Sorry a critical typo in the previous email - missed NOT:
One can use segment as a basic unit, BUT NOT in the way as implemented
in Depthmap.
On 12/10/2016 11:41 PM, Bin Jiang wrote:
> Thanks Alan for sharing your thoughts and arguments!
>
> I would like to clarify my criticism on some of space syntax methodology
> based on my research in particular empirical studies.
>
> (1) At city level, natural streets are a better representation than
> axial lines. There is little doubt on that. In this regard, we have two
> empirical studies that proved that natural streets are better than axial
> lines or segments.
>
> https://www.researchgate.net/publication/1764726_Street-Based_Topological_Representations_and_Analyses_for_Predicting_Traffic_Flow_in_GIS
>
>
> http://hig.diva-portal.org/smash/record.jsf?pid=diva2%3A656758&dswid=-1471
>
>
> (2) at architectural level, axial lines are still a good representation,
> since human movement occurs between buildings mainly. In this regard, we
> have AxialGen to auto-generate axial lines.
>
> https://www.researchgate.net/publication/23421243_Automatic_Generation_of_the_Axial_Lines_of_Urban_Environments_to_Capture_What_We_Perceive
>
>
> (3) We have found that why space syntax works, or why space syntax is
> able to predict human movement is nothing to do with how human
> conceptualize space as indicated by Bill Hillier in several of this
> papers. We have proved that both humans and monkeys (or random walkers
> in general) had the same traffic flow, because it is the underlying
> street structure that determines traffic flow. Or put it in a different
> way, at least 60% traffic (sometimes up to 80%) can be accounted for by
> the underlying topological structure. We had at least four studies, two
> of which adopted agent-based simulations:
>
> https://www.researchgate.net/publication/2177752_Ranking_Space_for_Predicting_Human_Movement_in_an_Urban_Environment
>
>
> https://www.researchgate.net/publication/45878700_Agent-Based_Simulation_of_Human_Movement_Shaped_by_the_Underlying_Street_Structure
>
>
> https://www.researchgate.net/publication/26858844_Characterizing_the_Human_Mobility_Pattern_in_a_Large_Street_Network
>
>
> and more recently,
>
> https://www.researchgate.net/publication/281936247_Can_Cognitive_Inferences_be_Made_from_Aggregate_Traffic_Flow_Data
>
>
> (4) Angular segmental representations work, because of topological
> rather than geometrical effect. This is in line with natural streets,
> because natural streets are defined by a smallest deflection angle, so
> essentially angular effect. One can use segment as a basic unit, BUT in
> the way as implemented in Depthmap. It must be done through topological
> representation of streets or axial lines: see this paper and Section 4.3
> in particular.
>
> https://www.researchgate.net/publication/1918773_Self-organized_Natural_Roads_for_Predicting_Traffic_Flow_A_Sensitivity_Study
>
>
>
> Any comments and criticisms are welcome.
>
> Cheers.
>
> Bin
>
> On 12/10/2016 10:56 PM, Penn, Alan wrote:
>> David,
>>
>> the paper and an open lecture are here:
>> http://spacesyntax.tudelft.nl/media/Long%20papers%20I/alan%20penn.pdf
>> https://youtu.be/NkePRXxH9D4
>>
>> Briefly, we need to be a bit careful about terminology, by which I
>> mean that the word ‘agent’ in this case may be misleading, and so
>> mustn’t be taken as a direct proxy for the philosophical concept.
>> Although we didn't really understand this at the time, the basis of
>> our EVAS ‘agent' based representation was in fact a deterministic
>> analysis of spatial geometry (and topology for that matter) and as
>> such extremely reductive. It happens to have the interesting property
>> of incorporating anisotropy (a property of an embodied agent perhaps)
>> in its geometric and topological representation. It is however
>> entirely deterministic and thus an ‘analysis’ or the environment
>> rather than any kind of ‘simulation’ of individuals with any kind of
>> autonomous agency aside from randomness. In this sense it is just as
>> holistic as any other space syntax representation.
>>
>> EVAS stands for 'exosomatic visual agent simulation’ since the idea
>> was that the representation in memory of the environment might lie
>> outside the body in the environment itself (this builds on the space
>> syntax notion that intelligibility might be a property of the
>> environment itself). The thesis is that as society constructs cities
>> through an essentially distributed process involving many different
>> decision takers it builds into the geometry, topology and other
>> aspects of the architecture - e.g. scale, land use, decoration etc. -
>> patterns of relations between properties that make the world
>> meaningful. This all sits ‘out there’ in the world and is readable by
>> all the individual users of the environment in common. It is the
>> distributed process of production of the built environment that leads
>> to it being holistic and so amenable to syntax type analysis.
>>
>> So one of the experiments we did was to place ‘merchandise’ in a
>> series of environments. Different ‘flavours’ of merchandise were
>> represented as a vectors on the surface of building surfaces in the
>> environment. Agents were given a ’taste’ for a specific ‘flavour’
>> (the hunger was also represented as a vector). That way the agent
>> could search the environment looking for merchandise that matched
>> it’s taste. This allowed us to measure how long it took agents to
>> find merchandise that best matched their taste under different
>> spatial conditions. This is about as far as we have got so far on the
>> specific ‘shopping’ activity work, but is obviously one reason that
>> we developed the so called ‘agent’ approach in that it allows us to
>> experiment with the twin notions of configuration and attraction as
>> drivers of human behaviour.
