• Title/Summary/Keyword: Response probability

Search Result 715, Processing Time 0.02 seconds

A Probabilistic Study on Seismic Response of Seismically Isolated Nuclear Power Plant Structures using Lead Rubber Bearing (LRB 면진장치를 적용한 원전구조물의 지진응답에 따른 확률론적 연구)

  • Kim, Hyeon-Jeong;Song, Jong-Keol;Moon, Ji-Ho
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.22 no.2
    • /
    • pp.45-54
    • /
    • 2018
  • The seismically isolated nuclear power plants shall be designed for design basis earthquake (DBE) and considered to ensure safety against beyond design basis earthquake (BDBE). In order to limit the excessive displacement of the seismic isolation system of the seismically isolated structure, the moat is installed at a certain distance from the upper mat supporting the superstructure. This certain distance is called clearance to stop (CS) and is calculated from the 90th percentile displacement of seismic isolation system subjected to BDBE. For design purposes, the CS can be obtained simply by multiplying the median displacement of the seismic isolation system against DBE by scale factor with a value of 3. The DBE and BDBE used in this study were generated by using 30 sets of artificial earthquakes corresponding to the nuclear standard design spectrum. In addition, latin hyper cube sampling was applied to generate 30 sets of artificial earthquakes corresponding to maximum - minimum spectra. For the DBE, the median displacement and the 99th percentile displacement of the seismic isolation system were calculated. For the BDBE, the suitability of the scale factor was assessed after calculating the 90th percentile displacement of the seismic isolation system.

Intrusion-Tolerant Jini Service Architecture for Enhancing Survivability of Ubiquitous Services (유비쿼터스 서비스 생존성 제고를 위한 침입감내 Jini 서비스 구조)

  • Kim, Sung-Ki;Park, Kyung-No;Min, Byoung-Joon
    • Journal of the Institute of Electronics Engineers of Korea CI
    • /
    • v.45 no.4
    • /
    • pp.41-52
    • /
    • 2008
  • Ubiquitous service environment is poor in reliability of connection and has a high probability that the intrusion and the system failure may occur. Therefore, in the environment, the capability of a system to collectively accomplish its mission in spite of active intrusions and various failure scenarios, that is, the survivability of services are needed. In this paper, we analyze the Jgroup/ARM framework that was developed in order to help the development of fault- tolerant Jini services. More importantly, we propose an intrusion-tolerant Jini service architecture to satisfy the security availability and quality of services on the basis of the analysis. The proposed architecture is able to protect a Jini system not only from faults such as network partitioning or server crash, but also from attacks exploiting flaws. It is designed to provides performance enough to show a low response latency so as to support seamless service usage. Through the experiment on a test-bed, we have confirmed that the architecture is able to provide high security and availability at the level that degraded services quality is ignorable.

Change in three dry rangeland species growth and soil properties by compost application

  • Sadeghi, Hossein;Shourije, Fatemeh Ansar;Masoudi, Masoud
    • Journal of Ecology and Environment
    • /
    • v.35 no.2
    • /
    • pp.131-140
    • /
    • 2012
  • There are different types of compost used as soil conditioners and fertilizers. Plants can have different responses to different forms of compost. This field study was performed to examine the effects of different types of compost on growth factors of three dry rangeland species (Atriplex, $Atriplex$ $lentiformis$; Saltwort, $Seidlitzia$ $rosmarinus$; Haloxylon, $Haloxylon$ $persicum$) and soil properties. The experiment was conducted in the Fars Province of Iran during the year 2010-2011. Compost applications consisted of compost tea, solid compost (SC), solid and liquid mixture (MX) and no compost as the control. The study was a factorial experiment based on a randomized complete block design with 3 replications. The results showed that all the tested compost applications enhanced the growth traits of all three species. It was also demonstrated that the use of compost significantly increased the organic matter (1% probability level [PL]), nitrogen concentration (5% PL), phosphorous (5% PL) and potassium (5% PL) concentrations of the soil. The soil's pH level was unchanged (range, 7.3 to 7.6), and the sodium concentration was also significantly decreased (1% PL) by the use of compost. The higher responses were observed in canopy volume and soil sodium and the lower were observed in stem diameter and soil pH level. Among the three plants in the study, Atriplex showed the best response to the application of compost. Based on the results of this study, it can be recommended that the best compost application to increase growth and improve soil condition is the mixed compost (MX) for Atriplex and the SC for Saltwort and Haloxylon.

