Applications of Folding Flat Sheets of Materials into 3-D ...

Description

• exposé - matière potentielle : to two methods

Applications of Folding Flat Sheets of Materials into 3-D Intricate Engineering Designs E. A. Elsayed and Basily B. Basily Department of Industrial and Systems Engineering Rutgers University 96 Frelinghuysen Road Piscataway, NJ 08854-8018 Abstract Folding of flat sheets of material into intricate three-dimensional structures provides a new technology for production of cores and sandwich structures of high strength/weight and/or strength/volume ratios. Geometric patterns are generated by transforming flat sheets of materials (traditional or composite) by imposing a permanent fold at specific edges of tessellated sheets.

• impact energy
• continuous folding
• core structure
• core structures
• simulation of composite sandwich structures for civil transportation
• b.b.
• b. b.
• patterns
• material
• load
• 3 materials
• materials

Sujets

• 11072 Hiraoka
• Rutgers University
• Chevron
• Impact
• Structure
• Sandwich
• Material

Informations

• Publié par: fewyang0
• Nombre de lectures: 27
• Langue: English

Extrait

JustOneDB 1.0 Cloud Reference
Documentation
JustOne Database Inc.
Release 1.0 Cloud Reference Documentation 1



JustOneDB 1.0 Reference Documentation
Copyright © 2011 JustOne Database Inc. All rights reserved.

This document pertains to JustOneDB software and to any subsequent release until otherwise
indicated. Information in this document is subject to change without notice. The software described
herein is furnished under a license agreement, and it may be used or copied only in accordance with
the terms of that agreement. No part of this publication may be reproduced, transmitted, or
translated in any form or by any means, electronic, mechanical, manual, optical, or otherwise,
without the prior written permission of JustOne Database Inc. JustOne Database Inc. makes no
warranty of any kind with respect to the completeness or accuracy of this document.

PostgreSQL is a trademark of Marc Fournier held in trust for The PostgreSQL Development Group. All
other company and product names used herein may be trademarks or registered trademarks of their
respective companies.

PostgreSQL is Copyright © 1996-2010 by the PostgreSQL Global Development Group and is
distributed under the terms of the license of the University of California below.

Postgres95 is Copyright © 1994-5 by the Regents of the University of California.

Release 1.0 Cloud Reference Documentation 2


Contents
Preface .................................................................................................................................................... 4
Conventions ............ 4
Overview ................. 5
Tablespaces ..................................................................................................................................... 5
Tables .............. 5
Indexes ............................................................................................................................................ 5
Partitioning...... 5
Statistics .......... 6
Inheritance ...................................................................................................................................... 6
Objects ............ 6
Release 1.0 Limitations ........................................................................................................................... 7
Reference ................................................ 8
Data Type Reference ........................... 8
SQL Reference ................................................................................................................................... 10


Release 1.0 Cloud Reference Documentation 3


Preface

This document provides information and instructions for using a JustOneDB database system in the
Cloud.
This document assumes some knowledge of relational database systems, structured query language
(SQL) and the standard interfaces for the PostgreSQL database.
This document contains the following sections
 Overview – provides an introduction to the JustOneDB system
 Release 1.0 Limitations – summarizes the temporary restrictions in this early release
 Reference – provides a reference for environment variables, data types and SQL commands.
 Support – details about the process for communicating product bugs

Throughout the document there are links to PostgreSQL documents for providing detailed
information about standard PostgreSQL features.
Conventions

This document uses the following typographical conventions throughout:
 Commands and responses are represented in Courier font.
 Placeholders that require replacement with an actual value are shown in italics font.
 Differences and emphasis are shown with a bold font.
 Square brackets [] are used to indicate optional parts of command or statement syntax.
 Braces {} and pipes | are used to indicate alternatives in command or statement syntax.
 Ellipses … are used to indicate repetition in a command or statement syntax.
 Dollar $ is used to represent an operating system prompt.

