Pub Date : 2000-01-31DOI: 10.1109/ACSC.2000.824391
D. Jeffery, F. Henderson, Z. Somogyi
The type systems of functional languages such as Haskell have recently become more powerful and expressive. They not only allow programmers to write code that works on values of any type (genericity), they also allow programmers to require that a particular type belongs to a given type class (constrained genericity). Such code may use any of the methods of the type class, since every type that is a member of the type class must implement those methods. This capability makes it significantly easier to express solutions to many common problems, and promotes code reuse. Incorporating type classes in a logic programming language provides some new challenges. In this paper, we explain how we have extended Mercury's type system to include support for type classes. We show that type classes integrate very nicely with Mercury's mode, determinism and uniqueness systems, and describe how our implementation works.
{"title":"Type classes in Mercury","authors":"D. Jeffery, F. Henderson, Z. Somogyi","doi":"10.1109/ACSC.2000.824391","DOIUrl":"https://doi.org/10.1109/ACSC.2000.824391","url":null,"abstract":"The type systems of functional languages such as Haskell have recently become more powerful and expressive. They not only allow programmers to write code that works on values of any type (genericity), they also allow programmers to require that a particular type belongs to a given type class (constrained genericity). Such code may use any of the methods of the type class, since every type that is a member of the type class must implement those methods. This capability makes it significantly easier to express solutions to many common problems, and promotes code reuse. Incorporating type classes in a logic programming language provides some new challenges. In this paper, we explain how we have extended Mercury's type system to include support for type classes. We show that type classes integrate very nicely with Mercury's mode, determinism and uniqueness systems, and describe how our implementation works.","PeriodicalId":304540,"journal":{"name":"Proceedings 23rd Australasian Computer Science Conference. ACSC 2000 (Cat. No.PR00518)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122209401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-31DOI: 10.1109/ACSC.2000.824397
Josef Meyer, R. Dale
A significant obstacle to the development of intelligent natural language processing systems is the lack of rich knowledge bases containing representations of world knowledge. For experimental systems it is common practice to construct small knowledge bases by hand; however, this approach does not scale well to large systems. An alternative is to attempt to extract the desired information from existing knowledge sources intended for human consumption; however, attempts to construct broad-coverage knowledge bases using in-depth analysis have met with limited success. In this paper we present some preliminary work on an alternative approach that involves using shallow processing techniques to build a hybrid knowledge representation that stores information in a partially analysed form.
{"title":"Building hybrid knowledge representations from text","authors":"Josef Meyer, R. Dale","doi":"10.1109/ACSC.2000.824397","DOIUrl":"https://doi.org/10.1109/ACSC.2000.824397","url":null,"abstract":"A significant obstacle to the development of intelligent natural language processing systems is the lack of rich knowledge bases containing representations of world knowledge. For experimental systems it is common practice to construct small knowledge bases by hand; however, this approach does not scale well to large systems. An alternative is to attempt to extract the desired information from existing knowledge sources intended for human consumption; however, attempts to construct broad-coverage knowledge bases using in-depth analysis have met with limited success. In this paper we present some preliminary work on an alternative approach that involves using shallow processing techniques to build a hybrid knowledge representation that stores information in a partially analysed form.","PeriodicalId":304540,"journal":{"name":"Proceedings 23rd Australasian Computer Science Conference. ACSC 2000 (Cat. No.PR00518)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124328327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-31DOI: 10.1109/ACSC.2000.824392
Brian Lederer, V. Plekhanova, C. Jay
Software Development Case Study is a capstone subject in the BSc (Computing) degree at the University of Technology, Sydney. Its purpose is to give students as realistic an experience as possible of working in an IT industry environment on software development. At the same time we are trying to ensure that certain educational aims, such as students being exposed to programming in the large and having a sense of engaging with this task and completing it, are met. In analysing the way we run the course we use Ashby's concept of requisite variety: that for a system's essential variables (subject coordinator) must be able to deploy enough variety (or manoeuvres) to match that of the system being regulated (class). In our case the regulatory variety relates to the type and complexity of the projects on offer as well as to the project roles; this has to match the variety of vocational needs and interests brought to us by the students. We give examples of how conflicts, e.g. between educational and industrial aims, can trigger the emergence of new regulatory variety (such as specialised approaches to the task). We also describe how the coordinator's regulatory variety is amplified by involving the students: e.g. in the framing of the project requirements, where we solicit input from the students via proposals: or in the running of the teams, where the students manage themselves but with monitoring by liaison officers. This student-centred approach is designed to promote project ownership and team responsibility. Although it also produces greater task uncertainty than the students are used to it provides them with greater opportunities for exploration and creativity.
