• 제목/요약/키워드: Secondary Damage

검색결과 466건 처리시간 0.021초

중등학교의 보안성 평가를 위한 지표 개발에 관한 연구 (A Study on the development of metrics for security evaluation of secondary schools)

  • 고진홍;안성진
    • 한국사이버테러정보전학회:학술대회논문집
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    • 한국사이버테러정보전학회 2004년도 제1회 춘계학술발표대회
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    • pp.145-151
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    • 2004
  • 학내 전산망은 정보의 주도로 교수학습에 필요한 네트워크 자산을 통한 교육적인 활동을 지원하기 위해서 많은 학교에 설치되었다 반면에 인터넷의 개방성과 학내 전산망의 보안 실태 때문에 내부자나 정보를 얻고자하는 하는 해커들에 의하여 상당한 피해를 당하고 있다. 그러므로, 본 연구에서는 학내 정보자산을 분류하고 보안항목 및 문제점을 제시하고 있다. 마지막으로, 정보자산의 부분별로 효율적이고 조직적으로 평가 지표를 제시하였다.

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제주도 산딸나무 군락의 생태적 특성 (Native Cornus kousa Community and Its Habitat in Jeju Island)

  • 안영희;심경구
    • 한국환경과학회지
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    • 제12권1호
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    • pp.15-22
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    • 2003
  • Fifteen major naturally populated habitats around the Mt. Halla, Jeju province for wild Cornus kousa are mostly located on the southeast side of the mountains at 850-1,550m in altitude at sea level and are in half sunney areas. More than 40.0% of the naturally populated area of Cornus kousa are edge of forest areas and 53.3% populate on the steep slope of the mountain in 0-5℃. The direction of the slop for about 40.0% of total populated areas is southeast. In the naturally populated areas, total of 64 taxa dividing into 42 families, 59 genera 56 species and 8 varieties have been shown, mostly Hydrangea petiolaris, Rubus oldhamii, Ilex crenata, Sasa quelpaertensis, Ligustrum obtusifolium. It is suggested that these areas are secondary forest in a typical deciduous forest in Mt. Halla where the second transition had been progressed after forest damage or environmental stress. The index of species diversity of plant groups in these areas is 1.286-4.238 based on the Shannon-Wiener's method.

휴대전자기기용 저용량 리튬이온 배터리의 충방전 열화 기구 분석 및 모니터링 (Evaluation and monitoring of degradation mechanism of Li-ion battery for portable electronic device)

  • 변재원
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제13권2호
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    • pp.129-140
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    • 2013
  • As a fundamental experimental study for reliability improvement of lithium ion secondary battery, degradation mechanism was investigated by microscopic observation and acoustic emission monitoring. Microstructural observation of the decomposed battery after cycle test revealed mechanical and chemical damages such as interface delamination, microcrack of the electrodes, and solid electrolyte interphase (SEI). Acoustic emission (AE) signal was detected during charge and discharge of lithium ion battery to investigate relationships among cumulative count, discharge capacity, and microdamages. With increasing number of cycle, discharge capacity was decreased and AE cumulative count was observed to increase. Observed damages were attributed to sources of the detected AE signals.

원통형 선형 유도전동기의 2차측 처짐에 관한 연구 (A Study on droop of Tubular Type Linear Induction Motor)

  • 정상용;천장성;임정필;정현교
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 A
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    • pp.28-30
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    • 1998
  • In the case of long secondary (applied in long distance), as it is established horizontal, the defects of droop arises resulting damage of entire system. Actually, it is difficult to expect reasonable characteristics and desirable operating in that case. This paper is about numerical analysis of secondary droop, non-symmetric and position displacement problems. In the base of this paper, the correction of mechanical difficulties in practical manufacturing and optimal design of TLIM considering these aspects can be progressed successively.

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A Numerical Study on Flow-Accelerated Corrosion in Two Adjacent Elbows

  • Yun, Hun;Hwang, Kyeongmo;Moon, Seung-Jae
    • Corrosion Science and Technology
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    • 제15권1호
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    • pp.6-12
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    • 2016
  • Flow-Accelerated Corrosion (FAC) is a well-known degradation mechanism that attacks the secondary piping in nuclear power plants. Since the Surry Unit 2 event in 1986, most nuclear power plants have implemented management programs to deal with damages in carbon and low-alloy steel piping. Despite the utmost efforts, damage induced by FAC still occurs in power plants around the world. In order to predict FAC wear, some computer programs were developed such as CHECWORKS, CICERO, and COMSY. Various data need to be input to these programs; the chemical composition of secondary piping, flow operating conditions and piping geometries. CHECWORKS, developed by the Electric Power Research Institute (EPRI), uses a geometry code to calculate geometry effects. Such a relatively simple geometry code is limited in acquiring the accuracy of FAC prediction. Recently, EPRI revisited the geometry code with the intention of updating it. In this study, numerical simulations were performed for two adjacent $90^{\circ}$ elbows and the results were analysed in terms of the proximity effect between the two adjacent elbows.

The postoperative trismus, nerve injury and secondary angle formation after partial masseter muscle resection combined with mandibular angle reduction: a case report

  • Kim, Jeong-Hwan;Lim, Seong-Un;Jin, Ki-Su;Lee, Ho;Han, Yoon-Sic
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제43권1호
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    • pp.46-48
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    • 2017
  • A patient, who underwent partial masseter muscle resection and mandibular angle reduction at a plastic surgery clinic, visited this hospital with major complaints of trismus and dysesthesia. A secondary angle formation due to a wrong surgical method was observed via clinical and radiological examinations, and the patient complained of trismus due to the postoperative scars and muscular atrophy caused by the masseter muscle resection. The need for a masseter muscle resection in square jaw patients must be approached with caution. In addition, surgical techniques must be carefully selected in order to prevent complications, and obtain effective and satisfactory surgery results.

