• Title/Summary/Keyword: Hazard-rate model

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Minimum loading requirements for areas of low seismicity

  • Lam, Nelson T.K.;Tsang, Hing-Ho;Lumantarna, Elisa;Wilson, John L.
    • Earthquakes and Structures
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    • v.11 no.4
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    • pp.539-561
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    • 2016
  • The rate of occurrence of intraplate earthquake events has been surveyed around the globe to ascertain the average level of intraplate seismic activities on land. Elastic response spectra corresponding to various levels of averaged (uniform) seismicity for a return period of 2475 years have then been derived along with modifying factors that can be used to infer ground motion and spectral response parameters for other return period values. Estimates derived from the assumption of uniform seismicity are intended to identify the minimum level of design seismic hazard in intraplate regions. The probabilistic seismic hazard assessment presented in the paper involved the use of ground motion models that have been developed for regions of different tectonic and crustal classifications. The proposed minimum earthquake loading model is illustrated by the case study of Peninsular Malaysia which has been identified with a minimum effective peak ground acceleration (EPGA) of 0.1 g for a return period of 2475 years, or 0.07 g for a notional return period of 475 years.

Real-time large-scale hybrid testing for seismic performance evaluation of smart structures

  • Mercan, Oya;Ricles, James;Sause, Richard;Marullo, Thomas
    • Smart Structures and Systems
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    • v.4 no.5
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    • pp.667-684
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    • 2008
  • Numerous devices exist for reducing or eliminating seismic damage to structures. These include passive dampers, semi-active dampers, and active control devices. The performance of structural systems with these devices has often been evaluated using numerical simulations. Experiments on structural systems with these devices, particularly at large-scale, are lacking. This paper describes a real-time hybrid testing facility that has been developed at the Lehigh University NEES Equipment Site. The facility enables real-time large-scale experiments to be performed on structural systems with rate-dependent devices, thereby permitting a more complete evaluation of the seismic performance of the devices and their effectiveness in seismic hazard reduction. The hardware and integrated control architecture for hybrid testing developed at the facility are presented. An application involving the use of passive elastomeric dampers in a three story moment resisting frame subjected to earthquake ground motions is presented. The experiment focused on a test structure consisting of the damper and diagonal bracing, which was coupled to a nonlinear analytical model of the remaining part of the structure (i.e., the moment resisting frame). A tracking indictor is used to track the actuator ability to achieve the command displacement during a test, enabling the quality of the test results to be assessed. An extension of the testbed to the real-time hybrid testing of smart structures with semi-active dampers is described.

Analysis of Characteristics for a Dividing Flow in Open Channels (개수로 분류흐름에서의 특성분석)

  • Park, Seong-Soo;Lee, Jin-Woo;Cho, Yong-Sik
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.2
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    • pp.53-57
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    • 2009
  • The dividing flow in an open channel has a number of distinctive characteristics. One of these is that the separation zone interacts with a secondary motion along the inner wall of a branch channel, generating sediment accumulation. To investigate this phenomenon, a two-dimensional numerical model based on the shallow-water equations, RMA2, which calculates water surface elevations and horizontal-velocity components, was used to analyze the dividing flow. The obtained numerical results fully coincide with the laboratory measurements reported by Hsu et al.(2002). For the analysis of the numerical results, a separation zone-discharge rate relationship was proposed. To reduce the size of a separation zone, the topographies of diagonal and curved edges were proposed, smoothly connecting the upstream corner to branch channel.

Response on New Credit Program In Indonesia: An Asymmetric Information Perspective

  • PURWONO, Rudi;NUGROHO, Ris Yuwono Yudo;MUBIN, M. Khoerul
    • The Journal of Asian Finance, Economics and Business
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    • v.6 no.2
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    • pp.33-44
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    • 2019
  • The Indonesian government launched a new people's business credit program as part of a package of economic policy and deregulation. The interest rate is set lower than the average of the current loan interest rates, especially when compared with rural bank interest rates. To capture the social spatial aspects, quota sampling is applied to ten areas that divided based on the social culture. Further, the method utilized in this research is logit models, which designed to analyse the determinants of asymmetric information particularly on the rural bank and small micro enterprises. The study was conducted in East Java as the province with the largest number of rural banks in Indonesia. Based on the estimation of asymmetric information model to the respondent of rural banks and small businesses, the result shows that adverse selection can be avoided by strengthening the information about prospective borrowers. Regarding moral hazard, rural banks and small businessmen argued that the imposition of the collateral to the debtor has an important role to avoid moral hazard. Rural bank respondents stated that the KUR program with low-interest rates has affected their business development. The results implied the need of broadening the collaboration schemes between this people's business credit program and rural banks.

