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        검색결과 930

        42.
        2022.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to determine fragility curves, the limit state of piers for each damage level is suggested in this paper based on the previous test results in Korea, including our test results. In previous studies, the quantitative measures for damage levels of piers have been represented by curvature ductility, lateral drift ratio, or displacement ductility. These measures are transformed to lateral drift ratios of piers for consistency, and the transformed values are compared and verified with our push-over test results for flexural RC piers with a circular cross-section. The test specimens are categorized concerning the number of lap-splices in the plastic hinge region and whether seismic design codes are satisfied or not. Based on the collected test results in Korea, including ours, the lateral drift ratio for each pier damage level is suggested.
        4,200원
        43.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        피부는 인체를 구성하는 가장 큰 장기로 생체 내부를 보호한다. 자외선은 피부에 광노화와 산화 적 손상을 비롯한 다양한 염증반응을 일으킨다. 본 연구의 목적은 섬유아세포에서 UVB를 조사하여 Saponaria 추출물의 보호 효과를 조사하는 것이다. 본 연구에서는 UVB에 의한 세포독성과 산화적 세포사 멸, NO 및 PGE2 생성에 대한 보호활성을 나타내는 Saponaria의 유효성을 평가하였다. HS68 세포를 UVB(120mJ/cm2)에 조사하고 100, 200, 400 μg/mL의 다양한 농도로 Saponaria 추출물로 24시간 동안 처리하였으며, 자외선 B에 의해 생성된 세포 내 활성 산소 종(ROS)은 DCF-DA 염색 후 분광 형광계를 사용하여 검출하였다. 또한 지질 과산화는 배양 배지로 분비되는 8-이소프로스탄의 수준을 측정하여 분석 하였다. 그 결과 Saponaria 추출물이 UVB에 의한 세포독성을 효과적으로 억제하였다. 산화적 세포 손상은 UVB로 유도된 HS68 섬유아세포에서 PGE2를 매개하였고, 이는 사포나리아 추출물 처리에 의하여 유의하 게 억제되었다. 또한, 이들 추출물의 보호 효과는 농도 의존적으로 세포내 ROS 생성 및 지질 과산화 억제 에 의해 매개되는 것으로 평가되었다. 이러한 결과는 Saponaria 추출물이 자외선 B에 의한 산화적 스트레 스로 매개한 피부 손상을 억제하여 세포 보호효과를 나타내므로 항노화 기능성 소재로 활용될 수 있을 것 으로 사료된다.
        4,000원
        47.
        2022.10 구독 인증기관·개인회원 무료
        It is still questionable if the Nuclear Damage Compensation Act can be applied to security accidents on nuclear facilities caused by hacking or drone attacks. If the Act is applied, the nuclear operator shall be liable for compensation for the damage even if there is no negligence, and no other person shall be liable. If it is not, victims must prove the negligence of nuclear operators and not only nuclear operators but also suppliers must be responsible. According to Article 5 of this Act, a nuclear operator cannot operate a reactor before signing liability insurance contract or a compensation contract or depositing in order to compensate for nuclear damage. The liability insurance contract includes the hacking accident, but it is not applied to drone attacks since only hacking accident is included in design basis accidents. However, Article 2 of this Act defines a nuclear accident as an event that may cause nuclear damage so it can be said that the ‘event’ includes intentional attacks. Article 3 stipulates that nuclear operators are not liable for compensation for damages caused by armed conflicts, hostile acts between countries, or civil war or rebellion. Therefore, if nuclear power plant is attacked by missiles from North Korea, the nuclear operator is not liable for compensation. And, it can be interpreted that the nuclear operator is liable for compensation for damages caused by actions of a third party that do not fall under this category. According to the Act on Indemnity Agreement For Nuclear Damage Compensation, nuclear damage caused during normal operation is included in the scope of compensation, but damage caused by actions of third parties is excluded. In the end, damage caused by actions of third parties is included in the scope of nuclear damage, but not included in the loss compensated by the government. According to the Act on Physical Protection, the Nuclear Safety & Security Commission is required to establish a design basis threat that is the standard for designing and evaluating physical protection systems. Therefore, it is reasonable to include the contents of design basis threats in liability insurance, or to apply the principle of no negligence liability and focus of responsibility to protect victims, if not.
