• Title/Summary/Keyword: DoS detection

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Studies on the Easy Detection Method of Fasciola Eggs by Kim's Sedimental Tube (K-식(式) 침전관(沈澱管)에 의한 간질충란(肝蛭蟲卵) 간이검사법(簡易檢査法)에 관한 연구(硏究))

  • Kim, Kyo Joon;Kim, Sang Keun;Hu, Min Do
    • Korean Journal of Agricultural Science
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    • v.9 no.2
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    • pp.562-568
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    • 1982
  • These studies were carried out to investigate of detection of Fasciola egg from positive cattle faces in the intradermal reaction method by laborsaving composition of sieves and Kim's sedimental tube method. The results obtained are summerized as follows: 1. Detection method of Fasciola eggs was improved by 3 meshes(100mesh, 150mesh, 250mesh) for filtration of fecal fluid contained Fasciola eggs. 2. III type of tube in the 3 kinds of sedimental tube had the highest recovery rate of Fasciola egg. Thus, this type of tube was selected and called as Kim's sedimental tube. 3. A-II, A-III, B-III and C-III type by Kim's sedimental tube method had the recovery rates of eggs in the 1st dropping as ranged 99 to 100% and A-I, B-II, C-I and C-II as 71 to 91%. 4. All types as themselves contained the special aspects. In the these type was useful to determine the results in the urgent cases add to shorten the time of the diagnostic procedures. 5. Kim's sedimental tube method high recovery rate and convenient procedures as compared with other detection methods reported. In addition, through this method can also obatained E. P. C. value. Therefore, it is desirable that Kim's sedimental tube method be recommended by clinicians.

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Development of Third-Party Damage Monitoring System for Natural Gas Pipeline

  • Shin, Seung-Mok;Suh, Jin-Ho;Im, Jae-Sung;Kim, Sang-Bong;Yoo, Hui-Ryong
    • Journal of Mechanical Science and Technology
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    • v.17 no.10
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    • pp.1423-1430
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    • 2003
  • In this paper, we develop a real time monitoring system to detect third-party damage on natural gas pipeline. When the damage due to third-party incidents causes an immediate rupture, the developed on-line monitoring system can help reducing the sequences of event at once. Moreover, since many third-party incidents cause damage that does not lead to immediate rupture but can grow with time, the developed on-line monitoring system can execute a significant role in reducing many third-party damage incidents. Also, when the damage is given at a point on natural gas pipeline, the acoustic wave is propagated very fast about 421.3 m/s. Therefore, the data processing time should be very short in order to detect precisely the impact position. Generally, the pipeline is laid under ground or sea and the length is very long. So a wireless data communication method is recommendable and the sensing positions are limited by laid circumstance and setting cost of sensors. The calculation and monitoring software is developed by an algorithm using the propagation speed of acoustic wave and data base system based on wireless communication and DSP systems. The developed monitoring system is examined by field testing at Balan pilot plant, KOGAS being done in order to demonstrate its validity through reactive detection of third-party contact with pipelines. Furthermore, the development system was set at the practical pipelines such as an offshore pipeline between two islands Yul-Do and Youngjong-Do, and a land branch of Pyoungtaek, Korea and it has been operating in real time.

A Pilot Project of Systematic Tuberculosis Screening in the Elderly in a South Korean Province

  • Kim, Hyunwoo;Kim, Hee-Jin;Oh, Kyung-Hyun;Oh, Hwan-Wook;Choi, Hongjo
    • Tuberculosis and Respiratory Diseases
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    • v.82 no.3
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    • pp.194-200
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    • 2019
  • Background: Tuberculosis (TB) is a major infectious disease in South Korea causing substantial disease burden, particularly in the elderly. This study aimed to identify the case detection rate of mobile TB screening for the elderly conducted in the Jeollanam-do region and to analyze risk factors of active TB. Methods: We screened the elderly population (${\geq}65$ years old) in Jeollanam-do from August to December 2017. Chest radiography was performed for all participants. Participants with TB presumptive signs were asked to submit sputum specimen(s). Sputum smear, culture, and polymerase chain reaction analyses were performed. Cascade analysis, chi-squared tests, and Fisher exact tests were used to evaluate screening performance. Results: In total, 12,402 participants were screened, and 211 (1.7%) were suspected to have active TB; 181 of the suspected patients (85.8%) underwent sputum smear test, and 16 (8.8%) patients were confirmed to have TB. The TB prevalence among the elderly was bacteriologically confirmed to be 129 per 100,000 individuals, which was similar to national TB notification data for the same age groups. The proportion of active TB cases increased with age, and differed based on sex and past TB history. However, TB-related symptoms, comorbidity status, and TB screening history within 12 months were not predictive of active TB. Conclusion: This study identified that the prevalence rate was similar to national TB notification data from the same age groups. Periodic, community-based, systematic TB screening among the elderly population is recommended.

