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      Transformation
      發布時間:2019年07月01日     發布人:nanyuzi  
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      Transformation

      (T) 轉換

       

      A formal linguistic operation which enables two levels of structural representation to be placed in correspondence. A transformational rule (T rule, transformation or transform) consists of a sequence of symbols which is rewritten as another sequence, according to certain convention. The ‘input’ to the rule is the structural description (‘structural analysis’ or ‘structure index’), which defines the class of phrase-markers to which the rule can apply. The rule then operates a structural change on this input, by performing one or more of several basic operations. Movement (reordering or permutation) transformations modify an input structure by reordering the elements it contains. When this operation is seen as one of moving elements to adjoining positions in a phrase-marker, it is known as adjunction. Insertion transformation add new structural elements to the input structure (as in element-copying, or the insertion of by in the passive transformation below). Deletion transformations eliminate elements from the input structure.

      One of the earliest illustrations of the operation of a transformational rule was the one which converted active sentences into passive ones, which can be formulated as follows:

      NP1 - Aux -V - NP2→NP2 - Aux + be + en - V - by + NP1

      (where be is a form of the verb to be, and en represents the past-participle ending of the lexical verb). The rule is said to ‘operate’ on the first, underlying phrase-marker, converting it into a second, ‘derived’, phrase-marker. The string produced by the derived phrase-marker may then serve as the underlying string for further transformations, as the analysis of the sentence proceeds. The sequence of phrase-markers assigned to a sentence constitutes its transformational derivation or transformational history.

      A grammar which operates using this notion is a transformational grammar (TG) or transformational generative grammar (TGG). This type of grammar was first discussed by Noam Chomsky in Syntactic Structures (1957) as an illustration of a generative device more powerful than finite-state grammars or phrase-structure grammars. In this view, very many sentence types can be economically derived by supplementing the constituent analysis rules of phrase-structure grammars with rules for transforming one sentence into another. Transformational grammars became the most influential type in the development of generative grammatical theory: indeed, the field as a whole for a time came to be variously known as ‘generative grammar’, ‘transformational-generative grammar’ (or simply ‘TG’).

      Several models of transformational grammar have been presented since its first outline. The standard model, as presented by Chomsky in Aspects of the Theory of Syntax (1965), consisting of three components: (a) a syntactic component, comprising a basic set of phrase-structure rules (sometimes called the base component), which together with lexical information provides the deep-structure information about sentences, and a set of transformational rules for generating surface structures; (b) a phonological component, which converts strings of syntactic elements into pronounceable utterance; and (c) a semantic component, which provides a representation of the meaning of the lexical items to be used in the sentence. The ways in which these components should be interrelated (especially the relationships between semantics and syntax) have proved to be a source of continuing controversy, since the appearance of Aspects, and alternative models of analysis have developed (compare especially the distinction between generative and interpretive semantics).

      As a result of these developments, the status and classification of transformations varied a great deal in the 1960s and 1970s. A distinction introduced early on is that between optional and obligatory transformations, and the former referring to a rule which may apply at a given stage in a derivation, the latter to a rule which must apply, if a well-formed sentence is to result. On the other hand, the classification and terminology of transformations in Syntactic Structures is different in many respects from that encountered in Aspects. In the former, two types of transformation are recognized: singulary (or single-base), where the rule operates on only one terminal string; and generalized, where the rule combines two or more terminal strings, as in conjoining and embedding transformations (which handle co-ordination and sub-ordination respectively). In Aspects, however, other distinctions are introduced, some of which replace those found in the former book. Of particular importance is a distinction drawn in one of the models outlined in Aspects between lexical and ‘non-lexical’ transformations: the former transform pre-lexical structures into deep structures containing complex symbols; the latter transform deep structures into surface structures. A further development is the much increased generality of transformations, culminating in the rule ‘move alpha’ - essentially a licence to move anything anywhere, except that the movement must be an instance of either substitution or adjunction, and must obey subjacency. 

