• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4560-4571
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• 2013

Current global issue of climate change is growing and greenhouse gases occur in most cities. To solve the problem of climate change, the city should be changed to low-carbon structure. Low-carbon city planning is a step-by-step plan from the initial establishment, from design and operation of urban structure, to maintenance and management should be considered as an integrated whole process. Under this background, this study evaluated the whole process of low-carbon urban planning ways. For this step, divided into three steps and eight divisions, 30 sub-indicators are derived. Through domestic and foreign cases analysis studies and survey of the relevant experts, results were derived. In order to improve these points, in the intial planning establishment stage, planning of urban policy and institutional steps should be made and the plan should be appropriate to the local characteristics. In the design and operation of urban structure stage, detailed and feasible approach is needed and maintenance and management stage, participation of various stakeholders, including establishing governance and management practices could see the need.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.131-137
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• 2010

The stormwater runoff from rest areas in highways are known as more polluted compared to highways because of more vehicle activities. This study is performed to find pollutant characteristics in the rest areas in the magnitude of statistical pollutant concentrations during storms. Washoff characteristics of pollutants from rest areas by monitoring of rainfall, runoff rate and runoff samples were evaluated. High concentrations of pollutants in runoff were observed at the beginning of runoff and rapid decrease thereafter, indicating that first-flush effects are clearly occurred. Event Mean Concentrations(EMCs) of TSS, COD, TN, and TP are estimated to be in the range of 31.04-127.11mg/L, 35.5-369.5mg/L, 2.62-9.86 mg/L, and 0.53-1.96mg/L, respectively. Heavy metals in runoff showed relatively high values, possibly due to the abrasion of brake pad or tire while cars are slowly moving for parking. EMCs of total Pb, total Cu, and total Ni are in the range of $1206-16293{\mu}g/L$, $237-7906{\mu}g/L$, and $53-6372{\mu}g/L$, respectively. Pollutant loading per rest area calculated by using EMC, flowrate and target area is also described for each pollutant.

• Journal of Korean Society of Steel Construction
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• v.10 no.1 s.34
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• pp.47-61
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• 1998

The behavior of horizontally curved I-girder bridges is complex because the flexural and torsional behavior of curved girders are coupled due to their initial curvature. Also, the behavior is affected by cross beams. To investigate the behavior of horizontally curved I-girder bridges, it is necessary to consider curved girders with cross beams. In order to perform free vibration analyses of horizontally curved I-girder bridges, a finite element formulation is presented here and a finite element analysis program is developed. The formulation that is presented here consists of curved and straight beam elements, including the warping degree of freedom. Based on the theory of thin-walled curved beams, the shape functions of the curved beam elements are derived from homogeneous solutions of the static equilibrium equations. Third-order hermits polynomials are used to form the shape functions of the straight beam elements. In the finite element analysis program, global stiffness and mass matrix are composed, based on the Cartesian coordinate system. The Gupta method is used to efficiently solve the eigenvalue problem. Comparing the results of several examples here with those of previous studies, the formulation presented is verified. The validity of the program developed is shown by comparing results with those analyzed by the shell element.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.908-908
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• 2012

국내 기후 특성상 하절기에 집중되는 강우로 인해 댐의 건설을 홍수조절, 용수확보 및 전력생산 등의 목적에 있어서 불가피하다. 이와 같은 저수지와 하류하천은 댐 수문 개폐에 따라 흐름변화로 인하여 수체의 거동 및 수질 변화가 발생하며, 일반적인 하천과는 다른 특성을 지니게 된다. 또한 수심이 깊은 저수지의 경우에는 흐름방향과 더불어 수심 방향의 특성도 중요하며, 수리 및 수질 모형의 연계를 통한 3차원적인 해석을 필요로 한다. 유역 내 지상 또는 대기에서 발생한 모든 오염물질은 강우에 의해 하천과 호수와 같은 수체로 유입되며, 강우가 발생했을 때 유역의 토지피복 상태와 수리, 지형, 강우강도, 토양의 특성에 의해 하천으로 유입되는 오염물질의 농도와 부하특성이 달라진다. 비점오염물질의 축적이 가능한 호수나 저수지에서는 비점오염원의 유입이 더 큰 문제가 되며, 유량이 극히 미미한 하천의 경우에는 강우초기에 일시에 집중적으로 유입되는 초기 오염 부하량이 문제가 된다. 강우유출수의 하천 유입은 강우 현상과 밀접한 관계를 맺고 있으므로 그 제어가 쉽지 않다. 이러므로 이를 총괄하는 유역통합관리기술이 필요로 하며, 기존의 유역통합관리기술은 댐 상류유역을 중심으로 개발되고 있으며, 댐 상류유역과 저수지, 하류하천으로 구분되어 연구되어 왔다. 또한 각각의 모형이 개별적으로 적용되어 통합적인 평가시스템이 표준화되지 않은 관계로 댐 상하류 모니터링 자료가 연계된 실무 적용이 이루어지지 않고 있다. 따라서 하천 수리 수문학적 역학구조를 이해하고 그 특성에 적합하게 평가할 수 있는 표준화된 시스템이 구축되어야 한다. 또한 효과적인 유역통합관리를 위해서는 하천의 현재 뿐만 아니라 장래에 대한 예측부분도 포함되어야 한다. 본 연구에서는 댐 유역에서의 유출과 수질 변화를 모의하고 이를 이용하여 저수지 내에서의 오염물질 거동에 대해서 해석하였다. 또한 기후변화에 따른 유역, 저수지 및 하천에 미치는 영향을 고려하기 위하여 고해상도 지역기후전망 모의자료를 이용하여 수문학적 스케일로 통계적 상세화한 후 지역별 상세수문시나리오를 생산하여 미래 예측에 활용하였다. 기후변화 시나리오의 상세화를 통한 상세지역의 기후를 예측하고, 예측된 기상자료를 이용하여 유역모델을 모의하여 미래의 유출 및 수질 변화를 파악할 수 있는 기술 개발로 인해 저수지의 운영에 도움을 주고, 주수지의 치수증대 사업 등 유출의 변화에 따른 하류하천 변화를 파악할 수 있고, 기후변화에 따른 하류하천에 대한 홍수기 때 치수, 이수 및 방재에 대하여 기초자료를 제공할 수 있을 것으로 판단된다.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.195-204
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• 2008

