• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2002년도 가을 학술발표논문집 Vol.29 No.2 (2)
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• pp.361-363
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• 2002

Version space는 목표 개념이 속성 값에 대한 제한조건의 연언(conjunction)으로 표현될 수 있는 귀납적 개념학습에서 가설공간을 표현하기 위해 사용된다. Version space의 크기는 속성 값의 수에 대해 지수적으로 증가하는데, 우리는 DNA 분자를 이용하여 version space를 표현하는 효율적인 방법을 제시한다. 또한 version space를 유지하기 위한 기본 연산과, 이를 DNA 분자를 이용하는 구현 방법이 제시된다. 또한 DNA 분자로 표현된 version space를 활용하여 새로운 example에 대한 분류를 예측하는 방법을 제시한다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 봄 학술발표논문집 Vol.30 No.1 (C)
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• pp.352-354
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• 2003

현재 분산 컴퓨팅 환경에서는 객체를 공유하기 위하여 Jini 서비스인 JavaSpace를 이용하여 다양한 응용 프로그램들이 개발되고 있다. 하지만 JavaSpace의 가장 큰 단점은 누구든지 객체를 저장하고, 또 그 객체를 읽거나 가져갈 수 있도록 설계되어있어 보안성이 매우 취약하다는 것이다. 본 논문에서는 이러한 JavaSpace를 보안등급에 따른 접근제어와 SSL SSL 패키지를 이용한 상호인증 모듈을 구현하여 JavaSpace의 새로운 보안모델을 제시하였으며, 개발된 안전한 JavaSpace를 이용하여 이동 에이전트간 통신 패러다임으로 적용하였다.

• 로봇학회논문지
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• 제4권2호
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• pp.147-154
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• 2009

Visions of ubiquitous robotics and ambient intelligence involve distributing information, knowledge, computation over a wide range of servers and data storage devices located all over the world, and integrating tiny microprocessors, actuators, and sensors into everyday objects as well in order to make them smart. In this paper, we introduce our ongoing research effort aimed at realizing ubiquitous robots in an information structured space. For this, a ubiquitous space and ambient intelligent systems for a librarian robot are introduced and the RFID technology based approach for these systems is described.

• Journal of Power Electronics
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• 제16권3호
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• pp.946-959
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• 2016

A novel Virtual Space Vector (VSV) modulation strategy for complete control of potential neutral point (NP) issues is proposed in this paper. The neutral point potential balancing problems of multi-level converters, which include elimination of low frequency oscillations and self-balancing for NP dc unbalance, are investigated first. Then a set of improved virtual space vectors with dynamic adjustment factors are introduced and a multi-objective optimization algorithm which aims to optimize these adjustment factors is presented in this paper. The improved virtual space vectors and the multi-objective optimization algorithm constitute the novel Virtual Space Vector modulation. The proposed novel Virtual Space Vector modulation can simultaneously recover NP dc unbalance and eliminate low frequency oscillations of the neutral point. Experiment results show that the proposed strategy has excellent performance, and that both of the neutral point potential issues can be solved.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2004년도 추계학술발표대회 논문집
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• pp.46-49
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• 2004

A contemporary office space is changed by the transformation to an information-oriented society from an industrial society. A contemporary office space is recognized as an interactional space which is more of a mental and psychological space than a physical space. I studied the basic concept of an office space and the relationship of a social change and an office space on this study. I also studied the concept of an ubiquitous computing and the relationship of an ubiquitous computing and an office space. Through this study, we can establish the new concept of an office space to be applied to an ubiquitous concept. The ubiquitous concept of an office space will be brought into a new prototype of an office space, and then there is no more important to a physical place and time. The office space must be redesigned by an ubiquitous space nowadays.

• 한국멀티미디어학회논문지
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• 제13권12호
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• pp.1843-1854
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• 2010

The utilization of underground space has recently increased with the complication of road, the rise of the land price, and the development of green technology. Underground space ranges from classical excavations to subway, underground cities, and shopping malls where there are crowds of people. At this time, government has spent a lot of money in installing various types of safety facilities for preparations of increasing potential disasters. Therefore, an effective facility management system is required. In this paper, we propose an information retrieval process to effectively extract the facilities' information based on the ontology and spatial analysis in underground space. The ontology-based searching supports hierarchical and associated results as well as knowledge sharing with hierarchy concepts. The spatial analysis based searching has "Buffer" and "Near" functions to operate on a map without understanding any property of the facility information.

