• Aerospace Engineering and Technology
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• v.13 no.1
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• pp.37-43
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• 2014

The ground station which operates the LEO satellite performs monitoring state of health of the satellite, sending the commands for the imaging mission of receiving the images during about 10 minutes of contact time. To finish the planned procedure in limited contact time, specific level of autonomy is applied in the satellite and the ground system. For example, the attitude and orbit control logic has high level of autonomy because it must be operated alone for long period without operator intervention. On the other hand, the fault management logic has relatively low level of autonomy because of that failure detection and safing operation are performed on-board, whereas failure identification and recovery are on-ground operation. The level of autonomy of the satellite affects also the ground operation. The command set for mission operation is generated by ground system. If the satellite has higher level of autonomy, some of operation currently done on-ground can be performed on-board, so the ground operation can be simplified. In this paper, we discuss the level of autonomy and propose a concept for improving the level of autonomy of an LEO satellite.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.111-117
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• 2017

The National Competency Standards (NCS) was designed to implement a competence-based society and solve the problem of inconsistency between the industrial field and education, training, and certification system. This study designed and developed the Korean NCS core vocational competence system, in accordance with the NCS, as an infrastructure to solve fundamental problems such as re-education and the social costs that are incurred in the workplace. Further, this study designed and developed standard indicators to evaluate the technical performance of the system for the global advancement of the Korean NCS core vocational competence system. The NCS core vocational competence system has been developed as an appropriate response type for multiple devices such as computers, tablet PCs, and cellular phones. For the global advancement of the Korean NCS core vocational competence system, this study designed and developed 10 performance evaluation indicators in accordance with 10 global standards, such as linkage-target operating system, interface protocol, packet format, encryption, class component, simultaneous access number, supervisor-to-testtaker response speed, server-to-admin response speed, auto-recovery speed for test answers, and real-time answer transmission speed.

• The Transactions of the Korea Information Processing Society
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• v.5 no.3
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• pp.649-661
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• 1998

If there is redeveloping into the system applying the object-oriented paradigm, productivity Improvement of software through reuse would be accomplished and maintenance cost be reduced. When a procedure-oriented system is transformed to a type applying the object-oriented paradigm, various techniques are studied to extract objects from source code automatically or semi-automatically. However, it is not easy to extract conceptuat objects when those techniques are applied, This problem entails another problem which drops the conceptual integrity of the extracted objects. In this paper, we suggest an object extraction method and tool development to resolve the problem occurring at the time when thc pr"~r"m, dcveloped through procedure-oriented is transformed to an object-oriented system. The suggested method allow to extract the desired objects using object modeling for various application domains of the real world given source code and design recovery information. During the extraction process, functionality and global variables of the source code as well as its intcrface arc rigorously analyzed. This process can enhance the conceptual integrity of the objects and make easy to construct class hierarchies.

• Journal of the Korean Geosynthetics Society
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• v.22 no.3
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• pp.27-35
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• 2023

Ensuring the stability of visible structures during excavation works are extremely crucial. While the stability of the ground is analyzed through numerical calculations the during design phase, the conditions during construction often differ. Therefore, it is imperative to analyze the stability of the wall through measurements. The cost of measurements on the construction site is set at a very low unit price, which increases the risk of accidents involving retaining walls. In this study, we argue for the importance of automated or wireless system measurements of retaining walls, by estimating construction duration and accident costs through the analysis of hypothetical accident cases, and comparing these with measurement costs. In case of a major destruction during excavation work, the accident handling cost could be less than 5% of the total measurement budget. Therefore, increasing the measurement budget to prevent accidents in advance can be economically beneficial.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06b
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• pp.13-16
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• 2011

과학 응용 분야에서 생성되는 대규모의 데이터를 빠른 시간 내에 효율적으로 처리해야 할 필요성이 대두 되면서 클라우드 컴퓨팅이 주목받고 있다. 하둡(Hadoop)은 대규모 데이터 처리 분석을 위한 소프트웨어 프레임워크를 제공하는 아파치의 오픈소스 프로젝트로서 클라우드 컴퓨팅의 대표적인 기술로서 널리 사용되고 있다. 특히, 하둡은 높은 확장성과 성능을 제공하면서 결함 탐지와 자동 복구 기능이 우수하여 과학 기술 분야에서도 점차적으로 도입 및 활용되고 있다. 본 논문에서는 하둡을 이용하여 천문 응용 분야에서 생성되는 대규모 데이터를 분석하기 위한 방법을 연구하였다. 본 논문에서 관심을 가지는 천문 응용 데이터는 대략 천만개의 작은 크기의 관측 데이터를 처리해야 하지만, 하둡은 대규모 데이터 처리에 특화되어 있어서 많은 개수의 작은 크기를 가지는 관측데이터 처리에는 적합하지 않다. 본 논문에서는 천문 응용 데이터 처리를 위한 입출력 파일을 하둡에서 제공하는 특수화된 데이터 구조를 이용하여 압축하였고, 천문 응용 실행 코드가 하둡에서 실행이 가능하도록 맵리듀스 작업으로 랩핑하여 구현하였다.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.129-139
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• 2012

This paper will describe the structure and characteristics of operator training system which was developed to maintain the quality of operational ability for COMS (Communication, Ocean and Meteorological Satellite) operators during a long-term nominal operations of missions and a contingency operations against an occurrence of anomaly. In particular it will present benefits and expected effects of the training system with a focus on three parts which are functions especially for trainer-friendly failure injection, an automatic sequencer of training scenario based on the predefined plan and additional functions of the existing COMS simulator. Furthermore, it will present a practical example of training on the training system to understand the overall mechanism of training process.

