SGML

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/12/24 12:34:25」(JST)

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Standard Generalized Markup Language

MIME Type	application/sgml, text/sgml
UTI	public.xml
開発者	ISO
種別	メタ言語
派生元	GML
拡張	HTML, XML
国際標準	ISO 8879

Standard Generalized Markup Language（スタンダード ジェネラライズド マークアップ ランゲージ、略：SGML）、文書記述言語SGMLは、マークアップ言語を定義するためのメタ言語の一つである。

簡単に言えば、マニュアルなどの文書の電子化のための書式の規格である。HTMLおよびXMLの、スーパーセット（親）にあたる。その標準規格はISOによって1986年に定められた (ISO 8879:1986、JIS X 4151:1992) 。

背景

オックスフォード英語辞典の電子版を記述するのにSGMLが利用された。

そもそもコンピュータやインターネットは軍事技術を目的として開発されたのが起源であり、SGMLも例外ではなかった。軍艦や軍用機などのマニュアルは膨大な量にのぼり、改良が加えられた時などにもマニュアルを新しく書き直す作業、いわゆるメンテナンスなどが大変であった。このことから、マニュアルを電子化して、大量の紙を削減し、かつメンテナンスの簡素化をはかるための技術が必要とされた。

ただし、軍艦や軍用機などは数十年という長期間の保有が必要になるため、長期間にわたりデータが利用可能とならなければならない。電子文書は特定の企業のワープロソフトを用いるとそのソフトのバージョンが上がったり、最悪の場合そのソフトを開発している会社が開発を中止したり、倒産したりしてソフトウェアが無くなった場合は、今まで作成したデータが読めなくなるという問題が発生してしまう。そこで、プレーンテキストのみを用いて、「タグ」を使うことによってデータに意味を持たせることが考えられた。

このようにして規格化されたのがSGMLであった。

歴史

1979年、IBMでプロジェクトマネージャをしていたチャールズ・ゴールドファーブ は、Edward MosherおよびRaymond Lorieらとともに、「GML」(Generalized Markup Language) を発表し、それは「DCF」(Document Composition Facility) の名で商業化された。この成功でゴールドファーブは有名になり、IBMを退職してGMLの後継言語であるSGMLを開発することになったのである。

ISOのSGML規約は1986年の出版後2ヶ月も経たないうちにベストセラーとなった（その10年前に発売されたFORTRANのISO規約の部数を2ヶ月で超えた）。

SGMLは、ISOから正式に承認される以前から、すでに、アメリカ国防総省やECの公式出版事務局など、数々の公的機関で使用され始めていた。ゴールドファーブの古巣のIBM社でも導入され、同社の文書システムに大変革をおこした。ヨーロッパでもCERN（欧州原子核研究機構）など、広く採用され、例えばフランスを例に挙げると、エアバス社、SNECMA（フランス国営の航空機エンジンメーカー）およびフランス軍などで採用されることになった。

日本においては、厚生省への新薬申請のデータ形式としてSGMLが採用された。それに伴い製薬会社やその関連企業においても導入された。他にも特許庁などでも導入された。航空機産業・防衛産業、自動車産業においても海外との共同開発や部品供給時の情報交換やマニュアル・報告書の電子化などに利用されることとなった。

特徴

• SGMLは「インスタンス」、「DTD」、「SGML宣言」の3つで構成されている。
• SGMLのデータ自体はプレーンテキストで作られている。
• レイアウト情報はスタイルシートを組み合わせて記述される。
• スタイルシートは「スタイルシート言語」で記述されている。
• 通常、人が読む時は、上記スタイルシートに沿って、レイアウトを整えられたうえで表示(出力)される。
• SGMLで使うことができるスタイルシート言語として、DSSSL (Document Style Semantics and Specification Language) の規格が定められた。

簡単な例

<!DOCTYPE memo PUBLIC "-//SuzukiCorp//DTD Memo//JP">
<memo>
<from>木村
<to>富田様
<date>2001/10/01
<subject>役員会議
<para>役員会議の場所は会議室Ｂに変更になりました。
</memo>

