• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.10-22
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• 2022

According to the Space Development Promotion Basic Plan, more than 110 satellites are expected to be deployed by 2031. Accordingly, the operation concept and technology for satellites constellation are required, compared to the existing few multi-satellite operations. It is essential to automate and optimize the mission operation system, for efficient operation of the satellite constellation, and preparations are urgently needed for the operation of satellite constellation in domestic as well. In this study, the development direction and strategy of the mission operation system applying automation and optimization for efficient operation of the satellite constellation are proposed. The framework for evaluating the automation level and priority of the mission operation system was developed, to identify the tasks to which automation should be applied preferentially.

• The Journal of the Acoustical Society of Korea
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• v.14 no.1E
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• pp.73-82
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• 1995

This paper presents a data structure that implements a mergeable double-ended priority queue ; namely, an improved relaxed min-max-pair heap. It suggests a sequential algorithm to merge priority queues organized in two relaxed min-max heaps : kheap and nheap of sizes k and n, respecrively. This new data sturuture eliminates the blossomed tree and the lazying method used to merge the relaxed min-max heaps in [8]. As a result, the suggested method in this paper requires the time complexity of O(log(log(n/k))*log(k)) and the space complexity of O(n+), assuming that $k{\leq}{\lfloor}log(size(nheap)){\rfloor}$ are in two heaps of different sizes.

• The KIPS Transactions:PartA
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• v.11A no.3
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• pp.213-216
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• 2004

Proirity queues(PQ) can be used in applications such as scheduling or sorting. The data structures for PQ can be constructed with or without pointers. The implicit representation without pointers uses less memory space than pointer-based representation. It if shown that a 2-heap, a traditional Implicit PQ based on a binary tree, is slower than an f-heap based on a 8-ary tree. This is because 8-heap utilizes cache memory more efficiently This paper presents a novel fast implicit heap called 8-heap＊ which is easier to implement. Experimental results show that the 8-heap＊ is faster than 8-heap as well as 2-heap.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.17-22
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• 2009

In this paper, we discuss two fundamental issues of hybrid scene representation: constructing and rendering. A hybrid scene consists of triangular meshes and point-set models. Consider the maturity of modeling techniques of triangular meshes, we suggest that generate a point-set model from a triangular mesh might be an easier and more economical way. We improve stratified sampling by introducing the concept of priority. Our method has the flexibility that one may easily change the importance criteria by substituting priority functions. While many works were devoted to blend rendering results of point and triangle, our work tries to render point-set models and triangular meshes as individuals. We propose a novel way to eliminate depth occlusion artifacts and to texture a point-set model. Finally, we implement our rendering algorithm with the new features of the shader model 4.0 and turns out to be easily integrated with existing rendering techniques for triangular meshes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.12
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• pp.2328-2339
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• 1994

The PBS(Partial Buffer Sharing) space priority mechanism is one of priority control methods which may improve the performance of a single server queueing system when mixed traffic with different performance requirements is applied to the system. This paper analyzes the cell loss behavior of PBS assuming loss sensitive traffic and delay sensitive traffic are applied to the system. To derive the successive cell loss probabilities. which are an important performance measure of realtime traffic, we develop a recursive algorithm. Performance results show the successive cell loss probabilities obtained by our method are lager than the probabilities derived from an independent cell loss assumption. These results may indicate the limitation of PBS for realtime traffic and the increase of the admissible load with the criterion of quality of service.

• Journal of the Korean Institute of Educational Facilities
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• v.12 no.6
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• pp.18-25
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• 2005

The purpose of this study is to investigate cognitive gap between users and architectural experts for architectural planning of elementary schools to support effective decision-makings. For this study, each architectural factor was selected from the journals published by Korean Institute of Education Facilities(KIEF) from 2000 to 2004. Among these factors, the priority planning factors were decided through Analytic Hierarchy Process(AHP). The results of this study showed users' emphasis on the amenities of physical environment such as orientation, ventilation, noise, view, but experts' preference on spatial composition of space and function such as orientation, circulation, zoning, parking lot, courtyard. This difference shows clear cognitive gaps between two groups and also suggests factors required to be considered to develop effective decision-making in elementary school planning.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.1
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• pp.89-100
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• 2016

Given the unpredictability of the space environment, satellite communications are manually performed by exchanging telecommands and telemetry. Ground support for orbiting satellites is given only during limited periods of ground antenna visibility, which can result in conflicts when multiple satellites are present. This problem can be regarded as a scheduling problem of allocating antenna support (task) to limited visibility (resource). To mitigate unforeseen errors and costs associated with manual scheduling and mission planning, we propose a novel method based on a genetic algorithm to solve the ground support problem of multiple satellites and antennae with visibility conflicts. Numerous scheduling parameters, including user priority, emergency, profit, contact interval, support time, remaining resource, are considered to provide maximum benefit to users and real applications. The modeling and formulae are developed in accordance with the characteristics of satellite communication. To validate the proposed algorithm, 20 satellites and 3 ground antennae in the Korean peninsula are assumed and modeled using the satellite tool kit (STK). The proposed algorithm is applied to two operation modes: (i) telemetry, tracking, and command and (ii) payload. The results of the present study show near-optimal scheduling in both operation modes and demonstrate the applicability of the proposed algorithm to actual mission control systems.

• The Transactions of the Korea Information Processing Society
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• v.2 no.1
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• pp.119-129
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• 1995

In this paper, we propose a schedulatility analysis method for real-time programs. Several approaches to anlayzing schedulability have been developed, but since these approaches use a fixed priority scheduling method and/or traverse all possible state spaces, there take place exponential time and space complexity of these methods, Therefore it is necessary to reduce the state space and detect schedulability at earlier time. Our schedulability analysis method uses a minimum unit time taken to terminate synchronization action, a minimum unit time taken to terminate actions after synchronization, and a deadline of processes to detect unschedulability at earlier time and dynamic scheduling scheme to reduce state space. We conclude that our method can detected unschedulability earlier 50 percent unit time than Fredette's method.

• Journal of Families and Better Life
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• v.20 no.4
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• pp.53-60
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• 2002

The purpose of this study was to comprehend the cognition of Korean tradition and the required basic educational contents among interior architects. The survey had been made 277 designers and the major findings of this study are as follows. First. It is revealed that only a half of interior architect have been taught about Korean tradition in university and their level of knowledge is entry level. Therefore it is found that the education in university on the Korean tradition was not sufficient enough Second, it is believed that one ideal way of expressing Korean tradition is re-interpreting traditional motive with modern views and another way is to express abstractly about Korean traditional space arrangement, composition and space concept. It is found that substantial knowledge and information is required to express Korean tradition effectively. Third. it is found that a lot of interior architect has faced difficulties in carrying out projects because of not having sufficient knowledge related to Korean tradition. Therefore it is recommended to educate basic theory about Korean tradition first and then reinforce the program by including field trip In university curriculum. Fourth. it is necessary to re-educate to current Interior architect because of lacking knowledge about Korean tradition. The recommended area in priority order is traditional Interior space, traditional architecture, traditional color, traditional pattern and traditional furniture

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.45-54
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• 1997

A mathodology to manage effectively urban open space using GIS(Geographic Information System) was developed to explore the methology of efficient urban open space management focusing on landscaped trees. Cartographic modeling technique was used for practical use of GIS as a case study of the Childeren's park in Kwangju city. First, spatial and attribute information for efficient landscaped tree management was acqired through the development of a tree management cartographic model. Second the information of location and the attribute of individual trees can be applied as a means of decision making in tree management. Thira optimal path of tree management and priority of management in work process of the selected urban open space could be determined according to the objective of park management.