>>
>> A paper on this is here:
>> http://dx.doi.org/10.1057/palgrave.udi.9000120
>>
>> I am not sure whether this would count as a ‘manifesto’, but
>> certainly these are some of the motivations behind developing this
>> methodology. What it is not, though, is something that would pass
>> muster amongst social simulators as any kind of simulation in which
>> the entities had any kind of ‘agency’. For that they would need
>> beliefs, desires and intentions as well as memory and some ability to
>> compute and so adapt behaviours depending upon their perceptions. In
>> this sense it is really an extension of space syntax representation
>> based analysis, but extending the range of kinds of things that we
>> incorporate in the representation (eg. forward face vision,
>> attractors in they environment).
>>
>> Now, Bin often seems to come back with a criticism of these kind of
>> developments in methodology. I find that hard to understand since
>> what really matters is the empirical utility of a methodology - does
>> it cast light on the phenomena we observe in the world? Angular
>> segmental representations clearly do since they account empirically
>> for observed human movement behaviours better than axial or ‘named
>> streets’ although these seem not to have been subjected to the same
>> level of testing against empirical movement data. I believe that the
>> agent simulations also do. This is not to detract from the simplicity
>> and elegance of the axial representation.
>>
>> All the best,
>>
>> Alan
>>
>>
>>
>>
>>
>>
>>> On 10 Dec 2016, at 19:18, David Seamon <[log in to unmask]> wrote:
>>>
>>> Alan,
>>>
>>> You mention your paper on the IKEA research: might you provide a
>>> reference?
>>>
>>> I understand your point about embodiment, though there is the
>>> phenomenological question of reductive activation in that the
>>> "agent" is limited in what its environmental and spatial
>>> "experiences" are. But I appreciate the direction you're attempting
>>> to move.
>>>
>>> One thing regarding the IKEA situation is that I don't see how the
>>> agent-based account can incorporate the merchandise displays along
>>> the sales route. The IKEA experience is more like a "stroll" than a
>>> trip with intention. I understand why some shoppers feel
>>> uncomfortable in an IKEA showroom space because one is quickly
>>> disoriented, and if one starts to try to figure out where he or she
>>> is, it becomes annoying. But my sense is (and I've only been to an
>>> IKEA store twice so keep that in mind) that most shoppers aren't too
>>> bothered because there is so much to see (and buy). So we move into
>>> a phenomenology of different movement and pathway experiences
>>> (stroll vs. constitutional vs. walk to work vs. walk through park
>>> etc.). In other words, not all movements are the same experientially.
>>>
>>> My larger confusion is what the "agent approach" has to do with
>>> space syntax, which to me is singular because it is topological and
>>> thereby holistic. The "agent perspective" is somewhat "global" in
>>> that the agent makes use of visual permeability. But it does seem to
>>> me that the emphasis remains more partial in that the amount of
>>> movement on a particular pathway, grounded in degree of integration
>>> in the pathway system, is somehow lost.
>>>
>>> Do you see the agent-based work as integral to space syntax theory,
>>> or should it be considered something different? If folks there are
>>> beginning to integrate it into space syntax theory, then it would be
>>> helpful to have a "manifesto" as to why. I'm not aware of any such
>>> discussion and would like to know of it, if has begun.
>>>
>>> David Seamon
>>>
>>> p.s. I apologize for starting new threads each time I post. For some
>>> reason, my "return email" for this list serve won't work. Reem is
>>> always kind to tell me "didn't go through" so I then post a new
>>> email. Thanks, Reem!
>
> --
> --------------------------------------------------------
> Bin Jiang
> Division of GIScience
> Faculty of Engineering and Sustainable Development
> University of Gävle, SE-801 76 Gävle, Sweden
> Phone: +46-26-64 8901 Fax: +46-26-64 8758
> Email: [log in to unmask] Web: http://fromto.hig.se/~bjg/
> --------------------------------------------------------
> Academic Editor: PLOS ONE
> Associate Editor: Cartographica
>
> BinsArXiv: http://arxiv.org/a/jiang_b_1
> Axwoman: http://fromto.hig.se/~bjg/axwoman/
> ICA: https://sites.google.com/site/commissionofica/
> Geomatics: http://fromto.hig.se/~bjg/geomaticsprogram/
> RG: https://www.researchgate.net/profile/Bin_Jiang3
>
> [Högskolan i Gävle]
>
> Högskolan i Gävle, 801 76 Gävle • 026 64 85 00 •
> www.hig.se<http://www.hig.se>
>
> För en hållbar livsmiljö för människan
>
> University of Gävle, SE-801 76 Gävle, Sweden • +46 (0) 26 64 85 00 •
> www.hig.se<http://www.hig.se>
--
--------------------------------------------------------
Bin Jiang
Division of GIScience
Faculty of Engineering and Sustainable Development
University of Gävle, SE-801 76 Gävle, Sweden
Phone: +46-26-64 8901 Fax: +46-26-64 8758
Email: [log in to unmask] Web: http://fromto.hig.se/~bjg/
--------------------------------------------------------
Academic Editor: PLOS ONE
Associate Editor: Cartographica
BinsArXiv: http://arxiv.org/a/jiang_b_1
Axwoman: http://fromto.hig.se/~bjg/axwoman/
ICA: https://sites.google.com/site/commissionofica/
Geomatics: http://fromto.hig.se/~bjg/geomaticsprogram/
RG: https://www.researchgate.net/profile/Bin_Jiang3
[Högskolan i Gävle]
Högskolan i Gävle, 801 76 Gävle • 026 64 85 00 • www.hig.se<http://www.hig.se>
För en hållbar livsmiljö för människan
University of Gävle, SE-801 76 Gävle, Sweden • +46 (0) 26 64 85 00 • www.hig.se<http://www.hig.se>
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