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Overview

JustOneDB is a fully functional relational database management system (RDBMS) that supports
multi-user transactional updates and analytical queries concurrently within the same database
instance.
JustOneDB does not require the design, build or maintenance of indexes, partitions or schema
transformations to efficiently service queries for fast response times and/or high throughput. This
ability to service arbitrary queries directly against operational data makes JustOneDB rapidly
adaptable to new requirements and provides analytical results in near real-time.
JustOneDB is built upon the open source PostgreSQL database. While the standard PostgreSQL
storage engine and optimizer have been replaced with the JustOneDB storage engine, the functional
features of PostgreSQL have been retained to provide the full functionality expected of a feature-
rich relational database.
Therefore JustOneDB functions in the same way as PostgreSQL except that users are able to create
tables and perform arbitrary queries against them without any need to think about indexing,
partitioning or data transformation (such as de-normalization).
JustOneDB is accessible through the standard PostgreSQL database drivers for DBI.
Note that JustOneDB is a relational database (RDBMS) rather than an object relational database
(ORDBMS) and therefore does not support the object extensions found in standard PostgreSQL such
as data type and operator extensions.
Tablespaces
The default tablespace in JustOneDB is called “jo_tablespace” and user tables will be created in this
tablespace unless specified otherwise. For this release of the product it is strongly recommended
that the tablespace NOT be explicitly specified for the creation of a user table or a temporary table.
Tables
The WITH clause is not relevant for JustOne tables and is silently ignored. See CREATE TABLE for
details of the WITH clause.
Indexes
JustOne tables do not require the definition of any indexes. While it is still possible to define an
index for a JustOne table, the definition will have no effect and is not required. However, the ability
to define such indexes allows legacy schemas to be imported with minimal change to the schema
definitions.
Partitioning
JustOne tables do not require partitioning. Partitioning in standard PostgreSQL is achieved through
table inheritance and this is not supported for JustOne tables. See Inheritance below.
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Statistics
JustOne tables do not require statistics to be gathered, maintained or analysed to optimize query
performance.
Inheritance
JustOne tables cannot be created using the INHERITS clause to link parent and child tables. Note that
JustOne tables do not require partitioning. An attempt to create an inheritance link will cause an
exception for the CREATE TABLE command.
Objects
JustOneDB is a pure relational database and does not support the object extensions available within
standard PostgreSQL. While the definition of new data types and operators are allowed, they cannot
be applied to JustOne tables.




Release 1.0 Cloud Reference Documentation 6


Release 1.0 Limitations
Release 1.0 is a first release which contains a subset of the functions that will be supported in
subsequent releases of the product.
Therefore there are some notable differences from standard PostgreSQL which are temporary
limitations specific to release 1.0. These limitations will be removed in subsequent releases. These
limitations are summarized in the table below.
Limitation Effect
The first column in a table cannot be NULL Currently, it is not possible to insert a NULL value into
the first column of a table.
Triggers are not currently supported. An attempt to execute a trigger will currently raise an
exception. This limitation will be removed in a
subsequent release.
Analytical queries use standard PostgreSQL Analytical queries are currently performed by
row scanning. PostgreSQL scanning the JustOneDB storage engine.
Therefore, analytical queries will perform like standard
PostgreSQL queries. This limitation will be removed in
a subsequent release.
Joins currently use standard PostgreSQL Joins are currently performed by PostgreSQL using its
join strategies. standard join strategies. This limitation will be
removed in a subsequent release.
Savepoints are not currently supported. Setting a savepoint is permitted; but rolling back to a
savepoint currently rolls back the entire transaction.
This also means that setting ON_ERROR_ROLLBACK
may not work as expected. This limitation will be
removed in a subsequent release.
Nested transactions are not supported. Nested transactions are not supported. This limitation
will be removed in a subsequent release.
Unique and key constraints are not Currently, it is possible to insert rows that violate
currently enforced. unique or key constraints. This limitation will be
removed in a subsequent release.