Incidence and Risk Factors of Dyslipidemia after Menopause (폐경 후 이상지질혈증 발생양상과 위험요인)

  • Jeong, Ihn Sook;Yun, Hae Sun;Kim, Myo Sung;Hwang, Youn Sun
    • Journal of Korean Academy of Nursing
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    • v.52 no.2
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    • pp.214-227
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    • 2022
  • Purpose: This study was aimed at investigating the incidence and risk factors of dyslipidemia in menopausal women using a Korean community-based longitudinal study. Methods: The subjects were 245 postmenopausal women without dyslipidemia who had participated in the Ansan-Ansung cohort study from 2001~2002 (baseline) to 2015~2016 (seventh follow-up visit). The dyslipidemia incidence was measured as incidence proportion (%) and incidence rate per 100 person-years. The predictors of developing dyslipidemia were analyzed with Cox's proportional hazard model. Results: The incidence of new dyslipidemia during the follow-up period was 78.4% (192 patients), and 11.9 per 100 person-years. Mean duration from menopause to developing dyslipidemia was 5.3 years in new dyslipidemia cases. The triglyceride/high density lipoprotein (TG/HDL-C) ratio at baseline (hazard ratio = 2.20; 95% confidence interval = 1.39~3.48) was independently associated with developing dyslipidemia. Conclusion: Dyslipidemia occurs frequently in postmenopausal women, principally within five years after menopause. Therefore, steps must be taken to prevent dyslipidemia immediately after menopause, particularly in women with a high TG/HDL-C ratio at the start of menopause.

Cost Analysis Model for Periodic Maintenance Policy with Maintenance Cost Factor (보전비용요소를 고려한 정기보전정책의 비용분석모델)

  • 김재중;김원중
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.18 no.36
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    • pp.287-295
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    • 1995
  • This paper is concerned with cost analysis model in periodic maintenance policy. Generally periodic maintenance policy in which item is repaired periodic interval times. And in the article minimal repair is considered. Mimimal repair means that if a unit fails, unit is instantaneously restored to same hazard rate curve as before failure. In the paper periodic maintenance policy with minimal repair is as follows; Operating unit is periodically replaced in periodic maintenance time, if a failure occurs between minimal repair and periodic maintenance time, unit is replaced by a new item until tile periodic maintenance time comes. Also unit undergoes minimal repair at failures in minimal-repair-for-failure interval. Then total expected cost per unit time is calculated according to scale parameter of failure distribution. Maintenance cost factors are included operating, fixed, minimal repair, periodic maintenance and new item replacement cost. Numerical example is shown in which failure time of system has weibull distribution.

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Estimating the Survival of Patients With Lung Cancer: What Is the Best Statistical Model?

  • Abedi, Siavosh;Janbabaei, Ghasem;Afshari, Mahdi;Moosazadeh, Mahmood;Alashti, Masoumeh Rashidi;Hedayatizadeh-Omran, Akbar;Alizadeh-Navaei, Reza;Abedini, Ehsan
    • Journal of Preventive Medicine and Public Health
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    • v.52 no.2
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    • pp.140-144
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    • 2019
  • Objectives: Investigating the survival of patients with cancer is vitally necessary for controlling the disease and for assessing treatment methods. This study aimed to compare various statistical models of survival and to determine the survival rate and its related factors among patients suffering from lung cancer. Methods: In this retrospective cohort, the cumulative survival rate, median survival time, and factors associated with the survival of lung cancer patients were estimated using Cox, Weibull, exponential, and Gompertz regression models. Kaplan-Meier tables and the log-rank test were also used to analyze the survival of patients in different subgroups. Results: Of 102 patients with lung cancer, 74.5% were male. During the follow-up period, 80.4% died. The incidence rate of death among patients was estimated as 3.9 (95% confidence [CI], 3.1 to 4.8) per 100 person-months. The 5-year survival rate for all patients, males, females, patients with non-small cell lung carcinoma (NSCLC), and patients with small cell lung carcinoma (SCLC) was 17%, 13%, 29%, 21%, and 0%, respectively. The median survival time for all patients, males, females, those with NSCLC, and those with SCLC was 12.7 months, 12.0 months, 16.0 months, 16.0 months, and 6.0 months, respectively. Multivariate analyses indicated that the hazard ratios (95% CIs) for male sex, age, and SCLC were 0.56 (0.33 to 0.93), 1.03 (1.01 to 1.05), and 2.91 (1.71 to 4.95), respectively. Conclusions: Our results showed that the exponential model was the most precise. This model identified age, sex, and type of cancer as factors that predicted survival in patients with lung cancer.

