How well does a vanilla loop fit into a frame?

The frame language FRL is compared with some newer object-oriented languages, namely LOOPS, the Flavor System and the Poor Man's Flavor System. The kernel features are investigated in detail and a simulation of FRL in the Flavor System is performed. The conclusion is that in general the object-oriented languages cannot be easily utilized as a substitute for FRL frames because of the different view these languages have of objects, but there are important special cases where object-oriented languages are very similar to FRL.     

DPDA's in ‘atomic normal form’ and applications to equivalence problems

In this paper, we introduce a new normal form for DPDA's, the ‘Atomic Normal Form’. As an application, using also the concept of ‘address language’ due to Gorn [19, 20], we give alternate and more direct proofs of results of Courcelle [3, 4] relating recursion schemes and DPDA's. Address languages enable us to encode trees even when they are not locally finite. As a consequence, the decidability of a new class of schemes corresponding to the ‘stateless DPDA's’ of [26] is obtained.     

Navigational facilities for relational data base

Charles Bachman's great idea of navigation in a data base is applied to the relational data model. This idea, understood as a way of user thinking, is formulated in such a manner, that no physical concepts are introduced to the user's awareness. Thus the demanded level of data independence is not reduced.A concept of “navigational statement” is defined. The navigational statements may be used to improve other relational languages, for example SEQUEL. It is shown that navigational statements simplify the grammar structure of language expressions and make them shorter and more readable. Elliptic (incomplete) navigational statements are also defined. Such statements may be regarded as a good tool for the casual user.This paper may be viewed as a (not necessarily complete) review of possibilities related to the idea of navigation in a relational data base.     

Modeling of storage properties of higher-level languages

The role of storage in the characterization of higher-level programming languages is discussed. Assignment, in particular, has significantly different meaning in different languages, which can hardly be understood without reference to an underlying model of storage. A general storage model is sketched which can be specialized to a model of ALGOL 68 or of PL/I storage. The same model is used to discuss language features allowing highly flexible data structures.Revised version of a paper presented at the ACM Symposium on Data Structures in Programming Languages, University of Florida, Gainesville, February 25–27, 1971.     

Languages for vector and parallel processors

This paper first considers the major developments which have occurred in the design of high level languages for sequential machines. These developments illustrate how languages which were independent of the hardware eventually evolved. Two major types of language for vector and parallel processors have evolved, namely, detection of parallelism languages and expression of machine parallelism languages. The disadvantages and advantages of each type of languages are examined. A third type of language is also considered which reflects neither the compiler's detection mechanism nor the underlying hardware. The syntax of this language enables the parallel nature of a problem to be expressed directly. The language is thus appropriate for both vector and array processors.     

A strong pumping lemma for context-free languages

A context-free language is shown to be equivalent to a set of sentences describable by sequences of strings related by finite substitutions on finite domains, and vice-versa. As a result, a necessary and sufficient version of the Classic Pumping Lemma is established. This result provides a guaranteed method of proving that a language is not context-free when such is the case. An example is given of a language which neither the Classic Pumping Lemma nor Parikh's Theorem can show to be non-context-free, although Ogden's Lemma can. The main result also establishes {aⁿba^mn} as a language which is not in the Boolean closure of deterministic context-free languages.     

Real time animation of dynamic processes

Animation and simulation processes are facilitated by the use of high level graphic languages. The results of these processes are not generally available in real time, developing of microfilm delaying the screening of the process until some time after the computer run.A technique is described which overcomes this problem whilst still allowing the use of a high level graphical language.The addition of a single feature to a ‘static’ graphical language has transformed it into a ‘dynamic’ graphical language allowing real time illustration of time varying processes.The technique is not restricted to the language described but may well be employed by other high level graphical languages.     

EOL languages are not codings of FPOL languages

One of the useful results concerning EOL languages states that a language is an EOL language if and only if it is a cording of OL language. In this paper we retine this result by demonstrating that there exist EOL languages that are not codings of languages that are generated by propagating OL systems with finite axiom sets. This solves Problem 10 from the L Systems Problem Book '75.     

