14. AIM/Common Database: A Tool for AIM
Family Linkage
Go Hibino1, Yuzuru Matsuoka2, and Mikiko Kainuma3
Summary. Several teams have been developing AIM models in different
countries to analyze their own policy options to mitigate greenhouse gas
emissions. Although they need to collect their own data, there are a lot of data thatcan be shared. The AIM/Common Database, consisting of common formats andcode system, has therefore been developed as a tool for AIM Family linkage.
There are several advantages by using this database. First, as the formats and code
system are common, one team can use data collected by the other teams without
special data conversion. Thus the duplication of data collection and conversion
can be greatly avoided. It also helps in setting up country specific data by referringto the data provided by other teams. Second, outputs of one model can be used byanother model without having to check the data formats. It helps to share therelevant outputs of different models in AIM family. Third, as AIM/Common
Database can provide a user-friendly interface based on the common data format,
it facilitates users to access input and output data stored in the database.

14.1 Background
The AIM Family consists of a number of models, including AIM/Enduse,
AIM/Trend, AIM/CGE, AIM/Material, AIM/Climate and AIM/Impact. Eachmodel has been developed in various countries such as China, India, South Korea
and Japan. As many teams in different countries are involved in model
development, AIM/Common Database plays a very important role in the AIM
Family by linking the different models and modelers in different locations.
It is necessary to collect and process a large amount of statistical data in themodel development and application stages. There is a significant overlap in thedata required by different models and modeling teams. To ensure efficient
implementation of this work, there is a need to develop standard database system
containing common formats and codes.
Within the AIM Family, the simulation results of one model are often utilized
as input by other models. Additionally, data and results of one modeling team areoften useful to other teams as well. Moreover, users of the simulation results are
not limited to the AIM development teams, but also include researchers,
government officials, NGOs, etc., who use them as a reference in their decision1

Fuji Research Institute Corporation, Tokyo 101-8443, Japan
Kyoto University, Kyoto 606-8501, Japan
3
National Institute for Environmental Studies, Tsukuba 305-8506, Japan2

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making. With this large number of widely dispersed users, data sharing must be
carried out under a unified code system and unified file format. Otherwise, eachuser would have to learn the data structure for each model independently, which
would impair efficiency.
The AIM/Common Database was developed in order to solve these problems
and construct linkages for the AIM Family.

14.2 Outline of AIM/Database
Figure 1 shows an outline of AIM/Database. AIM/Database contains various typesof datasets including statistics, outputs by AIM Family modelers, outputs by othermodelers, and estimates by international organizations and governments.
AIM/Database consists of the AIM/Primary Database and the AIM/Common
Database. The AIM/Primary Database is made up of observed value and estimatedvalue by international organizations, national governments and research
institutions. These file format is the original state, so is not standardized. There
are magnetic media including statistics edited by international organizations, thefirst processed statistics for the AIM/Common Database, worksheets input
manually from book type statistics, and so on.
On the other hand, the AIM/Common Database is used directly by other models
in the AIM Family. The code systems and data table formats are standardized so
as to allow easy use of the data. The AIM/Common Database mainly stores
datasets related to observed values quoted from statistics and estimated values
obtained by the models and organizations with a specific format. The statistical
data are stored automatically by a module from the AIM/Primary Database. The
module makes it easy to update the statistical data. As modelers use datasets in the
AIM/Common Database, the module developed by each modeler imports datafrom the database directly. The modelers do not necessarily have to use thestatistics for all input data in the database. As for the output of the model, themodelers are required to store data in the AIM/Common Database in a specificformat in view of data sharing. Both manual operation and the use of modules
developed by modelers are acceptable as export methods. Users other than AIM
development teams, such as administrators, other modelers, NGOs, and so on cantherefore efficiently use the datasets though the interface of the database without
knowing the detailed data structure of each model.
At the operational level, AIM/Database is a decentralized system. Specificdatabases and interfaces are maintained by different users in a decentralized way.
However, in order for the work related to data gathering and data exchange toproceed smoothly, certain guidelines have been established regarding thedevelopment and management of the AIM/Common Database.
The AIM/Common Database is distributed via a Web site, and the AIM project
teams in individual countries download the database files from this Web site. The
Web site has an area where access is restricted to the development teams only, andan area accessible to the public. The development data are published only in the14. AIM/Common Database

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Fig. 1. Outline of AIM/Databasearea restricted to the development teams. Users other than AIM development
teams, such as researchers, policy makers, and NGOs, can obtain the output of the
AIM Family from the site through the area accessible to the public.