Fitting Cure Rate Model to Breast Cancer Data of Cancer Research Center

  • Baghestani, Ahmad Reza;Zayeri, Farid;Akbari, Mohammad Esmaeil;Shojaee, Leyla;Khadembashi, Naghmeh;Shahmirzalou, Parviz
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.17
    • /
    • pp.7923-7927
    • /
    • 2015
  • Background: The Cox PH model is one of the most significant statistical models in studying survival of patients. But, in the case of patients with long-term survival, it may not be the most appropriate. In such cases, a cure rate model seems more suitable. The purpose of this study was to determine clinical factors associated with cure rate of patients with breast cancer. Materials and Methods: In order to find factors affecting cure rate (response), a non-mixed cure rate model with negative binomial distribution for latent variable was used. Variables selected were recurrence cancer, status for HER2, estrogen receptor (ER) and progesterone receptor (PR), size of tumor, grade of cancer, stage of cancer, type of surgery, age at the diagnosis time and number of removed positive lymph nodes. All analyses were performed using PROC MCMC processes in the SAS 9.2 program. Results: The mean (SD) age of patients was equal to 48.9 (11.1) months. For these patients, 1, 5 and 10-year survival rates were 95, 79 and 50 percent respectively. All of the mentioned variables were effective in cure fraction. Kaplan-Meier curve showed cure model's use competence. Conclusions: Unlike other variables, existence of ER and PR positivity will increase probability of cure in patients. In the present study, Weibull distribution was used for the purpose of analysing survival times. Model fitness with other distributions such as log-N and log-logistic and other distributions for latent variable is recommended.

A Study on the Seismic Damage Estimation in the Model District of Seoul City (서울시 모델 구역 지진피해 추정 연구)

  • Yoon, Eui-Taek;Ryu, Hyeuk;Kang, Tae-Seob;Kim, Jae-Kwan;Baag, Chang-Eob
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.9 no.6 s.46
    • /
    • pp.41-52
    • /
    • 2005
  • The seismic damage assessment due io the postulated earthquake was attempted for the buildings in the model district of Seoul City. The model district was selected to represent the typical structural and residential characteristics of Seoul City. The buildings in the model district were classified into 11 structural types. For each structural type, the capacity and fragility curves were constructed with parameters presented in HAZUS. The ground motions due to the postulated earthquakes were artificially generated and ground response analyses were done for three kinds of soil profiles classified with respect to the depth of surface soil layer. The probability of damage state of each structural type was calculated using capacity spectrum method and fragility curve. Finally, the calculated results were translated into GIS database and mapped to evaluate the seismic damage in the model district.

Seismic Performance Evaluation of Special Moment Steel Frames with Torsional Irregularities - II Improving Seismic Design Method (비틀림 비정형을 갖는 철골특수모멘트골조의 내진성능평가 - II 내진설계 방법개선)

  • Han, Sang Whan;Kim, Tae O
    • Journal of Korean Society of Steel Construction
    • /
    • v.29 no.5
    • /
    • pp.369-376
    • /
    • 2017
  • This paper is the sequel of a companion paper (I. Seismic Design) for design and assessment of the torsional irregular structure using ASCE 7-10 criteria. This study evaluates the influence of torsional provisions on the performance of the designed steel moment frame with different eccentricity, taking the collapse probability as performance metric using the methodology in FEMA P695. The result show that torsional irregular structure designed according to ASCE 7-10 has an excessive seismic performance and the collapse strength is low as the eccentricity increases. To make the design reasonable, a new design approach is proposed in this study.

Development of Diagnosis System Adopted Intelligent Smart Junction Box for Improving Vehicular Power Safety (차량 전원 안정성 향상을 위한 Diagnosis System 채택 Intelligent Smart Junction Box 개발)

  • Jeong, Min-Soo;Kim, Mun-Gyeom;Park, Young-Hoan;Bang, Soon-Young
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.57 no.2
    • /
    • pp.276-285
    • /
    • 2008
  • These days the automobile industry, which has rapidly progressed, has been an indispensable part in social and economic activities as well as its research and development have been activated in response to various needs of consumers and markets. The second and third generation control system, getting count on safety and convenience differently than early circuits, cause the hypertrophy of wire harness. The J/Box(Junction Box), which distributes power and wires, was developed to solve the problem. As vehicles have been better in quantity and intelligence, however, environment-friendly electric apparatus system has continuously increased and ITS(Intelligent Transport System) has been introduced in earnest. In result, wires got complicated and multilateral and also there has been a stronger probability that vehicles are out of order due to various problems including mechanical failure. In this study, ISJB(Intelligent Smart Junction Box) was introduced to solve the problem. The diagnosis system was applied to prevent the overload and short of ISJE. Also, the state of vehicles displayed so that drivers monitor it in motion. Likewise error data are saved in the memory so that such data can be analyzed retrospectively. The busbar was adopted in to the main power terminal and the part of power pattern was coverd by lead. Because ISJB is more sensitive to heat in comparison to the busbar type J/Box. With regard the circuits related with safe, alternative circuits were set up in order that electronic devices may be normally operated even when an error arises. ISJB is expected to improve the safety and quality of vehicles.