Multi-Criteria Analysis is one method for optimizing decisions that include numerous characteristics and objective functions. The Analytic Hierarchy Process (AHP) is used as a general Multi-Criteria Analysis considering many critical issues. However, since validation procedures for the decision reliability of AHP valuers had been left off existing methodologies, a new methodology including such validation procedures is required to make more reliable decisions. In this research, idea decision results are derived using Monte Carlo Simulation in cases where AHP valuers do not have expertise in the specific project, and these results are compared with the results derived from experts to develop a new analysis model to make more reliable decisions. Finally, this new analysis is applied to various field case studies of road and rail carried out by the Korea Development Institute (KDI) between 2003 and 2006 to validate the new analysis model. The study found that approximately 20% of decisions resulting from the existing methodology are considered prudent. In future studies, the authors suggest analyzing the correlation between initial weights and final results since final results are enormously influenced by the initial weight.

• The Korean Journal of Petroleum Geology
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• v.14 no.1
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• pp.63-73
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• 2008

The seismic interpretation was carried out to understand the evolution of the Sora and North Sora Sub-basins, South Sea of Korea. Both sub-basins belong to the Domi Basin, which is located in the northeastern margin of East China Sea Basin with Fukue Basin of Japan. Age assignment of each strata in this study was based on the data of boreholes and seismic interpretation in NW Japan. Four regional horizons were identified, and five geological units; Y(basement), Q(Eocene$\sim$Middle Oligocene), M(Middle Oligocene$\sim$Early Miocene), L(Early Miocene$\sim$Late Miocene) and D(Late Miocene$\sim$Present) groups in ascending order. Structural trends of the main boundary faults and the basin-fill sediment are different between the Sora and North Sora Sub-basins; i.e., trend of the main boundary-faults, dip of horizons, distribution of basin and development of growth fault. These results imply that the Sora Sub-basin would have opened earlier than the North Sora Sub-basin.

• Korean Journal of Construction Engineering and Management
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• v.21 no.4
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• pp.50-61
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• 2020

Safety management has been one of the most critical issues in the construction industry for a long time. Despite continuous efforts, it still shows a higher accident rate than other sectors. To reduce the accident rate, a lot of studies have been performed, mostly focused on contractors or construction phase. Although the initial stage of the construction project has the most significant impact on construction safety and decision-makers at the initial stage play an important role, the safety management system throughout the project entire life-cycle is still insufficient. In addition, although a great deal of information is generated in the construction project and the value is increasing, while it shows an inefficient aspect. This is believed to be due to insufficient information exchange and a lack of standards. In this context, this study aims to analyze the efficiency of information handover in construction safety. For this purpose, a safety management framework for systematically and efficiently managing and utilizing for construction safety information is referred to as 'safety business functions', 'project life-cycle', and 'industrial hierarchy'. The 'safety business functions' are classified into three levels. And then, in order to analyze the efficiency of safety information handover, 'importance of safety business function' and 'efficiency of safety information handover' were evaluated by interviewing with experts. This study can be used as reference data for implementing systematical and efficient safety management, and can also increase construction safety competency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.270-276
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• 2019