14.3 AIM/Primary Database
The AIM/Primary Database is made up of observed value and estimated value byinternational organizations, national governments and research institutions. These
file format is the original state, so is not standardized. The formats vary among thedifferent materials; e.g., magnetic media, books, Web sites, copies of theses, andso on. Magnetic media include not only media such as CD-ROMs and so on
issued by statistics institutions, research institutes, etc., but also worksheet format
files of data from printed matter input by AIM development teams, and files ofdata contained in CD-ROMs, etc. that have been converted or processed into aformat allowing them to be easily imported into the AIM/Common Database.

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With regard to the components of the AIM/Primary Database, lists describing
the items such as Media, Language, Data format, Abstract, Data collection period,
Published year, Price, etc. have been prepared in order to maintain and manage thecomponents.

14.4 AIM/Common Database
14.4.1 Structure of AIM/Common Database
The AIM/Common Database contains a large number of database files in
Microsoft Access format. One of these is a database file that manages the code
system of the AIM/Common Database, Code.mdb. The others are database files
that mainly manage the statistical datasets and output of AIM Family models.
These datasets are stored in the data table of the database file. Table 1 shows thedata table in Energy_IEA.mdb. The table stores the country-wise, sector-wise, andenergy-wise energy flows quoted in IEA (2001a, 2001b). The data table format in
the other database files is almost the same as this data table. The codes ITEM,COMMODITY, SECTOR, COUNTRY, and REFERENCE in the fields
correspond to the codes managed in Code.mdb.
Database file to manage code system, Code.mdb
Code.mdb is a database file that manages the code system of the AIM/Common
Database. The database file contains tables listing the codes for items,commodities, sectors, countries, districts, and references. Each table is explainedin turn below.
Code_Item. Code_Item is the code table for items (Table 2). An item shows whatvalue the data indicate. An item code with the same unit is used in all the tables.
The unit should always be listed in the NAME field. Input of the item is
indispensable in the data tables.
Code_Commodity. Code_Commodity is the code table for commodities (Table3). The code is used as the data table stores commodity-wise data; e.g., industrial
commodity production, energy consumption (energy-wise), or agriculturalcommodity production. When the commodity code is not required, it can beomitted in the data table.
Table 1. Data table in Energy_IEA.mdb
ITEM
EN_FLW
EN_FLW·······

COMMODITY SECTOR
EN_COLTPES
EN_COL
TPES
··············

COUNTRY
AUS
AUS
·······

YEAR
1961
1962
······VALUE REFERENCE
16107 IEA_99
16394 IEA_99
··············

14. AIM/Common Database
Table 2. Code_Item code table in Code.mdb
ID
101
102
···
201
202
···
401
402
···
501
502
503
···

CODE
EN_FLW
EN_ELE······
PP_TTL
PP_MAL······
IN_PRD
IN_PRD_L······
NA_GDP_DF
NA_GDP_CD
NA_GDP_CN······NAME
Energy flow (kTOE)
Electricity output (GWh)······
Female population (thousand)Male population (thousand)······Industrial commodity production (tons)
Industrial commodity production (meters)······GDP deflator
GDP (current million US$ )GDP (current million LCU)
······

NOTE

························

Table 3. Code_Commodity code table in Code.mdb
ID
···
203
204
205
···
401
402
···

CODE
······
EN_OLK
EN_OLG
EN_OLD······
MN_IRN
MN_LMS······

NAME
······
Kerosene
Gasoline
Diesel oil
······Iron ore
Limestone
······

NOTE
···················

Table 4. Code_Sector code table in Code.mdb
ID
···
201
202
203
···
401
402
403
···

