To complement this discussion, we have this interactive demo showing
moving behaviors, http://fromto.hig.se/~bjg/movingbehavior/
Bin Jiang wrote:
> 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/
FromToMap: http://fromtomap.org/ or http://fromto.hig.se/
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