• Smart Media Journal
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• v.12 no.2
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• pp.66-75
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• 2023

Recently, the number of cloud web applications is increasing owing to the accelerated migration of enterprises and public sector information systems to the cloud. Traditional network attacks on cloud web applications are characterized by Denial of Service (DoS) attacks, which consume network resources with a large number of packets. However, HTTP DoS attacks, which consume application resources, are also increasing recently; as such, developing security technologies to prevent them is necessary. In particular, since low-bandwidth HTTP DoS attacks do not consume network resources, they are difficult to identify using traditional security solutions that monitor network metrics. In this paper, we propose a new detection model for detecting HTTP DoS attacks on cloud web applications by collecting the application metrics of web servers and learning them using machine learning. We collected 18 types of application metrics from an Apache web server and used five machine learning and two deep learning models to train the collected data. Further, we confirmed the superiority of the application metrics-based machine learning model by collecting and training 6 additional network metrics and comparing their performance with the proposed models. Among HTTP DoS attacks, we injected the RUDY and HULK attacks, which are low- and high-bandwidth attacks, respectively. As a result of detecting these two attacks using the proposed model, we found out that the F1 scores of the application metrics-based machine learning model were about 0.3 and 0.1 higher than that of the network metrics-based model, respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.2
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• pp.129-139
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• 2008

Marine ecotoxicological standard method was applicated using marine rotifer and benthic copepod as primary consumer of marine ecosystem. Marine rotifer, Brachionus plicatilis and benthic copepod, Tigriopus japonicus were designated as standard test species with the endpoints of 24hr neonate mortality (24hr $LC_{50}$) and 48hr population growth (48hr $EC_{50}$) for rotifer, and 48hr nauplius mortality (48hr $LC_{50}$) for benthic copepod. Tests method was referred to those of ASTM (American Society for Testing and Materials) with the replacement of test species which are widely distributed in Korean waters. The two species showed a wide tolerance on salinity ($5{\sim}35\;psu$) and can be easily cultured in small space even they were not as sensitive as in the mortality test using the nauplius of marine invertebrates. However, these species revealed the significant "concentrationresponse relationship" tested with ocean disposal wastes, and reproducibility using cadmium as standard reference material between laboratories. Accordingly, these two species have good potential as test species for marine ecotoxicological test species. Also, we strongly recommend that at least one of these species be included in the test species of "battery test" in marine bioassay.

• Tuberculosis and Respiratory Diseases
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• v.65 no.1
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• pp.57-60
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• 2008

A fifty-seven year old female patient visited the emergency department with tachypnea and a decreased mental status. The patient had been receiving fluid therapy at home and a bolus of air was injected into the fluid bottle in order to increase the infusion speed. Chest computed tomography revealed air in the left brachiocephalic vein that was accompanied with pulmonary edema the diagnosis of venous air embolism was made. Venous air embolism can result from various procedures that are performed in almost all clinical specialties and they can be fatal in cases of massive air embolism. Therefore, it is important for all clinicians to be aware of this problem.

• Conservation Science in Museum
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• v.5
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• pp.31-36
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• 2004

The purpose of this experiment was to check the effects on metal corrosion of the 6 types of tree (Ash tree, Japanese cedar, black walnut, western hemlock, paulownia coreana and maple) which are currently being used, or the use of which is under study, by the Museum. As a method of test, an Oddy Test was conducted where the materials to be tested and the metal test piece are exposed to a specified temperature and humidity for a long period of time and the effects of materials on the test piece are observed. The results of the Oddy Test conducted on all 6 types of tree showed slight difference in the form of metal corrosion, and except for the blank, corrosion occurred on the entire surface of most iron (Fe) and lead (Pb) test pieces. Minor level of discoloration was noted in all test pieces of copper (Cu) even though different levels.

• Korean Journal of Medicinal Crop Science
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• v.10 no.3
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• pp.171-176
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• 2002

Antioxidative effect of 42 medicinal plant extracts was screened to search natural antioxidants. The extracts of Terminalia chebula, Caesalpinia sappan, Sanguisorba officinalis, Rubus coreanus, and Alpinia katsumadai showed strong inhibition effect on DPPH radical, and LDL oxidation. Those of Eugenia caryophyllata, Alpinia officinarum, Zingiber officinale, Xanthium strumarium, Sophora japonica, Aristolochia contorta, and Alpinia katsumadai exhibited potent antioxidative activity on linoleic acid peroxidation. Among 42 medicinal plant materials, the extract of Terminalia chebula showed the highest scavenging activity $(3.08\;{\mu}g/ml)$ on DPPH radical which was higher than that $(13.52\;{\mu}g/ml)$ of ${\alpha}-tocopherol$. The extract of Terminalia chebula showed also stronger inhibition activity on LDL oxidation than that of ${\alpha}-tocopherol$ did.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2002.05a
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• pp.131-131
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• 2002