• Korean Journal of Construction Engineering and Management
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• v.11 no.5
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• pp.24-31
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• 2010

Today many people live in various risks due to rapid industrialization. High-rise buildings and underground facilities are increasing in the heart of the city. It probably would be developed into a gigantic disasters complicated with sudden climate change. To effectively cope with these disasters, National Emergency Management Agency was set up, but it has been pointed that the Agency's role is limited to treat the problems. Therefore, emergency management system and disaster case study were reviewed and analyzed. And a Proposals for Improvement of the National Emergency Management System based on Past Disaster Cases was suggested in this paper.

• Annual Conference on Human and Language Technology
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• 2001.10d
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• pp.130-137
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• 2001

최대 엔트로피 모델(maximum entropy model)은 여러 가지 자연언어 문제를 학습하는데 성공적으로 적용되어 왔지만, 두 가지의 주요한 문제점을 가지고 있다. 그 첫번째 문제는 해당 언어에 대한 많은 사전 지식(prior knowledge)이 필요하다는 것이고, 두번째 문제는 계산량이 너무 많다는 것이다. 본 논문에서는 텍스트 단위화(text chunking)에 최대 엔트로피 모델을 적용하는 데 나타나는 이 문제점들을 해소하기 위해 새로운 방법을 제시한다. 사전 지식으로, 간단한 언어 모델로부터 쉽게 생성된 결정트리(decision tree)에서 자동적으로 만들어진 규칙을 사용한다. 따라서, 제시된 방법에서의 최대 엔트로피 모델은 결정트리를 보강하는 방법으로 간주될 수 있다. 계산론적 복잡도를 줄이기 위해서, 최대 엔트로피 모델을 학습할 때 일종의 능동 학습(active learning) 방법을 사용한다. 전체 학습 데이터가 아닌 일부분만을 사용함으로써 계산 비용은 크게 줄어 들 수 있다. 실험 결과, 제시된 방법으로 결정트리의 오류의 수가 반으로 줄었다. 대부분의 자연언어 데이터가 매우 불균형을 이루므로, 학습된 모델을 부스팅(boosting)으로 강화할 수 있다. 부스팅을 한 후 제시된 방법은 전문가에 의해 선택된 자질로 학습된 최대 엔트로피 모델보다 졸은 성능을 보이며 지금까지 보고된 기계 학습 알고리즘 중 가장 성능이 좋은 방법과 비슷한 성능을 보인다 텍스트 단위화가 일반적으로 전체 구문분석의 전 단계이고 이 단계에서의 오류가 다음 단계에서 복구될 수 없으므로 이 성능은 텍스트 단위화에서 매우 의미가 길다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.555-556
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• 2015

디지털변전소의 정보를 최적화하여 변전소 Self-Healing, 자동고장복구 등 다양한 차세대 응용시스템을 개발하기 위해서는 변전소의 모든 설비를 네트워크로 연결하여 디지털화하는 Process 버스기반 디지털변전시스템은 필수적으로 필요하며, 이를 통해 변전소를 구축하고 엔지니어링 하는 과정전반이 컴퓨터 프로그램에 의해 쉽고 간편한 작업이 가능하게 되어 공간활용을 극대화할 수 있고 건설 및 유지보수 비용을 큰 폭으로 감소시킬 수 있다. 본 논문은 이러한 디지털변전소의 시대적 변화에 부합하여 국내에서 개발된 Process 버스 기반의 IED와 MU에 대하여 현장 적용을 위한 성능검증 방안을 제시하고, 국내 최초로 Process 버스 기반 디지털변전시스템 실증시험장을 제주 성산변전소에 구축하는 과정에서 수행한 검증결과를 설명하고자 한다.

• Journal of the Society of Disaster Information
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• v.7 no.2
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• pp.140-150
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• 2011

Life Environment is rapidly changing and large scale disasters are increasing from the global warming. Although the disaster repair resources are deployed to the disaster fields, the prevention of the disasters is the most effective countermeasures. the disaster sign data is based on the rule of Heinrich. Automatic extraction of the disaster sign data from the web is the focused issues in this paper. We defined the automatic extraction processes and applied information, such as accident nouns, disaster filtering nouns, disaster sign nouns and rules. Using the processes, we implemented the disaster sign data management system. In the future, the applied information must be continuously updated, because the information is only the extracted and analytic result from the some disaster data.