        53.
        2022.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The acoustic emission (AE) is proposed as a feasible method for the real-time monitoring of the structural damage evolution in concrete materials that are typically used in the storage of nuclear wastes. However, the characteristics of AE signals emitted from concrete structures subjected to various environmental conditions are poorly identified. Therefore, this study examines the AE characteristics of the concrete structures during uniaxial compression, where the storage temperature and immersion conditions of the concrete specimens varied from 15℃ to 75℃ and from completely dry to water-immersion, respectively. Compared with the dry specimens, the water-immersed specimens exhibited significantly reduced uniaxial compressive strengths by approximately 26%, total AE energy by approximately 90%, and max RA value by approximately 70%. As the treatment temperature increased, the strength and AE parameters, such as AE count, AE energy, and RA value, of the dry specimens increased; however, the temperature effect was only minimal for the immersed specimens. This study suggests that the AE technique can capture the mechanical damage evolution of concrete materials, but their AE characteristics can vary with respect to the storage conditions.
        4,000원
        54.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Mecoprop-p, a chlorophenoxy herbicide, has been widely used since the 1980s. Due to its high water solubility, it could be detected in the aquatic environment, as it has already been detected in the surface water or groundwater in several countries. The toxicity of other chlorophenoxy herbicides has been reported; however, there are few studies on the toxicity of mecoprop-p, one of the chlorophenoxy herbicides, on aquatic organisms. Here, we investigated the toxic effects of mecoprop-p using zebrafish. After mecoprop-p exposure, we observed that the zebrafish larvae eyes did not form normally, heart edema was generated, and the body length was shortened. The number of cells undergoing apoptosis also increased in the anterior part including head, heart, and yolk sac of the mecoprop-p-treated zebrafish compared to the untreated controls. Moreover, cardiovascular structures, including the heart and aortic arches, were also malformed after exposure to mecoprop-p. Therefore, our results suggest that mecoprop-p could cause abnormal development in zebrafish larvae and there is also a high possibility that mecoprop-p would be toxic to other aquatic organisms.
        4,000원
        55.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 하수 재이용을 위한 역삼투막 공정에서 전처리 정밀여과막(MF) 손상에 대한 누출되는 다양한 수 질변화로써 막 손상 검지 방안을 제시하였다. 이를 위하여 역삼투막 유입수질 적합성 평가지표인 SDI (silt density index)를 3에서 5의 범위 내에서 막 손상 시 검지 감도를 정량화하기 위하여 전처리 분리막이 1에서 3가닥 파단에 따라 SDI는 1.92에 서 6.11까지 증가한 결과를 확인할 수 있었다. 일반적으로 3을 기준으로 역삼투막 유입수질로 설정하였을 때 분리막이 3가닥 까지 파단이 되어야만 막 손상 검지가 가능하다는 것을 의미하며 역삼투막의 오염은 잠재적으로 가속화되어 효율을 저하시 킬 수 있다. 또한 이때 누출되는 입자성과 유기물질에 대하여 0.45 μm 이상의 크기만 걸러주는 입자계수는 입도분포별 막 파 단 개수에 따라 일정한 패턴을 확인할 수 없었으며, TOC 농도는 약 2배의 변화패턴으로써 SDI와의 상관관계로써 TOC가 막 손상 수질지표로써 신뢰성이 높은 것으로 확인되었다. 수질분석결과와 더불어 USEPA에서 제시하는 막 손상 검지 방법 중 압력손실시험과 이를 기반으로 LRVDIT 모델의 적합성 평가를 한 결과 막 손상 또는 역삼투막 공정으로 유입되는 막오염물질 을 신속하게 확인할 수 있는 SDI 및 TOC를 포함한 LRVDIT 모니터링과 UCL 설정을 병행해야 한다.
