• Journal of the Korea Concrete Institute
• /
• v.23 no.4
• /
• pp.495-501
• /
• 2011

The load combinations in current KCI Design Code are determined with reference to those in ACI 318-05, which adopts the LRFD (load and resistance factor design) format. The load and resistance factors in LRFD format should be determined to meet the required levels of reliability index or probability of failure for various predetermined failure modes, which are also based on the statistical data reflecting locality and contemporary situation. However, the current KCI Design Code has been written utilizing foreign data, because of insufficiency in accrued data in Korea. This study considered the current safety levels of KCI Code based on published domestic data to evaluate appropriateness of the current KCI regulations. Based on the calibrated reliability index of the existing Code, the new resistance factors are suggested. The results presented in this paper can be considered as a basic research for establishment of unique design format for future Korean Codes.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.82-82
• /
• 2021

전 세계적으로 가뭄은 농업·식량안보·수자원관리·생태계 등 다양한 분야에서 부정적인 영향을 미치고 있다. 일반적으로 가뭄은 강수량의 부족으로 발생하고, 지표수와 지하수의 가용성이 제한됨에 따라 작물생산 및 사회·경제적으로 피해가 발생한다. 이러한 영향은 특정 가뭄 모니터링 및 조기 경보와 관련하여 가뭄 지표를 결정할 때 중요한 고려사항이다. 가뭄을 분석하기 위해서는 가뭄 지표를 적용하여 정확하게 반영하고 나타내는 것이 중요하다. 가뭄의 특성을 객관적으로 정량화하기 어렵기 때문에 다양한 지표와 계산을 통한 가뭄 모니터링 및 분석 기술이 필요하며, 강수량, 토양수분, 증발산량 및 식생과 관련하여 가뭄 지표가 개발되었다. 본 연구에서는 혼합 가뭄 지표 (Drought Indicator Blends) 활용하여 우리나라의 가뭄을 분석하였다. 혼합 가뭄 지표는 NOAA (National Oceanic and Atmospheric Administration)의 기후 예측 센터 (Climate Prediction Center, CPC)에서 여러 가뭄 지수를 단기 또는 장기로 구분하여 통합, 개발되었다. 단기 및 장기 혼합 제품은 PDSI (Palmer Drought Severity Index), Z-Index, SPI (Standardized Precipitation Index)를 결합하여 가뭄을 추정한다. 혼합 가뭄 지표는 해당 지역의 단기 및 장기 가뭄을 이해하는데 유용하게 활용할 수 있으며, 현재까지 미국에서 활발하게 연구가 진행되고 있다. 단기 지표는 비관개 농업, 토양수분 등 강수량에 밀접한 관련이 있는 가뭄과 관련되어 평가하며, 장기 지표의 경우 관개 농업, 지하수위 등 장기간 가뭄과 연관성을 가지고 있다. 단기 및 장기 혼합 가뭄 지표를 우리나라에 적용함으로써 기존 단일 가뭄 지수를 활용한 가뭄 분석 이상으로 다방면에서 효율적인 가뭄 모니터링을 할 수 있을 것이라 판단된다.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.03a
• /
• pp.643-650
• /
• 2002

The large planar failure has occurred in a rock cut slope of highway construction site in Boeun. This area is considered as unstable since the discontinuities whose orientations are similar to the orientation of the failure plane, are observed in many areas. Therefore, several analysis techniques such as SMR, stereographic analysis, limit equilibrium, numerical analysis, which are commonly used in rock slope stability analysis, are adopted in this area. In order to analyze the stress redistribution and nonlinear displacement caused by cut, which are not obtained in limit equilibrium method, the UDEC and shear strength reduction technique were used in this study Then the factors of safety evaluated by shear strength reduction technique and limit equilibrium were compared. In addition, the factor of safety under fully saturated slope condition was calculated and subsequently, the effect of the reinforcement was evaluated.

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2015.11a
• /
• pp.250-251
• /
• 2015

전 세계적으로 지구온난화로 인한 기후변화의 영향으로 예측이 어려운 돌발성 기후로 인한 재난 사례가 급증하고 있다. 이처럼 재해를 유발하는 위험기상 현상의 강도는 점점 증가하지만 인구와 사회기반 시설은 한 곳에 집중되면서 지역적 단위가 아닌 지구단위 규모의 국지적 기상재해가 증가하고 있는 추세이다. 이에 따른 재해의 안전성과 취약성을 평가하는 다양한 연구가 수행되고 있으나, 대응관점에서의 성능 평가에 대한 절차와 연구는 상대적으로 미비한 실정이다. 따라서 본 연구에서는 국내외 수재해 대응 평가요소를 조사하여 도출된 대응요소의 중요도를 AHP기법을 이용하여 분석하였다.

• Journal of Korean Society of Disaster and Security
• /
• v.13 no.2
• /
• pp.1-9
• /
• 2020

Vietnamese cities have a high risk of flooding under climate change due to their geographical characteristics. In this situation, the urban area is expanding with rapid growth of urban population. However, the risk of flooding is increasing due to the increase in impermeable areas and insufficient infrastructure. This study analyzed the urban expansion trend at the national level in Vietnam for the past 10 years (2007-2017) by using the Urban Expansion Intensity Index. Also, this study selected Hue City as a region with a large impact of climate change and a rapid expansion and found the possibility of flooding in the urban expansion area. The result showed that cities have been expanded around major cities in the Red River Delta, Mekong Delta, and coastal areas. In the case of Hue City, the area with fast expansion rate has a higher expected flood area. It implies that the risk of flood disasters may increase if the urabn expansion is carried out without disaster prevention measures. It is expected that Korean urban disaster prevention policies such as urban climate change disaster vulnerability analysis system will be helpful in establishing urban plans considering climate change in the fast growing regions such as Vietnam.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.23 no.2
• /
• pp.108-121
• /
• 2021