종이가 인류의 생활에 미치는 비중은 정보의 전달을 제 l의 목적으로 사용되고 있는 인쇄용 지와 필기용지가 차지하는 것이 가장 크다. 정보전달의 매개로 사용되는 종이의 용도 이외 의 것을 살펴보면 전사지, 감압.감열지, 절연지,OMR지, 항공권지, 벽지 등과 같은 특수지와 기능지가 있다. 특히 벽지는 다양한 문양과 색감으로 인간의 미적 감각과 정신적 안정감에 미치는 영향이 크다. 벽지의 기능은 여러 가지의 목적으로 우리들의 실생활에 있어서 없어서는 안될 중요한 건축 재료로서 사용되고 있다. 가장 중요한 벽지의 목적은 앞서 언급한 바와 같이 미려한 색상과 다양한 디자인으로 도안.인쇄 및 발포 처리된 벽지를 사용하여 단순한 벽면을 개인의 취향 에 맞게 함으로써 심리적 안정감을 가져옴과 동시에 미적 가치를 증가 시켜 문화 수준의 향 상에도 영향을 미치는 것으로 알려져 있다. 그러나 종이 벽지와 종이 벽지 원지를 기저로 하여 제조된 발포 벽지는 인화성이 강하기 때 문에 이들에 대한 적절한 난연 처리가 요구 되고 있다. 매년 발생되는 다양한 형태의 화재 는 돌이킬 수 없는 인명과 재산의 손실로 귀결되어 각별한 주의가 요구되기 때문에 주거공 간과 대중의 군집이 많이 이루어지는 공공장소에서의 난연 처리된 벽지 사용에 대한 중요성 이 나날이 그 강도를 더 해가고 있는 실정이다. 난연 처리된 벽지는 통상적인 벽지에 비하 여 제조 원가의 상승에 따라 가격이 비싸기 때문에 일반인들에게 있어서 그 사용은 주목할 정도로 증가되지 못하고 있으나, 생활 수준이 향상 될수록 안전에 대한 의식 강화와 정부의 노력으로 인하여 그 사용량은 크게 늘어날 것으로 기대된다. 따라서 본 연구에서는 종이의 제조에 사용되는 원지의 충전제 종류와 양 그리고 난연 처리 된 폴리에스테르 섬유의 혼합을 달리하여 제조된 원지를 사용하여 난연 처려한 후 이들의 인화 특성에 대해 고찰 함으로써 보다 향상된 성능을 발휘 할 수 있는 난연 벽지의 제조와 개발에 보탬이 되고자 하였다.

• Journal of Navigation and Port Research
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• v.38 no.2
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• pp.97-103
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• 2014

In these days, the world has been increasing navy forces such as aircraft carriers and high-tech destroyers etc. and the importance of submarines is being emphasized. Therefore, accurate values of the derivatives in equations of motion are required to control motion of the submarines. Hydrodynamic derivatives were measured by the vertical planar motion mechanism(VPMM) model test. VPMM equipment gave pure heave and pitch motion respectively to the submarine model and the forces and moments were acquired by load cells. As a result, the hydrodynamic derivatives of the submarine are provided through the Fourier analysis of the forces and moments in this paper.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.117-118
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• 2013

In these days, the world have been increasing navy forces such as aircraft carriers and high-tech destroyers etc. and the importance of submarines is being emphasized. Therefore, accurate values of the derivatives in equations of motion are required to control motion of the submarines. Hydrodynamic coefficients were measured by the vertical planar motion mechanism(VPMM) model test. VPMM equipment gave pure heave and pitch motion respectively to the submarine model and the forces and moments were acquired by load cells. As a result, the hydrodynamic coefficients of the submarine are provided through the fourier analysis of the forces and moments in this paper.

• Korean journal of applied entomology
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• v.42 no.4
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• pp.329-334
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• 2003

To study the interaction between rice weevil and storage molds, the preference of rice weevil to the four mold species (Aspergilus candidus, A. niger, A. flavus and Penicillium spp.) and the resulting reproduction of the rice weevil were observed. The rice weevil preferred rice grains contaminated with the molds to autoclaved ones regardless of the mold species tested. Among the four mold species, A. candidus and Penicillium sp. were highly preferred than the others. Reproduction of the rice weevil was higher on the grains contalminated with A. candidus and Penicillium sp., than on autoclaved ones, but was lower on the grains contaminated with A. flavus. The partial disagreement between preference and reproduction of the rice weevil might be a suggestion that both the weevil behavior adapting nutritional requirements and the process of the long intensive coadaptation of the rice weevil and storage molds requiring similar moisture niche are the major components of the population interaction between the weevil and molds.

• Journal of the Korea Society of Computer and Information
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• v.16 no.4
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• pp.179-187
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• 2011

Multiple roadmap DB providers are already available in these days, and try to reduce unknown roads in their own roadmaps. However, cooperation models or Win-Win approaches between roadmap providers are not considered yet. Thus, In this paper, We proposed a cloud-oriented real-time roadmap generation and update method between heterogeneous navigation systems for unknown roads. With the proposed method, the roadmap DB providers update the own roadmap DB for navigation systems in real time. Also, they can provide the complete roadmap without unknown roads to users instantly. Therefore, the proposed method can reduce the costs of an actual traveling test and the maintenance for the roadmap DB provides. Thus, the cloud-oriented roadmap generation method can more efficiently update the unknown road information.