A Clonorchiasis Case of a Leopard Cat, Prionailurus bengalensis euptilurus, Diagnosed by Ultrasonography and Egg Detection in Republic of Korea

  • Choe, Seongjun;Jeong, Dong-Hyuk;Yang, Jeong-Jin;Kim, Jeongho;Na, Ki-Jeong;Lee, Dongmin;Park, Hansol;Jeon, Hyeong-Kyu;Eom, Keeseon S.
    • Parasites, Hosts and Diseases
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    • v.57 no.3
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    • pp.299-302
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    • 2019
  • A clonorchiasis case in a captive leopard cat, Prionailurus bengalensis euptilurus, was confirmed by ultrasonographic findings and egg morphologies found in the bile juice sample in the Korea. The leopard cat was introduced from the wild habitat of Gyeongsangnam-do, to Cheongju Zoo in Cheongju-si, Chungcheongbuk-do, Korea in August 2014. Physical examinations were basically performed for quarantine and check-up health. The cat was comparatively good in health except anorexia. The cyst-like bile duct dilation and the increased echogenicity of gall bladder wall and hepatic parenchyma were observed by ultrasonography. Ultrasound-guided needle biopsy was conducted for collecting bile juice and the specimens were observed under light microscope. The numerous small trematode eggs were detected in the bile juice sample of the light microscopy. The eggs were $25-33(28{\pm}3){\mu}m$ by $18-22(20{\pm}1){\mu}m$ in size and showed typical characteristics of Clonorchis sinensis egg, i.e., a dominantly developed operculum, shoulder rim and dust-like wrinkles in surface. To treat the liver fluke infection, 20 mg/kg of praziquantel was orally administered only once to the case. Follow-up studies including fecal examinations were conducted during 2 years after treatment. But no more eggs were detected from the case. In the present study, we described the first clonorchiasis case of leopard cat, which was confirmed by ultrasonographic findings and egg morphologies from the bile juice sample in Korea.

Development of Cloud and Shadow Detection Algorithm for Periodic Composite of Sentinel-2A/B Satellite Images (Sentinel-2A/B 위성영상의 주기합성을 위한 구름 및 구름 그림자 탐지 기법 개발)

  • Kim, Sun-Hwa;Eun, Jeong
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.989-998
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    • 2021
  • In the utilization of optical satellite imagery, which is greatly affected by clouds, periodic composite technique is a useful method to minimize the influence of clouds. Recently, a technique for selecting the optimal pixel that is least affected by the cloud and shadow during a certain period by directly inputting cloud and cloud shadow information during period compositing has been proposed. Accurate extraction of clouds and cloud shadowsis essential in order to derive optimal composite results. Also, in the case of an surface targets where spectral information is important, such as crops, the loss of spectral information should be minimized during cloud-free compositing. In thisstudy, clouds using two spectral indicators (Haze Optimized Tranformation and MeanVis) were used to derive a detection technique with low loss ofspectral information while maintaining high detection accuracy of clouds and cloud shadowsfor cabbage fieldsin the highlands of Gangwon-do. These detection results were compared and analyzed with cloud and cloud shadow information provided by Sentinel-2A/B. As a result of analyzing data from 2019 to 2021, cloud information from Sentinel-2A/B satellites showed detection accuracy with an F1 value of 0.91, but bright artifacts were falsely detected as clouds. On the other hand, the cloud detection result obtained by applying the threshold (=0.05) to the HOT showed relatively low detection accuracy (F1=0.72), but the loss ofspectral information was minimized due to the small number of false positives. In the case of cloud shadows, only minimal shadows were detected in the Sentinel-2A/B additional layer, but when a threshold (= 0.015) was applied to MeanVis, cloud shadowsthat could be distinguished from the topographically generated shadows could be detected. By inputting spectral indicators-based cloud and shadow information,stable monthly cloud-free composited vegetation index results were obtained, and in the future, high-accuracy cloud information of Sentinel-2A/B will be input to periodic cloud-free composite for comparison.