パーサ

SGML文書を、人間が読めるように、レイアウトして表示することは、SGMLパーサという名のプログラムが行う。つまり構文解析およびレイアウトを行うプログラムである。SGMLパーサの最も初期の市販品としては、ブリュッセルのSOBEMAP社のものおよび、シカゴのDatalogics データロジックス社のものがあった。

問題

SGMLは機能が満載されていたことにより、そのままでは全てを実装することは困難であった。また、タグの構造が原因で、パーサのアルゴリズムが比較的複雑になることも難点だった。そこで後に、SGMLを簡略化および改良した形のXMLが開発され、普及してゆくことになった。SGML文書はXML文書へと順次、変換・移行されることになった。

貢献

• 上記のごとく、SGMLをもとにして、XMLが開発された。
• SGMLを基にした応用技術の一つが、HTML である。ウェブページを記述する言語HTMLなくしては現在の爆発的なインターネットの普及は考えられない。

SGMLはこれら2つのマークアップ言語の源流であり、現在のインターネット利用者は皆SGMLの恩恵に浴しているのである。

参考文献

• 『SGML入門』Martin Bryan 著、山崎俊一、福島誠　訳、アスキー出版局、1991年 ISBN 4-7561-0069-4

脚注

注

出典

関連項目

• Document Type Definition (DTD)
  • 文書型宣言
• Document Style Semantics and Specification Language (DSSSL)
• Extensible Markup Language (XML)
• HyperText Markup Language (HTML)
• マークアップ言語
• SGML実体

外部リンク

• The SGML History Niche
• SGML: In memory of William W. Tunnicliffe
• JIS X 4151-1992 文書記述言語SGML

wiki en

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For other uses, see SDIF (disambiguation).

Standard Generalized Generic Markup Language

Internet media type	application/sgml, text/sgml
Uniform Type Identifier	public.xml
Developed by	ISO
Type of format	Markup Language
Extended from	GML
Extended to	HTML, XML
Standard(s)	ISO 8879

The Standard Generalized Markup Language (SGML; ISO 8879:1986) is an ISO-standard technology for defining generalized markup languages for documents. ISO 8879 Annex A.1 defines generalized markup:

Generalized markup is based on two novel postulates:^{[citation needed]}

• Markup should be declarative: it should describe a document's structure and other attributes, rather than specify the processing to be performed on it. Declarative markup is less likely to conflict with unforeseen future processing needs and techniques.
• Markup should be rigorous so that the techniques available for processing rigorously-defined objects like programs and databases can be used for processing documents as well.

HTML is an example of an SGML-based language.

Standard versions

SGML is an ISO standard: "ISO 8879:1986 Information processing — Text and office systems — Standard Generalized Markup Language (SGML)", of which there are three versions:

• Original SGML, which was accepted in October 1986, followed by a minor Technical Corrigendum.

• SGML (ENR), in 1996, resulted from a Technical Corrigendum to add extended naming rules allowing arbitrary-language and -script markup.

• SGML (ENR+WWW or WebSGML), in 1998, resulted from a Technical Corrigendum to better support XML and WWW requirements.

SGML is part of a trio of enabling ISO standards for electronic documents developed by ISO/IEC JTC1/SC34 (ISO/IEC Joint Technical Committee 1, Subcommittee 34 – Document description and processing languages) :

• SGML (ISO 8879)—generalized markup language
  • SGML was reworked in 1998 into XML, a successful profile of SGML. Full SGML is rarely found or used in new projects.

• DSSSL (ISO/IEC 10179)—document processing and styling language based on Scheme.
  • DSSSL was reworked into W3C XSLT and XSL-FO which use an XML syntax. Nowadays, DSSSL is rarely used in new projects apart from Linux documentation.

• HyTime—Generalized hypertext and scheduling.
  • HyTime was partially reworked into W3C XLink. HyTime is rarely used in new projects.