Aspects as Modular Language Extensions

Extensible programming languages and their compilers use highly modular specifications of languages and language extensions that allow a variety of different language feature sets to be easily imported into the programming environment by the programmer. Our model of extensible languages is based on higher-order attribute grammars and an extension called “forwarding” that mimics a simple rewriting process. It is designed so that no additional attribute definitions need to be written when combining a language with language extensions. Thus, programmers can remain unaware of the underlying attribute grammars when building customized languages by importing various extensions. In this paper we show how aspects and the aspect weaving process from Aspect-Oriented Programming can be specified as a modular language extension and imported into a base language specified in an extensible programming language framework.     

基于LAAE网络的跨语言短文本情感分析方法

跨语言短文本情感分析作为自然语言处理领域的一项重要的任务, 近年来备受关注. 跨语言情感分析能够利用资源丰富的源语言标注数据对资源匮乏的目标语言数据进行情感分析, 建立语言之间的联系是该任务的核心.与传统的机器翻译建立联系方法相比, 迁移学习更胜一筹, 而高质量的跨语言文本向量则会提升迁移效果. 本文提出LAAE网络模型, 该模型通过长短记忆网络(LSTM)和对抗式自编码器(AAE)获得含上下文情感信息的跨语言向量, 然后利用双向GRU (Gated Recurrent Unite)进行后续情感分类任务. 其中, 分类器首先在源语言上进行训练,最后迁移到目标语言上进行分类任务. 本方法的有效性体现在实验结果中.     

A representation of trees by languages I

A tree can be represented by a language consisting of a suitable coding of its finite branches. We investigate this representation and derive a number of reductions between certain equivalence problems for context-free tree grammars and recursive program schemes and the (open) equivalence problem for DPDA's. This is the first part of this work: it is devoted to technical results on prefix-free languages and strict deterministic grammars. Application to context-free tree grammars will be published in the second part.     

On inverse deterministic pushdown transductions

Classes of source languages which can be mapped by a deterministic pushdown (DPDA) transduction into a given object language (while their complement is mapped into the complement of the object language) are studied. Such classes of source languages are inverse DPDA transductions of the given object language. Similarly for classes of object languages. The inverse DPDA transductions of the Dyck sets are studied in greater detail: they can be recognized in deterministic storage (log n)' but do not comprise all context free languages; their emptiness problem is unsolvable and their closure under homomorphism constitutes the r.e. sets. For each object language L we can exhibit a storage hardest language for the class of inverse DPDA transductions of L; similarly for the classes of regular, deterministic context free, and context free object languages. Last, we classify the classes of inverse DPDA transductions of the regular, deterministic context free, context free and deterministic context sensitive languages.     

The use of a generic simulation model in evaluating manufacturing processes

In recent years the application of simulation models to analyze the production capabilities of manufacturing processes has been increasing at IBM's Poughkeepsie plant. To avoid major programming effort for each new application, a generic simulation model was developed. The model, written in SIMPL/1 (Simulation Language Based on PL/1), was designed in modules defined on a functional basis. This language was chosen because it allowed full use of the PL/1 programming language, reduced the excessive run times experienced with large, specialized GPSS models, simplified the procedure for making input changes and provided output that could be easily interpreted by the non-programmer. The input data bases are user-oriented so that changes can be made to the system being modeled without programming support. The output generated by the model can provide the user with information on resource utilization, major process bottlenecks, overtime requirements, process throughput and process cycle time. This data is evaluated by the user to determine how well the process functions under given operating conditions so that cost effective decisions can be made. An example is provided on the model's application to a logic and memory card assembly process.     

Analysis and modeling of acoustic information for automatic dialect classification

A primary challenge in the field of automatic speech recognition is to understand and create acoustic models to represent individual differences in their spoken language. Individual’s age, gender; their speaking styles influenced by their dialect may be few of the reasons for these differences. This work investigates the dialectal differences by measuring the analysis of variance of acoustic features such as, formant frequencies, pitch, pitch slope, duration and intensity for vowel sounds. This paper attempts to discuss methods to capture dialect specific knowledge through vocal tract and prosody information extracted from speech that can be utilized for automatic identification of dialects. Kernel based support vector machine is utilized for measuring the dialect discriminating ability of acoustic features. For the spectral feature shifted delta cepstral coefficients along with Mel frequency cepstral coefficients gives a recognition performance of 66.97 %. Combination of prosodic features performs better with a classification score of 74 %. The model is further evaluated for the combination of spectral and prosodic feature set and achieves a classification accuracy of 88.77 %. The proposed model is compared with the human perception of dialects. The overall work is based on four dialects of Hindi; one of the world’s major languages.     