Design and Implementation of a Web Application Firewall with Multi-layered Web Filter (다중 계층 웹 필터를 사용하는 웹 애플리케이션 방화벽의 설계 및 구현)

  • Jang, Sung-Min;Won, Yoo-Hun
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.12
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    • pp.157-167
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    • 2009
  • Recently, the leakage of confidential information and personal information is taking place on the Internet more frequently than ever before. Most of such online security incidents are caused by attacks on vulnerabilities in web applications developed carelessly. It is impossible to detect an attack on a web application with existing firewalls and intrusion detection systems. Besides, the signature-based detection has a limited capability in detecting new threats. Therefore, many researches concerning the method to detect attacks on web applications are employing anomaly-based detection methods that use the web traffic analysis. Much research about anomaly-based detection through the normal web traffic analysis focus on three problems - the method to accurately analyze given web traffic, system performance needed for inspecting application payload of the packet required to detect attack on application layer and the maintenance and costs of lots of network security devices newly installed. The UTM(Unified Threat Management) system, a suggested solution for the problem, had a goal of resolving all of security problems at a time, but is not being widely used due to its low efficiency and high costs. Besides, the web filter that performs one of the functions of the UTM system, can not adequately detect a variety of recent sophisticated attacks on web applications. In order to resolve such problems, studies are being carried out on the web application firewall to introduce a new network security system. As such studies focus on speeding up packet processing by depending on high-priced hardware, the costs to deploy a web application firewall are rising. In addition, the current anomaly-based detection technologies that do not take into account the characteristics of the web application is causing lots of false positives and false negatives. In order to reduce false positives and false negatives, this study suggested a realtime anomaly detection method based on the analysis of the length of parameter value contained in the web client's request. In addition, it designed and suggested a WAF(Web Application Firewall) that can be applied to a low-priced system or legacy system to process application data without the help of an exclusive hardware. Furthermore, it suggested a method to resolve sluggish performance attributed to copying packets into application area for application data processing, Consequently, this study provide to deploy an effective web application firewall at a low cost at the moment when the deployment of an additional security system was considered burdened due to lots of network security systems currently used.

Detection of short-term flux variability and intraday variability in polarized emission at millimeter-wavelength from S5 0716+714

  • Lee, Jeewon;Sohn, Bong Won;Byun, Do-Young;Lee, Jeong Ae;Lee, Sang Sung;Kang, Sincheol;Kim, Sungsoo S.
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.33.1-33.1
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    • 2016
  • We report detection of short-term flux variability in multi-epoch observations and intraday variability in polarized emission at millimeter-wavelength from S5 0716+714 using Korean VLBI Network (KVN) radio telescopes. Over the whole observation epochs, the source shows significant inter-month variations at K- and Q-band with modulation indices of 19% at K-band and 36% at Q-band. In each epoch, the source shows monotonic flux increase in Epoch 1 and 3, and monotonic flux decrease in Epoch 2 and 4. We found an inverted spectrum with mean spectral indices of -0.57 in Epoch 1 and -0.15 in Epoch. On the contrary, we found relatively steep indices of 0.24 and 0.17 in Epoch 2 and Epoch 4, respectively. In the study of intraday variability of polarization, we found significant variations in the degree of linear polarization at 86 GHz, and in polarization angle at 43 and 86 GHz during ~10 h. The spectrum of the source is quite flat with spectral indices of -0.07 to 0.07 at 22-43 GHz and -0.23 to 0.04 at 43-86 GHz. The measured degree of the linear polarization ranges from 2.3% to 3.3 % at 22 GHz, from 0.9% to 2.2 % at 43 GHz and from 0.4 % to 4.0 % at 86 GHz, yielding prominent variations at 86 GHz over 4-5 h. The linear polarization angle is in the range of 4 to $12^{\circ}$ at 22 GHz, -39 to $81^{\circ}$ at 43 GHz, and 66 to 119 at 86 GHz with a maximum rotation of $110^{\circ}$ at 43 GHz over ~4 h. We estimated the Faraday rotation measures (RM) ranging from -9200 to 6300 rad m-2 between 22 and 43 GHz, and from -71000 to 7300 rad m-2 between 43 and 86 GHz, respectively. The frequency dependency of RM was investigated, yielding a mean power-law index, a, of 2.0. This implies that the polarized emission from S5 0716+714 at 22-86 GHz moves through a Faraday screen in or near the jet of the source.

