• 응용통계연구
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• 제30권6호
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• pp.851-865
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• 2017

최근 워너크라이라는 이름의 랜섬웨어가 전 세계적으로 큰 화두에 오르면서, 악성 소프트웨어로 인한 피해를 줄이기 위한 방법들이 재조명 되고 있다. 새로운 악성 소프트웨어가 발생했을 때 피해를 최소화하기 위해서는 해당 소프트웨어가 어떤 공격 유형을 가진 악성 소프트웨어인지 빠르게 분류할 필요가 있다. 본 연구 목적은 다양한 통계적 기법을 이용하여 악성 소프트웨어를 효과적으로 분류할 수 있는 모형을 구축하는 데 있다. 모형 적합 시 다항 로지스틱, 랜덤 포레스트, 그래디언트 부스팅, 서포트 벡터 기계 등의 기법들을 이용하였으며, 본 연구를 통해 악성 소프트웨어를 분류하는 데에 있어 중요한 역할을 하는 변수들이 존재한다는 사실을 발견하였다.

• 한국산업융합학회 논문집
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• 제23권2_2호
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• pp.301-306
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• 2020

본 연구에서는 전국의 산불 발생 현황을 국가화재정보시스템의 통계자료를 바탕으로 원인별, 연도별, 지역별, 피해 규모별로 분석하였다. 분석결과 산불 발생의 주요한 원인은 사람의 실수에 의한 인재가 가장 많았다. 또한, 산화 횟수는 인구 밀집도가 높은 지역 다른 시도에 비해 많은 것으로 나타났다. 그리고 산림 훼손의 면적은 임업 자원이 풍부한 강원도가 가장 넓은 것으로 확인되었으며 계절적으로는 따뜻한 기온과 강한 바람 낮은 습도로 인해 봄철에 많이 발생하였다. 이러한 산불의 재해는 자연 자원의 파괴는 물론 주택 등의 산림시설물과 문화재에 직접적인 피해를 준다. 이에 본 연구에서는 산림 자원과 산림시설물의 산화에 의한 피해 방지를 위해 국립산림청의 산불 방지 종합 대책과 더불어 예방 정책을 제안하였다.

• 한국자원식물학회지
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• 제23권6호
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• pp.487-497
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• 2010

ROS have been associated with pathogenic processes including carcinogenesis through direct effect on DNA and play an important role in the pathogenesis of inflammation. Because of many types of phenolic acid derivatives and flavonoids, apples have been one of the human diet since ancient times and are one of the most commonly consumed fruits in worldwide. In this study, catechin, chlorogenic acid and phlorizin dihydrate were purified and identified by HPLC and GC/MS. The contents of catechin, chlorogenic acid and phlorizin dihydrate were 1.01 mg, 7.01 mg and 3.67 mg/ kg wet weight, respectively. Catechin and phlorizin dihydrate were found to significantly inhibit oxidative DNA damage, while chlorogenic did not affect. Also, catechin inhibits NO and $PGE_2$ production via suppressing iNOS and COX-2 expression. However, chlorogenic acid and phlorizin dihydrate did not affect. Our results show that catechin may be the most active phenolic compound in anti-oxidative damage and anti-inflammatory effect.

• Steel and Composite Structures
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• 제51권1호
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• pp.53-61
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• 2024

Aluminum foams sandwich panel (AFSP) has been used in engineering field, where cyclic loading is used in most of the applications. In this paper, the fatigue life of AFSP prepared by the bonding method was investigated through a three-point bending test. The mathematical statistics method was used to analyze the influence of different plate thicknesses and core densities on the bending fatigue life. The macroscopic fatigue failure modes and damage mechanisms were observed by scanning electron microscopy (SEM). The results indicate that panel thickness and core layer density have a significant influence on the bending fatigue life of AFSP and their dispersion. The damage mechanism of fatigue failure to cells in aluminum foam is that the initial fatigue crack begins the cell wall, the thinnest position of the cell wall or the intersection of the cell wall and the cell ridge, where stress concentrations are more likely to occur. The fatigue failure of aluminum foam core usually starts from the semi-closed unit of the lower layer, and the fatigue crack propagates layer by layer along the direction of the maximum shear stress. The results can provide a reference for the practical engineering design and application of AFSP.

