• Journal of Communications and Networks
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• v.4 no.3
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• pp.170-175
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• 2002

An optical fiber code-division multiple-access (CDMA) network is proposed in which encoding is based on the use of concatenated sequences of relatively large weight. The first short component sequence in the concatenated sequence permits realistic electronic encoding of each data bit. The chips of this sequence are then all-optically encoded at substantially higher rate. In spite of the relatively large weight of the sequence the all-optical encoder is practical by virtue of the shortness of the component sequences. The use of Gold and Lempel sequences as component sequences for generating the concatenated sequences is studied and the bit-error rate (BER) performance of the proposed system is presented as a function of the received optical power with the number of simultaneous users as parameter.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.955-958
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• 2005

In this study, the wind load characteristics for a transmission tower is investigated considering the effect of the transmission lines through stochastic analysis. The assemblage of the transmission line and insulator are modeled as a double pendulum system connected to the SDOF model of the tower It is observed that the background component of the overturing moment induced by the wind response of the transmission line has considerable portion in the total overturning moment. Based on this result, a rotational viscoelastic damper (VED) is proposed for the mitigation of the transmission line reactions, which act as wind load transferred to the tower. To verify the effectiveness of the proposed strategy, time history analysis is conducted for different wind velocities and VED damping constants. From the analysis, the proposed VED is proved to be effective for mitigation of the background component rather than the resonance component of the transmission line reaction.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10a
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• pp.441-443
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• 1999

소프트웨어의 재사용에 관한 문제는 오래 전부터 풀어야 할 과제로 내려왔다. 계속적인 개발에 따른 재사용의 심각함을 인식하고 기존의 제품이나 기능코드 모듈들을 어떻게 재활용 할지에 대해서 연구해 왔었다. 이러한 관점에서 컴포넌트라는 개념의 중요성이 부각되어지고 계속적인 노력을 하고 있는데, 체계화가 잡히지 않은 무분별한 컴포넌트 개발로 인해, 컴포넌트 홍수라는 새로운 문제를 발생시킨다. 따라서, 본 논문에서 컴포넌트 레지스트리라는 어플리케이션을 만들어 컴포넌트들을 응용분야별, 기능별 등으로 분류하여 재사용을 용이하게 하였다. 또한, 컴포넌트 레지스트리를 이용하여 개발자나 사용자들에게 컴포넌트를 공급함으로서 시간과 노력을 줄일 수 있고 통합된 관리로서 표준화가 가능하게 만들었다. 이렇게 체계화된 컴포넌트 관리로서 공유환경을 구축할 수 있고 CBDMS(Component-Based Development & Management System)의 개발을 용이하게 할 수 있다.

• The KIPS Transactions:PartD
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• v.12D no.3 s.99
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• pp.395-408
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• 2005

Ubiquitous computing spans a very broad range of technologies and needs very complicated user's requirements. There are many scenarios and technologies involved in ubiquitous computing. We need new software development tools and methodology to meet the requirements. A software product line is one of promising new technology for it. A software product line is a set of software intensive systems that share a common, managed set of features satisfying the specific needs of a particular market segment or mission and that are developed from a common set of core assets. Software architecture-based development is the exploration and maturation of the role of software architecture in the product line life cycle. In this thesis, we identify the foundational concepts underlying software product lines and the essential activities to develop the mobile application systems. So, we define, design, and implement the Mobile Application System Architecture(MASA) that includes the development process for applying into mobile business domain and encompass scoping and gathering requirements for the Product line based on Component Based Development(CBD).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.241-245
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• 2003

In this paper, a microassembly system based on hybrid manipulation schemes is proposed and applied to the assembly of a photonic component. In order to achieve both high precision and dexterity in microassembly, we propose a hybrid microassembly system with sensory feedbacks of vision and force. This system consists of the distributed 6-DOF micromanipulation units, the stereo microscope, and haptic interface for the force feedback-based microassembly. A hybrid assembly method, which combines the vision-based microassembly and the scaled teleoperated microassembly with force feedback, is proposed. The feasibility of the proposed method is investigated via experimental studies for assembling micro opto-electrical components. Experimental results show that the hybrid microassembly system is feasible for applications to the assembly of photonic components in the commercial market with better flexibility and efficiency.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.1
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• pp.1-7
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• 2007

This paper addresses a the maintenance system based on the concept of RAMS (Reliability, Availability, Maintenance, Safety) for the effective maintenance of the urban transit. A systematic approach for developing a cost-effective maintenance strategy based on the component reliability of the system in question is performed according to the following steps : definition of function, functional failures of the systems, construction of RBD (Reliability Block Diagram), and the calculation of reliability indices. The developed preventive maintenance system generates maintenance plan and repair request based on the analysed RAMS data of components and maintenance experience.