SGML is supported by various technical reports, in particular

• ISO/IEC TR 9573 – Information processing – SGML support facilities – Techniques for using SGML
  • Part 13: Public entity sets for mathematics and science
    • In 2007, the W3C MathML working group agreed to assume the maintenance of these entity sets.

History

SGML descended from IBM's Generalized Markup Language (GML), which Charles Goldfarb, Edward Mosher, and Raymond Lorie developed in the 1960s. Goldfarb, editor of the international standard, coined the “GML” term using their surname initials. The syntax of SGML is closer to the COCOA format. As a document markup language, SGML was originally designed to enable the sharing of machine-readable large-project documents in government, law, and industry. Many such documents must remain readable for several decades—a long time in the information technology field. SGML also was extensively applied by the military, and the aerospace, technical reference, and industrial publishing industries. The advent of the XML profile has made SGML suitable for widespread application for small-scale, general-purpose use.

A fragment of the OED (1985), showing SGML markup

Document validity

SGML (ENR+WWW) defines two kinds of validity. According to the revised Terms and Definitions of ISO 8879 (from the public draft):

A conforming SGML document must be either a type-valid SGML document, a tag-valid SGML document, or both. Note: A user may wish to enforce additional constraints on a document, such as whether a document instance is integrally-stored or free of entity references.

A type-valid SGML document is defined by the standard as

An SGML document in which, for each document instance, there is an associated document type declaration (DTD) to whose DTD that instance conforms.

A tag-valid SGML document is defined by the standard as

An SGML document, all of whose document instances are fully tagged. There need not be a document type declaration associated with any of the instances. Note: If there is a document type declaration, the instance can be parsed with or without reference to it.

Terminology

Tag-validity was introduced in SGML (ENR+WWW) to support XML which allows documents with no DOCTYPE declaration but which can be parsed without a grammar or documents which have a DOCTYPE declaration that makes no XML Infoset contributions to the document. The standard calls this fully tagged. Integrally stored reflects the XML requirement that elements end in the same entity in which they started. Reference-free reflects the HTML requirement that entity references are for special characters and do not contain markup. SGML validity commentary, especially commentary that was made before 1997 or that is unaware of SGML (ENR+WWW), covers type-validity only.

The SGML emphasis on validity supports the requirement for generalized markup that markup should be rigorous. (ISO 8879 A.1)

Syntax

An SGML document may have three parts:

1. the SGML Declaration,
2. the Prologue, containing a DOCTYPE declaration with the various markup declarations that together make a Document Type Definition (DTD), and
3. the instance itself, containing one top-most element and its contents.

An SGML document may be composed from many entities (discrete pieces of text). In SGML, the entities and element types used in the document may be specified with a DTD, the different character sets, features, delimiter sets, and keywords are specified in the SGML Declaration to create the concrete syntax of the document.

Although full SGML allows implicit markup and some other kinds of tags, the XML specification (s4.3.1) states:

Each XML document has both a logical and a physical structure. Physically, the document is composed of units called entities. An entity may refer to other entities to cause their inclusion in the document. A document begins in a "root" or document entity. Logically, the document is composed of declarations, elements, comments, character references, and processing instructions, all of which are indicated in the document by explicit markup.

For introductory information on basic, modern SGML syntax, see XML. The following material concentrates on features not in XML and is not a comprehensive summary of SGML syntax.

Optional features

SGML generalizes and supports a wide range of markup languages as found in the mid 1980s. These ranged from terse Wiki-like syntaxes to RTF-like bracketed languages to HTML-like matching-tag languages. SGML did this by a relatively simple default reference concrete syntax augmented with a large number of optional features that could be enabled in the SGML Declaration. Not every SGML parser can necessarily process every SGML document. Because each processor's System Declaration can be compared to the document's SGML Declaration it is always possible to know whether a document is supported by a particular processor.

Many SGML features relate to markup minimization. Other features relate to parallel asynchronous markup (CONCUR), to linking processing attributes (LINK), and to embedding SGML documents within SGML documents (SUBDOC).

