• Title/Summary/Keyword: Lifetime Analysis

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A Study on the Use Scope of Lifetime Sports Facilities (생활체육시설 이용권에 관한 연구)

  • Min, Young-Gi
    • Journal of The Korean Digital Architecture Interior Association
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    • v.7 no.2
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    • pp.73-78
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    • 2007
  • Proper methods for facilities distribution are suggested by the examination of researches on facilities distribution, the analysis of the scope that facilities are used, and the consideration of facilities demand, and proper distribution and placement of facilities suitable for each stage is suggested. The theoretical examination for proper distribution and the analysis of the use scope is made. As a result. the area covers four dongs(administrative unit) within 1km. The $80{\sim}90%$ of residents who use the existing facilities are the ones living within 1km and so the zone of life in everyday life depending on walking as a means of movement is found to be expanded by the developments in transportation means and road construction. Therefore I suggested that lifetime sports facilities be established within the use scope whose radius and area are 1km and 4km2, respectively, regarding the sports facilities as a community center which can playa role of an institution of community center.

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Thermal Analysis and Equivalent Lifetime Prediction of Insulation Material for Nuclear Power Cable (원전 케이블용 절연재료의 열분석과 등가수명)

  • Kim, Ji-Yeon;Yang, Jong-Suk;Park, Kyeung-Heum;Seong, Baek-Yong;Bang, Jeong-Hwan;Park, Dae-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.1
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    • pp.17-22
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    • 2016
  • The activation energy of a material is an important factor that significantly affects the lifetime and can be used to develop a degradation model. In this study, a thermal analysis was carried out to evaluate and collect quantitative data on the degradation of insulation materials like EPR and CSP used for nuclear power plant cables. The activation energy was determined from the relationship between log ${\beta}$ and 1/T based on the Flynn.Wall.Ozawa method, by a TGA test. The activation energy was also derived from the relationship between ln(t) and 1/T based on isothermal analysis, by an OIT test. The activation energy of EPR derived from thermal analysis was used to calculate the accelerated aging time corresponding to the number of years of use, employing the Arrhenius equation, and determine the elongation corresponding to the accelerated aging time.

Life-Cycle Cost Effective Optimal Seismic Retrofit and Maintenance Strategy of Bridge Structures - (I) Development of Lifetime Seismic Reliability Analysis S/W (교량의 생애주기비용 효율적인 최적 내진보강과 유지관리전략 - (I) 생애주기 지진신뢰성해석 프로그램 개발)

  • Lee, Kwang-Min;Choi, Eun-Soo;Cho, Hyo-Nam;An, Hyoung-Jun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.6A
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    • pp.965-976
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    • 2006
  • A realistic lifetime seismic-reliability based approach is unavoidable to perform Life-Cycle Cost (LCC)-effective optimum design, maintenance, and retrofitting of structures against seismic risk. So far, though a number of researchers have proposed the LCC-based seismic design and retrofitting methodologies, most researchers have only focused on the methodological point. Accordingly, in most works, they have not been quantitatively considered critical factors such as the effects of seismic retrofit, maintenance, and environmental stressors on lifetime seismic reliability assessment of deteriorating structures. Thus, in this study, a systemic lifetime seismic reliability analysis methodology is proposed and a program HPYER-DRAIN2DX-DS is developed to perform the desired lifetime seismic reliability analysis. To demonstrate the applicability of the program, it is applied to an example bridge with or without seismic retrofit and maintenance strategies. From the numerical investigation, it may be positively stated that HYPER-DRAIN2DX-DS can be utilized as a useful numerical tool for LCC-effective optimum seismic design, maintenance, and retrofitting of bridges.