        4,200원
        56.
        2022.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        매년 우리나라 연안해역에서 항해 중인 소형선박 및 소형어선과 연안에 어 로작업을 위해 설치된 시설물과의 접촉 사고가 빈번하게 발생한다. 이러한 사 고들은 주로 연안해역에 설치된 양식장, 정치망, 자망 등으로 인해 발생하며,선박 사고의 일반적인 원인으로는 항해 중인 선박에서 선원의 상무인 경계 소 홀, 침로 유지 및 선위 확인의 미충실, 항해 일반원칙과 국제해상충돌방지규칙 의 미준수 등 여러 가지가 될 수 있다. 본 논문에서는 어구손상사고와 관련된 사고의 원인을 검토하기 위해 해양안전심판원 재결서를 통해 분석하였으며, 그 결과 사고의 원인으로 경계 소홀, 설치된 어구와 적절한 거리 미확보, 항해 계 획 수립 미비 등이 사고의 원인으로 작용한 것을 알 수 있었다. 이러한 인적요 인으로 발생하는 사고를 줄이기 위해서는 선원의 꾸준한 안전교육이나 선박 안 전관리체제의 시스템 변경과 같은 오랜 시간과 많은 비용이 필요하다. 본 논문 에서는 어구를 조금 더 빨리 직관적으로 발견하여 인적요소를 제외한 다른 사 고요인을 제거하는 방법으로 사고 발생을 줄일 수 있는 방안을「수산업법」, 「어업면허의 관리 등에 관한 규칙」,「양식장ㆍ어장 표지시설의 설치 기준」, 「양식산업발전법」 등에서 문제점을 파악하고 개선하여 어구손상사고를 줄일 수 있는 방법을 모색해보고자 한다.
        5,100원
        57.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to provide basic data on controlling boring insect pests by identifying the damage and the occurrence ecology of beetles, which are boring insect pests that seriously damage Castanea crenata, an income tree of mountain farms. By location, the damage rate was 62.5% at the foot of mountain, 61.4% at the mountain range, and 61.3% at the mountain peak. By region, the damage rate was the highest in Hapcheon at 65.3%, followed by 62.5% at Hadong and 58.1% at Jinju. The total number of adult fables was 171, followed by 49.1% (84) for Moechotypa diphysis, 39.2% (67) for Batocera lineolata, and 11.7% (20) for Anoplophora malasiaca. As for the male and female ratio of imago, Moechotypa diphysis had 51.2% (43) female and 48.4% (41) male. The percentage of emergence of beetles, which are boring insect pests appearing in the specimen collected by the survey area, was 46.0% in Hapcheon, 32.9% in Hadong, and 21.1% in Jinju. As for the prevalence of beetles, Batocera lineolata appeared from June 22 which is the first day of the emergence period to August 30, and the amount of emergence by the prevalence period was 3.0% in June, 46.2% in July, and 47.8% in August. Anoplophora malasiaca appeared from May 20 to July 20, and the amount of emergence by prevalence period was 5.0% in May, 10.0% in June, and 75.0% in July. Moechotypa diphysis first appeared from August 10 to September 30, and the amount of emergence by prevalence period was 1.2% in July, 51.2% in August, and 46.4% in September. As for the number of eggs laid by beetles, Anoplophora malasiaca laid 90±6, Batocera lineolate laid 75±5, and Moechotypa diphysis laid 60±6.