The notion of customizable features was not appropriate for Web use, so one goal of XML was to minimize optional features. However XML's well-formedness rules cannot support Wiki-like languages, leaving them unstandardized and difficult to integrate with non-text information systems.

Concrete and abstract syntaxes

The usual (default) SGML concrete syntax resembles this example, which is the default HTML concrete syntax:

<QUOTE TYPE="example"> 
  typically something like <ITALICS>this</ITALICS> 
</QUOTE>

SGML provides an abstract syntax that can be implemented in many different types of concrete syntax. Although the markup norm is using angle brackets as start- and end- tag delimiters in an SGML document (per the standard-defined reference concrete syntax), it is possible to use other characters—provided a suitable concrete syntax is defined in the document's SGML declaration. For example, an SGML interpreter might be programmed to parse GML, wherein the tags are delimited with a left colon and a right full stop, thus, an :e prefix denotes an end tag: :xmp.Hello, world:exmp.. According to the reference syntax, letter-case (upper- or lower-) is not distinguished in tag names, thus the three tags: (i) <quote>, (ii) <QUOTE>, and (iii) <quOtE> are equivalent. (NOTE: A concrete syntax might change this rule via the NAMECASE NAMING declarations).

Markup Minimization

SGML has features for reducing the number of characters required to mark up a document, which must be enabled in the SGML Declaration. SGML processors need not support every available feature, thus allowing applications to tolerate many types of inadvertent markup omissions; however, SGML systems usually are intolerant of invalid structures. XML is intolerant of syntax omissions, and does not require a DTD for validation.

OMITTAG

Both start tags and end tags may be omitted from a document instance, provided:

1. the OMITTAG feature is enabled in the SGML Declaration,
2. the DTD indicates that the tags are permitted to be omitted,
3. (for start tags) the element has no associated required (#REQUIRED) attributes, and
4. the tag can be unambiguously inferred by context.

For example, if OMITTAG YES is specified in the SGML Declaration (enabling the OMITTAG feature), and the DTD includes the following declarations:

<!ELEMENT chapter - - (title, section+)>
<!ELEMENT title o o (#PCDATA)>
<!ELEMENT section - - (title, subsection+)>

then this excerpt:

<chapter>Introduction to SGML
<section>The SGML Declaration
<subsection>
...

which omits two <title> tags and two </title> tags, would represent valid markup.

Note also that omitting tags is optional - the same excerpt could be tagged like this:

<chapter><title>Introduction to SGML</title>
<section><title>The SGML Declaration</title>
<subsection>
...

and would still represent valid markup.

Note: The OMITTAG feature is unrelated to the tagging of elements whose declared content is EMPTY as defined in the DTD:

<!ELEMENT image - o EMPTY>

Elements defined like this have no end tag, and specifying one in the document instance would result in invalid markup. This is syntactically different than XML empty elements in this regard.

SHORTREF

Tags can be replaced with delimiter strings, for a terser markup, via the SHORTREF feature. This markup style is now associated with wiki markup, e.g. wherein two equals-signs (==), at the start of a line, are the “heading start-tag”, and two equals signs (==) after that are the “heading end-tag”.

SHORTTAG

SGML markup languages whose concrete syntax enables the SHORTTAG VALUE feature, do not require attribute values containing only alphanumeric characters to be enclosed within quotation marks—either double “ ” (LIT) or single ’ ’ (LITA)—so that the previous markup example could be written:

<QUOTE TYPE=example> 
  typically something like <ITALICS>this</> 
</QUOTE>

One feature of SGML markup languages is the "presumptuous empty tagging", such that the empty end tag </> in <ITALICS>this</> "inherits" its value from the nearest previous full start tag, which, in this example, is <ITALICS> (in other words, it closes the most recently opened item). The expression is thus equivalent to <ITALICS>this</ITALICS>.

NET

Another feature is the NET (Null End Tag) construction: <ITALICS/this/, which is structurally equivalent to <ITALICS>this</ITALICS>.