WSN Lifetime Analysis: Intelligent UAV and Arc Selection Algorithm for Energy Conservation in Isolated Wireless Sensor Networks

  • Perumal, P.Shunmuga;Uthariaraj, V.Rhymend;Christo, V.R.Elgin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.3
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    • pp.901-920
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    • 2015
  • Wireless Sensor Networks (WSNs) are widely used in geographically isolated applications like military border area monitoring, battle field surveillance, forest fire detection systems, etc. Uninterrupted power supply is not possible in isolated locations and hence sensor nodes live on their own battery power. Localization of sensor nodes in isolated locations is important to identify the location of event for further actions. Existing localization algorithms consume more energy at sensor nodes for computation and communication thereby reduce the lifetime of entire WSNs. Existing approaches also suffer with less localization coverage and localization accuracy. The objective of the proposed work is to increase the lifetime of WSNs while increasing the localization coverage and localization accuracy. A novel intelligent unmanned aerial vehicle anchor node (IUAN) is proposed to reduce the communication cost at sensor nodes during localization. Further, the localization computation cost is reduced at each sensor node by the proposed intelligent arc selection (IAS) algorithm. IUANs construct the location-distance messages (LDMs) for sensor nodes deployed in isolated locations and reach the Control Station (CS). Further, the CS aggregates the LDMs from different IUANs and computes the position of sensor nodes using IAS algorithm. The life time of WSN is analyzed in this paper to prove the efficiency of the proposed localization approach. The proposed localization approach considerably extends the lifetime of WSNs, localization coverage and localization accuracy in isolated environments.

The Effects of Droplets Arrangement and Size Difference on the Vaporization and Combustion Characteristics of Liquid Fuel Droplets (액체 연료 액적들의 배열 및 크기차이가 증발 및 연소특성에 미치는 영향)

  • Lee, Dong-Jo;Kim, Ho-Young;Cho, Chong-Pyo;Yoon, Suk-Goo
    • 한국연소학회:학술대회논문집
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    • 2007.05a
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    • pp.107-113
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    • 2007
  • The burning characteristics of interacting droplets with internal circulation in a convective flow are numerically investigated at various particle arrangement and size difference. In this simulation some conditions are fixed, surround gas temperature is 1250K, pressure is 10 atm and drolet's initial temperature is 300K. The transient combustion of arranged droplets, the fixed droplet distances of 4 radii to 20 radii horizontally, is studied. And the range of size of droplet is 75${\mu}m$ to 100${\mu}m$. The results obtained from the present numerical analysis reveal that the transient flame configuration and retardation of droplet internal motion with the horizontal spacing substantially influence lifetime of interacting droplets. At a Reynolds number 10, lifetime of the three droplets with decreasing horizontal droplet spacing increases monotonically. But when droplet spacing decreases further to 4radii, Lifetime of interacting droplets are increase. So Lifetime of interacting droplets exhibits a strong dependence on the horizontal droplet spacing and size difference. It can be investigated well with these conditions to that of single burning droplet.

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Development of Precise Lunar Orbit Propagator and Lunar Polar Orbiter's Lifetime Analysis

  • Song, Young-Joo;Park, Sang-Young;Kim, Hae-Dong;Sim, Eun-Sup
    • Journal of Astronomy and Space Sciences
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    • v.27 no.2
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    • pp.97-106
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    • 2010
  • To prepare for a Korean lunar orbiter mission, a precise lunar orbit propagator; Yonsei precise lunar orbit propagator (YSPLOP) is developed. In the propagator, accelerations due to the Moon's non-spherical gravity, the point masses of the Earth, Moon, Sun, Mars, Jupiter and also, solar radiation pressures can be included. The developed propagator's performance is validated and propagation errors between YSPOLP and STK/Astrogator are found to have about maximum 4-m, in along-track direction during 30 days (Earth's time) of propagation. Also, it is found that the lifetime of a lunar polar orbiter is strongly affected by the different degrees and orders of the lunar gravity model, by a third body's gravitational attractions (especially the Earth), and by the different orbital inclinations. The reliable lifetime of circular lunar polar orbiter at about 100 km altitude is estimated to have about 160 days (Earth's time). However, to estimate the reasonable lifetime of circular lunar polar orbiter at about 100 km altitude, it is strongly recommended to consider at least $50\;{\times}\;50$ degrees and orders of the lunar gravity field. The results provided in this paper are expected to make further progress in the design fields of Korea's lunar orbiter missions.

