• Title/Summary/Keyword: 주기 조건

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Seismic Performance Evaluation of Highrise Steel Diagrid Frames (초고층 철골대각가새골조의 내진성능평가)

  • Kim, Seon-Woong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.3
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    • pp.307-317
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    • 2011
  • This paper is to investigate the possibility of the elastic seismic design for highrise buildings through seismic performance evaluation for potential earthquakes that wind-designed highrise buildings located in strong wind zone and low seismicity can be experienced. Highrise steel diagrid frames which is the most loved structural system in recent years were wind-designed and the substantial system overstrength due to wind design procedure is verified, For the highrise steel diagrid frames, the response spectrum analysis and the seismic performance evaluation by various soil sites were conducted. It was showed that highrise steel diagrid frames with slenderness of greater than 5.2 under strong wind and low seismic zones such as Korea peninsula can resist elastically for the 500 year return period earthquake and have the possibility of seismic design for the 2400 year return period earthquake. In the member level, highrise steel diagrid frames with slenderness of greater than 5.2 all presented the immediate occupancy level regardless of soil sites for the 500 year return earthquake and excluding the $S_E$ soil site for the even 2400 year return period earthquake. In the system level, highrise steel diagrid frames with slenderness of greater than 5.2 showed the immediate occupancy level for $S_A$ and $S_B$ soil sites and the life safety for $S_C$ to $S_E$ soil site in the 500 year return period. The seismic performance level of highrise steel diagrid frames for the 2400 year return period earthquake displayed one step lower than the 500 year return period earthquake.

Growth Performance and Photosynthesis of Two Deciduous Hardwood Species under Different Irrigation Period Treatments in a Container Nursery System (시설양묘과정에서 관수 주기 처리에 따른 두 활엽수종의 생장 및 광합성 기구 변화)

  • Cho, Min-Seok;Lee, Soo-Won;Hwang, Jae-Hong;Kim, Jae-Won
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.14 no.1
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    • pp.28-38
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    • 2012
  • This study was conducted to investigate growth performance, photosynthesis, water use efficiency (WUE), and stomatal conductance ($g_s$) of container seedlings of Liriodendron tulipifera and Zelkova serrata growing under three different irrigation periods (1 time/1 day, 1 time/2 days and 1 time/3 days) for high seedling quality. The root collar diameter and height of L. tulipifera and Z. serrata seedlings were highest with 1 time/1 day irrigation, whereas they were lowest with 1 time/3 days irrigation. The two species showed low drought tolerance. As irrigation period was shortened, biomass and seedling quality index (SQI) of the two species increased. The ratio of height to root collar diameter (H/D) and the ratio of below to aboveground biomass (T/R) of the two species were lower with 1 time/3 days than at other irrigation periods. L. tulipifera and Z. serrata seedlings showed significantly higher photosynthetic capacity with 1 time/1 day irrigation. As irrigation period was shortened, $g_s$ of two species increased, while their WUE decreased significantly (P<0.05) These results show that 1 time/1 day irrigation provides the most optimal water condition for container seedling production of two species and irrigation controlling is very important for growth and quality of container seedlings.

DUPIC 핵연료 공정에서의 핵임계 안전성

  • 신명원;김명현
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05a
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    • pp.169-172
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    • 1996
  • 본 연구에서는 DUPIC 핵연료 주기개발이 상업화 됨을 전재로 하였을때 핵연료 제조 공정에 대하여 핵임계 해석을 수행하였다. 계산 과정은 PWR 핵연료봉을 해체하는 공정과 분말을 취급하는 공정으로 나누었으며, 이중 우발성의 원리를 기초하여 가상 사고 조건을 고려하였다. 핵임계 해석의 결과, DUPIC 핵연료 제조 공정에서는 특별한 가상조건을 제외하고는 핵임계의 위험은 없는 것으로 나타났다.

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A Linkage Method for the Life Cycle Cost Breakdown Structure through an Analysis of Boundary Conditions (경계조건 분석을 통한 LCCBS 연계방안)

  • Jeong, Jae-Hyuk;Kim, Tae-Hui
    • Journal of the Korea Institute of Building Construction
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    • v.13 no.4
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    • pp.321-332
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    • 2013
  • Costs and expenses are intertwined and incurred throughout an entire construction project, even from the pre-construction phase, and each phase has a different impact on the life cycle cost (LCC). However, the cost breakdown structure (CBS) is different in each phase of a building construction project, which makes it hard to reasonably calculate construction cost. For this reason, the boundary conditions were analyzed in this study based on the life cycle cost break structure (LCCBS). In addition, breakdown factors were analyzed based on the boundary conditions to derive a linkage method. The validity of the linkage method was verified through application to actual construction projects. Through the analysis, it was found that the problem of items being left out was reduced by more than 97.2 percent, and the work was done an average of 6 hours faster compared to the conventional method. It is expected that by applying the new LCC system, LCC will be both reduced and calculated in a more efficient manner.

Development of Site Classification System and Modification of Design Response Spectra considering Geotechnical Site Characteristics in Korea (III) - Modification of Desing Response Specra (국내 지반특성에 적합한 지반분류 방법 및 설계응답스펙트럼 개선에 대한 연구 (III) - 설계응답스펙트럼 개선방법)

  • Yoon, Jong-Ku;Kim, Dong-Soo;Bang, Eun-Seok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.10 no.2 s.48
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    • pp.63-71
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    • 2006
  • In the companion paper (II, Development of Site Classification System), new size classification system based on site periods $(T_G)$ was recommended for legions of shallow bedrock depth in Korea. Despite the site classification method was improved, the response spectrum would be required to be modified by adjusting the integration interval to calculate the site coefficients because the response spectra did not match well the average spectral accelerations obtained by site response analyses in the range of long periods. In this paper, new response spectra for each site categories were determined by adjusting the integration interval of long period site coefficient $F_v\;from\;0.4{\sim}2.0\;to\;0.4{\sim}1.5$ second. It matched well the average spectral accelerations and new response spectrum, and it was also improved compared to the current she classification system.

A Study on the Support Conditions of Cable-stayed Bridge System (사장교계의 지지조건에 대한 연구)

  • An, Zu-Og;Yoon, Young-Man
    • Journal of the Korean Society of Hazard Mitigation
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    • v.2 no.3 s.6
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    • pp.119-125
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    • 2002
  • The objective of this study is to evaluate elastic modulus of bridge-axis direction for optimum structure system in the cable-stayed bridge design. In numerical example of this study, a slight change in axis direction elastic modulus causes major modifications of the bridge characteristics when it is $1\times10^4$ tonf/m/bearing or less. Therefore, the elastic modulus was set at this lower limit of $1\times10^4$ tonf/m/bearing where the strength of the entire bridge system is still determined by girder strength and the entire system is insensitive to variations in elastic modulus. Besides, cable-stayed bridge with freely supported girders have slightly longer vibration periods in the horizontal direction for earthquake forces.