Other features

Additionally, the SHORTTAG NETENABL IMMEDNET feature allows shortening tags surrounding an empty text value, but forbids shortening full tags:

<QUOTE></QUOTE>

can be written as:

<QUOTE// <!-- not a typo! -->

Wherein the first slash ( / ) stands for the NET-enabling “start-tag close” (NESTC), and the second slash stands for the NET. NOTE: XML defines NESTC with a /, and NET with an > (angled bracket)—hence the corresponding construct in XML appears as <QUOTE/>.

The third feature is 'text on the same line', allowing a markup item to be ended with a line-end; especially useful for headings and such, requiring using either SHORTREF or DATATAG minimization. For example, if the DTD includes the following declarations:

<!ELEMENT lines (line*)
<!ELEMENT line O - (#PCDATA)>
<!ENTITY   line-tagc  "</line>">
<!SHORTREF one-line "&#RE;&#RS;" line-tagc> 
<!USEMAP   one-line line>

(and "&#RE;&#RS;" is a short-reference delimiter in the concrete syntax), then:

<lines>
first line 
second line
</lines>

is equivalent to:

<lines>
<line>first line</line> 
<line>second line</line>
</lines>

Formal characterization

SGML has many features that defied convenient description with the popular formal automata theory and the contemporary parser technology of the 1980s and the 1990s. The standard warns in Annex H:

The SGML model group notation was deliberately designed to resemble the regular expression notation of automata theory, because automata theory provides a theoretical foundation for some aspects of the notion of conformance to a content model. No assumption should be made about the general applicability of automata to content models.

A report on an early implementation of a parser for basic SGML, the Amsterdam SGML Parser, notes

the DTD-grammar in SGML must conform to a notion of unambiguity which closely resembles the LL(1) conditions

and specifies various differences.

There appears to be no definitive classification of full SGML against a known class of formal grammar. Plausible classes may include tree-adjoining grammars and adaptive grammars.

XML is described as being generally parsable like a two-level grammar for non-validated XML and a Conway-style pipeline of coroutines (lexer, parser, validator) for valid XML. The SGML productions in the ISO standard are reported to be LL(3) or LL(4). XML-class subsets are reported to be expressible using a W-grammar. According to one paper, and probably considered at an information set or parse tree level rather than a character or delimiter level:

The class of documents that conform to a given SGML document grammar forms an LL(1) language. ... The SGML document grammars by themselves are, however, not LL(1) grammars.

The SGML standard does not define SGML with formal data structures, such as parse trees, however, an SGML document is constructed of a rooted directed acyclic graph (RDAG) of physical storage units known as “entities”, which is parsed into a RDAG of structural units known as “elements”. The physical graph is loosely characterized as an entity tree, but entities might appear multiple times. Moreover, the structure graph is also loosely characterized as an element tree, but the ID/IDREF markup allows arbitrary arcs.

The results of parsing can also be understood as a data tree in different notations; where the document is the root node, and entities in other notations (text, graphics) are child nodes. SGML provides apparatus for linking to and annotating external non-SGML entities.

The SGML standard describes it in terms of maps and recognition modes (s9.6.1). Each entity, and each element, can have an associated notation or declared content type, which determines the kinds of references and tags which will be recognized in that entity and element. Also, each element can have an associated delimiter map (and short reference map), which determines which characters are treated as delimiters in context. The SGML standard characterizes parsing as a state machine switching between recognition modes. During parsing, there is a stack of maps that configure the scanner, while the tokenizer relates to the recognition modes.

Parsing involves traversing the dynamically-retrieved entity graph, finding/implying tags and the element structure, and validating those tags against the grammar. An unusual aspect of SGML is that the grammar (DTD) is used both passively — to recognize lexical structures, and actively — to generate missing structures and tags that the DTD has declared optional. End- and start- tags can be omitted, because they can be inferred. Loosely, a series of tags can be omitted only if there is a single, possible path in the grammar to imply them. It was this active use of grammars that made concrete SGML parsing difficult to formally characterize.

