In the introduction to the UN HABITAT report State of the World’s Cities 2012/2013: Prosperity of Cities it is written:
“As the world moves into the urban age, the dynamism and intense vitality of cities become even more prominent. A fresh future is taking shape, with urban areas around the world becoming not just the dominant form of habitat for humankind, but also the engine-rooms of human development as a whole. This ongoing evolution can be seen as yet another assertion, albeit on a larger scale, of the time-honoured role of cities as centres of prosperity. In the 21st as in much earlier centuries, people congregate in cities to realize aspirations and dreams, fulfil needs and turn ideas into realities.”
(United Nations 2012, v)
I could not agree more, and this is one of the reasons that I was captivated by cities from an early age, long before I started my academic career – or even had an idea of what an academic career is, for that matter. Cities interest me, cities fascinate me, and cities defined me. Having lived in Munich, Frankfurt, and Tokyo, and having visited many other amazing specimen worldwide has definitely had an impact on me and taught me many things. Studying cities is never boring and continues to surprise and astonish me on a regular basis.
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Today I was faced with the task of having to load a massive amount of shape files into my PostGIS database. The data in question is the Advanced Digital Road Map Database (ADF) (拡張版全国デジタル道路地図データベース) by Sumitomo Electric System Solutions Co., Ltd. (住友電工システムソリューション株式会社). It contains very detailed information (spatial and attributive) about the road network of all Japan and is thereby quite heavy.
Therefore, it was split into a plethora of files using the following naming schema: mmmmmm_ttt.shp, where mmmmmm represents a six-digit mesh code and ttt represents a 2- to 3-digit thematic code. The mesh code is a result of the data being split spatially into small, rectangular chunks. It follows a simple logic, whereby bigger mesh units (represented by the first four digits) are further subdivided into smaller units (represented by the last two digits). It took only a small amount of time to figure out this naming schema and filter the files that would be necessary for my analysis.
Basically I wanted to merge the shape files into PostGIS tables divided by their topic (i.e. road nodes, road links, additional attribute information, etc.). So I had to find a way to batch import the shape files into PostGIS and merge them at the same time. Yet, since the node IDs were only unique within each mesh unit (i.e. shape file), I also had to find a way to incorporate the mesh codes themselves into the data, so I could later on create my own ID schema for the nodes, based on the mesh code and the original node ID (e.g. mmmmmmnnnnn, where mmmmmm represents a six-digit mesh code and nnnnn represents the original 5-digit node ID).
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Being a researcher in Japan means I often have to work with Japanese data. While generally data is data is data, there are some peculiarities I came across that seem to be related to the fact that those data are about and produced in Japan.
Firstly there is the way they are delivered. I’m no so much talking about deliveries on “hard media” such as CD-ROMs and DVDs being snail-mailed, even though this seems to be the major way of obtaining data until this day. Luckily I’m embedded in an ecosystem of research institutions and university laboratories that engage in joint research projects and thereby share the necessary datasets online using portal websites. I’d especially like to mention the JoRAS portal of the Center for Spatial Information Science (CSIS) at the University of Tokyo (東京大学) here, since their stock is quite extensive and they are always open for collaboration inquiries.
Secondly there is the fact that, not very surprising, Japanese datasets often contains Japanese data. By this I’m not referring to the fact that this data is dealing with information about Japan, but to the fact that it is making use of Japanese script. This introduces some technical difficulties, which I would like to elucidate in this article.
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