Genotoxic and Neurotoxic Potential in Marine Fishes Exposed to Sewage Effluent from a Wastewater Treatment Plant

  • Park, So-Yun;Kim, So-Jung;Rhee, Yong;Yum, Seung-Shic;Kwon, Tae-Dong;Lee, Taek-Kyun
    • Molecular & Cellular Toxicology
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    • 제5권3호
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    • pp.265-271
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    • 2009
  • Concentrations of industrial, agricultural and natural chemicals have been increasing in secondary effluents without their combined sub-lethal effects having been elucidated. In this study, two assays (the comet and acetylcholinesterase assays) were combined to evaluate the genotoxic and neurotoxic effects of effluent from the Noksan wastewater treatment plant (WWTP) on two local marine fish species (flounder and sea eel). The fish were exposed to WWTP secondary effluent that had been diluted with filtered seawater to final concentrations of 1%, 10% and 50%. Analysis of fish samples collected 3 and 5 days after exposure showed that DNA damage occurred in flounder exposed to 50% effluent and in sea eels exposed to 10% or 50% effluent. Furthermore, it was found that acetylcholinesterase (EC:3.1.1.7, AChE) activity decreased in both species when exposed to 10% effluent, indicating the presence of large amounts of genotoxic and neurotoxic chemicals in the effluent. Our results indicate that the comet and AChE assays are promising tools for biomonitoring of secondary effluents.

Secondary Analysis on Ventilator-Associated Pneumonia and Pressure Injury

  • Hyun, Sookyung;Moffatt-Bruce, Susan;Newton, Cheryl;Kaewprag, Pacharmon
    • International Journal of Advanced Culture Technology
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    • 제6권3호
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    • pp.211-215
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    • 2018
  • Ventilator-associated pneumonia (VAP) is a lung infection that develops in patients receiving mechanical ventilation. VAP contributes to about 50% of hospital-acquired pneumonia in ICU settings. One of the recommendation of the Institute of for Healthcare Improvement ventilator bundle is HOB elevation. HOB elevation affects shearing forces and makes higher risk for pressure injury development. Pressure injury (PI) is localized damage to the skin over a bony prominence. PI prevention guidelines recommend that HOB positioning should be lower to reduce risk for PI development which contradicts VAP prevention guidelines for the HOB between 30 and 45 degrees for ICU patients. This presents a care dilemma and tension. The purpose of this study was to perform a secondary data analysis using cumulative electronic health record data in order to determine the association of HOB elevation with VAP and PI in ICU patients. A secondary data analysis was conducted to determine whether HOB elevation is associated with VAP and PI. HOB elevation was not likely to be associated with VAP prevention whereas it was likely to be related to PI development. This is somewhat contrary to popular data and publications. Prospective cohort study is desired to inform us in an evidence-based fashion what actually is optimal HOB elevation for ventilated patients in ICU settings.

감마나이프 방사선수술 후 발생한 급속 순환성 이차성 조증 1예 (A Case of Rapid Cycling Secondary Mania after Gamma-knife Radiosurgery)

  • 정찬호;채정호;김임렬;이정균;이규항
    • 생물정신의학
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    • 제3권2호
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    • pp.302-308
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    • 1996
  • A case of rapid cycling mania secondary to gamma-knife radiosurgery for the treatment of refractory epilepsy was reported. A 21-year old woman who had a gamma-knife radiosurgical operation for the treatment of refractory seizure two years ago was admitted because of manic episodes. Although seizure was relieved, manic symptoms like decreased need for sleep, elated mood, unprovoked laughing, grandiose delusion and bizarre behaviors were developed 11 months after the operation. These symptoms recurred lour rimes for eight months. There were no past personal and family history of mood disorders. Laboratory examinations including electroencephalogram ana endocrinological study did not show any abnormal findings. The rapid cycling secondary manic was relieved by lithium. She was then discharged after 5 months. Mood change was not significant during follow-up while hypomania emerged by dose reduction. The secondary mania seemed to be caused or triggered by the right temporal lobe damage induced by gamma-knife radiosurgery.

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현무암섬유를 이용한 LNG 화물창 2차 방벽의 기계적 특성에 대한 연구 (Effects of Basalt Fiber on the Mechanical Properties of Secondary Barrier for LNG Cargo Containment System)

  • 노우승;신해름;여승준;김만태
    • 한국산업융합학회 논문집
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    • 제27권1호
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    • pp.207-212
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    • 2024
  • Recently, with the strengthening of environmental regulations, there has been an increasing interest in eco-friendly energy sources, leading to a trend of the increasing scale of Cargo Containment Systems (CCS) for Liquefied Natural Gas (LNG) carriers. Among these systems, membrane tanks have gained popularity in LNG transport vessels due to their superior spatial utilization and competitiveness. However, due to high initial investment costs and the difficulty in repair in case of damage, a safety layer, the secondary barrier, must be installed without fail. In this study, in order to apply a new secondary barrier to the existing membrane-type LNG CCS, tests were conducted on the fiberglass layer previously used in the Triplex-Flexible Secondary Barrier (FSB), substituting it with basalt fiber. Tensile and vertical tensile tests were performed to assess the newly applied material. Environmental tests were conducted at room temperature (25℃) and extremely low temperatures (-170℃), considering the temperatures to which substances may be exposed during LNG vessel operations. The basalt-FSB produced in this study demonstrated superior results compared to the specifications of the existing product, confirming its potential applicability for implementation.