According to the International Maritime Organization (IMO) 2020 Regulation, ships operating outside designated emission control areas (ECA) have to use low-sulfur oil with a sulfur content of 0.5% or less by January 2020. To minimize the consumption of high-priced low-sulfur oil, it is urgent to introduce efficient energy-saving devices (ESD), and contra-rotating propeller (CRP) systems are well known to be the most effective one. The shafting system that drives a CRP is composed of an inner shaft and an outer one and has a mutually influential system that is much more complex and heavier than a general shafting system. An initial design was carried out to install a CRP system for the first time in Korea. The purpose of this study is to verify whether the journal bearing meets the classification's design criteria through a bearing reaction force analysis for the classification's approval of the initial design. It is ideal for the thrust of the propeller to act on the center of the shaft, but thrust eccentricity occurs due to the uneven wake caused by the stern shape. Load conditions were applied while considering thrust eccentricity to perform the shaft analysis, and the results were compared with the classification's criteria.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.422-422
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• 2018

우리나라의 간척사업은 고려시대 중엽부터 서남해안에 다수 산재되어 있는 천혜적인 간척 적지를 대상으로 지속적으로 추진되어 국토확장 및 식량 자급달성에 기여하여 왔다. 그러나, 최근 들어 쌀 수급 등 농업정책의 변화, 비용에 대한 경제성 평가의 변화, 개발과 보전에 관한 이해당사자간의 대립 등으로 신규 간척사업의 추진이 어려워지고 기존 간척지의 토지이용 목적 변화와 이치수 기능개선을 목적으로 배수갑문을 확장하는 등의 사업이 추진되고 있다. 본 연구에서는 방조제 상류지역 및 지천에서 이상홍수 유입에 따른 방조제 안정성 검토를 실시하였다. 호내로 유입되는 빈도별 홍수량에 따른 각 지점별 수위변화를 이용하여 방조제 비상대처계획에 대한 재난관리 지표로 활용할 수 있는지를 확인한다. 이를 위해 선정된 방조제를 중심으로 빈도별 홍수량을 산정하여 수문학적 안정성을 검토하고, 빈도별 홍수량에 따른 호내의 홍수위 변화를 통하여 비상대처계획 시나리오를 구성하고자 한다. 새만금 유역의 수치모델링에 필요한 범위를 설정하고, 모델 구성 및 자료를 입력한 후 검 보정을 통하여 모델의 신뢰성을 검증한 후 모델운영 조건을 설정하였다. 새만금 종합개발계획(MP)이 완료되었을 경우를 가정하여 통합운영을 실시하였다. 호내 관리수위에 따른 100, 200, 500, PMF 홍수량 유입시에 호내 홍수위 모의를 수행하였다. 또한, 비상단계 중 초기단계인 '관심단계'를 "이상홍수 발생부터 관리수위 EL-1.5m까지"로 설정한다면 방조제 초기 재난대응이 유리해 질 것으로 판단된다. 또한, '주의단계'는 "관리수위 EL-1.5m부터 호내 관리홍수위 EL+1.5m까지"로 '경계단계'를 "호내 관리홍수위 EL+1.5m부터 제당 내측사석보호공 홍수위까지", '심각단계'를 "제당 내측사석보호공(만경유역 EL+4.5m, 동진유역 EL+2.5m) 이상의 홍수위"로 설정한다면 방조제 관리자에게 세부화된 정보 및 지표를 제공해 줄 것이라 판단된다. 방조제 비상상황 단계별 분류에서 이상홍수위 발생후의 시간을 수치모의를 통해 구분하였으며 정성적인 위기상황 판단이 아닌 구체적인 수치로 된 지표들을 방조제 위기상황 재난지표로 활용한다면 상황 관리자의 위기상황 판단과 대처를 위한 의사결정에 도움이 될 것으로 기대한다.

• The Korean Journal of Malacology
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• v.22 no.1 s.35
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• pp.13-22
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• 2006

Gonadosomatic index (GSI), oogenesis and reproductive cycle of Glossaulax didyma were investigated by the cytological histological obserbations and morphometric data. Samples were collected monthly from the intertidal zone of Biin Bay, Seocheon, Korea, for one year. Monthly variations in the GSI showed similar patterns with gonadal development. In the early vitellogenic oocyte, the Golgi complex and mitochondria were invovled in the formation of lipid droplet and yolk precursor. In the late vitellogenic oocytes, the rough endoplasmic reticulum and multivesicular bodies were involved in the formation of profeid yolk granules in the cytoplasm. A mature yolk granule was composed of three components: main body (central core), superficial layer, and the limiting membrane. The spawning season was from early June to late August, and the main spawning occurred between July and August when the seawater temperature was above $19^{\circ}C$. The female reproductive cycle can be classified into five successive stages: early active stage (December to February), late active stage (February to March), ripe stage (April to July), spawning stage (June to August), recovery stage (August to November). Fully mature oocytes were approximately $250-270{\mu}m$ in diameter.