• Journal of the Korea Society of Computer and Information
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• v.23 no.11
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• pp.25-30
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• 2018

Pattern classification system is often an important component of intelligent systems. In this paper, we present a pattern classification system consisted of the feature selection module, knowledge base construction module and decision module. We introduce a feature impact evaluation selection method based on fuzzy cluster analysis considering computational approach and generalization capability of given data characteristics. A fuzzy neural network, OFUN-NET based on unsupervised learning data mining technique produces knowledge base for representative clusters. 240 blemish pattern images are prepared and applied to the proposed system. Experimental results show the feasibility of the proposed classification system as an automating defect inspection tool.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.40-41
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• 2021

Recently, particulate matter(PM) caused by internal factors such as industrialization and urbanization as well as external factors such as Asian dust is a serious problem in Korea. In particular, while the emission due to construction appears to be very serious among the internal factors, it is necessary to manage PM in consideration of the characteristics of construction sites. Accordingly, in this study, a PM management system suitable for construction sites was developed to reduce civil complaints caused by PM and to minimize damage to field workers and nearby residents by supporting the fine dust management system of the state and local governments. The factors to be considered when measuring PM due to the specificity of construction sites were considered, and the system components were developed based on the considerations. As a result, an IoT based construction site PM monitoring system (CPMS) that integrates each component was established.

• Earthquakes and Structures
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• v.17 no.6
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• pp.635-647
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• 2019

Tests and theoretical studies for seismic responses of a transmission tower-line system under coupled horizontal and tilt (CHT) ground motion were conducted. The method of obtaining the tilt component from seismic motion was based on comparisons from the Fourier spectrum of uncorrected seismic waves. The collected data were then applied in testing and theoretical analysis. Taking an actual transmission tower-line system as the prototype, shaking table tests of the scale model of a single transmission tower and towers-line systems under horizontal, tilt, and CHT ground motions were carried out. Dynamic equations under CHT ground motion were also derived. The additional P-∆ effect caused by tilt motion was considered as an equivalent horizontal lateral force, and it was added into the equations as the excitation. Test results were compared with the theoretical analysis and indicated some useful conclusions. First, the shaking table test results are consistent with the theoretical analysis from improved dynamic equations and proved its correctness. Second, the tilt component of ground motion has great influence on the seismic response of the transmission tower-line system, and the additional P-∆effect caused by the foundation tilt, not only increases the seismic response of the transmission tower-line system, but also leads to a remarkable asymmetric displacement effect. Third, for the tower-line system, transmission lines under ground motion weaken the horizontal displacement and acceleration responses of transmission towers. This weakening effect of transmission lines to the main structure, however, will be decreased with consideration of tilt component.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.12 no.2
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• pp.121-130
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• 2012

This paper proposes an intuitive real-time robot control system using human body movement. Recently, it has been developed that motion generation for humanoid robots with reflecting human body movement, which is measured by a motion capture. However, in the existing studies about robot control system by human body movement, the detailed structure information of a robot, for example, degrees of freedom, the range of motion and forms, must be examined in order to calculate inverse kinematics. In this study, we have proposed Associative Motion Generation as humanoid robot motion generation method which does not need the detailed structure information. The associative motion generation system is composed of two neural networks: nonlinear principal component analysis and Jordan recurrent neural network, and the associative motion is generated with the following three steps. First, the system learns the correspondence relationship between an indication and a motion using training data. Second, associative values are extracted for associating a new motion from an unfamiliar indication using nonlinear principal component analysis. Last, the robot generates a new motion through calculation by Jordan recurrent neural network using the associative values. In this paper, we propose a real-time humanoid robot control system based on Associative Motion Generation, that enables user to control motion intuitively by human body movement. Through the task processing and subjective evaluation experiments, we confirmed the effective usability and affective evaluations of the proposed system.