Assessment of Rainfall Runoff and Flood Inundation in the Mekong River Basin by Using RRI Model

  • Try, Sophal;Lee, Giha;Yu, Wansik;Oeurng, Chantha
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.191-191
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    • 2017
  • Floods have become more widespread and frequent among natural disasters and consisted significant losses of lives and properties worldwide. Flood's impacts are threatening socio-economic and people's lives in the Mekong River Basin every year. The objective of this study is to identify the flood hazard areas and inundation depth in the Mekong River Basin. A rainfall-runoff and flood inundation model is necessary to enhance understanding of characteristic of flooding. Rainfall-Runoff-Inundation (RRI) model, a two-dimensional model capable of simulating rainfall-runoff and flood inundation simultaneously, was applied in this study. HydoSHEDS Topographical data, APPRODITE precipitation, MODIS land use, and river cross section were used as input data for the simulation. The Shuffled Complex Evolution (SCE-UA) global optimization method was integrated with RRI model to calibrate the sensitive parameters. In the present study, we selected flood event in 2000 which was considered as 50-year return period flood in term of discharge volume of 500 km3. The simulated results were compared with observed discharge at the stations along the mainstream and inundation map produced by Dartmouth Flood Observatory and Landsat 7. The results indicated good agreement between observed and simulated discharge with NSE = 0.86 at Stung Treng Station. The model predicted inundation extent with success rate SR = 67.50% and modified success rate MSR = 74.53%. In conclusion, the RRI model was successfully used to simulate rainfall runoff and inundation processes in the large scale Mekong River Basin with a good performance. It is recommended to improve the quality of the input data in order to increase the accuracy of the simulation result.

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Estimation of Shelf-life of Frankfurter Using Predictive Models of Spoilage Bacterial Growth

  • Heo, Chan;Choi, Yun-Sang;Kim, Cheon-Jei;Paik, Hyun-Dong
    • Food Science of Animal Resources
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    • v.29 no.3
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    • pp.289-295
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    • 2009
  • The aim of this research was to develop predictive models for the growth of spoilage bacteria (total viable cells, Pseudomonas spp., and lactic acid bacteria) on frankfurters and to estimate the shelf-life of frankfurters under aerobic conditions at various storage temperatures (5, 15, and $25^{\circ}C$). The primary models were determined using the Baranyi model equation. The secondary models for maximum specific growth rate and lag time as functions of temperature were developed by the polynomial model equation. During 21 d of storage under various temperature conditions, lactic acid bacteria showed the longest lag time and the slowest growth rate among spoilage bacteria. The growth patterns of total viable cells and Pseudomonas spp. were similar each other. These data suggest that Pseudomonas spp. might be the dominant spoilage bacteria on frankfurters. As storage temperature increased, the growth rate of spoilage bacteria also increased and the lag time decreased. Furthermore, the shelf-life of frankfurters decreased from 7.0 to 4.3 and 1.9 (d) under increased temperature conditions. These results indicate that the most significant factor for spoilage bacteria growth is storage temperature. The values of $B_f$, $A_f$, RMSE, and $R^2$ indicate that these models were reliable for identifying the point of microbiological hazard for spoilage bacteria in frankfurters.

A Diagnostic Study on the Variables Related to Smoking Behavior among College Students - Based the PRECEDE Model - (대학생의 흡연 관련 요인에 대한 진단적 연구 - PRECEDE 모형을 근간으로 -)

  • Yoo, Jae-Soon
    • The Journal of Korean Academic Society of Nursing Education
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    • v.13 no.2
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    • pp.266-276
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    • 2007
  • Purpose: The purpose of this study was to identify variables related to smoking behaviors (never smoked, former smoker, current smoker) among college students on the basis of the PRECEDE model. Method: Data were collected from 327 college students in Chungbuk Province from May to June 2006 using a self-reported questionnaire. Result: The rate of current smokers was 19.0%. The rate of current smokers in male students (41.1%) was significantly higher than that of female students(8.3%). Also, there were significant differences by general characteristics such as major, academic achievements, satisfaction with major and alcohol consumption. Number of smokers among five close friends was 1.72 and it showed significant differences among different gender, majors, levels of satisfaction with majors and alcohol consumption. In discriminant analysis, discriminant variables on smoking behavior were the number of smokers among close friends, the referent persons' responses about smoking and subject's belief about smoking. Conclusion: These research findings suggest that we can enhance the prevention of college students' smoking by strengthening the related factors such as enforcing a non-smoking environment and strengthening college health education strategies of non-smoking including a negative belief of smoking and the hazard of passive smoking.

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