This paper gives an overview of the Lee Carter method and reiterates the feasibility of using it to construct mortality forecast for the population data. In a first step, the model is fitted in a traditional way and u...This paper gives an overview of the Lee Carter method and reiterates the feasibility of using it to construct mortality forecast for the population data. In a first step, the model is fitted in a traditional way and used to extrapolate forecast of the time-varying mortality index. The observed pattern of the mortality rates shows a different variability at different ages, highlighting that the homoscedasticity hypothesis is quite unrealistic. Thus, in a second step, the paper aims to produce more reliable mortality forecasting, focusing on the errors in the estimation of the model parameters. The robustness of the estimated parameter is analysed throughout an experimental strategy which allows to assess the robustness of the Lee Carter model by inducing the errors to satisfy the homoscedasticity hypothesis. The graphical and numerical results are tested by means of a comparison in terms of prediction accuracy.展开更多
As one part of the National Highway Network Planning in China, the Qinghai-Tibet Expressway （QTE） from Golmud to Lhasa will be built in the interior of the Qinghai-Tibet Plateau （QTP） across about 630 km of permaf...As one part of the National Highway Network Planning in China, the Qinghai-Tibet Expressway （QTE） from Golmud to Lhasa will be built in the interior of the Qinghai-Tibet Plateau （QTP） across about 630 km of permafrost lands. Due to the problematic interactions between the engineering foundations and permafrost, the frozen-soil roadbed of the QTE will be subjected to the more intense thermal disturbances due to the wider black surface. The design and construction for long-term thermal and mechanical stability will face more severe challenges than those in ordinary highways and railways in the same region. In order to provide scientific support for cold regions engineering practices, the QTE Experimental Demonstration Project （EDP） was constructed in situ in the vicinity of the Beilu＇he Permafrost Station in the interior of the QTP. In this paper, the anticipated problems of the proposed QTE project are enumerated, and the structures of the test sections for QTE EDP are described. Through numerical simulations, it was found that the heat transfer processes occurring in each specific road structure are significantly different. The heat accumulation in the highway embankment is mainly due to the black bituminous pavement, but in the railway embankment with its gravel surfaces, it mainly comes from the side slopes. As a result, the net heat accumulation of the highway embankment is three times higher than that in the railway. In expressway, the heat accumulation is further increased because of the wider pavement so that significantly more heat will be accumulated in the roadbed beneath the centerline area. Thus, the thermal stability of the fro- zen-soil roadbed and the underlying permafrost of the QTE can be seriously threatened without proper engineering measures protection against thawing. Based on research and practical experiences from the operating Qinghai-Tibet Railway （QTR） and the Qinghai-Tibet Highway （QTH）, combined with the predicted characteristics of heat transfer in an expressway embankment, nine kinds of engineering measures for mitigating the thaw settlement of foundation soils through the cooling the roadbed soils were built and are being tested in the EDP. The design of the monitoring system for the EDP and the observed parameters were also described.展开更多
Purpose: The purpose of this study was to clarify the relationship and experiences of occupational health nurses (OHNs) and related departments in project development of mental health care for primary treatment in the...Purpose: The purpose of this study was to clarify the relationship and experiences of occupational health nurses (OHNs) and related departments in project development of mental health care for primary treatment in the Japanese occupational health setting. Method: A total of 235 OHNs who are members of the Japan Academy of Occupational Health Nursing were sent an anonymous self-administered questionnaire survey. The questionnaire included items on the following: the OHN’s background, whether the OHN had experience in project development, the communication between the associated departments, the Japanese version of the Work Engagement Scale (UWES-J), occupational assessments, workplace assessments, and the Transtheoretical Model (TTM) for health promotion in companies and the OHN’s working environment. We performed logistic regression analysis to examine the relationship between experience and these harmonious relationships with other associated departments. Result: Responses from 61 OHNs (valid response rate: 25.9%) were analyzed. The mean number of years of service as an OHN was 18.9, and 82% of respondents had experience in project development. The logistic analysis further revealed that OHNs who had experience in project development of mental health care usually had a harmonious relationship with other associated departments. Conclusion: To promote mental health care for workers, OHNs have the capability to create individual and workplace assessments, enhance their work engagement, and make further improvements to their working environment. .展开更多
文摘This paper gives an overview of the Lee Carter method and reiterates the feasibility of using it to construct mortality forecast for the population data. In a first step, the model is fitted in a traditional way and used to extrapolate forecast of the time-varying mortality index. The observed pattern of the mortality rates shows a different variability at different ages, highlighting that the homoscedasticity hypothesis is quite unrealistic. Thus, in a second step, the paper aims to produce more reliable mortality forecasting, focusing on the errors in the estimation of the model parameters. The robustness of the estimated parameter is analysed throughout an experimental strategy which allows to assess the robustness of the Lee Carter model by inducing the errors to satisfy the homoscedasticity hypothesis. The graphical and numerical results are tested by means of a comparison in terms of prediction accuracy.