软件开发案例研究是悉尼科技大学(University of Technology, Sydney)理学士(计算机)学位的一个顶点课程。它的目的是给学生提供尽可能真实的在IT行业环境中从事软件开发工作的经验。与此同时，我们也在努力确保某些教育目标得到满足，比如让学生接触到大量的编程，并有一种参与这项任务并完成它的感觉。在分析我们运行课程的方式时，我们使用了阿什比的必要多样性概念:对于一个系统的基本变量(主体协调者)，必须能够部署足够的多样性(或策略)，以匹配被调节的系统(类)。在我们的案例中，监管的多样性与所提供项目的类型和复杂性以及项目角色有关;这与学生给我们带来的各种职业需求和兴趣相匹配。我们举例说明冲突，例如教育和工业目标之间的冲突，如何引发新的监管品种的出现(例如对任务的专门方法)。我们还描述了如何通过学生的参与来扩大协调员的监管多样性:例如，在项目要求的框架中，我们通过提案征求学生的意见;或者在团队的运行中，学生管理自己，但由联络官监督。这种以学生为中心的方法旨在促进项目所有权和团队责任。虽然它也产生了比学生习惯的更大的任务不确定性，但它为他们提供了更多的探索和创造的机会。
{"title":"Teaching a capstone subject in computing science- a variety engineering approach","authors":"Brian Lederer, V. Plekhanova, C. Jay","doi":"10.1109/ACSC.2000.824392","DOIUrl":"https://doi.org/10.1109/ACSC.2000.824392","url":null,"abstract":"Software Development Case Study is a capstone subject in the BSc (Computing) degree at the University of Technology, Sydney. Its purpose is to give students as realistic an experience as possible of working in an IT industry environment on software development. At the same time we are trying to ensure that certain educational aims, such as students being exposed to programming in the large and having a sense of engaging with this task and completing it, are met. In analysing the way we run the course we use Ashby's concept of requisite variety: that for a system's essential variables (subject coordinator) must be able to deploy enough variety (or manoeuvres) to match that of the system being regulated (class). In our case the regulatory variety relates to the type and complexity of the projects on offer as well as to the project roles; this has to match the variety of vocational needs and interests brought to us by the students. We give examples of how conflicts, e.g. between educational and industrial aims, can trigger the emergence of new regulatory variety (such as specialised approaches to the task). We also describe how the coordinator's regulatory variety is amplified by involving the students: e.g. in the framing of the project requirements, where we solicit input from the students via proposals: or in the running of the teams, where the students manage themselves but with monitoring by liaison officers. This student-centred approach is designed to promote project ownership and team responsibility. Although it also produces greater task uncertainty than the students are used to it provides them with greater opportunities for exploration and creativity.","PeriodicalId":304540,"journal":{"name":"Proceedings 23rd Australasian Computer Science Conference. ACSC 2000 (Cat. No.PR00518)","volume":"185 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115899863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-31DOI: 10.1109/ACSC.2000.824394
Kevin C. F. Lew, A. L. Brown
This paper presents a proposal that allows large distributed persistent applications to be composed from one or more hyper-worlds. Hyper-worlds are self-contained hyper-programs that can be dynamically composed to form larger applications. To support hyper-worlds and their distribution, the concepts of a locality and an indirection are presented. A locality is a self-contained persistent entity that does not allow direct pointers to leak across its boundaries. An indirection is a network-wide typed pointer that can address the services provided by localities. It is shown that localities can directly implement hyper-worlds with indirections providing the necessary glue to build large distributed applications.
{"title":"A model of persistent software composition","authors":"Kevin C. F. Lew, A. L. Brown","doi":"10.1109/ACSC.2000.824394","DOIUrl":"https://doi.org/10.1109/ACSC.2000.824394","url":null,"abstract":"This paper presents a proposal that allows large distributed persistent applications to be composed from one or more hyper-worlds. Hyper-worlds are self-contained hyper-programs that can be dynamically composed to form larger applications. To support hyper-worlds and their distribution, the concepts of a locality and an indirection are presented. A locality is a self-contained persistent entity that does not allow direct pointers to leak across its boundaries. An indirection is a network-wide typed pointer that can address the services provided by localities. It is shown that localities can directly implement hyper-worlds with indirections providing the necessary glue to build large distributed applications.","PeriodicalId":304540,"journal":{"name":"Proceedings 23rd Australasian Computer Science Conference. ACSC 2000 (Cat. No.PR00518)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131249111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-31DOI: 10.1109/ACSC.2000.824410
J. Zobel, H. Williams, Sam Kimberley
Computer technology is continually developing, with ongoing rapid improvements in processor speed and disk capacity. At the same time, demands on retrieval systems are increasing, with, in applications such as World-Wide Web search engines, growth in data volumes outstripping gains in hardware performance. We experimentally explore the relationship between hardware and data volumes using a new framework designed for retrieval systems. We show that changes in performance depend entirely on the application: in some cases, even with large increases in data volume, the faster hardware allows improvements in response time; but in other cases, performance degrades far more than either raw hardware statistics or speed on processor-bound tasks would suggest. Overall, it appears that seek times rather than processor limitations are a crucial bottleneck and there is little likelihood of reductions in retrieval system response time without improvements in disk performance.
