• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2006년도 춘계 학술발표회 논문집
• /
• pp.466-475
• /
• 2006

Reliability analysis between safety factor and reliability index for driven and bored pile load capacity was analyzed in this study. 0.1B, Chin, De Beer, and Davisson's methods were used for determining pile load capacity by using load-settlement curve from pile load test. Each method define ultimate, yield and allowable pile load capacities. LCPC method using CPT results was performed for comparing with results of pile load test. Based on FOSM analysis using load factors, it is obtained that reliability indices for ultimate pile load capacity were higher than those of yield and allowable condition. Present safety factor 2 for yield and allowable load capacities are not enough to satisfy target reliability index $2.0\sim2.5$. However, it is sufficient for ultimate pile load capacity using safety factor 3.

• 한국수소및신에너지학회논문집
• /
• 제14권4호
• /
• pp.305-312
• /
• 2003

A study is presented of the adsorption capacity of a number of different activated carbons for hydrogen at 100 bar aad 298 K. The hydrogen adsorption isotherm was measured by isothermal gravimetric analysis, using a microbalance. The effect of activated carbon's porosity on hydrogen adsorption capacity is surveyed. It is concluded that hydrogen adsorption capacity of activated carbon is lineally increased according to the increase of specific surface area and total pore volume, It seems that microporosity is more contributive than mesoporosity. Most of the adsorbed quantity is due to physical adsorption and chemisorption is negligible, In this work, 0.79 wt.% of hydrogen adsorption capacity is reached.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1999년도 하계종합학술대회 논문집
• /
• pp.126-129
• /
• 1999

In this paper, it is assumed that a mobile radio channel is a Rayleigh distributed multipath fading channel and Erlang capacity and equivalent channel numbers are calculated for the reverse link of a imperfect power controlled DS/CDMA cellular system considering both shadowing and multipath fading. The DS/CDMA blocking probability is calculated based on a new analysis method that considers Erlang capacity and ICF(interference correction factor) using the median value of $E_{b(i)}$/ $I_{o}$ corresponding to each reverse link user. It is showed that the effect of multipath fading must not be ignored in Erlang capacity of the IS-95 DS/CDMA cellular system and the Erlang capacity is decreased according to the increase of the deviation of the imperfect power control, to the decrease of the processing gain, to the increase of the voice activity.y.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2010년도 춘계학술대회 논문집
• /
• pp.1596-1602
• /
• 2010

The government have plans to improve the railway transport capacity and transport hub for the sustainable national transport and logistics system. Specially, there are much efforts to improve transportation capacity such as high speed transportation of rail freight, enlargement of BT train, development of double stack train, etc. between railway transport hubs. If the transport capacity between railway logistics hubs is increased as planned, we must increase the handling capacity of railway hub terminals. But there are limits to enlarge the terminal infrastructure because of investment scale, location circumstances and urban development plans. To ensure the capacity, with the minimum required enlargement of infrastructure, it is necessary to extremely increase the efficiency of terminal operations. For improving the efficiency, we have to introduce the efficient terminal operation systems based on u-IT and operation optimize technologies. In this paper, we analyse the issues and problems of railway terminals(including ICD) and suggest the concept of intelligent railway terminal and the construction components of technology.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
• /
• pp.805-810
• /
• 2000

The purpose of this study is to predict long-term structural safety on the Yonggwang Unit 3 prestressed concrete containment building. The aging-related degradations of its main structural materials are investigated and the effects of the property variation of time-dependent materials on the structural behavior of containment building are also assessed through the analysis on the ultimate pressure capacity. The nonlinear finite element analyses for both the design criteria condition a the present aging condition are conducted to assess the present structural capacity of the containment building As a result, it is verified that the structural capacity of the Yonggwang Unit 3 containment building under the present aging condition is judged to be still rugged. n addition, the sensitivity of the ultimate pressrue capacity of containment building according to th degradation levels of the structural materials are assessed. Finally, it is showed that the sensitivity levels are in the order of the tendon, rebar and concrete in case of individual material degradations, and the tendon-rebar, tendon-concrete and rebar-concrete in case of coupled material degradations.

• Ocean and Polar Research
• /
• 제42권1호
• /
• pp.21-31
• /
• 2020

Shorebirds migrating along the East Asian-Australasian Flyway (EAAF) have been drastically decreasing due to continuous area loss and quality degradation of intertidal mudflats in the Yellow Sea. Evaluating the current habitat quality by means of habitat carrying capacity estimation could be effective in predicting the magnitude of impacts caused by habitat loss and provide better understanding to improve management strategies. In this study, we estimated the total biomass of Macrophthalmus japonicus, a main prey item of curlews in the Korea peninsular as habitat carrying capacity of the southern intertidal mudflat of Ganghwa Island, one of the key stopover sites for curlews in the EAAF. The result of the estimation took into account spatial differences of prey biomass and the available foraging time by tide patterns. Accordingly, it was found that curlew populations account for 30.26% of the habitat carrying capacity. When we calculated the mean biomass of the area and extrapolated it to the whole area to calculate the total biomass, it was found that the curlews have consumed 10.92% of the total biomass. The results show that the habitat carrying capacity of the southern intertidal mudflat of Ganghwa Island has decreased by 7.8% compared to a study conducted twenty years ago employing the same method. This study shows that there can be considerable differences in the results of habitat carrying capacity estimation between different methods, indicating that various environmental factors that affect the estimation results of habitat carrying capacity must be considered to achieve a more precise analysis and assessment.

