Suchergebnisse

AbstractWe consider a design problem for wastewater treatment systems that considers uncertainty in pollutant concentration levels at water sources. The goal is to optimize the selection of treatment technologies and pipeline connections, so that treated wastewater can achieve specified effluents discharge limits as well as possible. We propose a new two‐stage model to optimize a set of guarantee levels, that is, the maximum concentration level of source pollutants for which treated wastewater can be compliant with discharge limits. In the first stage, treatment technologies and pipeline connections are selected. In the second stage, when pollutant concentration levels are revealed, wastewater distribution and mixing are determined. A key attractiveness of the proposed guarantee rate optimization model is that it can be simplified into a single‐stage mixed‐integer linear program. In our numerical experiments based on real‐world pollutants data, the guarantee rate model demonstrates its advantages in terms of computational efficiency, scalability and solution quality, compared with the standard probability maximization model. Finally, the methodology proposed in this paper can also be applied to other two‐stage problems under uncertainty with similar uncertainty characteristics.

Background: In China, where follow-up with hospitalized attempters is generally lacking, there is a great need for inexpensive and effective means of maintaining contact and decreasing recidivism. Aims: Our objective was to test whether mobile telephone message contacts after discharge would be feasible and acceptable to suicide attempters in China. Methods: Fifteen participants were recruited from suicide attempters seen in the Emergency Department in Wuhan, China, to participate in a pilot study to receive mobile telephone messages after discharge. All participants have access to a mobile telephone, and there is no charge for the user to receive text messages. Results: Most participants (12) considered the text message contacts an acceptable and useful form of help and would like to continue to receive them for a longer period of time. Conclusions: This suggests that, as a low-cost and quick method of intervention in areas where more intensive follow-up is not practical or available, telephone messages contacts are accessible, feasible, and acceptable to suicide attempters. We hope that this will inspire future research on regular and long-term message interventions to prevent recidivism in suicide attempters.

Abstract
Since the 21st century, the solution of poverty has become the focus of international assistance. And education is considered as one of the important ways to reduce poverty, more and more attention by international organizations and developing countries. Kenya, as one of the countries with the backwardness but most promising economic and social development in East Africa. It has received the attention of the World Bank. With the assistance of the World Bank, the Government of Kenya launched the KYEP project on the basis of Vision 2030, which is based on the training concept of "Education poverty reduction for youth entrepreneurship and employment", with the goal of "Empowering young people in employment", implementing a demand-oriented "four-in-one" skills training course through cooperative training of the World Bank and the Government of Kenya and the private sector, and ensuring the effectiveness of the project through the establishment of a multi-entity cooperative training guarantee mechanism. Practice shows that KYEP highlights Kenya's demand-oriented approach and has achieved remarkable results in addressing youth unemployment and education for poverty reduction.