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Detection of Perfluorinated Compounds (PFCs) in Nakdong River Basin (낙동강 수계에서의 과불화 화합물(PFCs) 검출 특성)

  • Son, Hee-Jong;Hwang, Young-Do;Yoom, Hoon-Sik;Choi, Jin-Taek;Kwon, Ki-Won
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.2
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    • pp.84-93
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    • 2013
  • The aims of this study were to investigate and confirm the occurrence and distribution patterns of perfluorinated compounds (PFCs) in Nakdong River basin (mainstream and its tributaries). 7 (PFOS, PFHpA, PFOA, PFNA, PFDA, PFUnDA and PFDoDA) out of 11 PFCs were detected in 29 sampling sites and PFOA and PFHpA were predominant compounds in upstream, but PFUnDA, PFDoDA and PFOS were predominant compounds in middle stream of Nakdong River basin. The total concentration levels of PFCs on February 2009 and on August 2009 in surface water samples ranged from 4.3. to 1168.2 ng/L and 16.4 to 627.8 ng/L, respectively. The highest concentration level of PFCs in the mainstream and tributaries in Nakdong River were Goryeong and Jincheon-cheon, respectively. The sewage treatment plants (STPs) along the river affect the PFCs levels in river and the PFCs levels decreased with downstream because of dilution effects.

Spirometra decipiens (Cestoda: Diphyllobothriidae) Collected in A Heavily Infected Stray Cat from the Republic of Korea

  • Jeon, Hyeong-Kyu;Park, Hansol;Lee, Dongmin;Choe, Seongjun;Eom, Keeseon S.
    • Parasites, Hosts and Diseases
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    • v.56 no.1
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    • pp.87-91
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    • 2018
  • Morphological and molecular characteristics of spirometrid tapeworms, Spirometra decipiens, were studied, which were recovered from a heavily infected stray cat road-killed in Eumseong-gun, Chungcheongbuk-do (Province), the Republic of Korea (=Korea). A total of 134 scolices and many broken immature and mature proglottids of Spirometra tapeworms were collected from the small intestine of the cat. Morphological observations were based on 116 specimens. The scolex was 22.8-32.6 mm (27.4 mm in average) in length and small spoon-shape with 2 distinct bothria. The uterus was coiled 3-4 times, the end of the uterus was ball-shaped, and the vaginal aperture shaped as a crescent moon was closer to the cirrus aperture than to the uterine aperture. PCR amplification and direct sequencing of the cox1 target fragment (377 bp in length and corresponding to positions 769-1,146 bp of the cox1 gene) were performed using total genomic DNA extracted from 134 specimens. The cox1 sequences (377 bp) of the specimens showed 99.0% similarity to the reference sequence of S. decipiens and 89.3% similarity to the reference sequence of S. erinaceieuropaei. In the present study, we report a stray cat heavily infected with S. decipiens identified by mitochondrial cox1 sequence analysis and morphological examinations of the adult worms.

Detection and Identification of Sarcocystis cruzi (Protozoa: Apicomplexa) by Molecular and Ultrastructural Studies in Naturally Infected Korean Cattle (Bos taurus coreanae) from Daejeon, Korea

  • Choi, Tong-Il;Hong, Eui-Ju;Ryu, Si-Yun;Sim, Cheolho;Chae, Joon-Seok;Kim, Hyeon-Cheol;Park, Jinho;Choi, Kyoung-Seong;Yu, Do-Hyeon;Yoo, Jae-Gyu;Park, Bae-Keun
    • Parasites, Hosts and Diseases
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    • v.56 no.2
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    • pp.121-127
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    • 2018
  • To survey the prevalence of Sarcocystis infections, 210 heart samples were collected from Korean native cattle (Bos taurus coreanae) at an abattoir in Daejeon Metropolitan City, Republic of Korea. Sarcocysts were detected form 31 specimens (14.8%) and identified as Sarcocystis cruzi via transmission electron microscopy. The wall of S. cruzi has flattened protrusions that did not contain fibrils or microfilaments. The protrusions arose irregularly from the base, contained a fine granular substance, lacked internal microfilaments, and measured approximately $0.21-1.25{\mu}m$ in length and $0.05-0.07{\mu}m$ in width. Sequence analysis revealed 99.5% homology to S. cruzi. This is the first report on the prevalence of S. cruzi in native cattle from the Republic of Korea.