{"title":"Trends in retrieval system performance","authors":"J. Zobel, H. Williams, Sam Kimberley","doi":"10.1109/ACSC.2000.824410","DOIUrl":"https://doi.org/10.1109/ACSC.2000.824410","url":null,"abstract":"Computer technology is continually developing, with ongoing rapid improvements in processor speed and disk capacity. At the same time, demands on retrieval systems are increasing, with, in applications such as World-Wide Web search engines, growth in data volumes outstripping gains in hardware performance. We experimentally explore the relationship between hardware and data volumes using a new framework designed for retrieval systems. We show that changes in performance depend entirely on the application: in some cases, even with large increases in data volume, the faster hardware allows improvements in response time; but in other cases, performance degrades far more than either raw hardware statistics or speed on processor-bound tasks would suggest. Overall, it appears that seek times rather than processor limitations are a crucial bottleneck and there is little likelihood of reductions in retrieval system response time without improvements in disk performance.","PeriodicalId":304540,"journal":{"name":"Proceedings 23rd Australasian Computer Science Conference. ACSC 2000 (Cat. No.PR00518)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127336176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-31DOI: 10.1109/ACSC.2000.824374
T. Bell
Science shows are commonly presented for the general public, and especially children, at science centres and festivals. Usually they use attention-grabbing experiments from the physical sciences, and the science of computing is absent from such presentations. This paper describes a series of demonstrations that present fundamental ideas from Computer Science in a manner that will be engaging to a general audience. The show has been presented to school classes, at science festivals, and as a children's event. The results from questionnaires distributed at the shows indicate a favourable reaction from the public.
{"title":"A low-cost high-impact computer science show for family audiences","authors":"T. Bell","doi":"10.1109/ACSC.2000.824374","DOIUrl":"https://doi.org/10.1109/ACSC.2000.824374","url":null,"abstract":"Science shows are commonly presented for the general public, and especially children, at science centres and festivals. Usually they use attention-grabbing experiments from the physical sciences, and the science of computing is absent from such presentations. This paper describes a series of demonstrations that present fundamental ideas from Computer Science in a manner that will be engaging to a general audience. The show has been presented to school classes, at science festivals, and as a children's event. The results from questionnaires distributed at the shows indicate a favourable reaction from the public.","PeriodicalId":304540,"journal":{"name":"Proceedings 23rd Australasian Computer Science Conference. ACSC 2000 (Cat. No.PR00518)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126803744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-31DOI: 10.1109/ACSC.2000.824382
M. Evered, G. Menger, J. L. Keedy, Axel Schmolitzky
Object-oriented languages can potentially make a great contribution to enhancing software quality and supporting the software engineering process. Despite this potential, we contend that a number of central features of object-oriented languages are in fact contrary to well-known software engineering principles and goals and therefore represent a hindrance to software engineering rather than a contribution. In this paper we look at the class construct, inheritance, genericity and at object-oriented collection frameworks and suggest ways these could be modified to better supporting software engineering principles.
{"title":"Software engineering despite object-orientation","authors":"M. Evered, G. Menger, J. L. Keedy, Axel Schmolitzky","doi":"10.1109/ACSC.2000.824382","DOIUrl":"https://doi.org/10.1109/ACSC.2000.824382","url":null,"abstract":"Object-oriented languages can potentially make a great contribution to enhancing software quality and supporting the software engineering process. Despite this potential, we contend that a number of central features of object-oriented languages are in fact contrary to well-known software engineering principles and goals and therefore represent a hindrance to software engineering rather than a contribution. In this paper we look at the class construct, inheritance, genericity and at object-oriented collection frameworks and suggest ways these could be modified to better supporting software engineering principles.","PeriodicalId":304540,"journal":{"name":"Proceedings 23rd Australasian Computer Science Conference. ACSC 2000 (Cat. No.PR00518)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131457312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-31DOI: 10.1109/ACSC.2000.824407
A. Skabar, Kousick Biswas, Binh Pham, A. Maeder
Supervised machine learning techniques generally require that the training set on which learning is based contains sufficient examples representative of the target concept, as well as known counter-examples of the concept. However in many application domains it is not possible to supply a set of labeled counter-examples. This paper presents a technique that combines supervised and unsupervised learning to discover symbolic concept descriptions from a training set in which only positive instances appear with class labels. Experimental results obtained from applying the technique to several real world datasets are provided. These results suggest that in some problems domain learning without labeled counter-examples can lead to classification performance comparable to that of conventional learning algorithms, despite the fact that the latter use additional class information. The technique is able to cope with noise in the training set, and is applicable to a broad range of classification and pattern recognition problems.
