%, 정밀도 약 96%, 재현율 약 95%, f1 score 약 95%의 성능을 확인하였다. 결과 확인 방법으로는 설명 가능한 인공지능(XAI) 알고리즘 중 하나인 Grad-CAM을 적용하였다. 이러한 광섬유 복합가공 지선 설비의 양/불량 판별은 점검원의 단순 작업에 대한 비용 및 점검 시간을 줄이며, 부가가치가 높은 업무에 집중할 수 있게 해준다. 또한, 고장 결함 발견에 있어서 객관적인 점검을 수행하기 때문에 일정한 점검 품질을 유지한다는 점에서 적용 가치가 있다.

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A Network Intrusion Security Detection Method Using BiLSTM-CNN in Big Data Environment

  • Hong Wang
    • Journal of Information Processing Systems
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    • v.19 no.5
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    • pp.688-701
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    • 2023
  • The conventional methods of network intrusion detection system (NIDS) cannot measure the trend of intrusiondetection targets effectively, which lead to low detection accuracy. In this study, a NIDS method which based on a deep neural network in a big-data environment is proposed. Firstly, the entire framework of the NIDS model is constructed in two stages. Feature reduction and anomaly probability output are used at the core of the two stages. Subsequently, a convolutional neural network, which encompasses a down sampling layer and a characteristic extractor consist of a convolution layer, the correlation of inputs is realized by introducing bidirectional long short-term memory. Finally, after the convolution layer, a pooling layer is added to sample the required features according to different sampling rules, which promotes the overall performance of the NIDS model. The proposed NIDS method and three other methods are compared, and it is broken down under the conditions of the two databases through simulation experiments. The results demonstrate that the proposed model is superior to the other three methods of NIDS in two databases, in terms of precision, accuracy, F1- score, and recall, which are 91.64%, 93.35%, 92.25%, and 91.87%, respectively. The proposed algorithm is significant for improving the accuracy of NIDS.

Statistical Studies on the Gestation and Delivery of the Pregnant Women and on the Neonates (한국부인의 임신.분만 및 신생아에 대한 통계적 연구)

  • Choi, Joong-Myung
    • Journal of Preventive Medicine and Public Health
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    • v.17 no.1
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    • pp.193-202
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    • 1984
  • Clinical and statistical observations were performed on 1,930 cases of pregnant women who were admitted for delivery in the Department of Obstetrics, Kyung Hee University Hospital during 1 year (1982) and on 1,961 cases of neonates who were born to the former. The results were obtained as follows: 1. Concerning maternal age distribution, the commonest age group was that of $25{\sim}29$ and the proportion of the age group $20{\sim}29$ was 82.4% of all. 2. Concerning obstetrical history, the proportion of the women who had no prior experience of delivery nor abortion was the highest, 45.5%. 3. Concerning abortion history, 36.1% of the women had experienced it and the mean number was 1.8. 4. Type of delivery was as follows: Spontaneous delivery; 58.1%, Vacuum extracted delivery; 22.4%, Cesarean section; 18:8%, Breech delivery; 0.7%. 5. Gestational period distribution of the neonates was as follows: Under 37 weeks (Preterm); 7.1%, Between 38 and 42 weeks (Term); 87.2%, More than 43 weeks (Postterm); 5.7%. 6. Sex ratio of male to female of the neonates was 1.03:1. 7. Birth weight distribution was as follows: Under 2,500gm.; 9.0%, Between 2,501 and 4,000 gm.; 85.5%, More than 4,001gm.; 5.5%. 8. The measured growth data of neonates were as follows: Body weight; 3.28kg. for male, 3.18kg. for female, Body height; 50.40cm for male, 49.77cm for female, Chest circumference; 32.54cm for male. 32.17cm for female, Head circumference; 33.49cm for male, 33.11cm for female. 9. The mean values of Apgar score per 1 minute were 7.70 for male and 7.63 for female. 10. The incidence rate of neonatal jaundice was 50.0% and no difference in sex respectively, but more prevalent in preform baby. 11. The incidence rate of neonatal diseases was 8.9% and the commonest disease was neonatal infection (35.6%). 12. Concerning multiple pregnancy, ratio to single births was 1 : 64.3 and the sex ratio of male to female was 1 : 1.03. 13. The incidence rate of congenital anomaly was 2.4% and the commonest anomaly was digestive system anomaly (30.9%). 14. The neonatal mortality rate was 11.73 per 1,000 neonates, and the majority of neonatal deaths were in low birth weight and preform neonates (78.3%). 15. The causes of neonatal deaths in decreasing order of frequency were abnormal ventilation (39.1%), prematurity (30.4%), congenital anomaly (13.0%) and etc.

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A Study on the Health Status of Korean Vietnam Veterans' Children - A Result of Questionnaire Survey on Vietnam Veterans of Pusan Area Who Diagnosed as Cases by Korean Veteran's Hospital Diagnostic Criteria - (베트남전 참전자 2세의 건강상태에 관한 조사 - 부산지역 고엽제 위해증 환자를 대상으로 한 설문조사 결과 -)

  • Kim, Hak-Joon;Sohn, Hae-Sook;Urm, Sang-Hwa;Park, Soo-Kyung;Yu, Byung-Chul;Lee, Jong-Tae;Chun, Jin-Ho
    • Journal of Preventive Medicine and Public Health
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    • v.33 no.1
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    • pp.17-24
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    • 2000
  • Objectives : To propose the referential data to evaluate the health impacts of Vietnam veterans' children whose father were exposed to herbicides in Vietnam War. Methods : Vietnam veterans who visited to Pusan Veteran Hospital for medical care were recruited from April to October, 1998. They were 71 and asked about their own combat history, symptoms and illness, and health status of their 182 children. The informations were collected by direct and phone interview. Exposure estimation was also performed as exposure score depending on year and unit of participation, and personal episodes related to exposure to herbicide in the war. It classified into three groups; lower(<18.0), moderate(18-53), high$(\geq53)$ exposure group. Results : The mean age and the period into the combat of the veterans were 52.8 years and 15.0 months. The mean exposure score was $18.1{\pm}9.9$, and mainly distributed in lower (46.5%) and moderate(52.1%) exposure group. Most(90.1%) of them were diagnosed as sequelae(21 cases) and suspected sequelae(43 cases) of the herbicides by Korean veteran's hospital diagnostic criteria. The major sequelae was peripheral neuropathy 13 cases, chloracne 5 cases, and the major suspected sequelae was hypertension 20 cases, diabetes mellitus 18 cases, liver disease 12 cases, central neuropathy 11 cases, etc. About birth, 42.2% and 16.9% experienced spontaneous abortion and stillbirth, respectively. The mean exposure score was higher in stillbirth experience group(p<0.05). About half of the children(90 cases, 49.5%) hold the abnormal health status: those were skin pigmentation 38 cases, rash 23 cases, congenital anomaly 15 cases, general weakness 12 cases, purpura 8 cases, visual disturbance 8 cases, etc. These health problems had no association with father's exposure level(p>0.05). Conclusions : These results were depend on their own answers, and expectation for compensation did not excluded, therefore, this study may have limitations: inaccuracy of informations due to recall bias and response bias. Nevertheless, through this study, we could image the fundamental aspect for health impacts of Vietnam veterans' children for preparing the national control program and policy. A large scale epidemiologic study with valid exposure assessment on the health impacts of Vietnam veterans' children is recommneded.

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