• Journal of Applied Reliability
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• v.18 no.1
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• pp.20-32
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• 2018

Purpose: The purpose of this study is to set up an anomaly detection criteria for sensor data coming from a motorcycle. Methods: Five sensor values for accelerator pedal, engine rpm, transmission rpm, gear and speed are obtained every 0.02 second from a motorcycle. Exploratory data analysis is used to find any pattern in the data. Traditional process control methods such as X control chart and time series models are fitted to find any anomaly behavior in the data. Finally unsupervised learning algorithm such as k-means clustering is used to find any anomaly spot in the sensor data. Results: According to exploratory data analysis, the distribution of accelerator pedal sensor values is very much skewed to the left. The motorcycle seemed to have been driven in a city at speed less than 45 kilometers per hour. Traditional process control charts such as X control chart fail due to severe autocorrelation in each sensor data. However, ARIMA model found three abnormal points where they are beyond 2 sigma limits in the control chart. We applied a copula based Markov chain to perform statistical process control for correlated observations. Copula based Markov model found anomaly behavior in the similar places as ARIMA model. In an unsupervised learning algorithm, large sensor values get subdivided into two, three, and four disjoint regions. So extreme sensor values are the ones that need to be tracked down for any sign of anomaly behavior in the sensor values. Conclusion: Exploratory data analysis is useful to find any pattern in the sensor data. Process control chart using ARIMA and Joe's copula based Markov model also give warnings near similar places in the data. Unsupervised learning algorithm shows us that the extreme sensor values are the ones that need to be tracked down for any sign of anomaly behavior.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.157-164
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• 2006

The Recently, most of Internet attacks are zero-day types of the unknown attacks by Malware. Using already known Misuse Detection Technology is hard to cope with these attacks. Also, the existing information security technology reached the limits because of various attack's patterns over the Internet, as web based service became more affordable, web service exposed to the internet becomes main target of attack. This paper classifies the traffic type over the internet and suggests the Threat Management System(TMS) including the anomaly intrusion detection technologies which can detect and analyze the anomaly sign for each traffic type.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.1
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• pp.85-94
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• 2022

To detect anomaly signs of thermal runaway in advance, this study analyzed the signals from various sensors installed in lithium-ion batteries. The thermal runaway mechanism was analyzed, and measurement variables for anomalies of a battery cell were surface temperature, strain, and gas concentration. The changes and characteristics of three variables during the thermal runaway process were analyzed under the abuse environment: the overheat and the overcharge. In experiment, the thermal runaway of the battery proceeded in the initial developing stage, the outgassing stage, and the ignition stage. Analysis from the measured data indicated that the suitable variable to detect all stages of thermal runaway is the surface temperature of the battery, and surface strain is alternative.

• The KIPS Transactions:PartC
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• v.11C no.6 s.95
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• pp.719-724
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• 2004

Recently, since the number of internet users is increasing rapidly and, by using the public hacking tools, general network users can intrude computer systems easily, the hacking problem is getting more serious. In order to prevent the intrusion, it is needed to detect the sign in advance of intrusion in a positive prevention by detecting the various foms of hackers' intrusion trials to know the vulnerability of systems. The existing network-based anomaly detection algorithms that cope with port- scanning and the network vulnerability scans have some weakness in intrusion detection. they can not detect slow scans and coordinated scans. therefore, the new concept of algorithm is needed to detect effectively the various forms of abnormal accesses for intrusion regardless of the intrusion methods. In this paper, SPAD(Session Pattern Anomaly Detector) is presented, which detects the abnormal service patterns by comparing them with the ordinary normal service patterns.

• Advances in pediatric surgery
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• v.8 no.2
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• pp.107-112
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• 2002

Branchial anomaly is a frequently occurring congenital abnormality in childhood. It is important for the pediatric surgeon alike to be familiar with the embryology and differentiation of head and neck structure to accurately diagnose and treat these lesions. Eighty-five patients with branchial anomaly treated at Hanyang University Hospital between 1980 and 2001 were reviewed to determine relative frequency, clinical classification and appropriate treatment. The male to female ratio of branchial anomaly was 1.2:1. The most commonly presenting age was before 1 year (32%) and the age group between 1 and 3 year (22%) followed it. According to the classification of branchial anomalies, 73 of 85 cases were second branchial anomaly, 9 had the first type and 3 did fourth type. One patient showed combined anomalies of the first and the second type. Infection sign were seen in 70% of patients at the time of the first visit to our hospital and also patients' symptoms were frequently related with the infection. Forty-one cases (48%) were fistula, 21 (25%) were cysts, 21 (25%) were sinuses, and two were only cartilage remnants. The most common type of the branchial anomalies is the second branchial fistula and the most common symptoms of the anomalies are related with infection. Initial proper diagnosis and anatomical classification of the anomalies are very important in managing the lesions. The efforts to find the exact anatomical location of the fistula or sinus tract are necessary because total excision of the lesions including those tracts is the only way to prevent recurrence.

