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| | [[Image:SFDD VAL.gif|centre|年存量和流量值=0至15|frame]] | | [[Image:SFDD VAL.gif|centre|年存量和流量值=0至15|frame]] |
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| − | ===连续时间方程 Equations in continuous time=== | + | ===连续时间方程=== |
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| − | To get intermediate values and better accuracy, the model can run in continuous time: we multiply the number of units of time and we proportionally divide values that change stock levels. In this example we multiply the 15 years by 4 to obtain 60 trimesters, and we divide the value of the flow by 4.<br>
| + | 为了得到中间值和更好的准确性，该模型可以在连续时间内运行: 我们乘以时间单位的数量，并按比例除以改变存量水平的值。在这个例子中，我们把15年乘以4得到60个三个月，然后我们把流量的值除以4。 |
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| − | To get intermediate values and better accuracy, the model can run in continuous time: we multiply the number of units of time and we proportionally divide values that change stock levels. In this example we multiply the 15 years by 4 to obtain 60 trimesters, and we divide the value of the flow by 4.<br>
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| − | 为了得到中间值和更好的准确性，该模型可以在连续时间内运行: 我们乘以时间单位的数量，并按比例除以改变存量水平的值。在这个例子中，我们把15年乘以4得到60个三个月，然后我们把流量的值除以4。 Br
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| − | Dividing the value is the simplest with the [[Euler method]], but other methods could be employed instead, such as [[Runge–Kutta methods]].
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| − | Dividing the value is the simplest with the Euler method, but other methods could be employed instead, such as Runge–Kutta methods.
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| | 用欧拉法除值是最简单的方法，但也可以用其他方法代替，如龙格-库塔法。 | | 用欧拉法除值是最简单的方法，但也可以用其他方法代替，如龙格-库塔法。 |
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| − | List of the equations in continuous time for trimesters = 1 to 60 :
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| − | List of the equations in continuous time for trimesters = 1 to 60 :
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| | 连续时间方程列表1至60的三个月: | | 连续时间方程列表1至60的三个月: |
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| − | *They are the same equations as in the section ''Equation in discrete time'' above, except equations ''4.1'' and ''4.2'' replaced by following : | + | *除将式4.1和式4.2替换为以下形式外，与上述“离散时间方程”一节相同: |
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| − | <math>10) \ \mbox{Valve New adopters}\ = \mbox{New adopters} \cdot TimeStep </math>
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| − | <math>10) \ \mbox{Valve New adopters}\ = \mbox{New adopters} \cdot TimeStep </math>
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| − | 10) mbox { Valve New adopters } mbox { New adopters } cdot TimeStep / math
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| − | <math>10.1) \ \mbox{Potential adopters}\ -= \mbox{Valve New adopters} </math>
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| − | <math>10.1) \ \mbox{Potential adopters}\ -= \mbox{Valve New adopters} </math>
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| − | 数学10.1) mbox { Potential adopters } - mbox { Valve New adopters } / math
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| − | <math>10.2) \ \mbox{Adopters}\ += \mbox{Valve New adopters } </math>
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| − | <math>10.2) \ \mbox{Adopters}\ += \mbox{Valve New adopters } </math>
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| − | 10.2) mbox { Adopters } mbox { Valve New Adopters } / math
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| − | <math> \ TimeStep = 1/4 </math>
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| − | <math> \ TimeStep = 1/4 </math>
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| − | 数学 time step 1 / 4 / math
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| | + | <math>10) \ \mbox{Valve New adopters}\ = \mbox{New adopters} \cdot TimeStep </math> |
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| − | *In the below stock and flow diagram, the intermediate flow 'Valve New adopters' calculates the equation :
| + | <math>10.1) \ \mbox{Potential adopters}\ -= \mbox{Valve New adopters} </math> |
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| | + | <math>10.2) \ \mbox{Adopters}\ += \mbox{Valve New adopters } </math> |
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| | + | <math> \ TimeStep = 1/4 </math> |
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| − | <math> \ \mbox{Valve New adopters}\ = \mbox{New adopters } \cdot TimeStep </math>
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| − | <math> \ \mbox{Valve New adopters}\ = \mbox{New adopters } \cdot TimeStep </math>
| + | *在下面的库存和流程图中，中间流''Valve新采用者''计算公式: |
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| − | { Valve New adopters } mbox { New adopters } cdot TimeStep / math | + | <math> \ \mbox{Valve New adopters}\ = \mbox{New adopters } \cdot TimeStep </math> |
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| − | [[Image:Adaption SFD continuous time.png|centre|Dynamic stock and flow diagram of ''New product adoption'' model in continuous time|frame]] | + | |
| | + | [[Image:Adaption SFD continuous time.png|centre|连续时间下“新产品采用”模型的动态库存及流程图|frame]] |
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