General structure

OCA© database and browser consists of 3 main parts: a Data Mining and Indexing engine, a Query mechanism (including enhanced Thesaurus and spelling automatic verification), and a Display agent that offers a fully annotated rich Atlas page.

Technology

At any given time, one or more of the following techniques and tools are working together to collect, integrate and deliver the data you need:
Cache Management, Client/Server Programming, Data Mining & Knowledge Discovery, Glimpse, HTTP Client/Server Internals, Middleware, Object Oriented System Design, Perl, Robots and Agents, Spelling & Thesaurus, Structured Query Language

To err is human

One of the main concerns for us, as database-interface developers, is the "false negatives", that is, to not return data after a query, even when the data is available in the database. Frequently this happens because the user was unable to express the query in a way compatible with the search engine, or used words or keywords unknown to the search engine.

OCA© browser deals with these problems by incorporating several automatic and semi-automatic mechanisms to help the user in retrieving the requested data. The request from the user gets filtered and transformed by one or more of the following engines. At the end, the resulting query is the one used for the search.

• american-british: 'amoeba' and 'ameba' are equivalent

• synonyms: 'protease' is equivalent to 'proteinase'

• spelling search: based on a dictionary built from the current OCA© data, the spelling engine will produce words that are close to the entered one. As an example, entering 'imune' will offer 'immune' as a valid alternative.

• soundex search: based on the soundex algorithm that approximates the sound of the word when spoken by an English speaker. Looking for author 'weich' will offer as alternatives: Weiss, Wess, Wyss ...

• stemming: engine applied in the 'function' and 'diseases' fields, goes trough a process for removing the commoner morphological and inflectional endings from words in English, using the algorithm described by Porter, M.F., 1980, An algorithm for suffix stripping, Program, 14(3) :130-137.

• nomenclature: automatic word expansion when searching on CRYST1 record using the short and extended Hermann-Mauguin symbols. 'P 1 21 1' or 'P 21' are equivalents.