• Journal of Internet Computing and Services
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• v.24 no.1
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• pp.49-59
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• 2023

Recently, attention to the pandemic situation represented by COVID-19 emerged problems caused by unexpected shortage of medical personnel. In this paper, we present a method for diagnosing the presence or absence of lesional sign on PA chest X-ray images as computer vision solution to support diagnosis tasks. Method for visual anomaly detection based on feature modeling can be also applied to X-ray images. With extracting feature vectors from PA chest X-ray images and divide to patch unit, region-specific abnormality can be detected. As preliminary experiment, we created simulation data set containing multiple objects and present results of the comparative experiments in this paper. We present method to improve both efficiency and performance of the process through hard masking of patch features to aligned images. By summing up regional specificity and global anomaly detection results, it shows improved performance by 0.069 AUROC compared to previous studies. By aggregating region-specific and global anomaly detection results, it shows improved performance by 0.069 AUROC compared to our last study.

• Advances in pediatric surgery
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• v.17 no.2
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• pp.162-169
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• 2011

Branchial cleft anomalies are the second most common head and neck congenital lesions seen in children. Amongst the branchial cleft malformations, second cleft lesions account for 95 % of the branchial anomalies. This article analyzes all the cases of second branchial cleft anomalies operated on at Seoul National University Hospital from September 1995 to February 2011. We analyzed sex, age, symptom and sign, accompanied anomaly, diagnosis, treatment, pathologic report and outcome via retrospective review of medical records. In this series, we had 61 patients (27 female and 34 male). The mean age at the time of operation was 38 months. 31 lesions were on the right, 20 were on the left and 10 were bilateral. The most frequent chief complaints at presentation were non-tender mass and cervical opening without any discharge. According to anatomic type, 29 patients had branchial cleft sinuses, 14 had cysts, 14 had fistulas and 4 had skin tags. Complete excision was attempted if possible and antibiotics challenged when infection was suspected. Complete excision was achieved in 96.7 % of cases. Incision and drainage was done in 2 cases due to severe inflammation, and both recurred. Postoperative complications included wound infection in 2 cases. Microscopic examonation revealed squamous epithelium in 90.2 % and squamous metaplasia in one case in the branchial cleft cyst wall. In summary, second branchial anomaly is found more frequently on right side of neck. Fistulas are diagnosed earlier than cystic forms. Most cases could be diagnosed by physical examination. The definitive treatment is complete excision and sufficient antibiotics coverage for cases with inflammation. After drainage of infected lesions, follow up excision after 1 year might be beneficial for preventing recurrence.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.9-16
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• 2005

Recently, since the number of internet users is increasing rapidly and, by using the Public hacking tools, general network users can intrude computer systems easily, the hacking problem is setting more serious. In order to prevent the intrusion. it is needed to detect the sign in advance of intrusion in a Positive Prevention by detecting the various forms of hackers intrusion trials to know the vulnerability of systems. The existing network-based anomaly detection algorithms that cope with port-scanning and the network vulnerability scans have some weakness in intrusion detection. they can not detect slow scans and coordinated scans. therefore, the new concept of algorithm is needed to detect effectively the various. In this Paper, we propose a detection algorithm for session patterns and FCM.

• Journal of Chest Surgery
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• v.13 no.4
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• pp.448-454
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• 1980

The juxtaposition of atrial appendage may possibly be diagnosed by angiography recently, and it is widely regarded as an ominous sign of severe cyanotic congenital heart disease. However, it is apparently rare congenital cardiac anomaly in which the atrial appendages lie side by side, both to the left or right of the great arteries, known as left or right juxtaposition of the atrial appendages. Juxtaposition of the atrial appendages has no functional significance, since it does not, itself, cause any hemodynamic disturbance. But it`s presence always indicates the coexistence of other major cardiac anomalies. In review of literatures TGA and VSD are invariable present, and ASD is common. Other anomalies, such as, tricuspid atresia, pulmonary outflow that, obstruction bicuspid pulmonic valve, persistent SVC etc. are relatively high incidence. In this report, we present one case of 6 year old female child having left juxtaposition of atrial appendage combined with TGA [D-looping, D-transposition], TAPVD, large ASD, small VSD, and vertical vein.

• Progress in Superconductivity
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• v.4 no.1
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• pp.32-36
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• 2002

We have measured the Hall effect in infinite-layer Sr／sub 0.9／La／sub 0.1／$CuO_2$ thin films grown by molecular beam epitaxy. We do not observe $T^{2}$ dependence of the cotangent of Hall angle, which is commonly observed in other cuprate High-Tc superconductors. Therefore, this result cannot be interpreted within two different scattering mechanism based on charge-spin separation theory. The mixed-state Hall effect shows no sign anomaly, implying that tile hydrodynamic contribution of vortex core is negligibly small.