Field studies at Suwon, Cheorwon, and Jinbu were carried out to determine the relationship between mean temperature from transplanting to heading (MT) and growth at heading stage of rice. P lant height (P H) and dry weight (DW) at heading stage were significantly correlated with MT, showing second degree polynomials. The optimal temperatures for PH and DW were 23.2 ℃ and 22.8 ℃, respectively. Little differences in rice growth among soils collected from the experimental sites and the temperature-response in a phytotron study supported that MT was the main determinant of the growth shown in the field study. Though number of days to heading increased as MT decreased, cumulative temperatures (CT) affected by sites and MT for given varieties were fairly constant. When applying specific CT for each of the varieties to the temperature in North Korea, (1) five regions (Kaesong, Haeju, Sariwon, Nampo, Pyongyang) were suitable for early to mid-maturing varieties and (2) 14 regions (Yongyon, Singye, Anju, Kusong, Sinuiju, Changjon, Wonsan, Hamhung, Pyonggang, Yangdok, Huichon, Supung, Sinpo, Kanggye) were suitable only for early-maturing varieties. In (1) regions, the similar extent of growth with that in Suwon could be achieved when mid-maturing varieties grown in Suwon are cultivated. Among (2) regions, early-maturing varieties are expected to demonstrate the similar extent of growth with that in Cheorwon in 9 regions except Hamhung, Kanggye, Pyonggang, Yangdok, and Sinpo. For Hamhung and Kanggye, the target PH was assessed as 4cm higher than that shown in Cheorwon. P lant height of 8-14cm and DW of 2-4g per hill greater than those shown in Cheorwon were the target growth for P yonggang, Yangdok, and Sinpo to attain the similar amount of growth with that in Cheorwon. It is suggested that rice varieties for North Korea could be bred by adjusting the target growth at the breeding sites in South Korea.

• Economic and Environmental Geology
• /
• v.34 no.6
• /
• pp.601-615
• /
• 2001

The study area. Boeun-eup Boeun-kun, belongs to Ogchon metamorphic belt which is highly metamorphosed and consisted of complex geologic formations. Even though the geological structures and formations are complex and metamorphosed, the geological investigation and consideration are not enough and consequently the plane failure is occurred in the rock slope which was under construction on 1 : 0.5 gradient. This area is assessed as unstable and additional failure is possible by the discontinuity with same direction of failure surface. Therefore, the authors evaluate the slope stability using various analysis methods such as SMR, stereographic projection method, and the limit equilibrium analysis. In order to analyze stress redistribution and nonlinear displacement behavior caused by stress release, the authors conduct numerical analysis with UDEC and then the behavior of rock mass is analyzed after reinforcements are applied.

• Journal of Cadastre & Land InformatiX
• /
• v.45 no.2
• /
• pp.161-173
• /
• 2015

The influence of climate change on rainfall patterns has triggered landslide and debris flow with casualties and property damage. This study constructed DSM and Orthophoto by using UAV surveying technique and evaluated landslide risk area by applying GIS data into the infinite slope stability model. As a result of the estimation of slope stability in a site, the slope instability has $SI{\leq}1.0$ with cover area 46,396m2, and the distribution percentage was 18.2%. The most dangerous section has $SI{\leq}0.0$ with its cover area 7,988m2, and the ratio was 0.8%. The reviews regarding the risk of landslide and debris flow risk by stability index and river channel analysis respectively help being able to designate the hazard zone due to heavy rainfall. Therefore the analysis result of this study will need to reinforce soil slope and plan their safety measures in the future.

• Journal of the Korean association of regional geographers
• /
• v.21 no.4
• /
• pp.739-750
• /
• 2015

This study aims to investigate the possibility of crime prevention through CCTV by analyzing the appropriateness of the CCTV location, whether it is installed in the hotspot of crime-prone areas, and exploring the crime prevention effect and transition effect. The real crime and CCTV locations of case city were converted into the spatial data by using GIS. The data was analyzed by hotspot analysis and weighted displacement quotient (WDQ). The results demonstrated that there was no significant effect in the installation of CCTV on crime prevention. This indicates that CCTV should be installed and managed in a more scientific way reflecting local crime situations. In terms of CCTV, the methods of spatial analysis such as GIS, which can evaluate the installation effect, and the methods of economic analysis like cost-benefit analysis should be developed. In addition, these methods should be distributed to local governments across the nation for the appropriate installation of CCTV and operation. This study intended to find a design guideline of the optimum CCTV installation. In this regard, this study is meaningful in that it will contribute to the creation of a safe city.

• The KIPS Transactions:PartD
• /
• v.11D no.1
• /
• pp.31-38
• /
• 2004

This paper is about to implement a system for ground water safety evaluation. Since ground water quality is affected from the contamination source of surface water, one can estimate the magnitude of affection and the source themselves. This paper suggests a method to evaluate the spatial relationship of ground water and its contamination sources, using“contain”and“distance”operators in GIS. The research area is the Kunsan City in Chonbuk province, and are 75th wells those are located between the 4th alluvium land types. The results of measured chemical factors and results of related evaluation of these wells are stored and represented in ZEUS 2000 GIS DBMS, and an interface for searching and studying, is implemented by using ZEUS/SQLX, ZEUS/COM, and Visual Basic 6.0 programming languages. After this research, the spatial relationship between hydro-geological geo-objects and ground water is verified and a efficient evaluation system using GIS is suggested. It is the topic of further study that tries to calibrate the suggested evaluation model by applying it to wider area.