• Journal of the Korea Society for Simulation
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• v.21 no.4
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• pp.47-56
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• 2012

In this study, we use a parallel simulator PASENS(Parallel SEnsor Network Simulator) to predict power consumption and data reception rate of the hierarchical routing protocols for sensor network - LEACH (Low-Energy Adaptive Clustering Hierarchy), TL-LEACH (Two Level Low-Energy Adaptive Clustering Hierarchy), M-LEACH (Multi hop Low-Energy Adaptive Clustering Hierarchy) and LEACH-C (LEACH-Centralized). According to simulation results, M-LEACH routing protocol shows the highest data reception rate for the wider area, since more sensor nodes are involved in the data transmission. And LEACH-C routing protocol, where the sink node considers the entire node's residual energy and location to determine the cluster head, results in the most efficient energy consumption and in the narrow area needed long life of sensor network.

• Journal of the Korean association of regional geographers
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• v.3 no.2
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• pp.105-120
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• 1997

One of the most important issues of object-oriented geographical database system is to develop an indexing technique which enables more efficient I/O processing within aggregation hierarchy or inheritance hierarchy. Up to present, several indexing schemes have been developed for this purpose. However, they have separately focused on aggregation hierarchy or inheritance hierarchy of object-oriented data model. A recent research is proposing a nested-inherited index which combines these two hierarchies simultaneously. However, this new index has some weak points. It has high storage costs related to its use of auxiliary index. Also, it cannot clearly represent the inheritance relationship among classes within its index structure. To solve these problems, this thesis proposes a pointer-chain index. Using pointer chain directory, this index composes a hierarchy-typed chain to show the hierarchical relationship among classes within inheritance hierarchy. By doing these, it could fetch the OID list of objects to be retrieved more easily than before. In addition, the pointer chain directory structure could accurately recognize target cases and subclasses and deal with "select-all" typed query without collection of schema semantic information. Also, it could avoid the redundant data storing, which usually happens in the process of using auxiliary index. This study evaluates the performance of pointer chain indexing technique by way of simulation method to compare nested-inherited index. According to this simulation, the pointer chain index is proved to be more efficient with regard to storage cost than nested-inherited index. Especially in terms of retrieval operation, it shows efficient performance to that of nested-inherited index.

• Journal of the Korean Institute of Rural Architecture
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• v.19 no.4
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• pp.1-8
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• 2017

The purpose of this study is to deduce dwelling selection criterion and to consider change of values and consciousness of dwelling on people who return to farming & going to village. For that, questionnaire of evaluation of housing choice is conducted by people who return to farming & going to village in Jellanam-do by the AHP. The results are as follows. First, four factors as the primary hierarchy structure and 12 factors as the secondary hierarchy structure of dwelling selection criterion are deduced. The primary hierarchy are "education environment", "economic & Convenience in life", "residence safety and image", and "economic value". Second, weight value deduced from the primary hierarchy structure is showed that "economic & convenience in life(0.345)" is the highest and next is "education environment(0.262)". "Residence safety and image(0.237)", and e "economic value(0.157)" is relatively low(C.I. 0.213). Third, for the secondary hierarchy structure, the case of life convenience is showed that economic condition(0.403) is the highest, the case of educational condition is showed that education facilities(0.479), the case of residence safety and image is showed that residence area(0.490) is the highest, and the case of economic importance is showed that financial technology(0.470) is the highest.