SGML uses the term validation for both recognition and generation. XML does not use the grammar (DTD) to change delimiter maps or to inform the parse modes, and does not allow tag omission; consequently, XML validation of elements is not active in the sense that SGML validation is active. SGML without a DTD (e.g. simple XML), is a grammar or a language; SGML with a DTD is a metalanguage. SGML with an SGML declaration is, perhaps, a meta-metalanguage, since it is a metalanguage whose declaration mechanism is a metalanguage.

SGML has an abstract syntax implemented by many possible concrete syntaxes, however, this is not the same usage as in an abstract syntax tree and as in a concrete syntax tree. In the SGML usage, a concrete syntax is a set of specific delimiters, while the abstract syntax is the set of names for the delimiters. The XML Infoset corresponds more to the programming language notion of abstract syntax introduced by John McCarthy.

Derivatives

XML

Main article: XML

The W3C XML (Extensible Markup Language) is a profile (subset) of SGML designed to ease the implementation of the parser compared to a full SGML parser, primarily for use on the World Wide Web. In addition to disabling many SGML options present in the reference syntax (such as omitting tags and nested subdocuments) XML adds a number of additional restrictions on the kinds of SGML syntax. For example, despite enabling SGML shortened tag forms, XML does not allow unclosed start or end tags. It also relied on many of the additions made by the WebSGML Annex. XML currently is more widely used than full SGML. XML has lightweight internationalization based on Unicode. Applications of XML include XHTML, XQuery, XSLT, XForms, XPointer, JSP, SVG, RSS, Atom, XML-RPC, RDF/XML, and SOAP.

HTML

Main article: HTML

While HTML was developed partially independently and in parallel with SGML, its creator Tim Berners-Lee, intended it to be an application of SGML. The design of HTML (Hyper Text Markup Language) was therefore inspired by SGML tagging, but, since no clear expansion and parsing guidelines were established, most actual HTML documents are not valid SGML documents. Later, HTML was reformulated (version 2.0) to be more of an SGML application, however, the HTML markup language has many legacy- and exception- handling features that differ from SGML's requirements. HTML 4 is an SGML application that fully conforms to ISO 8879 – SGML.

The charter for the recently revived World Wide Web Consortium HTML Working Group says, "the Group will not assume that an SGML parser is used for 'classic HTML'". Although HTML syntax closely resembles SGML syntax with the default reference concrete syntax, HTML5 abandons any attempt to define HTML as an SGML application, explicitly defining its own parsing rules which more closely match existing implementations and documents. It does, however, define an alternative XHTML serialization, which conforms to XML and therefore to SGML as well.

OED

The second edition of the Oxford English Dictionary (OED) is entirely marked up with an SGML-based markup language.

The third edition is marked up as XML.

Others

Other document markup languages are partly related to SGML and XML, but — because they cannot be parsed or validated or other-wise processed using standard SGML and XML tools — they are not considered either SGML or XML languages; the Z Format markup language for typesetting and documentation is an example.

Several modern programming languages support tags as primitive token types, or now support Unicode and regular expression pattern-matching. An example is the Scala programming language.

Applications

Document markup languages defined using SGML are called "applications" by the standard; many pre-XML SGML applications were proprietary property of the organizations which developed them, and thus unavailable in the World Wide Web. The following list is of pre-XML SGML applications.

• TEI (Text Encoding Initiative) is an academic consortium that designs, maintains, and develops technical standards for digital-format textual representation applications.
• DocBook is a markup language originally created as an SGML application, designed for authoring technical documentation; DocBook currently is an XML application.
• CALS (Continuous Acquisition and Life-cycle Support) is a US Department of Defense (DoD) initiative for electronically capturing military documents and for linking related data and information.
• EDGAR (Electronic Data-Gathering, Analysis, and Retrieval) system effects automated collection, validation, indexing, acceptance, and forwarding of submissions, by companies and others, who are legally required to file data and information forms with the US Securities and Exchange Commission (SEC).
• LinuxDoc. Documentation for Linux packages has used the LinuxDoc SGML DTD and Docbook XML DTD.