• 대한토목학회논문집
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• 제38권1호
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• pp.29-39
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• 2018

본 연구에서는 IPCC에서 제시한 기후변화 취약성 평가 이론, OECD에서 개발한 PSR 모형, EEA에서 개발한 DPSIR 모형을 활용하여 산정된 홍수위험지수들의 적용성을 분석하였다. 홍수위험지수 산정을 위하여 세부 지표로 일 최대 강수량, 1시간 최대 강수량, 10분 최대 강수량, 연평균 강수량, 1일 강수량이 80mm 초과한 일수, 인구 밀도, 자산 밀도, DEM, 도로연장, 하천개수율, 유수지용량, 하수도 보급률, 배수펌프시설 등의 2000년에서 2015년도 자료를 정규화하여 전국 113 중권역 단위로 구축하였다. 산정된 홍수위험지수는 4개의 홍수피해유형 즉 인명피해, 피해면적, 피해액, 피해빈도와 비교 분석하였다. 홍수위험지수와 피해유형별 상관분석 결과 피해액, 인명피해 및 피해면적에 대해서는 PSR 기법이, 홍수발생빈도에 대해서는 DPSIR 기법에 따른 지수의 적용성이 높은 것으로 나타났다.

• 한국방재안전학회논문집
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• 제7권1호
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• pp.17-25
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• 2014

최근 기후변화 영향으로 인한 해수면 상승, 태풍내습, 돌발홍수, 국지성 집중호우, 산사태 및 연안지역 침수 등이 발생하여 자연재해로 인한 인명 및 재산 피해가 끊임없이 이어지고 있다. 이러한 경향은 도시화 산업화와 함께 이전에 안전했던 지역이 새로운 재해 취약지역으로 변화되면서 인적 경제적 피해를 증가시키는 요인으로 작용하고 있기 때문이다. 본 논문은 우리나라의 여름철 자연재해 취약지역에 대한 인명피해 최소화 방안을 마련하는데 그 목적을 두고 연구를 진행하였다. 이를 위해 취약지역에 대한 관리 실태와 피해 양상을 고찰하였으며 인명피해 사례 검토 및 통계분석을 실시하고, 문제점을 도출하여 인명피해 최소화방안을 구조적 대책과 비구적 대책으로 제시하였다.

• 한국방재안전학회논문집
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• 제13권4호
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• pp.13-24
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• 2020

최근 급속한 경제발전과 온난화로 인해 이상기후 현상이 빈번하게 발생하고 있다. 자연재난의 유형 중 풍수해에 해당되는 호우, 태풍, 강풍, 풍랑, 대설 등은 대규모 인적·물적 피해를 발생시킨다. 피해를 최소화하기 위해서는 재난발생 전 피해규모를 예측하는 것이 중요하다. 본 연구는 풍수해의 재난유형 중 강풍피해를 중심으로 재난에 대비할 수 있는 강풍피해예측함수를 개발한다. 본 함수는 재해 연보의 강풍피해이력을 기반으로 기상요소와 지역적 특성을 반영하였으며, 기상정보를 실시간으로 수집할 수 있는 시스템에 탑재할 경우 단시간에 피해규모를 예측할 수 있다. 또한, 본 함수는 국가 혹은 지자체에서 수립하는 재난관리정책에 근거자료로 활용하여 강풍발생 시 피해를 최소화할 수 있다.

