• The KIPS Transactions:PartA
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• v.11A no.1
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• pp.89-96
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• 2004

Abstraction is an important concept applied widely to variables, functions, complex data, abstract data types, classes and polymorphism in programming languages. However, the concept of abstraction has been considered as ambiguous and explained differently because it is not defined clearly and uniformly. In this paper, we analyse many aspects of abstraction in programming languages, and propose the taxonomy of abstraction. We classify abstraction according to the mechanism of formation into 4 categories such as napping abstraction, bundling abstraction. integrating abstraction and extending abstraction. We also consider many concepts related closely to abstraction such as functions, abstract data types, objects, encapsulation and classes in the view of abstraction. These analysis and consideration will make it possible to explain uniformly various aspects of abstraction which have been treated individually and differently, and to understand the meanings, necessity and importance of abstraction more intensively.

• Journal of Digital Convergence
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• v.12 no.9
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• pp.193-199
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• 2014

In the application development process is an important task to improve the quality of the data is the principal means for achieving the functional requirements of the wireless sensor network applications because it is the data obtained in the real world. It should be possible to meet the requirements for the quality improvement to those detailed for improving the quality in a short period of time for developing a prototype of an application and low cost. However, development of the existing methods can not be satisfied simultaneously in order to use a consistent abstraction because antinomical relation between ability of description and ease of description. In this paper, we propose a meta-data designed to support the improvement of data quality through abstract modeling language is also used in combination to a multiple of the other.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.121-123
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• 2003

이동체 색인에 관한 기존 연구는 시간도메인에 따라 과거궤적에 대한 색인과 현재 및 미래위치색인 등으로 구분된다. 그러나 실 세계 응용에서는 과거 궤적뿐만 아니라 현재 및 미래위치를 모두 필요로 하는 경우가 많기 때문에 각 시간도메인 별로 두 개의 색인을 유지해야 하며 이 방법은 불필요한 비용을 필요로 한다. 따라서 과거, 현재, 미래에 대한 위치 데이터를 통합하여 불필요한 비용을 줄인 새로운 색인을 개발할 필요가 있다. 이 논문에서는 이동체의 과거궤적과 현재 및 미래위치데이터를 추상데이터 타입으로써 통합한 새로운 색인을 제안한다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.11a
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• pp.30-39
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• 2003

GML 데이터는 공간 및 비공간 정보를 동시에 갖는 GIS 데이터의 특징과 구조적(structured)인 XML 데이터의 성격을 함께 가지고 있어 일반적인 DBMS에 저장되기 힘들다. XML 저장이 가능한 데이터베이스는 공간데이터 처리 능력이 부족하고, 공간데이터베이스는 XML 데이터를 저장하기 어렵다. 본 연구는 GML 데이터가 공간데이터베이스에 저장될 수 있도록 GML 응용스키마로부터 공간데이터베이스 스키마를 모델링하는 방법을 제안한다. 이를 위하여 객체관계형 데이터베이스의 특징인 복합 애트리뷰트(composite attribute)와 추상데이터타입(ADT)을 이용한 GML 스키마의 맵핑 규칙을 정하였다. 맵핑 규칙은 OGC SQL 스키마에 적합하도록 GML 데이터의 공간 정보와 비공간 정보를 분리하여 저장시킨다. 따라서 저장된 데이터는 공간데이터베이스가 제공하는 공간 연산자/함수 및 인덱스를 통하여 다양한 공간/비공간 질의가 빠르게 수행될 수 있다.

• Journal of the Korea Society of Computer and Information
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• v.28 no.2
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• pp.111-119
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• 2023

In this paper, we investigate the feasibility of functional programming in the Scala language. The main issue is to what extent Scala is able to handle major properties of functional programming such as lambda expression, high-order functions, generic types, algebraic data types, and monads. For this purpose, we implement an interpreter of an imperative language. In this implementation, the same functional programming techniques are applied to both Haskell and Scala languages, and then these two versions of implementations are compared and analyzed. The abstract syntax tree of an imperative language is expressed as algebraic data types with generics and enum classes in Scala, and the state transition of imperative languages is implemented by using state monad. Extension and given, new features of Scala, are used as well.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.4
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• pp.37-50
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• 2003

In the paper, we describe the query extension techniques for spatiotemporal query functionalities on object-relational DBMS. The spatial objects in real world change the shapes over time. Spatiotemporal databases support to manage a temporal dimension as well as a spatial dimension for history of the objects. The proposed techniques can make conventional object-relational databases to support spatiotemporal databases system by the implementation and inheritance of abstract data types. We define and implement spatial and temporal classes as superclass. And, spatiotemporal classes inherits and extends the classes. The proposed extensions make it easy that conventional database systems not only are transformed into the spatiotemporal database systems, but also do not need to be changed to support spatiotemporal applications.

• Journal of Intelligence and Information Systems
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• v.9 no.3
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• pp.99-115
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• 2003

In this paper, we present a knowledge-based object-oriented spatial database system called KOBOS. A knowledge-based approach is introduced to the object-oriented spatial database system for data modeling and approximate query answering. For handling the structure of spatial objects and the approximate spatial operators, we propose three levels of object-oriented data model: (1) a spatial shape model; (2) a spatial object model; (3) an internal description model. We use spatial type abstraction hierarchies(STAHs) to provide the range of the approximate spatial operators. We then propose SOQL, a spatial object-oriented query language. SOQL provides an integrated mechanism for the graphical display of spatial objects and the retrieval of spatial and aspatial objects. To support an efficient hybrid query evaluation, we use the top-down spatial query processing method.