Algorithm for Adjusting Cluster Size according to Location Information in WSN (무선 센서네트워크에서 센서노드의 위치 정보를 이용한 클러스터 크기 조정 알고리즘)

  • Kwak, Tae-Kil;Jin, Kyo-Hong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.06a
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    • pp.389-392
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    • 2007
  • In this paper, we propose an algorithm that improve network lifetime by adjusting cluster size according to location information of sensor node in wireless sensor network (WSN) using clustering technique. The sensed information in each cluster transfers to sink node through inter-cluster communications. Cluster head (CH) that nearby located in sink node much more spend own energy than far away CHs, because nearer CH forwards more data, so network lifetime is decreased. Proposed algorithm minimizes energy consumption in adjacent cluster to sink node by decreasing cluster site, and improve CH lifetime by distributing transmission paths. As a result of analysis, the proposed algorithm shows longer network lifetime in WSN.

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Effects of constituents in CNT pastes on the field emission characteristics of carbon nanotubes

  • Yoon, Seung-Il;Kim, Sam-Soo;Lee, Yang-Kyu;Kim, Tae-Kwon;Lee, Dong-Gu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1206-1209
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    • 2006
  • Carbon nanotubes (CNTs) have been significantly used for the field emitters for display applications. However, the lifetime of CNT emitters which are formed by screen printing technique is not guaranteed yet, because the constituents in CNT paste affect the lifetime of CNTs. The CNT pastes for screen printing are normally composed of organic vehicles (nitro cellulose, ethyl cellulose, etc) and additives (glass frits, ITO, etc) with CNTs. In this study, the effects of constituents in CNT pastes on the lifetime and emission characteristics of CNTs were investigated by thermal and electrical analysis. Use of glass frits worsened the lifetime and electron emission of CNTs. However, an addition of ITO to CNT paste rather improved the lifetime of CNTs. Degradation of CNTs was small when nitro cellulose was used in CNT paste as an organic vehicle.

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An Accelerated Degradation Test of Nuclear Power Plants Communication Cable Jacket (원자력 발전소용 통신케이블 자켓의 가속열화시험)

  • Jung, Jae Han;Kim, Yong Soo
    • Journal of Korean Society for Quality Management
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    • v.45 no.4
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    • pp.969-980
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    • 2017
  • Purpose: The purpose of this study was to estimate the lifetime, and verify the target lifetime at steady state temperature, of communication cable jackets used in nuclear power plants. Method: This study was completed according to test and analysis methods required by international standards. After measuring the residual elongation(%) of specimens at specific points in time with the accelerated degradation test, average failure time of each temperature was computed. Thus, the activation energy could be derived by applying the temperature-Arrhenius law to estimate cable jacket lifetime at steady state temperature. Results: The cable jacket lifetime was estimated as 363.8 years assuming a normal nuclear power plant operating temperature of $90^{\circ}C$. Conclusion: To ascertain stable operating conditions for a nuclear power plant, accelerated degradation tests were performed according to the Arrhenius law for components of the nuclear power plants. The lifetime was estimated from the degradation data collected during the accelerated degradation test.

Study on the Free Volume in Polymer by Positron Annihilation Lifetime Spectroscopy (PALS) (양전자소멸 수명시간 측정을 통한 폴리머소재의 자유부피에 관한 연구)

  • Kim, Yongmin;Shin, Jungki;Kwon, Junhyun
    • Journal of the Korean Society of Radiology
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    • v.6 no.6
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    • pp.489-493
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    • 2012
  • Positron Annihilation Lifetime Spectroscopy is a non-destructive technique to study voids and defects in solids by the measurement of gammas from electron-positron annihilation. In this study, we measured the lifetime of CR, EPDM, NBR, all of which are widely used polymer in various fields. A conventional fast-fast coincidence system in KAERI(Korea Atomic Energy Research Institute) has been used to measure the lifetime spectra, Three lifetime components were analyzed from each lifetime spectra. According to Tao-Eldrup model equation, the size and fraction of free-volume were calculated. Mean radius and free volume fraction of CR, EPDM NBR are $0.1217nm^3$(1.9103%), $0.14780nm^3$(5.3147%), $0.1216nm^3$(2.6381%), respectively. Through these measurements, we identified the feasibility of the PAL system for polymer analysis.