Open source implementations

Significant open source implementations of SGML have included:

• ASP-SGML
• ARC-SGML, by Standard Generalized Markup Language Users', 1991, C language
• SGMLS, by James Clark, 1993, C language
• Project YAO, by Yuan-ze Institute of Technology, Taiwan, with Charles Goldfarb, 1994, object
• SP by James Clark, C++ language

SP and Jade, the associated DSSSL processors, are maintained by the OpenJade project, and are common parts of Linux distributions. A general archive of SGML software and materials resides at SUNET. The original HTML parser class, in Sun System's implementation of Java, is a limited-features SGML parser, using SGML terminology and concepts.

See also

• SGML Open
• S-expression
• DSSSL – a Scheme-based processing language similar to XSL
• LaTeX
• List of general purpose markup languages
• Markup language
• SGML entity
• HyTime
• XML

References

External links

• Overview of SGML Resources at W3C's website.
• Introduction and Examples of Software Documentation in SGML
• SC34 Committee Records, Charles Babbage Institute – Collection on the development of SGML and other standards influential in the development of current XML tools; documents include early drafts of SGML administrative materials, documentation, working group papers, and standards for computer languages.
• SGML Syntax Summary by Charles Goldfarb
• SGML document introducing you to SGML; Some reasons why SGML is important
• The SGML Declaration, in SGML and HTML Explained, Martin Bryan (1997)
• SGML Declarations Wayne Wohler, IBM Corporation, 1994.
• ISO 9069:1988 – Information processing – SGML support facilities – SGML Document Interchange Format (SDIF)
• ISO/IEC 9070:1991 – Information technology – SGML support facilities – Registration procedures for public text owner identifiers

English Journal

• Comparison between linear and proportional hazard models for the analysis of age at first lambing in the Ripollesa breed.

• Casellas J1.
• Animal : an international journal of animal bioscience.Animal.2016 Mar;10(3):365-71. doi: 10.1017/S1751731115002220. Epub 2015 Nov 9.
• Age at first lambing (AFL) plays a key role on the reproductive performance of sheep flocks, although there are no genetic selection programs accounting for this trait in the sheep industry. This could be due to the non-Gaussian distribution pattern of AFL data, which must be properly accounted for
• PMID 26549545

• Effect of Performance Speed on Trunk Movement Control During the Curl-Up Exercise.

• Barbado D1, Elvira JL1, Moreno FJ1, Vera-Garcia FJ1.
• Journal of human kinetics.J Hum Kinet.2015 Jul 10;46:29-37. doi: 10.1515/hukin-2015-0031. eCollection 2015.
• Trunk exercise speed has significant effects on neuro-mechanical demands; however, the influence of a variety of exercise speeds on motor control of the trunk displacement remains unknown. The aim of this study was to assess the effect of performance speed on trunk motion control during the curl-up
• PMID 26240646

Japanese Journal

• オブジェクト・リレーショナルデータベース管理システムにおけるプラグイン機構の開発

• 情報処理学会論文誌データベース（TOD） 4(1), 50-63, 2011-03-25
• NAID 40019601225

• SGML型添付文書データからのチトクロームP450関連相互作用の自動抽出

• 薬局薬学 3(1), 16-28, 2011
• NAID 40018834227

Related Links

• SGML（Standard Generalized Markup Language）とは - IT ...

SGML【Standard Generalized Markup Language】とは、文書の構造やデータの意味などを記述するマークアップ言語を定義することができるメタ言語の一つ。文字データのみのテキスト形式(プレーンテキスト)で文書を記述し、本文中に ...

• SGMLとは｜「分かりそう」で「分からない」でも「分かった」気 ...

用語「SGML」の説明です。正確ではないけど何となく分かる、IT用語の意味を「ざっくりと」理解するためのIT用語辞典です。専門外の方でも理解しやすいように、初心者が分かりやすい表現を使うように心がけています。

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