Optimum design and vibration control of a space structure with the hybrid semi-active control devices

  • Zhan, Meng;Wang, Sheliang;Yang, Tao;Liu, Yang;Yu, Binshan
    • Smart Structures and Systems
    • /
    • v.19 no.4
    • /
    • pp.341-350
    • /
    • 2017
  • Based on the super elastic properties of the shape memory alloy (SMA) and the inverse piezoelectric effect of piezoelectric (PZT) ceramics, a kind of hybrid semi-active control device was designed and made, its mechanical properties test was done under different frequency and different voltage. The local search ability of genetic algorithm is poor, which would fall into the defect of prematurity easily. A kind of adaptive immune memory cloning algorithm(AIMCA) was proposed based on the simulation of clone selection and immune memory process. It can adjust the mutation probability and clone scale adaptively through the way of introducing memory cell and antibody incentive degrees. And performance indicator based on the modal controllable degree was taken as antigen-antibody affinity function, the optimization analysis of damper layout in a space truss structure was done. The structural seismic response was analyzed by applying the neural network prediction model and T-S fuzzy logic. Results show that SMA and PZT friction composite damper has a good energy dissipation capacity and stable performance, the bigger voltage, the better energy dissipation ability. Compared with genetic algorithm, the adaptive immune memory clone algorithm overcomes the problem of prematurity effectively. Besides, it has stronger global searching ability, better population diversity and faster convergence speed, makes the damper has a better arrangement position in structural dampers optimization leading to the better damping effect.

Incremental dynamic analyses of concrete buildings reinforced with shape memory alloy

  • Mirtaheri, Masoud;Amini, Mehrshad;Khorshidi, Hossein
    • Steel and Composite Structures
    • /
    • v.23 no.1
    • /
    • pp.95-105
    • /
    • 2017
  • The use of superelastic shape memory alloys (SMAs) as reinforcements in concrete structures is gradually gaining interest among researchers. Because of different mechanical properties of SMAs compared to the regular steel bars, the use of SMAs as reinforcement in the concrete may change the response of structures under seismic loads. In this study, the effect of SMAs as reinforcement in concrete structures is analytically investigated for 3-, 6- and 8-story reinforced concrete (RC) buildings. For each concrete building, three different reinforcement details are considered: (1) steel reinforcement (Steel) only, (2) SMA bar used in the plastic hinge region of the beams and steel bar in other regions (Steel-SMA), and (3), beams fully reinforced with SMA bar (SMA) and steel bar in other regions. For each case, columns are reinforced with steel bar. Incremental Dynamic Analyses (IDA) are performed using ten different ground motion records to determine the seismic performance of Steel, Steel-SMA and SMA RC buildings. Then fragility curves for each type of RC building by using IDA results for IO, LS and CP performance levels are calculated. Results obtained from the analyses indicate that 3-story frames have approximately the same spectral acceleration corresponding with failure of frames, but in the cases of 6 and 8-story frames, the spectral acceleration is higher in frames equipped with steel reinforcements. Furthermore, the probability of fragility in all frames increases by the building height for all performance levels. Finally, economic evaluation of the three systems are compared.

Online condition assessment of high-speed trains based on Bayesian forecasting approach and time series analysis

  • Zhang, Lin-Hao;Wang, You-Wu;Ni, Yi-Qing;Lai, Siu-Kai
    • Smart Structures and Systems
    • /
    • v.21 no.5
    • /
    • pp.705-713
    • /
    • 2018
  • High-speed rail (HSR) has been in operation and development in many countries worldwide. The explosive growth of HSR has posed great challenges for operation safety and ride comfort. Among various technological demands on high-speed trains, vibration is an inevitable problem caused by rail/wheel imperfections, vehicle dynamics, and aerodynamic instability. Ride comfort is a key factor in evaluating the operational performance of high-speed trains. In this study, online monitoring data have been acquired from an in-service high-speed train for condition assessment. The measured dynamic response signals at the floor level of a train cabin are processed by the Sperling operator, in which the ride comfort index sequence is used to identify the train's operation condition. In addition, a novel technique that incorporates salient features of Bayesian inference and time series analysis is proposed for outlier detection and change detection. The Bayesian forecasting approach enables the prediction of conditional probabilities. By integrating the Bayesian forecasting approach with time series analysis, one-step forecasting probability density functions (PDFs) can be obtained before proceeding to the next observation. The change detection is conducted by comparing the current model and the alternative model (whose mean value is shifted by a prescribed offset) to determine which one can well fit the actual observation. When the comparison results indicate that the alternative model performs better, then a potential change is detected. If the current observation is a potential outlier or change, Bayes factor and cumulative Bayes factor are derived for further identification. A significant change, if identified, implies that there is a great alteration in the train operation performance due to defects. In this study, two illustrative cases are provided to demonstrate the performance of the proposed method for condition assessment of high-speed trains.