{"title":"Inductive concept learning in the absence of labeled counter-examples","authors":"A. Skabar, Kousick Biswas, Binh Pham, A. Maeder","doi":"10.1109/ACSC.2000.824407","DOIUrl":"https://doi.org/10.1109/ACSC.2000.824407","url":null,"abstract":"Supervised machine learning techniques generally require that the training set on which learning is based contains sufficient examples representative of the target concept, as well as known counter-examples of the concept. However in many application domains it is not possible to supply a set of labeled counter-examples. This paper presents a technique that combines supervised and unsupervised learning to discover symbolic concept descriptions from a training set in which only positive instances appear with class labels. Experimental results obtained from applying the technique to several real world datasets are provided. These results suggest that in some problems domain learning without labeled counter-examples can lead to classification performance comparable to that of conventional learning algorithms, despite the fact that the latter use additional class information. The technique is able to cope with noise in the training set, and is applicable to a broad range of classification and pattern recognition problems.","PeriodicalId":304540,"journal":{"name":"Proceedings 23rd Australasian Computer Science Conference. ACSC 2000 (Cat. No.PR00518)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128396489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-31DOI: 10.1109/ACSC.2000.824405
N. Serbedzija
The World Wide Web has transformed itself in the last few years from a simple state-less multimedia platform to a global distributed processing environment. As Web computing gains in popularity, different techniques emerge facilitating application sharing over the Internet. This paper discusses the design and development issues concerning middleware for Web-aware systems. GoWeb has been developed as a distributed infrastructure where Web-enabled applications can be embedded. It supports collaborative work with multimedia user interface. The experience gained through its design, implementation, testing and enhancements is discussed with a goal to share experience and provide rationale for development of cost-effective, efficient and media-rich Web-based applications.
{"title":"Developing middleware for Web-aware systems: lessons learned","authors":"N. Serbedzija","doi":"10.1109/ACSC.2000.824405","DOIUrl":"https://doi.org/10.1109/ACSC.2000.824405","url":null,"abstract":"The World Wide Web has transformed itself in the last few years from a simple state-less multimedia platform to a global distributed processing environment. As Web computing gains in popularity, different techniques emerge facilitating application sharing over the Internet. This paper discusses the design and development issues concerning middleware for Web-aware systems. GoWeb has been developed as a distributed infrastructure where Web-enabled applications can be embedded. It supports collaborative work with multimedia user interface. The experience gained through its design, implementation, testing and enhancements is discussed with a goal to share experience and provide rationale for development of cost-effective, efficient and media-rich Web-based applications.","PeriodicalId":304540,"journal":{"name":"Proceedings 23rd Australasian Computer Science Conference. ACSC 2000 (Cat. No.PR00518)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125889180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-01-31DOI: 10.1109/ACSC.2000.824404
Andrew Rock, D. Billington
We report the first complete implementation of propositional plausible logic. Plausible logic is an extension of defeasible logic that overcomes the latter's inability to represent or prove disjunctions. This advantage is significant in dealing with practical applications such as the modeling of regulations. The system has a Web interface, which makes it available to researchers and students everywhere. The implementation language chosen was Haskell and some advantages and consequences of this choice are discussed.
{"title":"An implementation of propositional plausible logic","authors":"Andrew Rock, D. Billington","doi":"10.1109/ACSC.2000.824404","DOIUrl":"https://doi.org/10.1109/ACSC.2000.824404","url":null,"abstract":"We report the first complete implementation of propositional plausible logic. Plausible logic is an extension of defeasible logic that overcomes the latter's inability to represent or prove disjunctions. This advantage is significant in dealing with practical applications such as the modeling of regulations. The system has a Web interface, which makes it available to researchers and students everywhere. The implementation language chosen was Haskell and some advantages and consequences of this choice are discussed.","PeriodicalId":304540,"journal":{"name":"Proceedings 23rd Australasian Computer Science Conference. ACSC 2000 (Cat. No.PR00518)","volume":"365 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115442843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：