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    A simple intersection is analyzed for vehicle behavior in both upstream and downstream directions by applying shock wave theory. First, the shock wave and its variation are shown and important characteristics are indicated. Then, the upstream vehicle queue and its dynamics, the flow rates of the upstream and the downstream are formulated respectively. From the upstream queue analysis a relationship between its length and the average time headways, both upstream and downstream flow rates are formulated.
    Citations (1)
    Climate policies can be applied either upstream, where fossil fuels are extracted, or downstream, where emissions are generated. Specific policy instruments can be defined for either level, and can take the form of a price signal such as through a tax, or a quantity limit such as through direct regulation or a permit market. In this study, we present an agent-based model to compare the performance of these different instruments and regulation levels. Since policy coverage is often limited, i.e. not all firms being under the regulator's control, we also examine the impact of incomplete coverage on relative policy performance. Our analysis shows that only upstream regulation leads to an increase in fossil fuel prices, which is benefitial under limited coverage as it also affects firms not directly affected by the policy instruments; that prices under quantity-based regulation can decline after an initial peak, stabilizing at a lower level than under the tax; and that direct regulation is more efficient when applied upstream.
    The physicochemical parameters of water of four waterways crossing the town of Brazzaville were determined in upstream, the medium and downstream during the period from January 15 th to August 15 th , 2015. The results of physicochemical analysis showed that the variation of of the parameters makes it possible to classify them in four group: the parameters which the quantities increase from the upstream to the downstream, the parameters which the quantities decrease from the upstream to the downstream, the parameters which the quantities increase between the upstream and the medium then decrease between the medium and the downstream and finally the parameters  which the quantities remain constant between upstream and the downstream. Except the turbidity and the suspended matter which the quantities are higher than the standards of WHO, the other parameters have quantities which are in general below the standards. The nature of the crossed grounds, the nature and the volume of the rejections received by each waterways as well as the behavior of the population living near each waterway are as many elements to be taken account to explain the variation of the physicochemical and parameters.
    Turbidity
    Citations (2)
    Xin’an River Basin,Pearl River Basin,and the Yangtze River Basin were taken as study areas to make multi-scale analysis of Water Environmental Kuznets Curve(WEKC).Relationships between waste water discharge and per Capita GDP of provinces in a river basin were plotted in a figure.Through empirical analysis of WEKC in different regions from small to large scale watersheds,it could be discovered that the WEKC curves roughly follow a principle of repeating step by step from downstream to upstream districts.The curve experienced in the downstream usually reoccurs in the upstream later.The principle is evident especially when there are obvious disparities among development levels of the upstream and downstream.The main reason for this principle is possibly that economic development in downstream areas is generally earlier than the upstream.Consequently,the downstream areas usually possess stronger environmental protection capacity.So the downstream reaches the peak value of WEKC earlier than the upstream.The principle contributes to further understanding of the importance of upstream water resources protection.With background of West Development and Middle Rising Policies,this discovery also illuminates that upstream environmental protection capacity should be strengthened with supports of the country and downstream areas to promote entire and long term watershed protection.
    Citations (0)
    The decision strategies on merger of the upstream and dowstream firms in an industry are discussed in this paper. A competition model with two firms in both upstream and downstream is established. The analysis will show that when the upstream and downstream enterprises take the horizontal and vertical merging as strategies variables, the subgame perfect equilibrium is the upstream and downstream enterprises' horizontal merger respectively. Furthermore, the paper focuses on the conflict of interests among the enterprises, the government and the consumers in the merger.
    Subgame perfect equilibrium
    Citations (0)
    In this paper we evaluate the effects of horizontal mergers in a vertical relationship. Each downstream firm can create autonomous divisions. We show that an infinitesimal merger of downstream firms may exhibit a positive welfare effect if the upstream and downstream sectors are sufficiently unconcentrated. However, any merger of upstream firms reduces social welfare. Moreover, a decrease in the concentration in the upstream stage (respectively downstream stage or non‐merging stage) makes the welfare effects of the merger in the upstream stage (respectively downstream stage or non‐merging stage) less negative (respectively ambiguous or ambiguous).
    Horizontal and vertical