CODE
······
IN_STLIN_CHM
IN_NMT······
OT_AGR
OT_CMM
OT_RSD······

NAME
······Iron and steel
Chemical and petrochemicals
Non-metallic minerals
······
Agriculture
Commercial and public services
Residential······

NOTE
···················

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Code_Sector. Code_Sector is the code table for sectors (Table 4). The code isused as the data table stores sector-wise data; e.g., energy consumption or value
added. When the sector code is not required, it can be omitted in the data table.
Code_Country. Code_Country is the code table for countries (Table 5). The
relationships between the codes and major organizations’ codes are shown in thetable. The definition of a country, such as changes resulting from separation or
amalgamation, is listed in the NOTE field. Input of the country is indispensable inthe data tables.
Code_District. Code_District is the code table for districts in a country (Table 6).
The code is used as the data table stores district-wise data. When the district code
is not required, it can be omitted in the data table.
Code_Reference. Code_Reference is the code table for references (Table 7). The
data sources of values in the data table are listed. Input of the reference is
indispensable in the data tables.
Table 5. Code_Country code table in Code.mdb
ID CODE
4 AFG
8 ALB
12 DZA
16 ASM
20 AND
24 AGO
28 ATG
31 AZE
32 ARG
36 AUS
40 AUT······NAME
Afghanistan
Albania
Algeria
American Samoa
AndorraAngolaAntigua and Barbuda
Azerbaijan
Argentina
Australia
Austria······

UN
AFG
ALB
DZA
ASM
AND
AGO
ATG
AZE
ARG
AUS
AUT
······

WB
AFG
ALB
DZA
ASM
ADO
AGO
ATG
AZE
ARG
AUS
AUT
······

ISO1
AFG
ALB
DZA
ASM
AND
AGO
ATG
AZE
ARG
AUS
AUT
······

ISO2
4
8
12
16
20
24
28
31
32
36
40
··········

NOTE* UN: Country code used in UN statistics (2001), WB: Country code in World Bank (2002), ISO1:
ISO3166 code A3, ISO2: ISO3166 code number

Table 6. Code_District code table in Code.mdb
ID
1
2
3

COUNTRY
IND
IND
IND
······

CODE
101
102
104
······NAME
Adiladbad
Anantapur
Cuddapah······

NOTE

······

14. AIM/Common Database

239

Table 7. Code_Reference code table in Code.mdb
ID CODE101 IEA_99

NAME
IEA Energy Balance
1999

NOTE
IEA Energy Balances of OECD Countries
1960-1999 (CD-ROM),IEA Energy Balances of Non-OECD
Countries 1971-1999 (CD-ROM)
200 UN_STY_45 UN Statistical Yearbook UN Statistical Yearbook Forty-fifth issue
Forty-fifth issue(CD-ROM)
201 UN_CMM_01 UN Industrial
UN Industrial Commodity Production
Commodity Production Statistics Database 1950-1999 (CD-ROM)
1999
202 UN_POP_01 UN World Population
UN World Population Prospects 2000
Prospects 2000
(CD-ROM)
······ ······
············

Database files to manage datasets
The database files other than Code.mdb mainly manage statistical datasets andoutput of AIM Family models. The structure of the files is shown in Fig. 2. The
two upper tables manage datasets, while two tables, one form, and one module
play the role of importing data from the AIM/Primary Database and the output ofother models. The tables, form, and module are described below.
Data table. This table consists of data imported from the statistical data in the
AIM/Primary Database and the output of models using the unified code system.
The table format is standardized and is composed of the Item, Commodity, Sector,
Country, District, Year, Value, and Reference fields.
Code table. This table shows explanations concerning the codes used in the Item,
Commodity, Sector, Country, District, and Reference fields in the Data Table. It islinked with the table in Code.mdb.
Import file table. This table is used when the module imports statistical data fromthe Primary Database or the output of models to the Common Database. The tableindicates from which item and which file in the Primary Database to import thedata and to which item in the Common Database.
Database files

Data table
Code table
ImportImport file table
Import code table
Import file form
Import module

Fig. 2. Structure of database files

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Import code table. This table is used when the module imports statistical datafrom the Primary Database or the output of models to the Common Database. The
table indicates which code in the Common Database corresponds to the code in
the Primary Database.
Import form. This form is used when the module imports statistical data from thePrimary Database or the output of models to the Common Database. It is theinterface for importing data from the Primary Database and users can execute themodule on the form.
Import module. This module is used when the module imports statistical datafrom the Primary Database or the output of models to the Common Database. It is
written with Access VBA.

