尊重城市肌理融入城市空间——紫金长安家园建筑综合体设计

本文通过对紫金长安家园建筑综合体城市设计过程进行思考和总结,提出建筑创作不应局限于建筑本身,更应妥善处理复杂的建筑功能布局关系,遵循建筑法规的限制条件,协调城市既有环境关系与开发商的商业利益之间的矛盾,而对这些条件的协调和利用往往会塑造出建筑独特的品质。     

Associative Grammar Combination Operators for Tree-Based Grammars

Polarized unification grammar (PUG) is a linguistic formalism which uses polarities to better control the way grammar fragments interact. The grammar combination operation of PUG was conjectured to be associative. We show that PUG grammar combination is not associative, and even attaching polarities to objects does not make it order-independent. Moreover, we prove that no non-trivial polarity system exists for which grammar combination is associative. We then redefine the grammar combination operator, moving to the powerset domain, in a way that guarantees associativity. The method we propose is general and is applicable to a variety of tree-based grammar formalisms.     

The unification hierarchy is undecidable

In unification theory, equational theories can be classified according to the existence and cardinality of minimal complete solution sets for equation systems. For unitary, finitary, and infinitary theories minimal complete solution sets always exist and are singletons, finite, or possibly infinite sets, respectively. In nullary theories, minimal complete sets do not exist for some equation systems. These classes form the unification hierarchy.We show that it is not possible to decide where a given equational theory resides in the unification hierarchy. Moreover, it is proved that for some classes this problem is not even recursively enumerable.     

Parsing with restricted quantification: an initial demonstration1

The primary goal of this paper is to illustrate how smaller deductive search spaces can be obtained by extending a logical language with restricted quantification and tailoring an inference system to this extension. The illustration examines the search spaces for a bottom-up parse of a sentence with a series of four strongly equivalent grammars. The grammars are stated in logical languages of increasing expressiveness, each restatement resulting in a more concise grammar and a smaller search space. A secondary goal is to point out an area where further research could yield results useful to the design of efficient parsers, particularly for grammatical formalisms that rely heavily on feature systems.     

On the completeness of SLDENF-resolution

SLDENF-resolution combines the negation-as-failure principle for logic programs involving negation, and SLDE-resolution for logic programs with an underlying equational theory. Recently, J. Shepherdson proved the soundness of this resolution principle wrt. an extended completion semantics. In this note, we investigate the particular problems of obtaining completeness which are caused by adding equational theories. As a concrete result we show to what extent the classical result for hierarchical and allowed nonequational programs can be generalized.     

悲而不颓,柔与刚的统一──3个文学形象审美特征的论探

《诗经·氓》、《九歌·湘夫人3、《短歌行》（之一）中的3个文学形象具有共同的审美特征，即“悲而不颓，柔与刚的统一”。首先，3个文学形象的遭遇都是悲剧，弃妇氓妻是婚姻上的悲剧，湘君是恋情上的悲剧，抒情主人公曹操则是事业上的悲剧。其次，面对悲剧，三者皆是不颓丧、不气馁，或反抗、控诉，或追求、进取，性格上均表现出既有柔，又有刚，柔中有刚，刚柔兼济的审美特征。在审美鉴赏教学过程中，3个文学形象的共同审美特征地激起大学生们的强烈积极的反应，由此可以得到启示，民族优秀传统文化确是可供开掘而常新的宝库，从审美角度深化民族优秀传统文化的探讨研究确是有可为有所益的。     

Solution of the Robbins Problem

In this article we show that the three equations known as commutativity,associativity, and the Robbins equation are a basis for the variety ofBoolean algebras. The problem was posed by Herbert Robbins in the 1930s. Theproof was found automatically by EQP, a theorem-proving program forequational logic. We present the proof and the search strategies thatenabled the program to find the proof.     

快速汉克尔变换及光束均匀化

介绍快速汉克尔变换，以及它在二元光学设计中的应用，并就光束均匀化问题进行了数值模拟，结果表明快速汉克尔变换算法是一种能用于二元光学设计的有效算法。