Dear Peter,
Your purposive behavior seems to be mine as well. In our simulations,
each purposive moving agent starts from a randomly decided location and
moves to a randomly decided destination. Then this destination being as
a new origin, moves from this origin to a randomly decided destination.
... so on and so forth.
Cheers.
Bin
Urban Lists Sust Urb wrote:
> Dear Bin,
>
> Thank you for your response. I think that I was not clear in what I
> was trying to convey. I was discussing a broad urban scale, seeing as
> your paper was examining the city of Gävle, at the larger scale.
>
> If you take each person, or household, they have an activity sphere,
> which at X% confidence, they occupy. They move about this sphere from
> Core Origins to multiple destinations by a variety of modes of
> transport, walking being only one. If we take travel statistics as a
> guide, then walking will be a minority mode of choice. What we know
> from studies of cities across Europe, is that there is a pattern to
> these activities, which could most likely be reduced to an algorithm.
> The core origins are informed by human choices - living and working.
> Activitiy destinations outside of these are formed by our multiple
> life networks. Moving between these is defined by the available modal
> choices that that particular city offers as well as individual
> preferences for modal choice, as well as the network of the city.
>
> While underlying street pattern may influence choice of route, origins
> and destinations are informed by outside choice aspects, which,
> subsequently the networks influence. This is what I was meaning by
> purposeful behavior. I apologise for my lack of clarity.
>
> Kind regards
> Peter
>
>
> On 18/11/2009, at 5:13 AM, Bin Jiang wrote:
>
>> Dear Peter,
>>
>> Thanks for your comments. My feedback to your questions is as follows:
>>
>> Urban Lists Sust Urb wrote:
>>> I see what you say below in your response to Hans, but how do we
>>> translate the random generation to the purposeful use of a "world"
>>> network with destinations, where we are trying to understand the
>>> average overall purposeful behavior, as against average random
>>> behavior?
>> Sorry I am not sure if I capture your point. I was saying mobility
>> patterns formed by purposive walkers and random walkers are the same,
>> because they both are shaped by the underlying street structure.
>>>
>>> Maybe. if there is a misunderstanding, it is because I am not an ABM
>>> modeler?
>>>
>>> Kind regards
>>> Peter
>>>
>>> On 17/11/2009, at 9:13 PM, Bin Jiang wrote:
>>>
>>>> Many thanks Hans for the detailed comments, my feedback to which is
>>>> as follows:
>>>> Skov-Petersen wrote:
>>>>> Hi Bin,
>>>>> A few comments/questions:
>>>>> 1) Apparently you are using two sw products: ArcGIS (for G�vle)
>>>>> and NetLogo (for London). Ir is not clear to me how the two were
>>>>> applied. I would assume that NetLogo was used for the agent
>>>>> simulation while ArcGIS was used for network analysis (metrics),
>>>>> but as it reads boh programmes were used for both purposes (but in
>>>>> different regions). Can you clear me up?
>>>> In the paper we just say a few words of the difference between the
>>>> two platforms. At the beginning, we put Gävle data in ArcGIS, while
>>>> London data in NetLogo. However, this is NOT essential. In other
>>>> words, to get the statistics there is no difference between the
>>>> two, but they do differ if visualization is concerned. Obviously in
>>>> this connection, NetLogo outperforms.
>>>>> 2) Is the NetLogo model-code you used for agents interaction with
>>>>> the network publicly available?
>>>> Yes.
>>>>> 3) are your purposely agents (II) applying a 'shortest path'
>>>>> search towards their target?
>>>> Yes, but shortest path can be computed in real time. It would
>>>> reduce the simulation speed significantly.
>>>>> 4) Wouldn't you assume that the purposely agents (II) could be
>>>>> further 'improved' by taking the probability (i.e. the number of
>>>>> potential facilities) into account when selecting
>>>>> targets/destinations as a probability weight 't application of a
>>>>> temporal dimension be considered. As it is, the simulation mimics
>>>>> the behaviour of taxies quite well (roaming short distance, any
>>>>> where, all during the day), but not the way e.g. home-work
>>>>> journeys will take place.
>>>> Of course as long as one has all these locations of potential
>>>> facilities. In our experiments, the destinations are randomly
>>>> generated, and they are randomly distributed.
>>>>> 5) One main finding - as I read it - is that ABM's are not
>>>>> required to simulate traffic flows (which is quite disappointing
>>>>> for an abm-modeler :-)).
>>>> What do you mean by this point? We relied on ABM for simulating
>>>> traffic flows as you can see.
>>>>> Nevertheless, your conclude that abm's provide us with new ways to
>>>>> study the rational behind human (spatial) behaviour, but do not
>>>>> further elaborate on this.
>>>> My point here is that drawn from our experiments ABMs provide a
>>>> means to study human spatial behavior instead of observing from the
>>>> real world.
>>>>> To me - and that is probably what you are saying - the thing is
>>>>> that the network (obviously) is the mandatory, bounding condition
>>>>> for transport behaviour. It is interesting (and efficient) to come
>>>>> up with indicators (metrics) that can predict human behaviour
>>>>> patterns (at a gross level), but that we need the agent-based
>>>>> approach to further enhance our behavioural understanding,
>>>>> especially when considering behaviour beyond the 'average being'.
>>>>> Right?
>>>> No, this is not what I intended to say. Also see above point. My
>>>> focus is understand average being rather than individual being.
>>>>
>>>> Cheers.
>>>>
>>>> Bin
>>>>> Hans
>>>>>
>>>>>
>>>>> >>> Bin Jiang <[log in to unmask]> 11-06-2008 17:00 >>>
>>>>> Hi, this paper might be of interest to space syntax researchers
>>>>> http://arxiv.org/ftp/arxiv/papers/0804/0804.1630.pdf
>>>>> any comments are very welcome.
>>>>>
>>>>> Cheers.
>>>>>
--------------------------------------------------------
Bin Jiang
Division of Geomatics, KTH Research School
Department of Technology and Built Environment
University of Gävle, SE-801 76 Gävle, Sweden
Phone: +46-26-64 8901 Fax: +46-26-64 8828
Email: [log in to unmask] Web: http://fromto.hig.se/~bjg/
--------------------------------------------------------
European Associate Editor
Computers, Environment and Urban Systems: An International Journal
NordGISci: http://fromto.hig.se/~bjg/NordGISci/
ICA Commission: http://fromto.hig.se/~bjg/ica/
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