14.5 Development and Management of AIM/Common
Database
Maintenance and management of the AIM/Common Database is not carried out by
a specific team in a centralized way, but in a decentralized way by the model
development teams of each country. However, in order for the work related to data
gathering and data exchange to proceed smoothly, certain guidelines have been
established within the AIM development team regarding the development andmanagement of the AIM/Common Database. These guidelines are introduced
below.
14.5.1 Planning phase
The guidelines on planning phase of AIM/Common Database are described below.
! AIM/Common Database is to be developed with using MS Access 2000 orlater.
! Data table is to be made up of Item, Commodity, Sector, Country, District,Year, Value and Reference fields. Data in Item, Country, Year, Value, andReference are indispensable.
! The code system (Code.mdb) of the AIM/Common Database is to be common
to each development team in each country, and the codes in the data files must
conform to this system.
14.5.2 Accumulation phase
The guidelines on accumulation phase of AIM/Common Database are described
below.

14. AIM/Common Database241! Coordination and management of the code system is to be carried out by
AIM/Common Database coordinators (one to two persons for the overall AIM
project).
! When creating a database file for the AIM/Common Database, if a new data
source is used, the relevant information is to be added to the data source listsof the Primary Database following to the prescribed format.
! When a database file of the AIM/Common Database is created or updated, thedocument is to be prepared following the prescribed format for the contents ofthe file.
! When a database file of the AIM/Common Database is created or updated,
notification to that effect is to be given on the AIM Development Team Web
Site.
! When the creation of new data is desired, notification to that effect is to begiven on the AIM Development Team Web Site.
14.5.3 Communication phase with AIM family models
The guidelines on communication phase with AIM family models via
AIM/Common Database described below.
! Users within the AIM development teams need to have basic knowledge ofMS Access (database structure, how to view data, copying to MS Excel, etc.).
! A precondition for the development of AIM Family models is that they
conform to the data format and code system of the AIM/Common Database.
! The output of AIM Family models is to be provided following the data format
and code system of the AIM/Common Database so as to enable smoothexchanges of data between different teams.
! Since the database files of the AIM/Common Database are in Microsoft
Access format, modelers need to learn how to extract data files in MS Access.
14.5.4 Dissemination phase
The guidelines on dissemination phase of AIM/Common Database are described
below.
! AIM/Common Database is to be disseminated for external uses via Web site.
! For external users of data accessible to the public, an interface is to beprovided that enables use of the data without knowledge of MS Access.
Therefore, modelers of AIM Family are to provide the aggregated results in thehtml format for external users.
! Concerning detailed data, the files including simulation results are to be
uploaded in MS Access format. External users download the file and use it on
their end. Modelers are to provide not only data table but also pivot table andpivot chart in the file. The table and chart make it easy for external users
without knowledge of MS Access to use data.