        4,000원
        58.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Aralia elata, Chaenomeles sinensis fruit, and Glycyrrhizae radix have been widely used as oriental medicinal plants in Korea, China and Japan and found to possess anti-oxidative and anti-inflammatory activities. The current study was conducted to investigate the neuroprotective effect of an ethanol extract of a mixture of A. elata, C. sinensis fruit, and Glycyrrhizae radix (ACG) against ischemia-induced brain injury in rats and excitotoxic and oxidative neuronal death in primarily cultured rat cortical neurons. Transient focal cerebral ischemia was induced by 2 h middle cerebral artery occlusion followed by 24 h reperfusion (MCAO/R) in rats. Oral administration of ACG (10, 25, and 50 mg/kg) 30 min before MCAO, after 1 h of MCAO, and after 1 h of reperfusion reduced MCAO/R-induced brain infarct and edema formation. ACG also inhibited development of behavioral disabilities in MCAO/R-treated rats. Exposure of cultured cortical neurons to 500 μM glutamate for 12 h resulted in neuronal cell death. ACG (1, 10, and 50 μg/mL) inhibited glutamate-induced neuronal death. Furthermore, ACG inhibited 100 μM hydrogen peroxide (H2O2)- and hypoxia-induced neuronal death. These results suggest that the neuroprotective effect of ACG against ischemia-induced brain damage might be associated with its anti-excitotoxic and anti-oxidative activity and that ACG may have a therapeutic role for prevention of neurodegeneration in stroke.
        4,200원
        59.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        선박의 피로 손상 해석에는 운항적인 요소를 고려한 매개 변수들을 포함하고 있다. 이러한 운항적인 변수들 때문에 설계 단계 에서 예측하는 피로 손상도와 실제 운항 조건을 고려한 피로 손상도간의 차이가 발생한다. 마찬가지로 피로 해석에서 적재 하중 조건을 고려할 때 실제 컨테이너선은 다양한 적재 상태가 존재하지만 설계 단계에서 대표 하중 조건을 선택하여 피로 손상도를 계산한다. 실제 하중 조건과 설계시 하중 조건을 적용하였을 때 피로 손상 계산 결과의 차이가 예상됨에도 불구하고 컨테이너선의 하중 조건에 따른 피 로 손상 기여도에 관한 연구는 거의 이루어지지 않은 실정이다. 본 연구에서는 컨테이너선의 화물 중량 분포를 변화시켰을 때 피로 손상 기여도를 분석하고자 하였다. 일반적으로 설계 단계에서 적용하는 하중 조건뿐만 아니라 다양한 하중 조건을 생성하고 유체동역학 계산 으로 얻을 수 있는 선체 거더 하중 및 스펙트럴 피로 해석을 수행하여 얻은 피로 손상도를 확인하였다. 그 결과, 컨테이너선에서 화물 중 량 분포 변화는 선체 거더 하중을 변화시켰으며 선체 거더 응력에 영향을 주어 피로 손상의 변화를 야기시키는 것을 알 수 있었다.
        4,500원
        60.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to estimate the damage of Whole Crop Maize (WCM) according to abnormal climate using machine learning and present the damage through mapping. The collected WCM data was 3,232. The climate data was collected from the Korea Meteorological Administration's meteorological data open portal. Deep Crossing is used for the machine learning model. The damage was calculated using climate data from the Automated Synoptic Observing System (95 sites) by machine learning. The damage was calculated by difference between the Dry matter yield (DMY)normal and DMYabnormal. The normal climate was set as the 40-year of climate data according to the year of WCM data (1978~2017). The level of abnormal climate was set as a multiple of the standard deviation applying the World Meteorological Organization(WMO) standard. The DMYnormal was ranged from 13,845~19,347 kg/ha. The damage of WCM was differed according to region and level of abnormal climate and ranged from -305 to 310, -54 to 89, and -610 to 813 kg/ha bnormal temperature, precipitation, and wind speed, respectively. The maximum damage was 310 kg/ha when the abnormal temperature was +2 level (+1.42 ℃), 89 kg/ha when the abnormal precipitation was -2 level (-0.12 mm) and 813 kg/ha when the abnormal wind speed was -2 level (-1.60 ㎧). The damage calculated through the WMO method was presented as an mapping using QGIS. When calculating the damage of WCM due to abnormal climate, there was some blank area because there was no data. In order to calculate the damage of blank area, it would be possible to use the automatic weather system (AWS), which provides data from more sites than the automated synoptic observing system (ASOS).
        4,000원
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