降低可靠性验证试验用费的分析

分析了降低可靠性验证试验的用费问题,并以指数寿命型序贯试验方案为例,给出了降低用费的建模及计算方法。算例表明,根据模型计算关键参数的取值表,使得计算过程变得简单、实用。

Designand development of highway tunnel maintenance and management system

In order to solve the urgent problem of how to manage and sustain highway tunnels with advanced information technology with the background of the rapid development in the modem traffic, and achieve the cost- effectiveness optimal principle objectives under the premise of guaranteeing a smooth flow of traffic; a highway tunnel maintenance and management system framework and the key modules were proposed. First, the determined highway tunnel condition assessment index system was established according to the result of expert consulting forms. Secondly, the tunnel diseases, the corresponding maintenance measurements, and many-to-many relationship between diseases and maintenance measurements were introduced. Then, three kinds of 0-1 integer programming models were built according to different tunnel operators＇ needs in the optimization decision module. Finally, the further development and implementation of the system was prospected. The research results can provide references to tunnel researchers and managers.

Comparative analysis of perpetual pavement structures based on pavement performance and life cycle cost

Pavement performance and economic efficiency are researched on the perpetual test pavement of Yijiang-Suzhou Express Highway in Jiangsu province, China. Test sections were continuously monitored. The conditions and developing laws of deflection, rutting and cracking are compared among the perpetual pavement with the rich binder layer （RBL）, the perpetual pavement without the RBL, and the conventional semi-rigid asphalt pavement in the past eight years after opening for traffic. Economical evaluation is conducted via life cycle cost analysis （LCCA）. Based on the performance comparison and LCCA analysis, sections with the RBL have good crack resistance, but they are not very satisfactory in the aspect of permanent deformation; the conventional semi-rigid asphalt pavement is the least economic one due to requiring more frequent maintenance. Research results show that the perpetual pavement without RBL is a more appropriate structure for the test site.

Recreational value of glacier tourism resources：A travel cost analysis for Yulong Snow Mountain

Glaciers, with their unique and spectacular appearances and rich and varied terrain, have received widespread attention and become important tourist attractions. This paper uses the travel cost method to estimate the recreational value of the glacier tourism resources of Yulong Snow Mountain(also called Jade Dragon Snow Mountain), which is the most developed glacier tourist attraction in China. First-hand information was obtained through field surveys, and the travel costs of visitors visiting the Yulong Snow Mountain glacier were calculated before the method was applied to evaluate the recreational value of the focal glacier resource. The results show that the Yulong Snow Mountain consumer surplus associated with its glacier resources in 2016 ranged from 645.59-3439.10 million CNY, and the total recreational value ranged from 1.97-8.17 billion CNY. Approaches allocating travel costs across multiple recreational sites, however, can vary, and there is large difference in estimated results depending on used approaches. Nevertheless, the results of the analysis can help understand the socio-economic value of glacier resources and provide a reference for their development and protection.

Protective effect of alcohol consumption for fatty liver but not metabolic syndrome

AIM:To investigate the effect of alcohol on the metabolic syndrome (MS) and fatty liver in Japanese men and women.METHODS:A cross-sectional study was conducted in a medical health checkup program at a general hospital.This study involved 18 571 Japanese men and women,18-88 years of age,with a mean body mass index of 22.6 kg/m 2.A standardized questionnaire was administered.The total amount of alcohol consumed per week was calculated,and categorized into four grades.Fatty liver was examined by ultrasound modified criteria of the revised National Cholesterol Educa-tion Program Adult Treatment Panel Ⅲ and the new International Diabetes Federation.RESULTS:The prevalence of fatty liver decreased in men and women with light to moderate alcohol consumption,whereas the prevalence of MS was not so changed.The prevalence of fatty liver of any grade in men was lower than that in those with no or minimal alcohol consumption.In women with light to moderate alcohol consumption,prevalence of fatty liver was lower than that in women with no or minimal alcohol consumption.By logistic regression analysis,the odds ratio (OR) for MS in women with light alcohol consumption was decreased to < 1.0,but this change was not clear in men.The OR for fatty liver was clearly < 1.0 in men with any level of alcohol consumption and in women with light to moderate consumption.CONCLUSION:Light to moderate alcohol consumption has a favorable effect for fatty liver,but not for MS in Japanese men and women.