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14.6 An Example: How to Interact with AIM Family Models
Linkage between AIM/Enduse and AIM/Trend through the AIM/Common
Database is described here as an example of AIM Family linkage.
The AIM/Enduse model is the tool to estimate future greenhouse gases
emission with using detailed, sector-by-sector information about future driving
forces given externally. For example, the production volume of each industrial
product in the industrial sector and the demand volume of each application (e.g.,heating and air conditioning) in the home sector must be given. As most of theestimates provided by governments and international research institutes are macro
indicators such as economic growth rates and population, each analyst is often
required to individually estimate the driving forces on a segment-by-segment
basis. Analyses previously conducted in Japan, China, India, and Korea, based on
end-use models, also used estimated segment-by-segment future driving forces,
although they were based on the GDP, population, and other macro indicators
predicted and planned by governments.
The prediction of these future values is based on a very simple methodology.
First, regression equations are derived from the actual driving force volumes and
GDP measurements. Then, the future driving force volumes are estimated using
the regression values and future GDP measurements predicted by the governmentsor research institutes. Finally, the values obtained are converted into the form thatthe model can use for simulation. Despite the simplicity of the methodology, thisseries of actions is still not systematically documented, which makes it difficult to
update the estimated values and transfer the process of estimate to others.
Under the circumstances, new capabilities were added to the AIM Familymodels and databases to construct a system that can systemize and automate theabove series of actions. In addition, using the AIM/Trend Program Language

2

ATPL Regression

AIM/Common Database

Driving force(observed)

Driving force(observed)

1

National accounts(observed / estimate)

National accounts(observed / estimate)

MS ExcelMS Access

AIM/Enduse

Program execution

Driving force(estimate)
MS Excel

3

Driving force(estimate)

4

MS AccessFig. 3. Work flow: Linkage between AIM/Enduse and AIM/Trend
through AIM/Common Database

Driving force(future value)
MS Access14. AIM/Common Database

243(ATPL) developed by AIM Project Team (2001), ATPL Regression wasconstructed as a new program that derives future driving force volumes from theregression equations for driving forces and GDP measurements (Fig. 3 and Fig. 4).
1. The Import module of ATPL Regression imports the information about theactual driving force volumes and actual/estimated future value added figurescontained in the AIM/Common Database into an Excel file.
2. The Regression/Projection module of ATPL Regression derives regression
equations from the actual driving force volumes and actual value added figures.
Then, the derived regression equations and future value added figures are used
to estimate the future driving force volumes. The computation results are output
as Excel data.
3. The Import module of AIM/Common Database imports the computation results
provided by AIM/Trend into the AIM/Common Database as MS Access data.

Regression/Projection Moduleof ATPL Regression

National Accounts (Observed / Estimate)in AIM/Common Database

Industrial Commodity Production (Observed/ Estimate) in AIM/Common Database

Industrial Commodity Productionin AIM/Enduse

Fig. 4. Examples of model and database displays: Linkage between AIM/Enduse and
AIM/Trend through AIM/Common Database

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4. The Import module of AIM/Enduse imports the future driving force volumes
contained in the AIM/Common Database into AIM/Enduse as MS Access data.

14.7 Concluding Remarks
There are several AIM modeling teams in Asian countries such as China, India,
South Korea and Japan. Although they need to collect their own data, there are a
lot of data that can be shared. If an efficient database system is developed tofacilitate this sharing, data collection work can be reduced. The AIM/Common
Database, consisting of common formats and code system, has therefore beendeveloped as a tool for AIM Family linkage. Maintenance and management of the
AIM/Common Database is not carried out by a specific team in a centralized way,
but in a decentralized way by the model development teams of each country basedon certain guidelines.
The following effects have been realized through application of the
AIM/Common Database.
! A team is able to easily utilize statistical data gathered or processed by anotherteams, and overlapping of work is greatly reduced.
! Results of other models can be easily utilized as input data or reference data fora model, without having to check the data formats of the other models.
! The output of models is in a common format, allowing it to be readily used bystakeholders and promoting the efficient utilization of simulation results.
The AIM/Common Database should play an important role to link the models in
AIM Family that are used for integrated assessment. In order to maintain theefficiency, it is essential for each modeling team to observe the guidelines for its
proper maintenance and management.

References
AIM Project Team (2001) AIM Trend model user’s manual. AIM Project Team,
AIM/Trend Model distribution CD
IEA (2001a) Energy balances of OECD countries 1960-1999. International Energy Agency,
CD-ROM
IEA (2001b) Energy balances of non-OECD countries 1970-1999. International Energy
Agency, CD-ROM
UN (2001) Statistical yearbook. United Nations, CD-ROM
World Bank (2002) World development indicators. World Bank, CD-ROM