Sentence alignment using P-NNT and GMM

Parallel corpora have become an essential resource for work in multilingual natural language processing. However, sentence aligned parallel corpora are more efficient than non-aligned parallel corpora for cross-language information retrieval and machine translation applications. In this paper, we present two new approaches to align English–Arabic sentences in bilingual parallel corpora based on probabilistic neural network (P-NNT) and Gaussian mixture model (GMM) classifiers. A feature vector is extracted from the text pair under consideration. This vector contains text features such as length, punctuation score, and cognate score values. A set of manually prepared training data was assigned to train the probabilistic neural network and Gaussian mixture model. Another set of data was used for testing. Using the probabilistic neural network and Gaussian mixture model approaches, we could achieve error reduction of 27% and 50%, respectively, over the length based approach when applied on a set of parallel English–Arabic documents. In addition, the results of (P-NNT) and (GMM) outperform the results of the combined model which exploits length, punctuation and cognates in a dynamic framework. The GMM approach outperforms Melamed and Moore’s approaches too. Moreover these new approaches are valid for any languages pair and are quite flexible since the feature vector may contain more, less or different features, such as a lexical matching feature and Hanzi characters in Japanese–Chinese texts, than the ones used in the current research.     

嵌入路网图模型的自动驾驶场景描述语言

深度学习的快速发展带动着自动驾驶技术的迅速进步.深度学习感知模型在识别准确率逐步提升的同时,也存在鲁棒性和可靠性不足等隐患,需要在大量场景下进行充分测试以确保达到可接受的安全标准.基于场景的仿真测试是自动驾驶技术的核心和关键,如何描述和生成多样化仿真测试场景是需要解决的关键问题之一.场景描述语言能够描述自动驾驶场景并在虚拟环境中实例化场景获取仿真数据,但现有的场景描述语言大都缺少对于场景道路结构的高层抽象和描述.提出路网属性图来表示路网中抽象出的实体及他们的关系,并设计能简洁描述场景路网结构的语言SceneRoad. SceneRoad可以基于描述的场景道路结构特征构建路网特征查询图.这样,在路网中搜索符合描述的场景道路特征的问题被抽象为路网图上的子图匹配问题,该问题可用VF2算法求解.进一步地,将SceneRoad作为扩展集成到Scenic场景描述语言中.使用拓展后的语言随机生成大量多样的静态场景并构建仿真数据集.仿真数据集的统计信息表明生成的场景具有丰富的场景多样性.不同感知模型在真实和仿真数据集上的训练测试结果表明,模型在两个数据集上的表现呈正相关,意味着模型在仿真数据集上的评估...     

融合单语语言模型的汉越伪平行语料生成

神经机器翻译在资源丰富的语种上取得了良好的翻译效果,但是由于数据稀缺问题在汉语-越南语这类低资源语言对上的性能不佳。目前缓解该问题最有效的方法之一是利用现有资源生成伪平行数据。考虑到单语数据的可利用性,在回译方法的基础上,首先将利用大量单语数据训练的语言模型与神经机器翻译模型进行融合,然后在回译过程中通过语言模型融入语言特性,以此生成更规范质量更优的伪平行数据,最后将生成的语料添加到原始小规模语料中训练最终翻译模型。在汉越翻译任务上的实验结果表明,与普通的回译方法相比,通过融合语言模型生成的伪平行数据使汉越神经机器翻译的BLEU值提升了1.41个百分点。     

Typed operational semantics for higher-order subtyping

Bounded operator abstraction is a language construct relevant to object oriented programming languages and to ML2000, the successor to Standard ML. In this paper, we introduce , a variant of F_<:^ω with this feature and with Cardelli and Wegner’s kernel Fun rule for quantifiers. We define a typed-operational semantics with subtyping and prove that it is equivalent with , using logical relations to prove soundness. The typed-operational semantics provides a powerful and uniform technique to study metatheoretic properties of , such as Church–Rosser, subject reduction, the admissibility of structural rules, and the equivalence with the algorithmic presentation of the system that performs weak-head reductions.Furthermore, we can show decidability of subtyping using the typed-operational semantics and its equivalence with the usual presentation. Hence, this paper demonstrates for the first time that logical relations can be used to show decidability of subtyping.