基金The QTE EDP was funded by the Western Project Program of the Chinese Academy of Sciences (Grant No. KZCX2-XB2-10)Major Program of the National Natural Science Foundation of China (Grant No.40730736)National Science Foundation for Distinguished Young Scholars of China (Grant No. 40625004)
文摘As one part of the National Highway Network Planning in China, the Qinghai-Tibet Expressway （QTE） from Golmud to Lhasa will be built in the interior of the Qinghai-Tibet Plateau （QTP） across about 630 km of permafrost lands. Due to the problematic interactions between the engineering foundations and permafrost, the frozen-soil roadbed of the QTE will be subjected to the more intense thermal disturbances due to the wider black surface. The design and construction for long-term thermal and mechanical stability will face more severe challenges than those in ordinary highways and railways in the same region. In order to provide scientific support for cold regions engineering practices, the QTE Experimental Demonstration Project （EDP） was constructed in situ in the vicinity of the Beilu＇he Permafrost Station in the interior of the QTP. In this paper, the anticipated problems of the proposed QTE project are enumerated, and the structures of the test sections for QTE EDP are described. Through numerical simulations, it was found that the heat transfer processes occurring in each specific road structure are significantly different. The heat accumulation in the highway embankment is mainly due to the black bituminous pavement, but in the railway embankment with its gravel surfaces, it mainly comes from the side slopes. As a result, the net heat accumulation of the highway embankment is three times higher than that in the railway. In expressway, the heat accumulation is further increased because of the wider pavement so that significantly more heat will be accumulated in the roadbed beneath the centerline area. Thus, the thermal stability of the fro- zen-soil roadbed and the underlying permafrost of the QTE can be seriously threatened without proper engineering measures protection against thawing. Based on research and practical experiences from the operating Qinghai-Tibet Railway （QTR） and the Qinghai-Tibet Highway （QTH）, combined with the predicted characteristics of heat transfer in an expressway embankment, nine kinds of engineering measures for mitigating the thaw settlement of foundation soils through the cooling the roadbed soils were built and are being tested in the EDP. The design of the monitoring system for the EDP and the observed parameters were also described.
文摘Purpose: The purpose of this study was to clarify the relationship and experiences of occupational health nurses (OHNs) and related departments in project development of mental health care for primary treatment in the Japanese occupational health setting. Method: A total of 235 OHNs who are members of the Japan Academy of Occupational Health Nursing were sent an anonymous self-administered questionnaire survey. The questionnaire included items on the following: the OHN’s background, whether the OHN had experience in project development, the communication between the associated departments, the Japanese version of the Work Engagement Scale (UWES-J), occupational assessments, workplace assessments, and the Transtheoretical Model (TTM) for health promotion in companies and the OHN’s working environment. We performed logistic regression analysis to examine the relationship between experience and these harmonious relationships with other associated departments. Result: Responses from 61 OHNs (valid response rate: 25.9%) were analyzed. The mean number of years of service as an OHN was 18.9, and 82% of respondents had experience in project development. The logistic analysis further revealed that OHNs who had experience in project development of mental health care usually had a harmonious relationship with other associated departments. Conclusion: To promote mental health care for workers, OHNs have the capability to create individual and workplace assessments, enhance their work engagement, and make further improvements to their working environment. .