• Journal of the Korea Society of Computer and Information
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• v.11 no.3
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• pp.87-96
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• 2006

Most conventional database systems support specific queries that are concerned only with data that match a query qualification precisely. A cooperative query answering supports query analysis, query relaxation and provides approximate answers as well as exact answers. The key problem in the cooperative answering is how to provide an approximate functionality for alphanumeric as well as categorical queries. In this paper, we propose a metricized knowledge abstraction hierarchy that supports multi-level data abstraction hierarchy and distance metric among data values. In order to facilitate the query relaxation, a knowledge representation framework has been adopted, which accommodates semantic relationships or distance metrics to represent similarities among data values. The numeric domains also compatibly incorporated in the knowledge abstraction hierarchy by calculating the distance between target record and neighbor records.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.4
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• pp.37-45
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• 2003

Role-based Access Control(RBAC) model has advantage of easy management of access control with constraints such as permission inheritance and separation of duty in role hierarchy. However, previous RBAC studies could not properly reflect the real-world organization structure with its role hierarchy. User who is a member of senior role can perform all permissions because senior role inherits all permissions of junior roles in the role hierarchy. Therefore there is a possibility for senior role members to abuse permissions due to violation of the least privilege principle. In this paper, we present a new model of role hierarchy, which restricts the unconditional permission inheritance. In the proposed model, a role is divided into sub roles(unconditional inheritance. restricted inheritance, private role), keeping organization structure in corporate environment. With restricted inheritance, the proposed model prevents permission abuse by specifying the degree of inheritance in role hierarchy.

• Journal of Technology Innovation
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• v.13 no.1
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• pp.91-111
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• 2005

This paper aims to make a brief survey of the main concepts and theoretical frameworks proposed by Comparative Institutional Analysis. The main concepts to be discussed are 'institutional complementarity', 'diversity', 'system' and 'institutional hierarchy'. This paper also analyzes the recent evolution of U.S national innovation system using these concepts.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.574-575
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• 2008

In this paper, we have explored current hierarchy for demand side management programs and proposed an efficient structure for the successful implementation of DSM programs in Korea.

• Proceedings of the Korea Society of Design Studies Conference
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• 2005.05a
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• pp.302-303
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• 2005

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.4
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• pp.12-21
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• 2006

Recently, Very large and high resolution geological data from aerial or satellite imagery are available. Many researches and applications require to do realtime visualization of interest geological area or entire planet. Important operation of wide-spreaded terrain realtime visualization technique is the appropriate model resolution selection from pre-processed multi-resolution model hierarchy depend upon participant's view. For embodying such realtime rendering system with large geometric data, Preprocessing multi-resolution hierarchy from large scale geological information of interest area is required. In this research, recent Cubic multiresolution 4-8 tile hierarchy is selected for global planetary applications. Based upon the tile hierarchy, It constructs the selective terminal level tile mesh for original geological information area and starts to sample individual generated tiles for terminal level tiles. It completes the hierarchy by constructing intermediate tiles with low pass filtering in bottom-up direction. This research embodies series of efficient cubic 4-8 tile hierarchy construction mechanism with out-of-core storage. The planetary scale Mars' geographical altitude data and image data were selected for the experiment.

• The KIPS Transactions:PartD
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• v.10D no.5
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• pp.859-872
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• 2003

Class hierarchies often constitute the backbone of object-oriented software. Their quality is therefore quite crucial. Building class hierarchies with good qualify is a very important and common tasks on the object oriented software development, but such hierarchies are not so easy to build. Moreover, the class hierarchy structure under construction is frequently restructured and refined until it becomes suitable for the requirement on the iterative and incremental development lifecycle. Therefore, there has been renewal of interest in all methodologies and tools to assist the object oriented developers in this task. In this paper, we define a set of quantitative metrics which provide a wav of capturing features of a rough estimation of complexity of class hierarchy structure. In addition to, we suggest a set of algorithms that transform a original class hierarchy structure into reorganized one based on the proposed metrics for class hierarchy structure. Furthermore, we also prove that each algorithm is "object-preserving". That is, we prove that the set of objects are never changed before and after applying the algorithm on a class hierarchy. The technique presented in this paper can be used as a guidelines of the construction, restructuring and refinement of class hierarchies. Moreover, the proposed set of algorithms based on metrics can be helpful for developers as an useful instrument for the object-oriented software development.velopment.