• 대한공간정보학회지
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• 제20권4호
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• pp.105-115
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• 2012

현재, 국내에서의 건설분야는 지상영역에서 지하공간개발영역으로 변화하고 있다. 이와 함께 지하공간개발 추진시 난개발, 환경오염 등의 문제점들은 매우 중요한 화두가 되고 있다. 이러한 시점에서 지하공간을 파악할 수 있는 지하정보들의 활용이 급증될 것으로 예상되고 있다. 그러나, 아직 국내에서의 지하정보는 기관별 개별적으로 구축 관리 하고 있어 통합 활용이 어려운 실정이다. 그러므로 지하공간정보의 통합 활용이 필요한 시점에서 지하정보들의 통합 인프라 구축을 위해서는 통합 DB표준화가 반드시 실행되어져야 한다. 본 연구에서는 각 각의 지하정보들을 기반으로 지하공간정보 인프라 구축 통합 표준화 활용 방안을 연구하였다. 연구결과 지하공간정보 통합 표준화 내용으로는 지층별 표준화, 단위체계 표준화, 지하공간정보 연계 표준화를 제시하였으며 활용성 검토를 위해 각 기관의 전문가들에게 설문조사를 실시한 결과 높은 활용성이 검증 되었다.

• 한국컴퓨터정보학회논문지
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• 제23권4호
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• pp.139-145
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• 2018

In this paper, we propose the methodology and system to show weather information to spatial system. When using the spatial information system, it is easy and convenient to show information such as target location, mission contents, enemy threats and so on. However, drawing 1-dimensional weather information on 3-dimensional space in spatial information system is hard task. To fuse data, we need to add a spatial layer including weather information to spatial layers and perform space modeling for showing weather information as spatial data in a virtual space. The virtual space is shown by receiving meteorological data and then changing in real time through weather database linkage.

• Journal of Mechanical Science and Technology
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• 제16권8호
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• pp.1053-1063
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• 2002

This paper presents a robust nonlinear controller for a f degree of freedom (DOF) parallel manipulator in the task space coordinates. The proposed control strategy requires information on orientations and translations in the task space unlike the joint space or link space control scheme. Although a 6 DOF sensor may provide such information in a straightforward manner, its cost calls for a more economical alternative. A novel indirect method based on the readily available length information engages as a potential candidate to replace a 6 DOF sensor. The indirect approach generates the necessary information by solving the forward kinematics and subsequently applying alpha-beta-gamma tracker With the 6 DOF signals available, a robust nonlinear task space control (RNTC) scheme is proposed based on the Lyapunov redesign method, whose stability is rigorously proved. The performance of the proposed RNTC with the new estimation scheme is evaluated via experiments. First, the results of the estimator are compared with the rate-gyro signals, which indicates excellent agreement. Then, the RNTC with on-line estimated 6 DOF data is shown to achieve excellent control performance to sinusoidal inputs, which is superior to those of a commonly used proportional-plus-integral-plus-derivative controller with a feedforward friction compensation under joint space coordinates and the nonlinear controller under task space coordinates.

• 로봇학회논문지
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• 제14권3호
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• pp.170-178
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• 2019

This paper proposes a parking space detection method for autonomous parking by using the Around View Monitor (AVM) image and Light Detection and Ranging (LIDAR) sensor fusion. This method consists of removing obstacles except for the parking line, detecting the parking line, and template matching method to detect the parking space location information in the parking lot. In order to remove the obstacles, we correct and converge LIDAR information considering the distortion phenomenon in AVM image. Based on the assumption that the obstacles are removed, the line filter that reflects the thickness of the parking line and the improved radon transformation are applied to detect the parking line clearly. The parking space location information is detected by applying template matching with the modified parking space template and the detected parking lines are used to return location information of parking space. Finally, we propose a novel parking space detection system that returns relative distance and relative angle from the current vehicle to the parking space.