       

      指一種形式語言學的操作,它能夠在結構表征的兩個平面之間建立對應關系。轉換規則(或稱T規則、轉換)是按某種規約將一個符號序列重寫為另一個序列。規則的“輸入”是結構描寫(“結構分析”或“結構標引”),它確定該規則適用于哪一類短語標記。這條規則然后對這一輸入作某種結構變換,即實施一種或幾種基本操作。移位(重新排序或換位)轉換是通過對所含成分的重新排列來修改輸入結構。將成分移至短語標記內附接位置的操作稱作附接。插入轉換是給輸入結構增加新的結構成分(如成分復寫,或在下述被動式轉換中插入by“被”)。刪除轉換是從輸入結構中消除成分。

      有關轉換規則操作方式的最早示例之一是將主動句轉換成被動句,可具體闡述為:

      NP1 - Aux -V - NP2→NP2 - Aux + be + en - V - by + NP1

      (其中be是動詞to be的一種形式,en代表詞匯動詞的過去分詞詞尾。)按理論,這條規則“作用”于第一個即底層的短語標記,將其變接成第二個即“派生”的短語標記。由該派生的短語標記產生的語符列然后又可隨句子的進一步分析充作底層語符列并作進一步轉換。指派給一個句子組構成分的一系列短語標記稱作轉換派生過程或轉換歷史。

      用轉換這一概念進行操作的語法是轉換語法。這類語法最初由諾姆·喬姆斯基在《句法結構》一書中加以論述,并以此為例說明生成語法的生成力比有限狀態語法或短語結構語法都要強。按這種觀點,有許多類型的句子可以經濟地派生而成,只要在短語結構語法的組構成分分析規則之外再補充將一個句子轉換成另一個句子的規則。轉換語法成為生成語法理論發展過程中最有影響的一類語法:實際上整個領域現在有稱為“生成語法”的,也有稱為“轉換生成語法”的。

      自其最初的綱要提出以來,已有好幾種轉換語法的模型陸續出現。標準模型以喬姆斯基的《句法理論要略》(1965)為代表,包括三個組成部分:(a)句法部分,包括一組基本的短語結構規則(有時也稱作基礎部分)和一組轉換規則,前者與詞匯信息一起提供句子的深層結構的信息,后者生成表層結構;(b)音系部分,將句法成分語符列變換成可發音的話段;(c)語義部分,提供句子將使用的各詞項的意義表征式。這幾個組成部分以何種方式互相聯系(特別是語義學和句法的關系),實際已成為自《要略》以來不斷爭論的起因,也因此建立起一些其他分析模型(特別是參看生成語義學和解釋語義學之間的區別)。

      這些發展的結果導致60年代和70年代轉換的地位和分類發生很大變化。較早引入的一種區別是強制性與非強制性轉換的區別,前者指為得出合式的句子而必須應用的規則,后者指派生過程中某一階段可以應用的規則。另一方面,《句法結構》中各種轉換的分類和術語在許多方面不同于《要略》,前者區分兩類轉換:單一轉換(或單基轉換)是規則只作用于一個終端語符列;概化轉換是規則將兩個或多個終端語符列組合起來,如并聯轉換和嵌套轉換(分別處理并列關系和主從關系)。而在《要略》中還提出其他一些區分,其中有的取代前書中的區分。最重要的區分是,《要略》勾畫的多種模型之一區分詞匯轉換和“非詞匯”轉換:前者將前詞匯結構轉換成包含復雜符號的深層結構;后者將深層結構轉換成表層結構。還有一種變化是轉換的概括性有很大提高,最終概括為一條“移位α”規則—基本上允許任何成分移至任何位置,唯一的限制是移位必須屬于替換或附接兩類,并必須滿足鄰接條件。

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      在线精品国产一区二区三区,欧美最猛性XXXXX大叫,亚欧美日韩香蕉在线播放视频