• 여성건강간호학회지
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• 제27권4호
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• pp.379-387
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• 2021

Purpose: This study aimed to determine the actual state of childbirth in Korean women with natural childbirth and the degree of damage to the perineum during childbirth. Methods: This retrospective study analyzed the medical records of mothers who had natural childbirth at a hospital in Seoul, Korea in 2018. Data from 358 women with cephalic births at greater than 37 gestational weeks were analyzed. To determine natural childbirth characteristics and the degree of damage to the perineum, descriptive statistics were done. The difference in the degree of perineal injury according to obstetric characteristics was analyzed using independent t-test and one-way analysis of variance. Results: The mean age was 33.18±3.68 years, and 49.2% were primiparas, while 39% gave birth with a doula. The degree of perineal damage differed by age (F=9.15, p<.001), parity (t=19.13, p<.001), number of births in multiparity (F=3.68, p=.027), previous vaginal delivery in multiparity (F=3.00, p=.032) and birthing posture (F=7.44, p<.001). Having received therapeutic procedures (t=-4.62, p<.001), specifically fluid administration (t=-2.72, p=.007), oxygen supply (t=-2.76, p=.006) and epidural anesthesia (t=-2.77, p=.006) were statistically significant for perineal damage. There were no differences, however, by gestational period, doula use, water room use in labor, baby head circumference, or birth weight. Conclusion: Study findings suggest that support for older women, primiparas, and those who require therapeutic procedures may help to decrease the possibility of perineal damage during childbirth. As perineal damage was also associated with birthing posture, this should be considered when providing intrapartum nursing care.

• 한국안전학회지
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• 제35권6호
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• pp.25-31
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• 2020

Boiling Liquid Expanding Vapor Explosion(BLEVE) can cause not only economic damage to the plant but also serious casualties. LPG accidents account for 89.6 percent of all accidents caused by gas leaks in Korea over the past nine years, while casualties from accidents also account for 73 percent of all accidents, according to statistics from the Korea Gas Safety Corporation. In addition, a potential explosion and a fire accident from one LPG storage tank may affect the nearby storage tanks, causing secondary and tertiary damage (domino effect). The safety distance standards for LPG used by LPG workplaces, charging stations, and homes in Korea have become stricter following the explosion of LPG charging stations in Bucheon. The safety distance regulation is divided into regulations based on the distance damage and the risk including frequency. This study suggests two approaches to optimizing the safety distance based on the just consequence and risk including frequencies. Using the Phast 7.2 Risk Assessment software by DNV GL, the explosion overpressure and heat radiation were derived according to the distance caused by BLEVE in the worst-case scenario, and accident and damage probability were derived by considering the probit function and domino effect. In addition, the safety distance between LPG tanks or LPG charging stations was derived to minimize damage effects by utilizing these measures.

• Toxicological Research
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• 제20권2호
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• pp.89-100
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• 2004

The comet assay (also called the single-cell gel electrophoresis assay) has been widely used for detecting DNA damage and repair in individual cells. Since the conventional methods of evaluating comet assay data using frequency statistics are unsatisfactory we developed a new quantitative measure of DNA damage/repair that is based on all information residing in the dose/time-response curves of a comet experiment. Blood samples were taken from 25 breast cancer patients before undergoing radiotherapy. The comet assay was performed under alkaline conditions using isolated lymphocytes. Tail DNA, tail length, tail moment and tail inertia of the comet were measured for each patient at four doses of $\gamma$-rays (0, 2, 4 and 8 Gy) and at four time points after irradiation (0, 10, 20 and 30 min) using 100 cells each. The resulting three-dimensional dose-time response surface was modeled by multiple regression, and the second derivative, termed 2D, on dose and time was determined. A software module was programmed in SAS/AF to compute 2D values. We applied the new method successfully to data obtained from cancer patients to be assessed for their radiation sensitivity. We computed the 2D values for the four damage measures, i.e., tail moment, tail length, tail DNA and tail inertia, and examined the pairwise correlation coefficients of 2D both on the log scale and the unlogged scale. 2D values based on tail moment and tail DNA showed a high correlation and, therefore, these two damage measures can be used interchangeably as far as DNA repair is concerned. 2D values based on tail inertia have a correlation profile different from the other 2D values which may reflect different facets of DNA damage/repair. Using the dose-time response surface, other statistical models, e.g., the proportional hazards model, become applicable for data analysis. The 2D approach can be applied to all DNA repair measures, Le., tail moment, tail length, tail DNA and tail inertia, and appears to be superior to conventional evaluation methods as it integrates all data of the dose/time-response curves of a comet assay.