• 지식경영연구
• /
• 제23권1호
• /
• pp.89-109
• /
• 2022

최근 COVID-19, 동학개미운동 등 투자환경의 변화로 시스템 처리 허용 수준을 상회하는 트랜잭션이 발생하고 이로 인해 전산장애가 자본시장에서 빈번하게 나타나고 있다. 자본시장 IT시스템들은 장애 영향도가 매우 큰 시스템들로서, 2020년에 예측하지 못한 큰 규모의 트랜잭션이 상당한 기간 유입되어 전산장애가 급증하였다. 다수의 기업들이 높은 수준의 IT시스템 용량계획 정책을 유지하고 있던 상황임에도 불구하고, 이를 상회하는 트랜잭션이 유입된 것은 용량계획에 대한 새로운 접근 방법이 필요함을 시사하고 있다. 이에 본 연구는 다양한 머신러닝 기법을 활용하여 자본시장 IT시스템 용량계획 모델들을 개발하고 성능을 비교 분석한다. 또한, 동학개미운동과 같이 예측하기 힘든 투자자의 행동을 반영할 수 있는 심리지수를 예측에 활용함으로써 용량계획 모델의 성능을 높인다. COVID-19 기간을 포함한 실증데이터를 이용하여 본 연구에서 개발한 용량계획 모델은 실무에서 활용 가능한 수준의 높은 성능과 안정성을 가질 수 있다. 본 연구는 기업의 비용 효율성과 IT시스템 용량 변경에 수반되는 운영상의 제약을 모두 고려한 최적의 파라미터를 제시하였는데, 이것은 자본시장 도메인에서 유용하게 사용될 수 있다. 또한, 본 연구는 투자자의 심리를 반영하는 심리지수가 IT 시스템 용량계획에 중요한 예측요인이 될 수 있는 것을 입증함으로써, 심리지수가 다양한 수요예측에 적극적으로 활용될 수 있음을 보여준다.

• 대한전기학회논문지:전력기술부문A
• /
• 제52권7호
• /
• pp.363-370
• /
• 2003

This paper presents the analysis of the load transfer capacity and study of conductor size for variable contingencies in distribution systems. The operation capacity of feeders was changed to improve operation efficiency in KEPCO, considerations for contingencies are still based on the previous capacity. In order to cope with the changes such as operation capacity, it is necessary to study whether the present "contingency support criteria" is reasonable or not, also to confirm the whether the present criteria should be improved or not. We analyze the load transfer capacity and conductor size on a distribution system for contingency levels such as the substation-level, bank-level, feeder-level, and zone-level.one-level.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 춘계학술대회
• /
• pp.1518-1523
• /
• 2003

The objective of the present work is to investigate an effect on the solution crystallization temperature difference and the cooling capacity of the absorption chiller by a solution cooler in the absorber. The cooling capacity of the absorption chiller can be higher, with the enhanced performance of the solution heat exchangers. But, because the solution crystallization temperature difference becomes smaller at the absorber inlet, the heat capacity of the solution heat exchangers might be limited by the danger of crystallization, which can cause the serious damages. In this paper, the heat capacity ratio of the solution cooler is defined as the ratio of the heat capacity of the solution cooler to that of the absorber. If it becomes larger in the additional type solution cooler, the solution crystallization temperature difference is augmented and the cooling capacity is also increased.

• 한국철도학회논문집
• /
• 제2권4호
• /
• pp.20-31
• /
• 1999

When a foundation on the ground with tunnel is constructed, the ultimate bearing capacity of a footing is reduced by tunnel. In practice, structure may bate a considerable damage because of large settlement. This study shows that the settlement which is caused by variety of the ultimated bearing capacity leads fatal damages to the footing above tunnel. Therefore, it is necessary to study on the reduction both of the ultimate bearing capacity which leads a failure and of tolerable settlement which satisfies the safety of the building. For this reason, the variety of ultimated bearing capacity was analyzed using tub-dimensional elasto-plastic finite difference method in this paper. As a result, bearing capacity of the foundation above tunnel should be determined after establishing limit of allowable settlement and considering reduction-ratio of bearing capacity.