• The Journal of Society for e-Business Studies
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• v.1 no.1
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• pp.173-194
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• 1996

In order to adapt today's short product life cycle and rapid technology changes., integrated systems should be extended to support PDM (Product Data Management) or CE(Concurrent Engineering). A PDM/CE environment has been developed and a prototype is Presented in this paper. Features of the PDM/CE environment are 1) integrated product information model (IPIM) includes both data model and integrity constraints, 2) database systems are organized hierarchically so that working data C8Mot be referenced by other application systems until they are released into the global database, and 3) integrity constraints written in EXPRESS are validated both in the local databases and the global database. By keeping the integrity of the product data, undesirable propagation of illegal data to other application system can be prevented. For efficient validation, the constraints are distributed into the local and the global schemata. Separate triggering mechanisms are devised using the dependency of constraints to three different data operations, i.e., insertion, deletion, and update.

• Journal of Information Technology Applications and Management
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• v.10 no.1
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• pp.111-125
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• 2003

This paper proposes a product data model that can express and enforce integrity constraints on product structure during engineering changes (ECs). The model adopts and extends an active object-oriented database model in order to Integrate IC data and their integrity constraints. Tightly integrated with product structure, It will enable designers to maintain and exchange consistent EC data throughout the product life cycle. In order to properly support operations for ECs, the model provides the data, operations, and Event-Condition-Action rules for nested ECs and simultaneous EC applications to multiple options. in addition, the EC objects proposed In the model integrate the data and Integrity constraints into a unified repository. This repository enables designers to access all EC data and integrity constraints through the product structure and relationships between EC objects. This paper also describes a prototype product data management system based on the proposed model In order to demonstrate its effectiveness.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.691-694
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• 2010

Since the data collected at a sensor node is the stream data, for processing efficiently user queries, the query index should be constructed at each node. To construct the minimized query index at the node, it is required to reduce the number of query constraints inserted into the query index. In this paper, we propose the scheme of the query constraints distribution using the multi-dimensional data index in order to diminish the number of the inserted query constraints.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.726-729
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• 2004

Spatiotemporal phenomena are ubiquitous aspects of real world. In the spatial and temporal databases, integrity constraints maintain the semantics of specific application domain and relationship between domains when proceed update in the database. Efficient maintenance of data integrity has become a critical problem, since testing the validity of a large number of constraints in a large database and after each transaction is an expensive task. Especially, in spatiotemporal domain, data is more complex than traditional domains and very active. Additionally, it is not considered that unified frameworks deal with both spatial and temporal properties to handle integrity constraints. Therefore, there need a model to maintain integrity constraints in the unified frameworks and enforcement and management techniques in order to preserve consistence.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.7
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• pp.104-114
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• 1995

In this paper, an intermediate representation HSFG(Hanyang Sequential Flow GRaph) and a new scheduling algorithm for the control-dominated ASIC design is presented. The HSFG represents control flow, data dependency and such constraints as resource constraints and timing constraints. The scheduling algorithm minimizes the total operating time by reducing the number of the constraints as maximal as possible, searching a few paths among all the paths produced by conditional branches. The constraints are substitute by subgraphs, and then the number of subgraphs (that is the number kof the constraints) is minimized by using the inclusion and overlap relation among subgraphs. The proposed algorithm has achieved the better results than the previous ones on the benchmark data.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.7
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• pp.602-610
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• 2000

In communication networks used in safety-critical systems such as control systems in nuclear power plants there exist three types of data traffic : urgent or asynchronous hard real-time data hard real-time periodic data and soft real-time periodic data. it is necessary to allocate a suitable bandwidth to each data traffic in order to meet their real-time constraints. This paper proposes a method to meet the real-time constraints for the three types of data traffic simultaneously under a timer-controlled token bus protocol or the IEEE 802.4 token bus protocol and verifies the validity of the presented method by an example. This paper derives the proper region of the high priority token hold time and the target token rotation time for each station within which the real-time constraints for the three types of data traffic are met, Since the scheduling of the data traffic may reduce the possibility of the abrupt increase of the network load this paper proposes a brief heuristic method to make a scheduling table to satisfy their real-time constraints.

• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.53-63
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• 2011

Many techniques have been proposed to store and query XML data efficiently. One way achieving this goal is using relational database by transforming XML data into relational format. It is important to transform schema to preserve the content, the structure and the constraints of the semantics information of the XML document. Especially, key constraints are an important part of database theory. Therefore, the proposal technique has considered the semantics of XML as expressed by primary keys and foreign keys. And, the proposal technique can preserve not only XML data constraints but also the content and the structure and the semantics of XML data thru transformation process. Transforming information is the content and the structure of the document(the parent-child relationship), the functional dependencies, semantics of the document as captured by XML key and keyref constraints. Because of XML schema transformation ensures that preserving semantic constraints, the advantages of these transformation techniques do not need to use the stored procedure or trigger which these data ensures data integrity in the relational database. In this paper, there is not chosen the ID/IDREF key which supported in DTD, the inheritance relationship, the implicit referential integrity.

• Journal of Computing Science and Engineering
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• v.3 no.4
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• pp.260-277
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• 2009

In this paper we propose a model for checking integrity constraints of mobile databases called Three-Level (3-L) model, wherein the process of constraint checking to maintain the consistent state of mobile databases is realized at three different levels. Sufficient and complete tests proposed in the previous works together with the idea of caching relevant data items for checking the integrity constraints are adopted. This has improved the checking mechanism by preventing delays during the process of checking constraints and performing the update. Also, the 3-L model reduces the amount of data accessed given that much of the tasks are performed at the mobile host, and hence speeds up the checking process.

• Journal of the Korean Mathematical Society
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• v.42 no.1
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• pp.17-35
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• 2005

Necessary conditions for a deterministic optimal control problem which involves states constraints are derived in the form of a maximum principle. The conditions are similar to those of F.H. Clarke, R.B. Vinter and G. Pappas who assume that the problem's data are Lipschitz. On the other hand, our data are not continuously differentiable but only differentiable. Fermat's rule and Rockafellar's duality theory of convex analysis are the basic techniques in this paper.

• Journal of Family Resource Management and Policy Review
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• v.17 no.1
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• pp.241-263
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• 2013

Time pressure and financial burden have been reported as the main constraints on leisure participation. The purpose of this study was to explore a typology of leisure constraints, investigate the characteristics of leisure constraint types, and analyze the differences in leisure participation by the types of leisure constraints for married employees. The data source for this research was the 2009 Time Use Survey conducted by the Korea National Statistical Office (KNSO). Married employees aged 20 to 59 years completed 13,476 time diaries (7,984 for male, 5,492 for female), which were analyzed using chi-square, cluster analysis, and ANOVA analysis. Leisure constraints were classified into five types in two categories, working time per week and personal income for both males and females respectively. The three types for both males and females were time-income constraints, income constraints, and general constraints, with an additional type for men, $time^+$-income constraints, and an additional type for women, time constraint. The most common type was general constraints, for both males and females. Each type was further differentiated by the following socio-economic variables: age, educational level, job type, and weekly day-off. The study found that participation in study, sports, and religious activities varied with the types of leisure constraints.