Conceptual design of an extractive distillation process for the separation of azeotropic mixture of n-butanol-isobutanol-water

In many chemical processes, large amounts of wastewater containing butanol and isobutanol are produced.Given that n-butanol-isobutanol-water can form triple azeotrope, high-purity butanol cannot be recovered from the wastewater by ordinary distillation. To economically and effectively recover butanol from this kind of wastewater, 1,4-butanediol is selected as an extractant to break the formation of the azeotropes, and a doubleeffect extractive distillation process is proposed. The conceptual design of the proposed process is accomplished based on process simulation. With the proposed process, the purity of recovered butanol and water is greater than 99.99 wt%. In comparison with the conventional azeotropic distillation process, economic analysis shows that the operating cost of the proposed process is lower: when the capacity of wastewater treatment is 100 t·h^(-1), the total operating cost decreases by 5.385 ×10~6 USD per year, and the total annual cost of the new process decreases by 5.249 ×10~6 USD per year. In addition, in the extractive distillation system, variable effects on separation purities and cost are more complex than those in the ordinary distillation system. The method and steps to optimize the key variables of the extractive distillation system are also discussed in this paper and can provide reference for similar studies.

Bottleneck Analysis of the Minimum Cost Problem for the Generalized Network Based on Augmented Forest Structure

The bottleneck analysis of the minimum cost problem for the generalized network (MCPGN) is discussed. The analysis is based on the network simplex algorithm, which gains negative cost graphs by constructing augmented forest structure, then augments flows on the negative cost graphs until the optimal revolution is gained. Bottleneck structure is presented after analyzing the augmented forest structure. The negative cost augmented graphs are constructed with the bottleneck structure. The arcs that block the negative cost augmented graph are the elements of the bottleneck. The bottleneck analysis for the generalized circulation problem, the minimum circulation problem and the circulation problem are discussed respectively as the basal problems, then that for MCPGN is achieved. An example is presented at the end.

Housing Correlates of Under-Five Mortality in Urban Ethiopia

Little studies and analysis have been undertaken to investigate the housing determinants of under-five mortality in Ethiopia. This study, therefore, explores the impacts of urban housing variables on the levels and patterns of under-five mortality in the country based on the SPSS （Statistic Package for Social Science） file of the 2005 Ethiopian Demographic and Health Survey （EDHS）. This survey covered a sample of about 4,420 households/housing units of urban Ethiopia. The under-five deaths are computed for women in the age group 15-49 by subtracting the number of children living from children ever born （CEB） and established the proportion dead by dividing deaths by CEB corresponding to the categorical variables of housing structure, facilities, and household durables. The analytical techniques of the study included univariate, bivariate, and multivariate data analysis of the proportional variations of childhood mortality patterns being manifested by ＂bar graphs＂ with respect to housing situations as well as household durables. Amongst the categorical variables of the housing structures, facilities, and household durables with the highest no prevalence of under-five mortality levels are found to be the units of unconventional walls, thatched/leaf/reed roofing, animal dung flooring, shared pit latrine/use of bucket/bush, using kerosene, firewood/straw/charcoal for cooking, unconventional lighting, unprotected water supply, households with no durables.

Implications of clinical pathway reform on pharmaceutical costs at a hospital in Qingdao city

To study on the effect of clinical pathway （CP） on controlling pharmaceutical costs, we selected complex, chronic, non-communicable diseases, including cerebral infarction, cerebral hemorrhage, transient ischemic attack, and chronic obstructive pulmonary disease, as diseases to implement clinical pathways at a tertiary hospital in Qingdao. We then conducted intermittent time series analysis on pharmaceutical costs. After the implementation of clinical pathway, overall pharmaceutical costs of patients with transient ischemic attack reduced significantly. The effect was not significant for cerebral hemorrhage patients. The implementation of clinical pathway has a desirable outcome on controlling pharmaceutical costs.

Performance analysis of a solar-aided power generation(SAPG) plant using specific consumption theory

In contrast to a traditional coal-fired power generation plant where steam extracted from a turbine is used to preheat the feedwater in all preheating stages, a solar-aided power generation(SAPG) plant uses solar heat to replace a part or all of the extracted steam in one or more preheating stages. The performance of an SAPG plant with different replacements is investigated in this study by using specific consumption theory(SCT). Fuel-specific and cost-specific consumption models for SAPG plants are built based on the SCT. A typical 330 MW coal-fired power plant is used as the study case. The performance of the SAPG plant in terms of specific consumption, with steam obtained from the first through the eighth(except for the fourth) stages of extraction replaced by solar heat, is compared with that of the reference coal-fired power plant. The fuel-specific consumption of the SAPG plant is determined to be lower than that of the reference coal-fired power plant. The fuel-specific consumption accrual distribution in SAPG plants is used to assess the effect of each individual replacement. Effective strategies to reduce the specific costs of the SAPG and coal-fired power plants are proposed based on the results of this study.